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- _____________________________________________________________________________
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- Parallel.Exe Parallel Technologies, Inc.
- Parallel Port Information Utility PO Box 7
- (C) Copyright 1993 Jay Lowe Redmond, WA 98073-0007
-
- This program may be used Lab 206-869-1136
- free of charge subject to the Fax 206-869-9767
- Restricted License Agreement Compuserve 76640,203
- as stated below Internet 76640.203@COMPUSERVE.COM
- _____________________________________________________________________________
-
-
-
- Welcome to the Parallel Port Information Utility
- -----------------------------------------------------
-
- Parallel is a simple utility which displays the configuration of the
- parallel ports (LPT ports) in your system. Parallel is useful for:
-
- 1. Configuring parallel port software such as Windows printer
- connections, parallel port device drivers, and print spoolers.
-
- 2. Resolving technical support problems with parallel port devices,
- including printers and external peripherals such as network
- adapters, portable disks, tape drives, CD-ROMs, floppies, etc.
-
- 3. Configuring your parallel ports for best performance.
-
- 4. Resolving pesky IO address and IRQ contention problems.
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- 5. Discovering the performance capabilities of your parallel ports.
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- 6. Learning how your particular system's CMOS configuration
- relates to the actual configuration of your parallel ports.
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- 7. Making informed decisions when buying parallel ports and devices.
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- 8. Getting the best parallel port performance for your dollar.
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- 9. Experimenting with your parallel port configuration.
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- 10. Solving problems associated with print spoolers and network print
- capture programs which redirect printer output by changing the
- port mappings kept in the LPT Bios data area.
-
- Now is a good time for you to learn something about parallel ports,
- since parallel ports are becoming increasingly useful due to the recent
- explosion in the popularity of portable and external peripherals, and
- because new parallel port standards (EPP, ECP, IEEE 1284) are breaking
- performance barriers and allowing full bus speed operation. There are
- major performance differences between different types of ports and
- these differences are becoming of increasing significance to consumers.
-
- These applications of Parallel are dicussed in more detail below. But
- first let's take a quick look at how you run the program itself and
- interpret the various information it displays.
-
- PARALLEL.DOC Page 1
-
- Parallel Port Information Utility ────────────────────────────── User's Manual
-
-
-
- ------------------------------
- Quick Overview of Parallel
- ------------------------------
-
- Parallel operates by testing each of the standard addresses in your
- system where parallel ports might be found and gathering a broad
- assortment of useful information about the specific port behavior.
- Parallel tests the ports and then produces a compact display which
- is convenient and easy to read. You may need to refer to these
- instructions or the built-in reference screen a few times until you
- learn what the various columns of information mean.
-
- How to use Parallel:
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- Step 1 => Disconnect parallel port peripherals (printers, disks, etc)
- Step 2 => Disable parallel port software (device drivers, spoolers, etc)
- Step 3 => Attach the optional loopback connector(s) for IRQ detection
- Step 4 => Run PARALLEL
- Step 5 => Read the display...
-
- Parallel will display five columns of information containing one or
- more lines about each port. The columns are:
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- Port Type The parallel port's IO capabilities. Types are:
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- No Port -- No port is exists at the address
- 4 bit -- A slow "unidirectional" port
- 8 bit -- A faster "bidirectional" port
- EPP -- A very fast Enhanced Parallel Port
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- Address IO Base Address of the port (3BC, 378, 278)
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- IRQ Interrupt level associated with the port (5 or 7)
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- BIOS Name Logical device name of the port (LPT1, LPT2, LPT3)
-
- Notes A wide assortment of comments, warnings, etc.
-
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- Port Strangeness Factor. On a single line, after the columnar display,
- Parallel reports a magic number called the "Port Strangeness Factor".
- This is simply the total number of strange or unusual properties that
- Parallel has found when examining your configuration. If your ports are
- considered strange by Parallel, you might want to take some action
- to correct the situtation or at least be aware of the peculiarity.
- The Port Strangeness is not reported if your configuration is nominal.
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- PARALLEL.DOC Page 2
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- Parallel Port Information Utility ────────────────────────────── User's Manual
-
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- ------------------------------
- Detailed Program Operation
- ------------------------------
-
-
- Before running Parallel, temporarily remove all parallel port devices
- and software to establish a baseline configuration. Temporarily
- disconnect printers and other parallel port devices such as disks,
- network adapters, tape drives, etc, and disable any special parallel
- port software you may have running, like print spoolers or parallel
- port device drivers. The interaction of Parallel with external devices
- is discussed in some detail later on, and you may find that disconnecting
- these devices is simply not necessary in your configuration.
-
- Then, type PARALLEL at the command line. Parallel will display the
- parallel port type, IO address, IRQ level, BIOS name equivalence, and
- an assortment of informative notes about your parallel ports.
-
- If you have a relatively slow PC, you may notice that Parallel produces
- a certain amount of temporary "debugging" output as it attempts to
- determine your port configuration and then overlays this output with
- the final display. This is normal and has been included in the first
- release of the program for possible support purposes.
-
- Type PARALLEL ? for a reminder screen on interpreting the display.
-
- If, perchance, the display scrolls off the screen, which might happen
- if Parallel is reporting extensive notes about interesting conditions
- on your ports, then use the MORE command or redirect Parallel's output
- to a file. Redirection to a file can also be handy if you need to fax
- Parallel's output to someone.
-
- PARALLEL | MORE ; pauses the output every screen
- PARALLEL > filename ; redirects output to a file
-
- Parallel works best when you disconnect any parallel port devices, such
- as printers, external peripherals, or "laplink" cables. Even our 4bit,
- 8bit, or Univeral High-Speed Turbo cables for our handy parallel port
- network drivers (Pipx and Pndis) should be temporarily disconnected
- when you run Parallel, at least until you understand how Parallel can
- be affected by interference from devices attached to the port(s).
- Parallel may also affect active devices attached to parallel ports
- (printers, network adapters, external parallel port disks, etc),
- although we've made every attempt to minimize these effects. Parallel's
- interactions with devices are discussed in some detail below.
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- PARALLEL.DOC Page 3
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- Parallel Port Information Utility ────────────────────────────── User's Manual
-
-
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- -------------------
- Sample Displays
- -------------------
-
- ┌─────────────────────────────────────────────────────────────────────────────┐
- │ Parallel Port Information Utility, v1.00 (930308). Use PARALLEL ? for help. │
- │ (C) Copyright 1993 Jay Lowe, Parallel Technologies, Inc. We thank you. │
- ├─────────────┬─────────┬─────┬───────────┬───────────────────────────────────┤
- │ Port Type │ Address │ IRQ │ BIOS Name │ Notes │
- ├─────────────┼─────────┼─────┼───────────┼───────────────────────────────────┤
- │ 8 bit port │ 3BC │ 5 │ LPT1: │ IRQ determined by loopback │
- │ 4 bit port │ 378 │ 7 │ LPT2: │ IRQ determined by loopback │
- │ No port │ 278 │ - │ - │ No port found at this address │
- ├─────────────┴─────────┴─────┴───────────┴───────────────────────────────────┤
- │ Experts in parallel port technology and devices since 1987. CIS# 76640,203 │
- └─────────────────────────────────────────────────────────────────────────────┘
-
- The system above (a 486/33 clone with two LPT cards) shows:
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- o an 8BIT true bidirectional port at 3BC using IRQ 5
- o a 4BIT unidirectional port at 378 using IRQ 7
- o loopback connectors are installed in both ports
- o the IRQ configuration is healthy, but reversed from "standard"
- o the ports are well behaved (there are no special notes)
-
- ┌─────────────────────────────────────────────────────────────────────────────┐
- │ Parallel Port Information Utility, v1.00 (930308). Use PARALLEL ? for help. │
- │ (C) Copyright 1993 Jay Lowe, Parallel Technologies, Inc. We thank you. │
- ├─────────────┬─────────┬─────┬───────────┬───────────────────────────────────┤
- │ Port Type │ Address │ IRQ │ BIOS Name │ Notes │
- ├─────────────┼─────────┼─────┼───────────┼───────────────────────────────────┤
- │ 4 bit port │ 3BC │ 7 │ LPT1: │ IRQ determined by loopback │
- │ │ │ │ │ NOTE: Possible IRQ conflict! │
- │ 4 bit port │ 378 │ 7 │ LPT2: │ IRQ determined by loopback │
- │ │ │ │ │ NOTE: IRQ sense is INVERTED │
- │ No port │ 278 │ - │ - │ No port found at this address │
- ├─────────────┴─────────┴─────┴───────────┴───────────────────────────────────┤
- │ Your Port Strangeness Factor = 2. We suggest that you read Parallel.Doc. │
- ├─────────────────────────────────────────────────────────────────────────────┤
- │ Experts in parallel port technology and devices since 1987. CIS# 76640,203 │
- └─────────────────────────────────────────────────────────────────────────────┘
-
- The system above (an original IBM-PC) shows:
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- o a 4BIT unidirectional port at 3BC using IRQ 7
- o a 4BIT unidirectional port at 378 using IRQ 7
- o an IRQ Conflict - both ports are using the same IRQ
- o the interrupt sense of the second port is inverted
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- Notes:
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- o we can't use IRQ5 in this case because the IBM/PC disk uses IRQ5
- o these old expansion cards do not have IRQ5 capability anyway
- o when a new LPT card in placed at IRQ5, the interrupt test fails
- because the disk controller's interrupt line interferes with it
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- PARALLEL.DOC Page 4
-
- Parallel Port Information Utility ────────────────────────────── User's Manual
-
-
-
- -------------------------------
- Sample Displays (continued)
- -------------------------------
-
- ┌─────────────────────────────────────────────────────────────────────────────┐
- │ Parallel Port Information Utility, v1.00 (930308). Use PARALLEL ? for help. │
- │ (C) Copyright 1993 Jay Lowe, Parallel Technologies, Inc. We thank you. │
- ├─────────────┬─────────┬─────┬───────────┬───────────────────────────────────┤
- │ Port Type │ Address │ IRQ │ BIOS Name │ Notes │
- ├─────────────┼─────────┼─────┼───────────┼───────────────────────────────────┤
- │ No port │ 3BC │ - │ - │ No port found at this address │
- │ 4 bit port │ 378 │ ? │ LPT1: │ Need loopback to determine IRQ │
- │ │ │ │ │ See instructions in PARALLEL.DOC │
- │ │ │ │ │ Otherwise assume IRQ 7 or IRQ 5 │
- │ │ │ │ │ Port has latent EPP tendencies │
- │ │ │ │ │ EPP BIOS is not installed │
- │ No port │ 278 │ - │ - │ No port found at this address │
- ├─────────────┴─────────┴─────┴───────────┴───────────────────────────────────┤
- │ Your Port Strangeness Factor = 1. We suggest that you read Parallel.Doc. │
- ├─────────────────────────────────────────────────────────────────────────────┤
- │ Experts in parallel port technology and devices since 1987. CIS# 76640,203 │
- └─────────────────────────────────────────────────────────────────────────────┘
-
- The system above (a DELL NL25 laptop) shows:
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- o a 4BIT unidirectional port at 378 with unknown IRQ
- o IRQ is unknown because the loopback connector is not installed
- o The port has EPP capability, but it is not currently enabled
- o There is no EPP BIOS installed in the system
-
- ┌─────────────────────────────────────────────────────────────────────────────┐
- │ Parallel Port Information Utility, v1.00 (930308). Use PARALLEL ? for help. │
- │ (C) Copyright 1993 Jay Lowe, Parallel Technologies, Inc. We thank you. │
- ├─────────────┬─────────┬─────┬───────────┬───────────────────────────────────┤
- │ Port Type │ Address │ IRQ │ BIOS Name │ Notes │
- ├─────────────┼─────────┼─────┼───────────┼───────────────────────────────────┤
- │ No port │ 3BC │ - │ - │ No port found at this address │
- │ EPP port │ 378 │ 7 │ LPT1: │ IRQ determined by EPP hardware │
- │ │ │ │ │ EPP BIOS is installed │
- │ No port │ 278 │ - │ - │ No port found at this address │
- ├─────────────┴─────────┴─────┴───────────┴───────────────────────────────────┤
- │ Experts in parallel port technology and devices since 1987. CIS# 76640,203 │
- └─────────────────────────────────────────────────────────────────────────────┘
-
- The system above (the same DELL NL25) shows:
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- o the port has been switched into EPP mode with our own EPP BIOS
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- Notes:
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- o Enabling EPP on most EPP laptops requires a special EPP BIOS
- o These are usually provided by the laptop or peripheral vendor
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- PARALLEL.DOC Page 5
-
- Parallel Port Information Utility ────────────────────────────── User's Manual
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- ----------------------------
- Interpreting the Display
- ----------------------------
-
- Understanding the Port Type
- ---------------------------
-
- This can be 4bit, 8bit, EPP or No Port. We will add recognition for
- other ports such as Microsoft/HP ECP ports, and/or other IEEE 1284
- ports, as they begin to appear in end-user systems.
-
- No Port No port was found at the given IO Address.
-
- Parallel tests all the base addresses and displays at
- least one line of information about each base address,
- even if there is no port installed at that base address.
-
- Parallel uses a rather more robust technique for
- detecting a port than is used in any of the BIOSes we
- have seen. This means that Parallel can detect ports
- which fail the BIOS boot-time tests. Parallel uses a
- rotating bit test and assumes the port exists if any of
- the bits at the port location respond correctly.
-
- False Positives. Parallel can be fooled into thinking
- that a port is present when it is not (false positive)
- only if there is some other device which behaves like a
- parallel port located at the address being tested. We
- have only seen this on one system, an off-shore 286
- laptop which had several other design problems as well.
-
- False Negatives. There is one way in which Parallel
- can be fooled into thinking that a port does not exist
- (false negative). If an active device is connected to
- the data lines and is providing enough power to
- "overdrive" the port, then the port existance test will
- fail because the incoming data from the device will
- foil the readback test. We have only seen Parallel
- produce false negatives when an external device is
- actively driving the port's inputs or when the Loopback
- is incorrectly installed. By the way, in this case, the
- PC's BIOS will also fail to detect the port. Again,
- Parallel works best when you disconnect any parallel
- port devices.
-
- 4bit ports The port can do 8bit byte output and 4bit nibble input.
-
- These ports are often called "unidirectional", and are
- most commonly found on desktop bus cards (also called
- IO expansion cards, serial/parallel cards, or even 2S+P
- cards). This is still the most common type of port,
- especially on desktop systems.
-
- 4bit ports are capable of effective transfer rates of
- about 40 Kbytes/sec (KBPS) in typical devices and can
- be pushed upwards of 80 KBPS with certain design
- tricks. The port speed is also affected by electrical
-
- PARALLEL.DOC Page 6
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- Parallel Port Information Utility ────────────────────────────── User's Manual
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- characteristics of the noise suppression circuitry.
- Some ports have completely ridiculous arrangements of
- noise suppression circuits which slow them down quite
- dramatically and can prevent their functioning with
- parallel port peripherals.
-
- NOTE: The sample transfer rates given here reflect the actual
- performance of parallel port network adapters, disks,
- etc. The raw transfer rate of the port itself is higher
- but since most parallel devices use software strobing to
- control data access, the effective transfer rate is
- dependent on the quality of the driver software supplied
- with the device. Due to the recent explosion in the
- number of parallel port peripherals entering the market,
- there is an extreme degree of variability in the quality
- and performance of these devices and their drivers.
-
- 4bit ports are found on about 50% of all systems and
- about 75% or more of desktop systems.
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- We do not recommend 4bit ports; 8bit ports are better.
-
- NOTE: There is a class of "semi-bidirectional" parallel ports
- which appear to the PC to be 4bit ports, but actually
- have 8bit capability when they are connected to
- external devices with strong drivers. These include
- the original PC/AT parallel port. Parallel will report
- these ports as 4bit ports but they may actually function
- as 8bit ports with a few parallel port peripherals.
-
- A good example of a peripheral which handles these ports
- well are IQ Technologies' parallel port network adapters.
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- It is actually possible to identify this type of port
- using a side-effect of Parallel's loopback test. See
- the special section below on Semi-Bidirectional ports.
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- 8bit ports These ports can do both 8bit input and output.
-
- These ports are sometimes called "bidirectional ports",
- but that term is often misused by some vendors to refer
- to 4bit ports as well. Most newer laptops have 8bit
- capability although it may need to be enabled with the
- laptop's vendor-specific CMOS setup function. This is
- discussed below. A relatively smaller percentage of LPT
- bus cards have 8bit capability which sometimes must be
- enabled with a hardware jumper on the board itself.
-
- True 8bit ports are preferable to 4bit ports because
- they are considerably faster when used with external
- devices that take advantage of 8BIT capability.
-
- 8bit ports are capable of speeds ranging from 80-150
- KBPS, again depending on the speed of the attached
- device, the quality of the driver software, and on the
- port's electrical characteristics. 8bit ports are
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- PARALLEL.DOC Page 7
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- Parallel Port Information Utility ────────────────────────────── User's Manual
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- found on 25% of desktops, 50% of laptops, and about
- 90% of newer laptops built since 1991.
-
- CAVEAT: A number of vendors claim "bidirectional" capability
- EMPTOR for their parallel ports when they are actually just
- 4bit ports. When buying a parallel port expansion card,
- or an entire system, you might want to use Parallel to
- find out the REAL capabilities of the port. Be aware
- that a vendor's reputation for quality in other areas
- may not translate into good parallel ports. There are
- examples of well-known vendors making false claims for
- their parallel ports... sometimes, it appears, simply
- because they don't understand them... claims or ports.
-
- Of the 8bit add-in LPT cards we have tested, we like the
- Everex MagicIO the best, but it can be hard to find.
-
- We are not going to pan anyone's "bidirectional" add-in
- cards specifically, but be warned that the use of terms
- like "bidirectional" or "PS/2 compatible" may have
- nothing to do with the port's actual IO capability.
- You can use Parallel to test add-in cards to determine
- the parallel port's IO actual behavior.
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- EPP ports Can do both 8bit input and output at bus speeds.
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- These ports are as fast as 8bit bus cards and can
- achieve transfer rates of 1 Mbyte/sec and faster. For
- example, our EPP-capable external SCSI disk is faster
- on a very popular SL laptop than it's internal drive.
- EPP ports are supposed to conform to a well defined
- electrical standard and many of them actually do so.
- However, if you are buying a laptop and want to be sure
- of using fast EPP-capable external peripherals, then
- definitely arrange to try before you buy.
-
- Xircom has been active in creating and defining the EPP
- standard, and since their EPP-capable network adapters
- are fairly common, it's worth mentioning that these
- adapters can be used as a practical benchmark for the
- goodness of a particular EPP port. Crude but effective.
-
- EPP ports are most often found on laptops using the
- Intel 386SL chipset with the 360SL IO support chip. You
- can usually identify these laptops by the 'SL' suffix
- in their name, HOWEVER this is not a hard and fast
- rule, since there are non-'SL' systems with EPP ports
- as well as 'SL' systems which (in our tests) have non-
- functioning or sub-standard EPP ports. Other vendors
- offer add-in EPP cards for the ISA bus. Parallel will
- not currently recognize non-Intel EPP ports; we will be
- adding this feature in the near future. We know of one
- vendor now offering EPP-capable add-in cards:
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- FarPoint Communications 805-726-4420
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- The FarPoint card is quite nice because it is a "soft"
-
- PARALLEL.DOC Page 8
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- Parallel Port Information Utility ────────────────────────────── User's Manual
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- design with downloadable personalities. It comes with
- support for fast Windows printing and a fast Netware
- spooling NLM. We like it.
-
- SMC's Component Products Division is due to release
- EPP and ECP chips in the very near future, so users
- can expect to see EPP and ECP capabilities become
- available on a wider range of systems.
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- HOW TO: Run Parallel on any system you intend to buy to see
- what kind of parallel port(s) are provided. If you are
- buying a desktop with a built-in LPT card, try to get
- real 8bit capability instead of the more typical 4bit.
- Some LPT cards have hardware jumpers that are required
- to enable the bidirectional behavior. So make sure you
- get a manual for the LPT card when you buy a system.
-
- If you are buying a laptop and have any desire to use
- external peripherals like network adapters, portable
- hard disks, CD-ROMS, tape drives, etc, then seriously
- consider getting a laptop with an EPP port. They are a
- LOT faster running EPP-capable external peripherals. In
- any case, try before you buy. Few vendors (and users)
- are well-informed about parallel port technology and
- inappropriate claims, however inadvertant, are common.
-
- COMING: Microsoft, Hewlett-Packard, and others are espousing a
- SOON -- new standard for parallel ports, the ECP port, which is
- ECP PORTS may become part of the proposed IEEE 1284 specification,
- which also covers EPP. Some vendors are reported to
- have silicon for this port, but we haven't seen it in
- any end-user systems yet. The ECP port is pretty much
- the same as EPP ports in terms of performance but uses
- a quite different hardware design. The major difference
- is that ECP has Microsoft's blessing and they will
- probably support it (but perhaps only in Windows) if it
- actually materializes. Quite typically, there is no
- guarantee that MS will ever support EPP.
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- When using Parallel to make buying decisions, please
- make sure you've got the most recent release. Parallel
- port technology will be changing rapidly over the next
- year and we will be updating Parallel frequently.
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- PARALLEL.DOC Page 9
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- Parallel Port Information Utility ────────────────────────────── User's Manual
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- Understanding the IO Address
- ----------------------------
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- This is the base address of the port. It will be 3BC, 378, or 278 hex.
- The IO address specifies the port's location in the PC address space.
-
- Normally the first port is configured to 3BC, the second to 378, etc,
- however the ports can be assigned to any of these three addresses.
-
- On bus cards, the IO address is usually set by a arrangement of jumpers
- unique to the particular board. You will need a manual or the ability
- to read PC board traces (gacck!). These jumpers are usually arranged to
- allow you to select one of three addresses: 3BC, 378, 278.
-
- Sometimes these addresses are called by the "logical device names" of
- LPT1, LPT2, and LPT3, although this practice is quite misleading (see
- BIOS discussion below). Some boards offer a more limited selection of
- configurations (usually 378 and 278) and a few are actually hardwired
- to a specific address. Vendors do this to save a little money and also
- to eliminate the chance of creating an address collision with the
- "standard" address of 3BC. Because of the increasing number of clones
- which are assembled from various components, we often see systems with
- one LPT card, configured to address 378. In fact, a fair number of
- systems are shipped with this 378 configuration.
-
- A slightly interesting result we've seen in several desktops spins off
- when someone adds a second LPT card to a system which already has a LPT
- at 378, IRQ 7. Sometimes they naively reason that since 378 is taken,
- they can use 3BC and slap in the card without checking the IRQ level.
- This creates a configuration of 3BC and 378 both using IRQ 7, a
- situation which can lead to intermittent crashes when using interrupt
- driven parallel port software.
-
- By the way, a few systems have parallel ports and com ports built onto
- the motherboard itself and, in this case, the configuration jumpers
- will be found on the motherboard.
-
- Notice that there are three commonly used IO Addresses (3BC, 378, 278)
- and two available interrupt levels (IRQ 7 and IRQ 5). This means that
- if you have three LPT cards in a system, two of them will probably be
- sharing a hardware interrupt level. This is hardwarily permissible, and
- generally doesn't create any problems since most DOS and Windows
- software doesn't use interrupts for printing anyway. However, if you
- are using LPT software like an interrupt-driven print spooler or
- interrupt-driven LPT devices like external hard disks, external network
- adapters, and so forth, then you have to be sure that either (1) the
- ports are not using the same interrupt level, or (2) the software is
- capable of "interrupt sharing".
-
- When adding or configuring LPT cards, we suggest using 3BC, IRQ 7 for
- the first card; 378, IRQ 5 for the second card; and 278, no IRQ for the
- third card. This gives you two interrupt-capable LPT ports, and one
- port (at 278) which you should use only for non-interrupt driven usage,
- like the status-driven spooling provided by DOS.
-
- In any case, armed with this understanding and the Parallel Utility,
- you are equipped to select a configuration which works for you.
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- PARALLEL.DOC Page 10
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- Parallel Port Information Utility ────────────────────────────── User's Manual
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- HOW TO: The IO ADDRESS is a standard parameter in network
- configuration files where it takes on different names
- and syntaxes to confuse innocent users.
-
- Some simple-minded parallel port peripherals (ones
- without auto-configuring capability) require that you
- specify the IO address, IRQ level, and sometimes the
- Port Type in a vendor-specific way. Parallel provides
- you with this information. See Configuring Networks and
- Devices below.
-
- HOW TO: Resolving IO Address conflicts is usually fairly simple,
- since it is rare to find a device which uses the
- standard parallel port addresses.
-
- A good procedure for eliminating potential IO address
- conflicts when installing parallel port add-in boards
- is to remove all the boards, install one, use Parallel
- to see what addresses it finds, install the next, and
- so forth. If Parallel finds each board at a separate
- addresses as you install them, then you can be sure of
- your configuration.
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- PARALLEL.DOC Page 11
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- Parallel Port Information Utility ────────────────────────────── User's Manual
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- Understanding the IRQ Level
- ---------------------------
-
- This is the hardware interrupt level assigned to the port. It will
- always be either 7 or 5. Parallel displays "?" when it cannot detect
- the IRQ level of the port and "-" when the port doesn't exist. Parallel
- needs an external loopback connector to automatically detect the IRQ.
- With appropriate precautions (described in horrible and excruciating
- detail below) you can use a simple paperclip as a loopback connector.
-
- Normally IRQ 7 is assigned to the first port and IRQ 5 is assigned to
- the second port. However, due to the explosion of clones assembled from
- disparate parts, it is not uncommon to see systems with one LPT port
- located at 378 with an IRQ of 7 or 5. This is because clones are often
- assembled using offshore add-in LPT cards which are shipped configured
- to operate as a second LPT card.
-
- This is a good time to point out that there are few hard and fast rules
- when it comes to parallel port configuration. Ports can be located at any
- one of the three standard base address and can use either of the IRQ
- levels. If you are developing parallel port software, you should auto-
- detect the actual configuration rather than assume any standard usage.
- We offer libraries and source code for this purpose. Here at Parallel
- Technologies, we test our software using many strange configurations and
- delight in adding idiosyncratic ports to our extensive collection.
-
- The most common idiosyncrasy of port IRQ is IRQ inversion. The PC
- standard calls for interrupts to be generated on 0->1 transitions of
- the interrupt line. A small percentage of parallel ports generate
- their interrupts on 1->0 transitions. Ports with inverted IRQ can
- fail to operate with some interrupt software, particularly certain
- external network adapters, disks, and so forth. Parallel identifies
- these ports with a note "IRQ style is INVERTED".
-
- Some parallel ports have non-functioning IRQ lines. They are simply not
- capable of generating interrupts. Only a very few pieces of software
- are capable of dealing with these ports by using a polled mode of
- operation. It is sometimes possible to repair such systems by jumpering
- the interrupt enable line to the parallel port chip.
-
- On ISA cards (bus cards in ISA slots) the interrupt level is usually
- set with jumpers on the board - these jumpers are different for every
- card so you need to hunt around for the manual in order to change them.
- If you're lucky there will be readable labels on the card itself.
-
- On laptops, the interrupt level can usually be set using the vendor's
- specific CMOS configuration (setup) program. Sometimes these CMOS setup
- programs are built into the ROM; sometimes they exist as separate
- programs or as part of the vendor's diagnostic program(s). Refer to
- your manual to find out how to enter the CMOS setup mode. BE CAREFUL
- when using the CMOS setup, since it gives you access to parameters that
- can disable your system if wrongly changed. KNOW WHAT YOU ARE DOING.
-
-
-
-
-
-
- PARALLEL.DOC Page 12
-
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-
-
-
- ******************
- * IMPORTANT NOTE *
- ******************
-
- Misuse of your system's CMOS setup program can prevent
- your system from operating correctly, or in some cases,
- from operating at all! Be sure you know what you are
- doing; read your user's manual or get qualified help if
- you have any doubts.
-
- Another strange feature of these software configurable ports is that
- they often have very peculiar ideas about nomenclature. Often these
- CMOS setup programs use vendor specific "magic code words" to select
- various parallel port configurations, and these magic words can have
- non-obvious effects. Sometimes the vendor's manuals don't even provide
- a secret decoder ring to explain what their magic words really mean in
- terms of IO Address, IRQ, and Port Type. Parallel will be useful for
- determining the actual effect of the CMOS setup choices on your system.
-
- For example, on my Dell NL25 laptop, 4bit mode is called "Normal" and
- 8bit is called "Enhanced" and there is no choice at all for the real
- Enhanced Parallel Port (the SL's EPP port). So someone might obviously
- think they have enabled EPP by choosing "Enhanced". Futhermore, the IRQ
- level cannot be set directly, but rather is set as a by-product of
- selecting combinations of the IO address and the Port Type. Most of the
- choices on my Dell yield IRQ 7, but one lonely choice - LPT1, 278,
- Normal mode results in IRQ 5. It makes a strange sort of sense when you
- are experienced with parallel ports, but is likely to be confusing to
- the average user (if we ever find him, or her). The Dell is not alone
- in it's strange naming conventions, most laptops have confusing,
- misleading, or incomplete labels and controls in their CMOS setup
- programs. This sort of indirect control in very common in CMOS setups
- and creates a lot of tech support calls from frustrated users.
-
- In addition, most SL laptops don't have the capability to enable their
- EPP ports from CMOS. Usually you need to run a separate vendor-supplied
- BIOS extension to enable EPP capability. These take the form of a tiny
- TSR which adds INT 17h BIOS extensions for controlling the EPP port,
- and handles command line arguments for enabling and disabling EPP. An
- interesting sidelight of switching into EPP mode can be that your port
- IO address may change on the fly. The Intel EPP hardware allows EPP
- ports to be configured at IO Addresses 378 and 278. So if you have set
- your port address to 3BC (with CMOS for example) and then switch into
- EPP mode, your port will appear to have moved.
-
- Parallel will come in handy in trying to make sense of what your
- laptops' CMOS settings are actually doing to your parallel ports.
-
-
-
-
-
-
-
-
-
-
-
- PARALLEL.DOC Page 13
-
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-
-
-
- Understanding the BIOS Name
- ---------------------------
-
- This is the "human-readable" (hah!) name which you use to refer to the
- port when using DOS commands, Windows picklists, and so forth. It will
- be one of the following: LPT1, LPT2, LPT3. LPT4 is extremely rare and
- Parallel currently ignores it.
-
- The port address is NOT the same as the BIOS name for the port. For
- example, LPT1 can refer to a port at 3BC, 378, or 278.
-
- So, how does the BIOS associate the LPT names with the actual ports?
-
- Whenever your system boots, the BIOS goes out and tries to write and
- readback data from locations 3BC, 378, and 278. If it can read back
- what it writes, then the BIOS decides there is a port there and adds
- the IO address to a LPT table in the "Bios Data Area". This table is
- four words located at 40:8. A command like "copy foo.txt lpt2:" means
- "copy the file foo.txt to the second printer that BIOS knows" and DOS
- uses a software interrupt, INT 17h, to do just that. INT 17h looks in
- the Bios Data area to find out the IO address of the "second printer",
- which can be any of the IO Addresses - 3BC, 378, or 278.
-
- The result is that LPT1 refers to the first port BIOS finds at boot
- time, wherever it may be. So "LPT1" means "the first printer", not
- necessarily 3BC, 378, or 278. Some BIOSes have unique methods for
- finding their LPT ports.
-
- When you see LPT1, LPT2, or LPT3 used in hardware manuals to refer to
- port locations, be alert for possible misleading information. Some
- well-known vendor's manuals use LPT1 to refer to 378 and LPT2 to refer
- to 278, an entirely spurious practice which has confused many users.
-
- It is possible for some parallel port software to set the port into an
- IO mode that causes it to fail the BIOS test and seem to "disappear"
- from your system even after a soft boot (CTRL-ALT-DEL). Parallel has a
- better test, and finds such ports. A hard reset (a power-off reset)
- will clear the port. Parallel ports are not completely trivial devices;
- they have a number of states that can affect their operation. So if you
- are having a parallel port problem, one of the first things to do a
- power-off reset.
-
- Another factor here is that various programs can fiddle with the
- LPT table. The utility SWAPPRT, for example, can be used to swap
- LPTx with LPTy which it does by moving the entries in the LPT table.
- There are variations of this redirection theme.
-
- If Parallel does not display a BIOS name for a port, that means the
- IO Address for that LPT position has been replaced with a value that
- does not match a valid hardware port. Some parallel port device
- drivers do this as a way to grab possesion of the port and prevent
- other software from writing to the port while the driver is installed.
-
-
-
-
-
-
- PARALLEL.DOC Page 14
-
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-
-
-
- Understanding the Notes and Comments
- ------------------------------------
-
- The "Notes" field of the display will contain various comments,
- depending on what Parallel has detected. Each note may be followed by
- one or more comments giving further information or directions. These
- secondary comments are indented one space under their note.
-
- "No port found at this address"
-
- No parallel port is installed at this IO Address.
-
- However, it is also possible that an active external
- device is overdriving the port's inputs, which can
- prevent the software readback test from working.
-
- Be sure that you have disconnected all external devices.
-
- "Need loopback to determine IRQ"
-
- The port exists, but does not respond to attempts to
- generate IRQs. This is because a loopback connector
- is required for IRQ detection in most cases.
-
- "Port IRQs are not functioning"
-
- This is pretty bad. It means that the loopback connector
- is present and working correctly, but Parallel still
- can't generate any interrupts. Technically it means
- that transitions in the ACK line don't affect the PIC.
- Practically it means that interrupt devices and software
- probably won't work, unless they have polling support.
-
- Possible reasons for failing the IRQ test include:
-
- 1. The port's interrupt capability is disabled
-
- Check your CMOS configuration and/or the
- hardware jumpers on the parallel port board(s)
- to be sure that the interrupt is enabled.
- The function of CMOS parameters and/or hardware
- jumpers varies from system to system, so check
- your manual or contact your vendor if you have
- problems enabling the port's interrupt line.
-
- Note that most CMOS and jumper arrangements
- combine enabling the IRQ with selecting the
- level, ie, "enable IRQ5" or "enable IRQ7".
- Removing the jumper generally disables IRQ.
-
- 2. The port does not have IRQ capability
-
- Most ports DO have interrupt capability,
- but a small percentage (at a guess %1 to %5)
- do not. More laptops lack interrupts than
- add-in cards. Add-in cards without IRQ are rare.
- Most reports of non-functional parallel port
-
- PARALLEL.DOC Page 15
-
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-
-
-
- IRQs in desktop systems can be tracked to
- configuration problems which create interrupt
- conflicts (see #3) which effectively disable IRQ.
-
- 3. There is an IRQ conflict with another device
-
- It is possible that another device in your
- system is preventing the parallel port IRQs
- from functioning. For example, in IBM-PCs
- and XTs, the disk controller which uses IRQ 5
- can prevent parallel ports configured to IRQ5
- from creating interrupts.
-
- To isolate this problem, remove all boards from the
- system that are not required to perform the test.
- In other words, strip down to just the parallel port,
- floppy controller and video, and repeat the test.
-
- If possible, configure the parallel port to IRQ7.
- If the port can create IRQ7 interrupts, but not IRQ5
- interrupts, then an interrupt conflict is likely.
-
- "IRQ determined by loopback"
-
- The loopback was detected, is operating correctly,
- and the port's IRQs are functioning correctly. The
- IRQ level found is given in the IRQ column.
-
- "IRQ estimated by port float"
-
- No loopback connector was detected, but the port is
- generating IRQs anyway. This probably means that the
- port is connected to an inactive (unpowered) external
- device. Treat IRQs determined in this way with some
- skepticism; better to disconnect the device and use a
- loopback connector.
-
- "IRQ determined by EPP hardware"
-
- If the Port Type is determined to be EPP, then Parallel
- does not use the IRQ test, but rather reports the IRQ
- which is standard for an EPP port at that IO Address.
-
- "IRQ noise is present"
-
- Parallel has detected extraneous interrupts occuring
- on IRQ level 5 or 7 during the IRQ test.
-
- This condition is reported when the total number of
- interrupts occurring on both IRQ5 and IRQ7 exceeds
- the number of interrupts Parallel tests for.
-
- This can mean several things:
-
- 1. PIC errors. The PC's interrupt controller (PIC)
- is generating errors as described below.
-
-
- PARALLEL.DOC Page 16
-
- Parallel Port Information Utility ────────────────────────────── User's Manual
-
-
-
- 2. An active device other than the parallel port
- is generating interrupts on IRQ 5 or 7.
-
- 3. The port's interrupt line is electrically noisy.
- This has been seen with boards which have two
- parallel ports where transitions in one port's
- IRQ line causes noise on the other port's IRQ.
-
- This result may be ignored if you are not having any
- problems, but be informed that this condition is quite
- likely to confuse parallel port software which tries
- to autodetect the port's IRQ level.
-
- TECHNICAL NOTE: PIC errors are usually found with parallel port chips
- whose "open" condition on the ACK line may allow the
- IRQ signal to float randomly. This effect creates
- 8259 interrupt controller errors which are directed to
- IRQ7 where they can be mistaken for "real" interrupts.
- This effect may confuse some parallel port software.
-
- An 8259 error condition is defined to occur when the
- 8259 attempts to service the requesting device but the
- device's interrupt line has gone inactive. These
- are also known as "lost interrupts", which are not
- really lost but rather redirected to IRQ7. A noisy IRQ
- line can create the appearance of lost interrupts.
-
- This effect of lost interrupts explains why some
- parallel port driver software works well on IRQ7 but
- not IRQ5, or vice versa. Parallel port interrupt
- handlers have to account for conditions that are
- generally not seen by other device drivers. So if you
- are having problems with a parallel port device driver
- you may want to try configuring the port to the other
- interrupt level.
-
- "NOTE: Data port has stuck bits!"
-
- The rotating bit test has detected bits in the data
- port which cannot be set or cleared properly.
-
- You have probably inserted the Loopback incorrectly.
-
- Of course if there is no Loopback wire present, then
- something else must be happening! It could be that an
- active device is forcing some of the data lines to a
- fixed level. It could also mean that your port exists,
- but some of the data bits are not working, which is a
- polite way of saying that your port may be busted.
-
- Parallel may report a false Port Type in this case.
-
- Make sure that the loopback, if used, is correct. Make
- sure that no devices are plugged into the port.
-
- "IRQ style is INVERTED"
-
-
- PARALLEL.DOC Page 17
-
- Parallel Port Information Utility ────────────────────────────── User's Manual
-
-
-
- The port's IRQ line functions in an opposite sense from
- the PC standard. A significant amount of software will
- fail to work with such ports. There is no remedy for
- this condition in general; the best we can advise is to
- use a different port if you have a bus system or try
- other CMOS settings on a laptop if that is possible.
- You might try contacting your vendor.
-
- Parallel may falsely report inverted IRQ if there is
- an external device connected to the port.
-
- "Possible IRQ Conflict"
-
- Two or more ports in your system are using the same IRQ
- level. If you are not using interrupt-driven parallel
- port peripherals or printing software then you might
- simply ignore the warning if you are not experiencing
- any problems. However, you should know that some very
- strange results can occur when two parallel ports are
- trying to drive the same IRQ line. Sometimes one or both
- ports can falsely appear to have INVERTED IRQ.
-
- The best solution is to move one of the ports to another
- IRQ level, if that is possible.
-
- "BIOS Data doesn't match hardware"
-
- The contents of the BIOS Data Area LPT Table does not
- correspond to the expected initial state at boot time.
-
- This is probably due to a parallel port device driver
- or a SWAPLPT program having fiddled with the BIOS data,
- in which case it may be considered normal operation.
-
- This information is useful if you are having problems
- with print redirection. Also, some parallel port device
- drivers do not examine the hardware directly to determine
- which ports exist, but rather only look at the BIOS.
- If you have run some other parallel port software which
- has changed the BIOS in a non-standard way, then these
- device drivers may fail to find any parallel ports, or
- may try to access the wrong port. This can often be
- solved by changing the order of loading or by manually
- configuring the failing driver.
-
-
-
-
-
-
-
-
-
-
-
-
-
-
- PARALLEL.DOC Page 18
-
- Parallel Port Information Utility ────────────────────────────── User's Manual
-
-
-
- ---------------------------
- Automatic IRQ detection
- ---------------------------
-
- Parallel uses two methods for automatic detection of a port's IRQ
- level: port float or the external loopback connector.
-
- Understanding Port Float
- ------------------------
-
- Many parallel ports will "float" in a unstable logic state when
- connected to an unpowered external device such as a printer. This
- unstable logic state may cause the port to generate a limitless stream
- of apparent interrupts to the CPU if the port's interrupt line is
- enabled. This peculiar behavior is used to advantage by Parallel.
-
- If you have a unpowered (powered off) printer, or other device,
- attached to a port, then Parallel may be able to detect the interrupt
- level using this floating port behavior. In this case, Parallel will
- display "IRQ determined by port float". You should treat the IRQ
- determined in this way as a "best guess". To be sure of the IRQ,
- you need to disconnect the floating device and use loopback.
-
- In some cases, attaching a unpowered device to a port will enable
- Parallel to detect IRQ by loopback, since the combination of port and
- device appears indistinguishable from a loopback connector to Parallel.
-
- FLOAT NOTE: Powered on devices usually hold the interrupt line in a
- stable state and prevent IRQ autodetection. It is best to disconnect
- your parallel port device(s) and use the loopback connector when you
- need the absolute best results from Parallel.
-
- EXAMPLE: On my home system, an unpowered HP LaserJet II printer on an
- 8bit port "floats" and Parallel reliably reports IRQ5. Attached to a
- 4bit port on the same system, the LaserJet is indistinguishable from a
- loopback connector. So turning the LaserJet off converts it into an
- expensive, but handy, paperclip. Turning it on prevents IRQ detection.
-
- TECHNICAL NOTE: Whether or not a given device and port combination will
- float, emulate loopback, or be invisible to Parallel is determined by
- the pull-ups on each end, CMOS vs TTL logic behavior, and the power
- available at the port to a unpowered device. In the above example, I
- suspect that enough power is provided by the 8bit TTL port to drive the
- unpowered CMOS logic in the LaserJet into an unstable oscillating
- state, which appears to the system as a frenzy of level 5 IRQs.
-
- Port float is a handy effect, but use Loopback for best results.
-
- Loopback
- --------
-
- The most reliable way to determine IRQ is to use an external
- loopback connection. Loopback is described in the next section.
-
-
-
-
-
- PARALLEL.DOC Page 19
-
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-
-
-
- --------------------------------------------
- IRQ detection using the LoopBack Feature
- --------------------------------------------
-
- ******************
- * IMPORTANT NOTE *
- ******************
-
- First, DECIDE NOT TO SCREW UP YOUR PORT by crudely jamming wires into
- the wrong places with too much force. REMEMBER that the female DB-25
- connector is likely to be made out of CHEAP, BREAKABLE PLASTIC, so
- decide right now not to break it. WE ARE NOT LIABLE FOR ANY DAMAGE YOU
- MAY DO FOR WHATEVER REASON.
-
- The danger is that you will push too hard when inserting the loopback
- wire and force the female connector pin out of its position in the DB-
- 25 shell. That is why WE SUGGEST MAKING A LOOPBACK PLUG using a male
- DB-25 connector as described below. If you cannot make a loopback plug,
- then use a parallel port extension cable instead. This protects your
- port from physical damage and also makes it a lot easier to work with.
-
- The port is supposed to be electrically designed to tolerate the
- loopback perfectly well. However there is a DANGER OF DAMAGE BY STATIC
- DISCHARGE so make sure that you GROUND YOURSELF TO THE PORT before
- inserting the loopback wire. It would be terrible if you blew out a
- $25 parallel port on a $1000 486 motherboard simply because you failed
- to PAY ATTENTION TO THESE PRECAUTIONS. PROCEED AT YOUR OWN RISK.
-
- The other danger is that you will apply the loopback to a port which is
- not really a parallel port at all. DON'T DO THIS. If you are not sure
- of what you are doing STOP RIGHT NOW. We have no control over what you
- might damage if you try this with a port other than a parallel port.
-
- Whew... on with the instructions.
-
- 1. Find the parallel port(s) you want to test. They will be female
- DB-25 connectors. MAKE SURE THAT YOU HAVE CORRECTLY IDENTIFIED
- THE PARALLEL PORT. Disconnect any devices (printers, network
- adapters, external disks, etc) which might be attached to other
- parallel ports on your system.
-
- 2. Make sure that the connector IS NOT SOME OTHER TYPE OF CONNECTOR
- like an external SCSI connector or a COM port.
-
- SCSI ports can be either female DB-25s or a larger connector,
- like a 37, 40, or 50-pin connector. COM ports are usually male
- DB-25 or small male DB-9 connectors, but this is not guaranteed.
-
- Look in your manual if there is any doubt. DON'T PROCEED unless
- you are sure you have identified the parallel port(s) correctly.
-
- 3. Connect the Loopback Plug and go to Step 7.
-
- If you do not have a Loopback Plug, use a straight through M-F
- parallel port extension cable to prevent damage to your port.
- Connect the male end of the extension cable to your port and
- place the loopback wire into the female end of the cable.
-
- PARALLEL.DOC Page 20
-
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-
-
-
- 4. Identify Pin 10 and Pin 9 on the female end of the extension
- cable. Refer to the illustration below. Notice that a DB-25
- connector is wider on one side. The pins you want are the 4th
- and 5th from the left on the wider edge.
-
- USE A FLASHLIGHT TO FIND THE MARKINGS IF YOU HAVE ANY DOUBT.
-
- Front View -------- Pin 10 - 4th from left on wider edge
- Female DB-25 | ---- Pin 9 - 5th from left on wider edge
- Connector | |
- v v
- ____________________________________________________________
- / \
- \ 13 12 11 10 9 8 7 6 5 4 3 2 1 /
- \ /
- \ 25 24 23 22 21 20 19 18 17 16 15 14 /
- \______________________________________________________/
-
- Pin 10 is the interrupt line (the ACK line)
- Pin 9 is the high order data line (the 80h bit)
-
- 4. Create a loopback wire. A standard paperclip works fine. Just
- straighten it out and bend it into a "U" shape with the ends 1/8
- inch apart. Make sure the ends of the paperclip are SMOOTH and
- have NO ROUGH EDGES that might damage the plastic connector.
-
- 5. GROUND YOURSELF to the PC and to the parallel port by touching
- your hand and the loopback wire first to the PC's metal chassis
- near the parallel port connector and then to one of the connector
- nuts or the connector metal housing itself. Do this to DISCHARGE
- ANY STATIC ELECTRICITY you may have about you (created for
- example by scooting across the rug in a silk negligee on the
- way to your PC or by stroking your cat with woolen gloves).
-
- Parallel ports are usually resistant to static discharge, but not
- all ports are created equally, so don't ask for trouble.
-
- 6. Carefully insert the paperclip into the extension cable's DB-25
- connector so that Pin 9 is connected to Pin 10. DON'T FORCE IT.
- It will insert at most about 1 quarter of an inch (about .5 cm)
- and there should be absolutely no physical resistance.
-
- 7. Now run Parallel. It will automatically use the loopback to
- determine which IRQ level the port is actually using. You may
- loopback more than one, or all, ports at the same time.
-
- 8. Remove the loopback when you are done.
-
- 9. Congratulate yourself on using reasonable handling precautions
- when working with expensive equipment.
-
-
-
-
-
-
-
-
- PARALLEL.DOC Page 21
-
- Parallel Port Information Utility ────────────────────────────── User's Manual
-
-
-
- --------------------------------------
- Making Your Own Loopback Connector
- --------------------------------------
-
- We strongly advise that you make a loopback connector, inside of using
- the expedient paperclip approach.
-
- Simply obtain a male DB-25 connector and solder a permanent connection
- bewteen Pin 9 to Pin 10 on the back of the connector.
-
- Male DB-25 connectors are inexpensive and commonly available in
- electronics parts stores.
-
- This will prevent any physical damage to your port, which is the major
- source of risk with this procedure, and the reason for our incessant
- nagging about precautions. This sort of loopback connector will be no
- more dangerous to your system than a printer, and is a handy accessory
- if you frequently use Parallel.
-
- Connect Pin 10 to Pin 9
-
- Back View ----- Pin 10 - 4th from left on wider edge
- Male DB-25 | | Pin 9 - 5th from left on wider edge
- Connector | |
- v v
- ____________________________________________________________
- / \
- \ 13 12 11 10 9 8 7 6 5 4 3 2 1 /
- \ /
- \ 25 24 23 22 21 20 19 18 17 16 15 14 /
- \______________________________________________________/
-
- Pin 10 is the interrupt line (the ACK line)
- Pin 9 is the high order data line (the 80h bit)
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
- PARALLEL.DOC Page 22
-
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-
-
-
- --------------------------------------------
- Semi-Bidirectional Ports, A Special Case
- --------------------------------------------
-
- A port is semi-bidirectional when it is capable of performing 8BIT
- input when connected to a device which has strong drivers. So this
- semi-bidirectionality comes about as the relationship between the
- port and the device it is connected to.
-
- This type of port will appear to be a 4BIT port with most parallel
- port external peripherals, since low power CMOS drivers are by far
- the most common in these external devices.
-
- A few peripherals have stronger TTL drivers which can achieve 8BIT
- operation by overdriving the port. There are even sub-classes of
- ports which can achieve the effect depending on what data is used.
-
- Some vendors describe their ports as bidirectional when actually
- they are only semi-bidirectional and will only function as 4BIT ports
- with most peripherals. True 8BIT ports are preferable because they
- have a significant speed advantage with most external peripherals.
- Indeed, some parallel port peripherals require true 8BIT capability.
-
-
- Identifying semi-bidirectional ports
- ------------------------------------
-
- Step 0 => Read the cautions and disclaimers applying to loopback
-
- Step 1 => Select the port to test. The test only applies to 4BIT ports.
-
- Step 2 => Attach a parallel port extension cable to the port
-
- Step 3 => At the female DB-25 end, loopback Pin 8 to Pin 21 (GND).
-
- Step 4 => Run Parallel
-
- Step 5 => If Parallel reports "Data port has stuck bits" then the
- port is likely to have semi-bidirectional capability.
-
- We will probably build this test into the next version of Parallel.
-
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- PARALLEL.DOC Page 23
-
- Parallel Port Information Utility ────────────────────────────── User's Manual
-
-
-
- -----------------------------------------------------------------
- Using Parallel to Manually Configure Parallel Port Peripherals
- -----------------------------------------------------------------
-
- With the information that Parallel reports, you are equipped
- to perform manual configuration of network adapters and other
- parallel port peripheral devices, should they require such manual
- configuration. Here are a few examples of how Parallel's IO address
- and IRQ level are used in popular network software configuration
- files when them for use with parallel port adapters.
-
- Note that these examples also apply to our Pipx and Pndis drivers
- which allow Netware Lite, Windows for Workgoups, and Lan Manager
- networking using simple parallel port cables between two systems.
- TestDrive versions of Pipx and Pndis are available on Compuserve,
- or you can buy the commercial versions directly from us. These
- drivers allow you to use your favorite network software between
- two systems through the parallel port, without network adapters.
- This is a handy capability for laptops, and in other situations
- where you need truely portable and universal networking at low cost.
- Pipx and Pndis support several different types of cables, ranging
- from the low-performance "laplink" type cable you may already
- have up to our fabulous Universal High-Speed Turbo Cable (wow!)
- which can do parallel port networking at 200 Kbytes/sec or more.
-
- In the following examples, assume Parallel has reported a parallel
- port at IO address 3BC, IRQ 7.
-
- These examples are not meant to be cookbook instructions, but
- are offered to give you a feel for how to apply the information
- displayed by Parallel. Other manual configuration parameters may or not
- not be supported by specific vendors as custom keywords. Examples
- are: IOMODE, IRQMODE, CABLETYPE, PORTTYPE, BITMODE, and so forth.
-
- Netware NET.CFG file for ODI drivers
- ------------------------------------
-
- PORT 3BC
- INT 7
-
- Lan Manager or Windows Workgroups PROTOCOL.INI file
- ---------------------------------------------------
-
- IOBASE = 0x3BC
- IRQ = 7
-
-
- Other device configuration files and programs
- ---------------------------------------------
-
- If you are having trouble installing a parallel port peripheral, be
- prepared to run Parallel when calling your vendor for technical support.
- They will be better able to help you use their custom features if you
- can tell them your exact parallel port configuration.
-
-
-
-
- PARALLEL.DOC Page 24
-
- Parallel Port Information Utility ────────────────────────────── User's Manual
-
-
-
- ---------------------
- Technical Support
- ---------------------
-
- Parallel is Freeware, and comes with Freeware-style support. It has
- been extensively tested with a wide range of systems from original PCs
- to 486s and works with all parallel port hardware we've seen.
-
- We are willing to offer friendly assistance on an as-available basis,
- but only via Compuserve mail (CIS 76640,203) or in the IBMHW forum.
-
- Alas, we do not offer free telephone assistance to the general public.
-
- If you are in dire need of technical support in solving parallel port
- related problems, you may open a support account with us by contacting:
-
- Mailing Address Shipping Address
- --------------------------- ---------------------------
- Parallel Technologies, Inc. Parallel Technologies, Inc.
- PO Box 7 18080 NE 68th, # A-100
- Redmond, Wa 98073-0007 Redmond, Wa 98052
- (206) 869-1136
- (206) 869-9767 (fax) ( for UPS, FEDEX, etc )
- Compuserve ID# 76640,203
- InterNet ID# 76640.203@COMPUSERVE.COM
-
- The Parallel software itself, and other parallel port software
- utilities and developer's libraries, example drivers, hardware
- prototyping tools, contract development services, and a wide range of
- OEM parallel port products are available from Parallel Technologies.
-
- Custom versions of the Parallel Port Information Utility are available.
- Please call us if your firm would benefit from a custom version of the
- Parallel Port Information Utility.
-
- Vendors of parallel port hardware are invited and requested to contact us
- so that we may ensure that Parallel is compatible with their products.
-
- We offer consulting services in the design of parallel port hardware,
- parallel port peripheral devices, and DOS and Windows software.
-
- Permission is given to distribute and use Parallel without charge,
- provided you adhere to the terms and conditions of the license
- agreement given below. Specifically, you may not charge anyone for
- for sharing or using Parallel, and you may not modify it or change it.
- Nor may you use it as part of a commercial product or service without
- our written permission.
-
- Vendors may freely distribute Parallel on an individual basis, without
- charge, by electronic BBS or other means. However, you may not include
- it in or with your product without our written permission.
-
- We welcome your comments and suggestions by Email, phone, or fax.
-
- If you have particular features you would like to see supported by
- Parallel, we'd be more than glad to hear from you.
-
-
- PARALLEL.DOC Page 25
-
- Parallel Port Information Utility ────────────────────────────── User's Manual
-
-
-
- ---------------------------------------------
- Other Products from Parallel Technologies
- ---------------------------------------------
-
- We at Parallel Technologies' have been creating innovative parallel
- port devices and software since 1989. Here are a few highlights:
-
- o 1st ... network adapter for the parallel port
- o 1st ... built-in passthrough printing port
- o 1st ... automatic self-configuring drivers
- o 1st ... universal support for all parallel ports
- o 1st ... network adapters with multiple media support
- o 1st ... Windows 3.1 multimedia driver for parallel adapter
- o 1st ... Multiple Parallel Device API for shared devices
- o 1st ... intelligent parasitic power for self-powered devices
- o 1st ... daisychained parallel port peripherals
- o 1st ... multiplexed parallel port peripherals
- o 1st ... Parallel Port Expansion System
- o 1st ... product development tools for OEMs and developers
-
- o PC MAG Editor's Choice for Ethernet parallel port NIC
- o most total network adapters -- 6 and counting...
- o most total parallel port peripherals -- 12 and counting...
-
- We have in-depth experience with the wonderful and sometimes bizarre
- world of the PC parallel port and serve on both the EPP and IEEE 1284
- standards committees. Having created more than a dozen parallel port
- devices with their associated drivers and software utilities, we are
- the most experienced source for off-the-shelf technology, developer
- tools and components, and contract services.
-
- Here are a few of our current and forthcoming products that you may
- find interesting.
-
-
- Parallel -- the Parallel Port Information Utility
- -------------------------------------------------
-
- A handy utility which examines your system's parallel ports and
- reports the Port Type, IO address, IRQ level, BIOS name, and an
- assortment of informative notes and warnings in a compact and easy
- to read display. The output may be redirected to a file for tech
- support purposes. Parallel uses very sophisticated techniques for
- port and IRQ detection and is aware of a broad range of quirky port
- features.
-
- Parallel is the definitive parallel port Tech Support tool.
-
- Parallel is Freeware, subject to a restricted license agreement.
- It may be used free of charge for any personal, non-commercial
- purpose. Vendors should contact us regarding commercial licenses.
-
- A forthcoming commercial version of Parallel will use an active
- loopback connector enabling many new features including detailed
- resolution of port IO behavior and effective throughput testing.
-
-
-
- PARALLEL.DOC Page 26
-
- Parallel Port Information Utility ────────────────────────────── User's Manual
-
-
-
- Parallel Port Networking
- ------------------------
-
- Now you can network two PCs using your favorite network software
- with just a parallel port cable between the systems.
-
- Our family of parallel port network drivers (PIPX, PNDIS, PPACKET,
- and others TBA) work with standard network software to turn your
- parallel port into a network adapter. All types of ports are
- supported with a very few specific exceptions.
-
- Supports: Netware Lite, Workgroups for Windows, MS Lan Manager,
- various TCP/IP systems, and other network operating systems that
- use the ODI, NDIS, or packet driver interfaces.
-
- Performance is better than you might expect, ranging from a low
- end of 40 KBps between 4BIT ports all the way up to an effective
- 200 KBps between EPP ports using our TURBO cable. This upper range
- is better than many ethernet ISA cards.
-
- The drivers are available with or without cables, and existing cable
- types typically used with laplink type products are also supported.
-
-
- The MultiPort Parallel Port Expansion System
- --------------------------------------------
-
- The MultiPort 4-port multiplexor turns your parallel port into
- a general purpose expansion system, capable of supporting up to
- four simultaneously operating parallel port peripherals including
- network adapters, portable hard drives, tape backup units, CDROMs,
- floppies, and so forth. For example, you can use the MultiPort Mux
- to attach a network adapter, a hard disk, a CD-ROM, and a printer,
- all operating together through a single parallel port.
-
- Now your laptop (and desktop) can enjoy a full range of peripherals
- with all the portability, sharability, and convenience of parallel
- port devices.
-
-
- Parallel Port Developer's Kit
- -----------------------------
-
- Pipx was constructed with Parallel Technologies' advanced parallel
- port software, which has been used in over 10 parallel port devices
- including network adapters, parallel port disks, parallel port
- wireless IR adapters, parallel port MIDI interfaces, and so forth.
-
- This software includes support for all types of ports, IO code
- that is extremely resistant to port idiosyncrasies, and full
- autodetection of all port hardware features. The code is very well
- documented. A selection of sample drivers for parallel port devices
- is also available.
-
-
-
-
-
- PARALLEL.DOC Page 27
-
- Parallel Port Information Utility ────────────────────────────── User's Manual
-
-
-
- OEM Products
- ------------
-
- Most of our products are available for OEM licensing, including
- network adapters, EPP-capable hard disks, parallel-SCSI interface,
- parallel MIDI adapter, and the MultiPort parallel port expander.
-
-
- Development Services
- --------------------
-
- We specialize in contract development of parallel port peripherals
- and associated software including DOS and Windows device drivers.
- Our broad and deep experience with parallel port devices and our
- commitment to specialization allows us to design, implement, test,
- and support them very efficiently.
-
- You might be interested in our 30/90 development offer. We propose
- to convert any ISA peripheral into a parallel port device in only
- 30 days to prototype, 90 days to production.
-
- We also offer more limited development support, such as developing
- additional devices drivers for existing peripherals.
-
- We are quite experienced with EPP ports and are ready to upgrade
- your existing parallel port devices to full EPP performance.
-
-
- Consulting and Training
- -----------------------
-
- In support of in-house development, you will find our consulting
- and training services invaluable in avoiding the pitfalls of
- parallel port development while achieving the highest possible
- product performance and quality.
-
-
-
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- PARALLEL.DOC Page 28
-
- Parallel Port Information Utility ────────────────────────────── User's Manual
-
-
-
- ------------------------------
- Software License Agreement
- ------------------------------
-
- IMPORTANT
-
- Read this agreement before installing or using the Software. Installing
- and/or using the Software on your computer indicates your acceptance of
- these terms. If you do not agree to these terms and conditions, delete the
- Software and all it's associated files from your computer. This Software
- License Agreement gives you ONLY RESTRICTED RIGHTS to use the Software (and
- all it's associated files and documentation) as follows:
-
- YOU MAY
-
- 1. Use the Software without charge on as many systems as you wish,
-
- 2. Share the Software with others for their personal use, but only
- if you share it intact, without any changes or modifications of
- any kind, and complete with all it's documentation and associated
- files. You must pass it on exactly in the same form as we release
- it, or not pass it on at all.
-
- 3. Make backup copies of the Software, so long as you place our
- copyright notice on the backup copies,
-
- 4. Request and receive limited technical support as provided in the
- Freeware Product Support Policy below.
-
- 5. Vendors may distribute the Software free of charge by electronic
- or other means for the purpose of technical support, but may not
- include the Software in their products without our written permission.
-
- YOU MAY NOT
-
- 1. Use the Software in any way except as provided in this agreement,
-
- 2. Modify, alter, copy, transfer, or reproduce the Software in any
- way, except as expressly allowed in this agreement,
-
- 3. Translate, de-assemble, de-compile, reverse program, or reverse
- engineer the Software or any of its components,
-
- 4. Charge any kind of fee for distributing the Software without our
- written permission,
-
- 5. Use the Software for commercial purposes without our permission,
-
- 6. Sublicense, lease, rent, sell, distribute, or otherwise dispose
- of the Software without our written permission.
-
- This license is effective from the date of first use of the Software and
- shall remain in force until terminated. You may terminate this agreement by
- destroying any and all copies of the Software and its documentation.
-
-
-
-
- PARALLEL.DOC Page 29
-
- Parallel Port Information Utility ────────────────────────────── User's Manual
-
-
-
- Parallel Technologies, Inc. may terminate this agreement if you fail to
- comply with any of the terms and conditions of it. You agree to destroy any
- and all copies of the Software and its documentation, in whatever form, if
- we terminate this license agreement, and you agree to provide us written
- certification of such destruction upon our request.
-
- Statement of Exclusion of Warranty
-
- ALL PRODUCTS DELIVERED PURSUANT TO THIS AGREEMENT ARE DELIVERED ON AN
- "AS-IS" BASIS AND PARALLEL TECHNOLOGIES, ITS DEALERS AND DISTRIBUTORS,
- EXPRESSLY DISCLAIM ANY AND ALL WARRANTIES OR CONDITIONS OF MERCHANTABLE
- QUALITY OR FITNESS FOR A PARTICULAR PURPOSE.
-
- Limitation of Liability
-
- PARALLEL TECHNOLOGIES DISCLAIMS ALL WARRANTIES RELATING TO THIS SOFTWARE,
- WHETHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY IMPLIED
- WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, AND ALL
- SUCH WARRANTIES ARE EXPRESSLY AND SPECIFICALLY DISCLAIMED. NEITHER
- PARALLEL TECHNOLOGIES NOR ANYONE ELSE WHO HAS BEEN INVOLVED IN THE
- CREATION, PRODUCTION, OR DELIVERY OF THIS SOFTWARE SHALL BE LIABLE FOR ANY
- INDIRECT, CONSEQUENTIAL, SPECIAL, PUNITIVE, OR INCIDENTAL DAMAGES OR
- DAMAGES DUE TO LOST PROFITS, DATA, OR INFORMATION ARISING OUT OF THE USE OR
- INABILITY TO USE SUCH SOFTWARE EVEN IF PARALLEL TECHNOLOGIES HAS BEEN
- ADVISED OF THE POSSIBILITY OF SUCH DAMAGES OR CLAIMS. IN NO EVENT SHALL
- PARALLEL TECHNOLOGIES' LIABILITY FOR ANY DAMAGES EVER EXCEED THE PRICE PAID
- FOR THE LICENSE TO USE THE SOFTWARE, REGARDLESS OF THE FORM OF CLAIM. THE
- PERSON USING THE SOFTWARE BEARS ALL RISKS AS TO THE QUALITY AND PERFORMANCE
- OF THE SOFTWARE. This warranty gives you specific rights and you may have
- other rights.
-
- This agreement shall be governed by the laws of the State of Washington and
- shall inure to the benefit of Parallel Technologies, Inc. and any
- successors, administrators, heirs and assigns. Any action or proceeding
- brought by either party against the other arising out of or related to this
- agreement shall be brought only in a STATE or FEDERAL COURT of competent
- jurisdiction located in King County, Washington.
-
- =================================================================
- = FBI WARNING =
- = Failure to observe the restrictions of this license =
- = may be a violation =
- = of 17 United States Code sections 101 through 810 =
- = which carries severe personal and corporate penalties. =
- =================================================================
-
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- PARALLEL.DOC Page 30
-