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-
- From: garyf@wiis.wang.com (Gary Field)
- Subject: comp.periphs.scsi FAQ part 1 of 2
- Expires: Fri, 1 Jul 1994 05:00:03 GMT
- Reply-To: garyf@wiis.wang.com (Gary Field)
- Organization: Wang Labs, Lowell MA, USA
- Date: Thu, 2 Jun 1994 13:24:50 GMT
- Approved: news-answers-request@MIT.Edu
- Message-ID: <CqruLG.Mw5@wang.com>
- Followup-To: comp.periphs.scsi
- Summary: This posting contains a list of Frequently Asked
- Questions (and their answers) about SCSI. It
- should be read by anyone who wishes to post to the
- comp.periphs.scsi newsgroup.
- Sender: news@wang.com
- Nntp-Posting-Host: gfield.wiis.wang.com
- Lines: 940
- Xref: mmddvan comp.periphs.scsi:23542 comp.answers:5632 news.answers:23175
-
- Archive-name: scsi-faq/part1
-
-
- SCSI FAQ:
- Frequently Asked Questions for comp.periphs.scsi
-
- FAQ history: Created by Johnathan Vail (vail@tegra.com) from articles
- submitted to him by comp.periph.scsi readers.
- Maintained by Johnathan Vail until November 1993.
-
- Current Editor: Gary Field (garyf@wiis.wang.com)
-
- Last Modified: May 27, 1994
-
- Master Table of contents:
-
- Part 1
- What is SCSI ?
- Is it possible for two computers to access the same SCSI disks?
- What is the problem with the Adaptec 1542C and external cables?
- Where can I get SCSICNTL.EXE and other Adaptec files?
- What is the difference between the Adaptec 1542A and 1542B?
- What are the differences between the Adaptec 1542B and the 1542C?
- What are the differences between the 1542C and the 1542CF?
- What kinds of Optical Drives are available?
- Where can I get FTP/download SCSI documents?
- Where can I get SCSI documents?
- Where can I get information on various disk drives and controllers?
- What is the telephone number of Adaptec?
- What is the telephone number of Archive Corporation?
- What is the telephone number of Fujitsu?
- What is the address and telephone number for Quantum?
-
-
-
- What is the telephone number for Seagate?
- What is the telephone number and address of Conner Peripherals?
- What is the number for NCR?
- What is the address and telephone number of UltraStor?
- What is the address and telephone number of Wangtek?
- What is the address and telephone number of Western Digital?
- What is FAST SCSI?
- SCSI terminators should measure 136 ohms?
- Can someone explain the difference between 'normal' and differential scsi?
- What are the pinouts for differential SCSI?
- What are the pinouts for SCSI connectors?
-
- Part 2
- What is the difference between SCSI-1 and SCSI-2?
- Is SYNCHRONOUS faster than ASYNCHRONOUS?
- Is the 53C90 Faster than spec?
- What are the jumpers on my Conner drive?
- What are the jumpers for my Wangtek 5150 drive?
- What is CAM?
- What is FPT (Termination)?
- What is Active Termination?
- Why Is Active Termination Better?
- Why is SCSI more expensive than IDE?
- What is Plug and Play SCSI?
- Where can I get drivers (ASPI and other) for the WD7000 FASST2 host adapter?
- What if I have a drive larger than a gigabyte (1024k) ?
-
- ====
- QUESTION: What is SCSI?
- ANSWER From: LSD, L.J.Sak@Kub. Edited by Gary Field
- ====
-
- SCSI stands for Small Computer Systems Interface. It's a standard for
- connecting peripherals to your computer via a standard hardware interface,
- which uses standard SCSI commands. The SCSI standard can be divided into
- SCSI (SCSI1) and SCSI2 (SCSI wide and SCSI wide and fast).
- SCSI2 is the most recent version of the SCSI command specification and
- allows for scanners, hard disk drives, CD-ROM players, tapes [and many other
- devices] to connect.
- SCSI is becoming a popular standard. More and more computers use it daily.
- (e.g. ATARI Falcon and TT, expensive MS-PC's, Amiga, Apples and many others)
-
-
- ====
- QUESTION: Is it possible for two computers to access the same SCSI disks?
- ANSWER From: burke@seachg.uucp (Michael Burke)
- ====
-
- Yes, two (or more) systems can be on the same scsi bus as scsi disk and
- tape drives. As long as the scsi requirements are met - cable lengths,
- termination and type - the devices can share the scsi bus.
-
- The question should be - Are there any O/S' that will allow the sharing of
- file systems? It would not make sense for two hosts to go about treating
- shared disks as if they owned the device. Data would be destroyed pretty
-
-
-
- quickly.
-
- On the issue of tape devices, however, O/S' tend to give exclusive usage
- to an application. In this way, tape drives can be shared much more easily.
-
- Disks can be best shared by having two (or more) partitions on a disk. Each
- host "owning" its own file system.
-
-
-
- ====
- QUESTION: What is the problem with the Adaptec 1542C and external cables?
- ANSWER From: Scot Stelter, Adaptec (Product Manager for the AHA-1540)
- ====
-
- Several articles lately have cited the importance of SCSI-2-compliant
- cables when cabling SCSI bus subsystems. Perhaps the most accurate
- and technically detailed one was published in Computer Technology
- Review in March (Volume XIII, No. 3. PP. 6). In short, it explains
- the double-clocking mechanism that can occur due to cables whose
- impedance falls below the 90-Ohm SCSI-2 spec. Steep edge speeds on
- the REQ and ACK lines of the SCSI bus exacerbate the problem, but
- non-compliant cables are the root cause. Both LAN TIMES in the US
- (5/24/93, page 115) and CT Magazine in Germany (7/93, page 18) cite
- this cable problem.
-
- In an extensive survey of cables available in the US and Europe, we
- found that more than half of the cables available have single-ended
- impedances in the 65 to 80 Ohm range -- below the 90 to 132 Ohms
- specified in the SCSI-2 spec. It seems that some (not all) cable
- vendors do not understand the specification, describing their cables
- as SCSI-2 compliant when they are not. A common misconception is that
- SCSI-2 means a high-density connector. In fact, there are several
- connector options. I have published a technical bulletin that
- summarizes the critical requirements (TB 001, April 1993). An artifact
- of its faster design left the AHA-1540C with faster edge-speeds than
- its predecessor, the AHA-1540B. As I have said, this can exacerbate
- the effect of bad cables. This explains why some users could get
- their AHA-1540B to work when an early AHA-1540C might not.
- Essentially, the 1540B was more forgiving than the early 1540Cs. Good
- cables fixed the problem, but unfortunately for the user, good cables
- are hard to find.
-
- After surveying the cable market and many of our customers, we decided
- that bad cables were going to be here for a while, and we had to make
- the 1540C as forgiving as the 1540B was. At the end of April we made
- a change to the AHA-1540C that involved using a passive filter to
- reduce the slew rate of the ACK line, the signal that the host adapter
- drives during normal data transfers. Extensive testing with many
- intentionally illegal configurations confirms that we succeeded. Prior
- to release, we tested the AHA-1540C with over 200 peripherals, systems
- and demanding software programs with no failures. Then, a second team
- retested the AHA-1540C across a wild combination of temperatures,
- humidities and other stresses. This testing gives me confidence that
- the AHA-1540 line continues to serve as the gold standard for SCSI
-
-
-
- compatibility.
-
-
- ====
- QUESTION: What is the difference between the Adaptec 1542A and 1542B?
- ANSWER From: fishman@panix.com (Harvey Fishman)
- ====
-
- The AHA-1542A is obsolete and no longer supported by Adaptec. They
- stopped providing firmware upgrades at some level prior to the equivalence
- to the 3.10 level of the AHA-1542B firmware. I am not sure just where
- though. The present latest AHA-1542B firmware is version 3.20, and
- supports drives up to 8GB under MS-DOS.
-
-
- ====
- QUESTION: What are the differences between the Adaptec 1542B and the 1542C?
- ANSWER from: Terry Kennedy (terry@spcvxa.spc.edu)
- ====
-
- The 1542C is an an updated model which replaces the 1542B. The 1542C features
- jumperless setup, having only 8 DIP switches. All other configuration options
- are set using the 1542C's built-in BIOS configuration utility. Configurable
- features not found on the 1542B are:
-
- o Ability to enable/disable sync negotiation on a per-ID basis (the 1542B
- could only do it for all ID's on the SCSI bus)
- o Ability to send "start unit" commands on a per-ID basis
- o BIOS works with alternate I/O port settings on the adapter
- o Ability to boot from ID's other than 0
- o Software-selectable termination
- o Software-selectable geometry translation
- o Additional DMA speeds of 3.3 and 10 MB/sec
-
- Additionally, the 1542C uses a Z80 CPU and 8Kb buffer instead of an 8085 and
- 2Kb buffer as on the 1542B.
-
-
- ====
- QUESTION: What are the differences between the 1542C and the 1542CF?
- ANSWER from: Terry Kennedy (terry@spcvxa.spc.edu)
- ====
-
- The 1542CF includes all of the 1542C features, and adds "Fast" SCSI operation,
- providing SCSI data rates of up to 10MB/sec (compared with an upper limit of
- 5MB/sec on the 1542C). This is unrelated to the host DMA rate. It also has a
- software-configurable address for the floppy controller and a "self-healing"
- fuse for termination power.
-
-
- ====
- QUESTION: Where can I get SCSICNTL.EXE and other Adaptec files?
- ANSWER From: randy@psg.com (Randy Bush)
- and Timothy Hu timhu@ico.isc.com
- ====
-
-
-
-
- New files from Roy as follows:
-
- ftp.psg.com:{$de}/pub/adaptec/...
-
- -rw-rw-r-- 1 randy staff 110689 Feb 25 00:29 SCSICNTL.EXE.Z
- -rw-rw-r-- 1 randy staff 368640 Feb 25 00:27 adse.dd
- -rw-rw-r-- 1 randy staff 1959 Feb 25 00:25 adse.dd.readme
- -rw-rw-r-- 1 randy staff 17896 Feb 25 00:37 list
- -rw-rw-r-- 1 randy staff 99545 Feb 25 00:20 os2drv.zip
- -rw-rw-r-- 1 randy staff 70801 Feb 25 00:20 scsi drv.Z
- -rw-rw-r-- 1 randy staff 66508 Feb 25 00:24 scsi drv.readm
- -rw-rw-r-- 1 randy staff 118697 Feb 25 00:17 update.pkg.Z
-
-
- You can get the ASPI specs from Adaptec's Bulletin Board (408)945-7727.
-
-
- ====
- QUESTION: What kinds of Optical Drives are available?
- ANSWER From: joungwoo@mensa.usc.edu (John Kim)
- ====
-
- As I promised I am posting the summary of what I learned about 128mb optical
- drives through many kind replies and some effort on my part. The purpose of
- this informal survey was to aid people (starting from myself) in deciding on
- which 128mb optical drive to buy.
-
- When I posted my questions, it was done only on comp.mac.sys.hardware and
- forgot to do the same also on comp.arch.storage and comp.periphs.scsi where
- are less traffic than c.m.s.h. However, as a Macintosh owner myself, this
- survey was biased toward the Mac world and the mail order houses mentioned
- specializes in Mac-related products, although the below mentioned optical
- drives might be usable also with non-Mac platforms (Sun, NeXT,
- PC-compatibles).
-
- My questions were:
-
- o what kind of drive you bought from whom at what price
- o what drive mechanism (MOST, Epson, Fujitsu, Sony, ...) it uses
- o how fast it is in terms of average seek time & data transfer rate
- o how noisy the drive is
- o how large and heavy the drive is
- o what drive formatting program (eg, FWB or Silver Lining) you use what its
- goods/bads
- o the quality of the service of the seller (mail order company, retail store,
- etc.)
-
-
- Summary
-
- In general, these days, some magneto-optical (MO) drives seem to be
- almost as fast as (if not faster than) ordinary hard drives (HD). The
- access time of fastest 128MB MO drives (around 30ms) are slower than
- average HD's access time (15ms) but the transfer rate seems to be
-
-
-
- about the same (764KBytes/sec) or not much slower. The advantages of
- the MO drives over the HDs are that your storage space is almost
- limitless, expandable at a relatively cheap price ($40/120MB = 34
- cents/MB) compared to $1/MB rate of HDs or that of SyQuest drives, and
- the life of the media is very long (they say it's 30 years or
- rewritable 100,000 times.)
-
- Fijitsu 128 REM Portable: At this moment, to my knowledge, 128 MByte
- optical drives based on Fujitsu mechanism seems to be the fastest,
- roughly having average seek time of 30ms and average transfer rate of
- 768KBytes/sec. Another good thing about this Fujitsu drive is that it
- is more compact in size than previous 128mb optical drives, ie,
- "portable". I don't know how Fujitsu mechanism (FM) is different from
- Epson mechanism (EM) and how FM provides a similar performance at a
- cheaper price in a smaller frame. Maybe using split-head
- implementation to make the read-write head lighter? Could anybody post
- info on this? One person tells me that the eject mechanism is too
- strong, sometimes shooting the cartridge out making them land on the
- floor. He says Fujitsu told him that the FM's coming out in April will
- have gentler eject.
-
- Epson: The next fastest (or maybe just about the same speed) are Epson
- mechanism (EM) drives, having average access time of 34ms and transfer rate of
- 768KB/sec. These achieve faster speed compared to other old mechanisms by
- having a higher rpm (3600rpm vs. past 2400 rpm).
-
- Slower ones: Other mechanisms (Sony, Panasonic, etc.) seem to have
- been dominating the optical drive market before FM and EM's advent.
- These have a typical access rate of {$de}45ms. I don't know if now there
- are new implementations that make them perform better then FM and EM.
- Maybe someone can tell us.
-
- Noise Level: One thing to consider might be noise of the drive. Different
- mechanisms may have typical noise level, but one thing sure is that different
- resellers/companys' drive's noise level differs even for the same drive
- mechanism, eg, Sony. It looks like different casing produces different noise
- levels? (Could someone confirm/disconfirm this aspect?) Base on the report
- in Nov '92 issue of MacWorld, the noise level of MacDirect, MacProduct and
- DGR 128mb MO drives seem to be OK or quite quiet.
-
- This issue of MacWorld deals with removable media drives (optical drives of
- various capacity, SyQuest, Bernoulli and Flopticals) and you can get some
- idea on what the differences among different drive mechanisms are.
-
- Formatting Software: Another thing to consider is what kind of media
- formatting software you will use. All companys (or mail order places) seemed
- to provide for free formatting program with their drives. I don't have the
- details on this. But an inefficient formatting can result in slow drive
- performance. The most popular one used to be FWB's Hard Disk Toolkit but
- Anubis (advertised to improve performance up to 35% [compared to what?]) is
- beginning to be used also. I don't know if all formatting program and the
- drive hardware allows to have read and write verify off but by having these
- turned off you can obtain significant speed boost at the risk of less secure
- data transfer. MacWorld's report warned that drives from some companys don't
- let you turn on/off the verify. In the worst case, some come with verify off
-
-
-
- and no option to toggle it back to ON.
-
- 256mb MO drives: In general these have better transfer rate (1.23MB/sec) and
- a little slower access time (35ms). I feel that this capacity will soon be
- the next standard. These drives are able to also read/write 128mb cartridges
- and 256mb will soon be new ANSI and ISO standard. I once heard from a
- saleperson at a mail order place that these are not reliable yet and he saw
- many they sold came back with complaints. This may be a non-general instance
- on a typical drive mechanism (seems to be MOST mechanism). Personally, I feel
- 128mb is accomodating enough for personal usage at home unless you are
- dealing with very large data files (eg, large graphic images).
-
-
-
-
- ====
- QUESTION: Where can I get FTP/download SCSI documents?
- ANSWER From: news@mgse.UUCP (News Administator)
- ====
-
-
- Last Changed: Thu Sep 24 23:31:09 CDT 1992 (New BBS Phone number)
-
- This is a periodic posting of information about some of the archives at
- ftp.cs.tulane.edu and the available files from the SCSI-BBS, including
- SCSI, ESDI, IPI, and Fiber Channel documents from the standards committees.
-
- These files are available for FTP from ftp.cs.tulane.edu in the directory
- pub/scsi. Files are stored in file areas as they are found in the BBS with
- each area having a file named 'files.bbs' that tells what each file is. The
- file pub/scsi/index.Z list each file area, its descriptions and its files.
-
- Thanks to John Lohmeyer of NCR, a majority of the SCSI related files from the
- SCSI BBS are now available for anonymous ftp. These files were sent to me by
- Mr. Lohmeyer at his expense so that more people would have access to them.
- The SCSI BBS (719-574-0424) contains a large amount of data relating to SCSI,
- and ESDI as well as SCSI-2, IPI, and Fiber Channel, as well as the last
- revision of the SCSI-1 standard before it went to publication by ANSI.
-
- Most of the files in the SCSI archive are either archived with the ZIP utility
- or compressed with the 'compress' program. Most of the text files are stored
- as Wordstar word processing files. PKzip for PC/MS-DOS is included in the
- archive to allow users to break up the .ZIP files, and the PC/MS-DOS binaries
- and .C source are also in the archive to convert the Wordstar documents to
- ASCII text.
-
- [Added by Gary Field Dec 21,1993]
- There is also a lot of good information at ncrinfo.ncr.com
-
-
-
- ====
- QUESTION: Where can I get SCSI documents?
- ANSWER #1 From: kev@hpcpbla.bri.hp.com (Kevin Jones)
- and jmatrow@donald.WichitaKS.NCR.COM (John Matrow
-
-
-
- ====
-
- The only literature that I'm aware of is:
-
- The SCSI specification: Available from:
-
- Global Engineering Documents
- 15 Inverness Way East
- Englewood Co 80112-5704
- (800) 854-7179
- SCSI-1: X3.131-1986
- SCSI-2: X3.131-199x
- SCSI-3 X3T9.2/91-010R4 Working Draft
-
- (Global Engineering Documentation in Irvine, CA (714)261-1455??)
-
-
- SCSI-1: Doc # X3.131-1986 from ANSI, 1430 Broadway, NY, NY 10018
-
-
- IN-DEPTH EXPLORATION OF SCSI can be obtained from
- Solution Technology, Attn: SCSI Publications, POB 104, Boulder Creek,
- CA 95006, (408)338-4285, FAX (408)338-4374
-
- THE SCSI ENCYLOPEDIA and the SCSI BENCH REFERENCE can be obtained from
- ENDL Publishing, 14426 Black Walnut Ct., Saratoga, CA 95090,
- (408)867-6642, FAX (408)867-2115
-
- SCSI: UNDERSTANDING THE SMALL COMPUTER SYSTEM INTERFACE was published
- by Prentice-Hall, ISBN 0-13-796855-8 (Seems to be out of print)
-
-
- ANSWER #2 From: Gary Field (garyf@wiis.wang.com)
-
- A neat little book called "Basics of SCSI" second edition, was sent to me
- free of charge by Ancot Corporation, Menlo Park, CA (415) 322-5322.
- It gives a simplified description of how most aspects of the SCSI bus work
- and includes some discussion of SCSI-2 issues.
-
- ANSWER #3 From: Runar Jorgensen (runar.jorgensen@fys.uio.no)
-
- There was a two part article in Byte Magazine. The first part was in Feb 1990
- issue, p. 267-274 and the second was in Mar 1990 issue, p. 291-298.
- Another two part article appeared in Byte in May 1986 and June 1986.
-
- ====
- QUESTION: Where can I get information on various disk drives and controllers?
- ANSWER: ekrieger@quasar.hacktic.nl (Eric Krieger) (Updated Nov. 29, 1993)
- ====
-
- Drive and Controller Guide, Version 4.3
-
- THEREF(tm) is a comprehensive Directory of Hard Drives, Floppy Drives,
- Optical Drives, and Drive Controllers & Host Adapters. It is designed to
- help the novice and pro alike with integration problems and system setups.
-
-
-
-
- Information is provided in two handy formats; Portrait mode, for those
- who prefer a normal book-binding type print format, and(or) do not have a
- printer with Landscape capability. And Landscape mode, for those who pre-
- fer a computer-printout type format.
-
- For printing, a Laserjet is preferred, but not necessary, and setup
- info is provided. For viewing, LIST(tm) by Vernon Buerg, will provide an
- excellent result, and allow text searches for finding specific models.
-
- By F. Robert Falbo
-
-
- The archive is available at the following sites, all members of AmiNet
- (list valid in November '93):
-
- USA (MO) ftp.wustl.edu 128.252.135.4 pub/aminet/
- USA (TX) ftp.etsu.edu 192.43.199.20 pub/aminet/
- USA (CA) ftp.cdrom.com 192.153.46.2 pub/aminet/
- Scandinavia ftp.luth.se 130.240.18.2 pub/aminet/
- Germany ftp.uni-kl.de 131.246.9.95 pub/aminet/
- Germany ftp.uni-erlangen.de 131.188.1.43 pub/aminet/
- Germany ftp.cs.tu-berlin.de 130.149.17.7 pub/aminet/
- Germany ftp.th-darmstadt.de 130.83.55.75 pub/aminet/
- Germany ftp.uni-paderborn.de 131.234.2.32 pub/aminet/
- Germany ftp.uni-oldenburg.de 134.106.40.9 pub/aminet/
- Switzerland ftp.eunet.ch changing pub/aminet/
- Switzerland litamiga.epfl.ch 128.178.151.32 pub/aminet/ (*)
- UK src.doc.ic.ac.uk 146.169.2.1 pub/aminet/
- Australia splat.aarnet.edu.au 192.107.107.6 pub/aminet/ (*)
- (*) closed 6:30am to 4pm weekdays
-
-
- The archive is present at:
-
- pub/aminet/text/docs/TheRef43.lha [197 K]
- pub/aminet/text/docs/TheRef43.readme
-
-
- Note: When extracting the archive on non-Amiga machines (i.e.
- MS-DOS with LHA213, etc.) please use the option -a0 to disable
- the preservation of the file-attributes (otherwise LHA will
- skip the files inside the archive with the message "special
- attributes").
-
-
- The file is also on ftp.funet.fi:
-
- pub/doc/disks/TheRef43.lha.2 [197 K]
- pub/doc/disks/TheRef43.readme.2
-
-
- ====
- QUESTION: What is the telephone number of Adaptec?
- ANSWER From: jcaples@netcom.com (Jon D Caples)
-
-
-
- ====
-
- 408 945-8600 Main number
- 800 959 7274 tech support
- 800 442 7274 orders doc, new bios, etc.
-
- Adaptec's general inquiry number, 800-959-7274, affords access
- to a FAX-based information retrieval system. In order to
- preserve the accuracy of this information, I won't go into details
- about how to use it (since Adaptec may change things without telling
- me :).
-
- For those outside the CAN-US area, or local to Adaptec the direct
- FAX info number is (408) 957-7150.
-
- There are three general topics as of this writing:
-
- General Information
- Sales Information
- Technical Information
-
- Give it a call and request the directory! As of this writing
- there are over 130 documents available. You need a touchtone phone
- and the fax number. You'll also be asked for an extension number to
- stamp on the FAX which will be used to identify the recipient.
-
-
-
- ====
- QUESTION: What is the telephone number of Archive Corporation?
- ANSWER From: jdp@caleb.UUCP (Jim Pritchett)
- ====
- Archive Corporation (800) 537 2248
- Tech Support (800) 227 6296
- FAX (714) 641-2499
- [Archive was bought by Conner in 1993 - Gary Field]
-
- ====
- QUESTION: What is the telephone number of Fujitsu?
- ANSWER From: Ken Porter (72420.2436@compuserve.com)
- ====
- Fujitsu FactsLine FAX Back service (408) 428-0456
- A six page catalog of available documents can be ordered.
-
- ====
- QUESTION: What is the address and telephone number for Quantum?
- ANSWER From: kmartine@qntm.com (Kevin Martinez)
- ====
-
- Quantum Corporation
- 500 McCarthy Blvd.
- Milpitas, CA
- 95035
-
- Technical Support Telephone Numbers:
-
-
-
-
- 800 826-8022 Main Technical Support Number
- 408 894-3282 Technical Support Fax
- 408 894-3214 Technical Support BBS V.32 8N1
- 408 434-9262 Technical Support for Plus Development Products
- 408 894-4000 Main Quantum Phone number
-
-
-
-
- ====
- QUESTION: What is the telephone number for Seagate?
- ANSWER From: landis@sugs.tware.com (Hale Landis)
- ====
-
- Here are the numbers for Seagate's Technical Support.
-
- SeaBOARD - Bulletin Board System available 24 hours. Use 8 data
- bits, no parity, 1 stop bit (8-N-1).
-
- USA/Canada 408-438-8771 9600 baud*
- England 44-62-847-8011 9600 baud*
- Germany 49-89-140-9331 2400 baud*
- Singapore 65-292-6973 9600 baud*
- Australia 61-2-756-2359 9600 baud*
-
- * - Maximum baud rate supported.
-
- SeaFAX 408-438-2620
-
- Use a touch-tone phone to have information returned to you via
- FAX. Available 24 hours.
-
- Technical Support Fax 408-438-8137
-
- FAX your questions or comments 24 hours. Responses are sent
- between 8:00AM and 5:00PM PST Monday through Friday.
-
- SeaFONE 408-438-8222
-
- Provides recorded information 24 hours or talk to a technical
- specialist between 8:00AM to 5:00PM PST Monday through Friday.
-
- SeaTDD 408-438-5382
-
- Using a Telecommunications Device for the Deaf, you can send
- questions or comments 24 hours or have a dialog with a
- technical support specialist between 8:00AM and 5:00PM PST
- Monday through Friday.
-
-
-
- ====
- QUESTION: What is the telephone number and address of Conner Peripherals?
- ANSWER From: ekrieger@quasar.hacktic.nl (Eric Krieger)
-
-
-
- ====
-
- CONNER PERIPHERALS, Incorporated WATTS LINE:
- 3081 Zanker Road PAY LINE: (408)456-4500
- San Jose CA 95134 FAX LINE:
- BBS LINE: (408)456-4415 (V.32)
- CONNER (408)456-3200
-
-
-
- ====
- QUESTION: What is the number for NCR?
- ANSWER From: gkendall@ncr-mpd.FtCollinsCO.NCR.COM (Guy Kendall)
- ====
-
- For data manuals for any NCR chips, please call 800-334-5454 or
- 719-630-3384.
-
-
-
- ====
- QUESTION: What is the address and telephone number of UltraStor?
- ====
-
- UltraStor Corporation
- 47061 Warm Springs Blvd.
- Fremont, CA 94539
-
- General (714)453-8170
-
- Rob McKinley (mckinley@spss.com) writes that UltraStore is now in Chapter 11
- and their Tech. Support number has been temporarily disconnected.
-
- FAX (510)623-8953
- BBS (510)623-9091
-
-
-
- ====
- QUESTION: What is the address and telephone number of WANGTEK?
- ANSWER From: "Terry Kennedy, Operations Mgr" <uunet!spcvxa.spc.edu!TERRY>
- ====
-
- Wangtek can be reached at:
-
- WANGTEK Incorporated
- 41 Moreland Road
- Simi Valley, CA 93065
- (805) 583-5255 [voice]
- (805) 583-8249 [FAX]
- (805) 582-3370 [BBS] now changed to 582-3620
-
- WANGTEK-Europe
- Unit 1A, Apollo House
- Calleva Industrial Park
-
-
-
- Aldermaston, Reading
- RG7 4QW England
- (44) 734-811463 [voice]
- (44) 734-816076 [FAX]
- 851-848135 [telex]
-
-
-
-
- ====
- QUESTION: What is the address and telephone number of Western Digital?
- ANSWER From: uunet!whale.st.usm.edu!rniess (Rick Niess)
- ====
-
- 1-714-753-1068 Western Digital
- 1-714-756-8176 Western Digital
- 1-714-753-1234 Western Digital
- 1200/2400 baud: 714-753-1234
- 9600 baud (Hayes): 714-753-1068
-
-
-
-
- ====
- QUESTION: what is FAST SCSI?
- ANSWER From: kev@hpcpbla.bri.hp.com (Kevin Jones)
- ====
-
- There are 2 handshaking modes on the SCSI bus, used for transferring data:
- ASYNCHRONOUS and SYNCHRONOUS. ASYNCHRONOUS is a classic Req/Ack handshake.
- SYNCHRONOUS is "sort of" Req/Ack, only it allows you to issue multiple
- Req's before receiving Ack's. What this means in practice is that
- SYNCHRONOUS transfers are approx 3 times faster than ASYNCHRONOUS.
-
- SCSI1 allowed asynchronous transfers at up to 1.5 Mbytes/Sec and
- synchronous transfers at up to 5.0 Mbytes/Sec.
-
- SCSI2 had some of the timing margins "shaved" in order that faster handshaking
- could occur. The result is that asynchronous transfers can run at up to
- 3.0 Mbytes/Sec and synchronous transfers at up to 10.0 Mbytes/Sec.
- The term "FAST" is generally applied to a SCSI device which can do
- syncrhonous transfers at speeds in excess of 5.0 Mbytes/Sec. This term can
- only be applied to SCSI2 devices since SCSI1 didn't have the timing margins
- that allow for FAST transfers.
-
-
-
-
-
-
-
- ====
- QUESTION: SCSI terminators should measure 136 ohms?
- ANSWER From: stevel@coos.dartmouth.edu (Steve Ligett)
- ====
-
-
-
-
- Yes, that is what you should measure. Let's see how that is so. The
- terminator contains 18 220-ohm resistors from signals to termpower, and
- 18 330-ohm resistors from those signals to ground. I've drawn that
- below:
-
- termpower--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
- {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--}
- 220 ohms-> R R R R R R R R R R R R R R R R R R
- {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--}
- signals -> o o o o o o o o o o o o o o o o o o
- {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--}
- 330 ohms-> R R R R R R R R R R R R R R R R R R
- {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--}
- ground --+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
-
- When you measure from any one signal to termpower, you aren't measuring
- that resistor in isolation, you are measuring that resistor IN PARALLEL
- with the combination of the corresponding 330 ohm resistor plus 17
- 220+330 ohm resistor pairs in series. I've redrawn the schematic to
- make this easier to see:
-
- termpower--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
- {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--}
- {SHIFT--} R R R R R R R R R R R R R R R R R <- 220 ohms
- {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--}
- {SHIFT--} o o o o o o o o o o o o o o o o o
- {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--}
- {SHIFT--} R R R R R R R R R R R R R R R R R <- 330 ohms
- 220 ohms R {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--} {SHIFT--}
- {SHIFT--} +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+-- ground
- {SHIFT--} {SHIFT--}
- {SHIFT--} R <-- 330 ohms
- {SHIFT--} /
- signal -> o-/
-
- <our resistor><--------- other stuff that's in parallel ---------->
-
- We're trying to measure that one resistor from a signal to termpower,
- but there's a ton of other stuff in parallel. The resistance of that
- "stuff" is 330 + 550/17 ohms (the 330 ohm resistor, in series with a
- parallel combination of 17 550 ohm resistors). The general formula for
- the equivalent of two resistances in parallel is r1*r2/(r1+r2).
- Whipping out my trusty spreadsheet, I find that the "stuff" has a
- resistance of about 362 ohms, and that in parallel with 220 ohms is
- about 137 ohms.
-
-
-
-
- ====
- QUESTION: Can someone explain to me the difference between 'normal' scsi
- and differential scsi?
- ANSWER From: ralf@wpi.WPI.EDU (Ralph Valentino)
- ====
-
-
-
-
- "Normal" SCSI is also called "Single-ended" SCSI. For each signal
- that needs to be sent across the bus, there exists a wire to carry it.
- With differential SCSI, for each signal that needs to be sent across
- the bus, there exists a pair of wires to carry it. The first in this
- pair carries the same type of signal the single-ended SCSI carries.
- The second in this pair, however, carries its logical inversion. The
- receiver takes the difference of the pair (thus the name
- differential), which makes it less susceptible to noise and allows for
- greater cable length.
-
-
-
-
- ====
- QUESTION: What are the pinouts for differential SCSI?
- ANSWER From: ralf@wpi.WPI.EDU (Ralph Valentino)
- ====
-
- Differential SCSI Connector Pinouts
-
- ------------------------------------- -------------------------------------
- {SHIFT--} SCSI {SHIFT--} {SHIFT--} MINI {SHIFT--} {SHIFT--} {SHIFT--} SCSI {SHIFT--} {SHIFT--} MINI {SHIFT--} {SHIFT--}
- {SHIFT--} SIGNAL{SHIFT--} DD-50P {SHIFT--} MICRO {SHIFT--} DD-50SA {SHIFT--} {SHIFT--} SIGNAL{SHIFT--} DD-50P {SHIFT--} MICRO {SHIFT--} DD-50SA {SHIFT--}
- ------------------------------------ -------------------------------------
- {SHIFT--} -GND {SHIFT--} 2 {SHIFT--} 26 {SHIFT--} 34 {SHIFT--} {SHIFT--} (open){SHIFT--} 1 {SHIFT--} 1 {SHIFT--} 1 {SHIFT--}
- {SHIFT--} -DB(0){SHIFT--} 4 {SHIFT--} 27 {SHIFT--} 2 {SHIFT--} {SHIFT--} +DB(0){SHIFT--} 3 {SHIFT--} 2 {SHIFT--} 18 {SHIFT--}
- {SHIFT--} -DB(1){SHIFT--} 6 {SHIFT--} 28 {SHIFT--} 19 {SHIFT--} {SHIFT--} +DB(1){SHIFT--} 5 {SHIFT--} 3 {SHIFT--} 35 {SHIFT--}
- {SHIFT--} -DB(2){SHIFT--} 8 {SHIFT--} 29 {SHIFT--} 36 {SHIFT--} {SHIFT--} +DB(2){SHIFT--} 7 {SHIFT--} 4 {SHIFT--} 3 {SHIFT--}
- {SHIFT--} -DB(3){SHIFT--} 10 {SHIFT--} 30 {SHIFT--} 4 {SHIFT--} {SHIFT--} +DB(3){SHIFT--} 9 {SHIFT--} 5 {SHIFT--} 20 {SHIFT--}
- {SHIFT--} -DB(4){SHIFT--} 12 {SHIFT--} 31 {SHIFT--} 21 {SHIFT--} {SHIFT--} +DB(4){SHIFT--} 11 {SHIFT--} 6 {SHIFT--} 37 {SHIFT--}
- {SHIFT--} -DB(5){SHIFT--} 14 {SHIFT--} 32 {SHIFT--} 38 {SHIFT--} {SHIFT--} +DB(5){SHIFT--} 13 {SHIFT--} 7 {SHIFT--} 5 {SHIFT--}
- {SHIFT--} -DB(6){SHIFT--} 16 {SHIFT--} 33 {SHIFT--} 6 {SHIFT--} {SHIFT--} +DB(6){SHIFT--} 15 {SHIFT--} 8 {SHIFT--} 22 {SHIFT--}
- {SHIFT--} -DB(7){SHIFT--} 18 {SHIFT--} 34 {SHIFT--} 23 {SHIFT--} {SHIFT--} +DB(7){SHIFT--} 17 {SHIFT--} 9 {SHIFT--} 39 {SHIFT--}
- {SHIFT--} -DB(P){SHIFT--} 20 {SHIFT--} 35 {SHIFT--} 40 {SHIFT--} {SHIFT--} +DB(P){SHIFT--} 19 {SHIFT--} 10 {SHIFT--} 7 {SHIFT--}
- {SHIFT--} GND {SHIFT--} 22 {SHIFT--} 36 {SHIFT--} 8 {SHIFT--} {SHIFT--}DIFSENS{SHIFT--} 21 {SHIFT--} 11 {SHIFT--} 24 {SHIFT--}
- {SHIFT--} GND {SHIFT--} 24 {SHIFT--} 37 {SHIFT--} 25 {SHIFT--} {SHIFT--} GND {SHIFT--} 23 {SHIFT--} 12 {SHIFT--} 41 {SHIFT--}
- {SHIFT--}TERMPWR{SHIFT--} 26 {SHIFT--} 38 {SHIFT--} 42 {SHIFT--} {SHIFT--}TERMPWR{SHIFT--} 25 {SHIFT--} 13 {SHIFT--} 9 {SHIFT--}
- {SHIFT--} GND {SHIFT--} 28 {SHIFT--} 39 {SHIFT--} 10 {SHIFT--} {SHIFT--} GND {SHIFT--} 27 {SHIFT--} 14 {SHIFT--} 26 {SHIFT--}
- {SHIFT--} -ATN {SHIFT--} 30 {SHIFT--} 40 {SHIFT--} 27 {SHIFT--} {SHIFT--} +ATN {SHIFT--} 29 {SHIFT--} 15 {SHIFT--} 43 {SHIFT--}
- {SHIFT--} GND {SHIFT--} 32 {SHIFT--} 41 {SHIFT--} 44 {SHIFT--} {SHIFT--} GND {SHIFT--} 31 {SHIFT--} 16 {SHIFT--} 11 {SHIFT--}
- {SHIFT--} -BSY {SHIFT--} 34 {SHIFT--} 42 {SHIFT--} 12 {SHIFT--} {SHIFT--} +BSY {SHIFT--} 33 {SHIFT--} 17 {SHIFT--} 28 {SHIFT--}
- {SHIFT--} -ACK {SHIFT--} 36 {SHIFT--} 43 {SHIFT--} 29 {SHIFT--} {SHIFT--} +ACK {SHIFT--} 35 {SHIFT--} 18 {SHIFT--} 45 {SHIFT--}
- {SHIFT--} -RST {SHIFT--} 38 {SHIFT--} 44 {SHIFT--} 46 {SHIFT--} {SHIFT--} +RST {SHIFT--} 37 {SHIFT--} 19 {SHIFT--} 13 {SHIFT--}
- {SHIFT--} -MSG {SHIFT--} 40 {SHIFT--} 45 {SHIFT--} 14 {SHIFT--} {SHIFT--} +MSG {SHIFT--} 39 {SHIFT--} 20 {SHIFT--} 30 {SHIFT--}
- {SHIFT--} -SEL {SHIFT--} 42 {SHIFT--} 46 {SHIFT--} 31 {SHIFT--} {SHIFT--} +SEL {SHIFT--} 41 {SHIFT--} 21 {SHIFT--} 47 {SHIFT--}
- {SHIFT--} -C/D {SHIFT--} 44 {SHIFT--} 47 {SHIFT--} 48 {SHIFT--} {SHIFT--} +C/D {SHIFT--} 43 {SHIFT--} 22 {SHIFT--} 15 {SHIFT--}
- {SHIFT--} -REQ {SHIFT--} 46 {SHIFT--} 48 {SHIFT--} 16 {SHIFT--} {SHIFT--} +REQ {SHIFT--} 45 {SHIFT--} 23 {SHIFT--} 32 {SHIFT--}
- {SHIFT--} -I/O {SHIFT--} 48 {SHIFT--} 49 {SHIFT--} 33 {SHIFT--} {SHIFT--} +I/O {SHIFT--} 47 {SHIFT--} 24 {SHIFT--} 49 {SHIFT--}
- {SHIFT--} GND {SHIFT--} 50 {SHIFT--} 50 {SHIFT--} 50 {SHIFT--} {SHIFT--} GND {SHIFT--} 49 {SHIFT--} 25 {SHIFT--} 17 {SHIFT--}
- ----------------------------------------------------------------------------
-
- Please note that I can only verify the DD-50P connector. The Mini
- Micro and DD-50SA pinout above is a pin for pin mapping from the SCSI
- pinout in the FAQ.
-
-
-
-
- How to tell if you have a single ended or differential drive:
- - Use an ohm meter to check the resistance between pins 21 & 22.
- On a single ended system, they should both be tied together
- and tied to GND. On the differential drive, they should
- be open or have a significant resistance between them. Note
- that most drives today are single ended so you usually only
- have to worry about this with old drives scavenged from
- other systems.
-
- [ Editor's note: The preceeding comment about differential drives being old
- is not valid. Differential drives are less common than single-ended ones,
- because they are mainly used only where longer cable runs are necessary,
- and they are not generally used in PCs, but state of the art drives are
- available with differential interfaces. Generally only the higher
- performance drives have a differential option because of the added cost.
- - Gary Field ]
-
- ====
- QUESTION: What are the pinouts for SCSI connectors?
- ANSWER From: snively@scsi.Eng.Sun.COM (Bob Snively)
- ====
-
- Originally dated May 23, 1990
-
- The connector families described by the drawings have standard
- pin numberings which are described the same way by all vendors
- that I have encountered. The SCSI-2 specification identifies the
- standard numbering, using that convention. It happened to be
- documented by AMP, but all the vendors use the same convention.
-
- The following diagrams have the outline drawings of connector
- sockets at the bottom. This is really for reference only, because
- the connector sockets and plugs are both specified as to their
- numbering and usually are labeled.
-
- There are some minor problems in naming the microconnector conductor
- pairs, which I have corrected in the enclosed diagram. All the conductor
- pairs of the Mini-Micro (High Density) connector are in fact passed
- through on the cables. SCSI-2 defines the RSR (Reserved) lines as
- maybe ground or maybe open, but they are still passed through the cable.
- Most present standard SCSI devices will ground those lines.
-
- -------------------- microSCSI to SCSI Diagram ---------------------------
-
-
- SCSI Connector Pinouts
-
- ------------------------------------- -------------------------------------
- {SHIFT--} SCSI {SHIFT--} {SHIFT--} MINI {SHIFT--} {SHIFT--} {SHIFT--} SCSI {SHIFT--} {SHIFT--} MINI {SHIFT--} {SHIFT--}
- {SHIFT--} SIGNAL{SHIFT--} DD-50P {SHIFT--} MICRO {SHIFT--} DD-50SA {SHIFT--} {SHIFT--} SIGNAL{SHIFT--} DD-50P {SHIFT--} MICRO {SHIFT--} DD-50SA {SHIFT--}
- ------------------------------------ -------------------------------------
- {SHIFT--} -DB(0){SHIFT--} 2 {SHIFT--} 26 {SHIFT--} 34 {SHIFT--} {SHIFT--} GND {SHIFT--} 1 {SHIFT--} 1 {SHIFT--} 1 {SHIFT--}
- {SHIFT--} -DB(1){SHIFT--} 4 {SHIFT--} 27 {SHIFT--} 2 {SHIFT--} {SHIFT--} GND {SHIFT--} 3 {SHIFT--} 2 {SHIFT--} 18 {SHIFT--}
- {SHIFT--} -DB(2){SHIFT--} 6 {SHIFT--} 28 {SHIFT--} 19 {SHIFT--} {SHIFT--} GND {SHIFT--} 5 {SHIFT--} 3 {SHIFT--} 35 {SHIFT--}
- {SHIFT--} -DB(3){SHIFT--} 8 {SHIFT--} 29 {SHIFT--} 36 {SHIFT--} {SHIFT--} GND {SHIFT--} 7 {SHIFT--} 4 {SHIFT--} 3 {SHIFT--}
- {SHIFT--} -DB(4){SHIFT--} 10 {SHIFT--} 30 {SHIFT--} 4 {SHIFT--} {SHIFT--} GND {SHIFT--} 9 {SHIFT--} 5 {SHIFT--} 20 {SHIFT--}
- {SHIFT--} -DB(5){SHIFT--} 12 {SHIFT--} 31 {SHIFT--} 21 {SHIFT--} {SHIFT--} GND {SHIFT--} 11 {SHIFT--} 6 {SHIFT--} 37 {SHIFT--}
- {SHIFT--} -DB(6){SHIFT--} 14 {SHIFT--} 32 {SHIFT--} 38 {SHIFT--} {SHIFT--} GND {SHIFT--} 13 {SHIFT--} 7 {SHIFT--} 5 {SHIFT--}
- {SHIFT--} -DB(7){SHIFT--} 16 {SHIFT--} 33 {SHIFT--} 6 {SHIFT--} {SHIFT--} GND {SHIFT--} 15 {SHIFT--} 8 {SHIFT--} 22 {SHIFT--}
- {SHIFT--} -DB(P){SHIFT--} 18 {SHIFT--} 34 {SHIFT--} 23 {SHIFT--} {SHIFT--} GND {SHIFT--} 17 {SHIFT--} 9 {SHIFT--} 39 {SHIFT--}
- {SHIFT--} GND {SHIFT--} 20 {SHIFT--} 35 {SHIFT--} 40 {SHIFT--} {SHIFT--} GND {SHIFT--} 19 {SHIFT--} 10 {SHIFT--} 7 {SHIFT--}
- {SHIFT--} GND {SHIFT--} 22 {SHIFT--} 36 {SHIFT--} 8 {SHIFT--} {SHIFT--} GND {SHIFT--} 21 {SHIFT--} 11 {SHIFT--} 24 {SHIFT--}
- {SHIFT--} RSR {SHIFT--} 24 {SHIFT--} 37 {SHIFT--} 25 {SHIFT--} {SHIFT--} RSR {SHIFT--} 23 {SHIFT--} 12 {SHIFT--} 41 {SHIFT--}
- {SHIFT--}TERMPWR{SHIFT--} 26 {SHIFT--} 38 {SHIFT--} 42 {SHIFT--} {SHIFT--} OPEN {SHIFT--} 25 {SHIFT--} 13 {SHIFT--} 9 {SHIFT--}
- {SHIFT--} RSR {SHIFT--} 28 {SHIFT--} 39 {SHIFT--} 10 {SHIFT--} {SHIFT--} RSR {SHIFT--} 27 {SHIFT--} 14 {SHIFT--} 26 {SHIFT--}
- {SHIFT--} GND {SHIFT--} 30 {SHIFT--} 40 {SHIFT--} 27 {SHIFT--} {SHIFT--} GND {SHIFT--} 29 {SHIFT--} 15 {SHIFT--} 43 {SHIFT--}
- {SHIFT--} -ATN {SHIFT--} 32 {SHIFT--} 41 {SHIFT--} 44 {SHIFT--} {SHIFT--} GND {SHIFT--} 31 {SHIFT--} 16 {SHIFT--} 11 {SHIFT--}
- {SHIFT--} GND {SHIFT--} 34 {SHIFT--} 42 {SHIFT--} 12 {SHIFT--} {SHIFT--} GND {SHIFT--} 33 {SHIFT--} 17 {SHIFT--} 28 {SHIFT--}
- {SHIFT--} BSY {SHIFT--} 36 {SHIFT--} 43 {SHIFT--} 29 {SHIFT--} {SHIFT--} GND {SHIFT--} 35 {SHIFT--} 18 {SHIFT--} 45 {SHIFT--}
- {SHIFT--} -ACK {SHIFT--} 38 {SHIFT--} 44 {SHIFT--} 46 {SHIFT--} {SHIFT--} GND {SHIFT--} 37 {SHIFT--} 19 {SHIFT--} 13 {SHIFT--}
- {SHIFT--} -RST {SHIFT--} 40 {SHIFT--} 45 {SHIFT--} 14 {SHIFT--} {SHIFT--} GND {SHIFT--} 39 {SHIFT--} 20 {SHIFT--} 30 {SHIFT--}
- {SHIFT--} -MSG {SHIFT--} 42 {SHIFT--} 46 {SHIFT--} 31 {SHIFT--} {SHIFT--} GND {SHIFT--} 41 {SHIFT--} 21 {SHIFT--} 47 {SHIFT--}
- {SHIFT--} -SEL {SHIFT--} 44 {SHIFT--} 47 {SHIFT--} 48 {SHIFT--} {SHIFT--} GND {SHIFT--} 43 {SHIFT--} 22 {SHIFT--} 15 {SHIFT--}
- {SHIFT--} -C/D {SHIFT--} 46 {SHIFT--} 48 {SHIFT--} 16 {SHIFT--} {SHIFT--} GND {SHIFT--} 45 {SHIFT--} 23 {SHIFT--} 32 {SHIFT--}
- {SHIFT--} -REQ {SHIFT--} 48 {SHIFT--} 49 {SHIFT--} 33 {SHIFT--} {SHIFT--} GND {SHIFT--} 47 {SHIFT--} 24 {SHIFT--} 49 {SHIFT--}
- {SHIFT--} -I/O {SHIFT--} 50 {SHIFT--} 50 {SHIFT--} 50 {SHIFT--} {SHIFT--} GND {SHIFT--} 49 {SHIFT--} 25 {SHIFT--} 17 {SHIFT--}
- ----------------------------------------------------------------------------
-
- * NC = NOT CONNECTED
-
- CONNECTOR TYPES:
- DD-50SA
- ------------------------ MINI-MICRO
- DD-50P {SHIFT--} ------------------- {SHIFT--} ---------------------
- -------------- {SHIFT--}17 \o o o o o o o o o/1 {SHIFT--} {SHIFT--} ----------------- {SHIFT--}
- 49{SHIFT--} o o o o o o {SHIFT--}1 {SHIFT--} 33 \ o o o o o o o /18 {SHIFT--} {SHIFT--}25\ o o o o o o o /1{SHIFT--}
- 50{SHIFT--} o o o o o o {SHIFT--}2 {SHIFT--} 50 \o o o o o o o/ 34 {SHIFT--} {SHIFT--} 50\o o o o o o o/26{SHIFT--}
- --------------- {SHIFT--} ------------- {SHIFT--} {SHIFT--} -------------- {SHIFT--}
- -------------------------- ----------------------
-
- (VIEWED FROM FACE OF CONNECTOR - USE VENDOR NUMBERING SYSTEM AS SPECIFIED)
-
-
- ANSWER From: Gary Field (garyf@wiis.wang.com)
-
- Macintosh Plus SCSI Connector Pinouts
-
- Note that this connector is NON COMPLIANT WITH ANY SCSI STANDARD!
- The grounding is insufficient and does not allow for proper twisted-pair
- transmission line implementation. It is recommended that a short adapter cable
- be used to convert to the more common Centronics style 50 pin connection
- rather than extend the 25 pin connection any further than necessary.
- The Macintosh Plus used a NCR 5380 SCSI chip controlled by the MC68000
- processor.
-
- -------------------
- {SHIFT--} SCSI {SHIFT--} {SHIFT--}
- {SHIFT--} SIGNAL{SHIFT--} DB-25S {SHIFT--}
- +-----------------+ DB-25S (female)
- {SHIFT--} -DB(0){SHIFT--} 8 {SHIFT--} -----------------------------
- {SHIFT--} -DB(1){SHIFT--} 21 {SHIFT--} 13\ o o o o o o o o o o o o o /1
- {SHIFT--} -DB(2){SHIFT--} 22 {SHIFT--} 25\ o o o o o o o o o o o o /14
- {SHIFT--} -DB(3){SHIFT--} 10 {SHIFT--} ------------------------
- {SHIFT--} -DB(4){SHIFT--} 23 {SHIFT--} View from rear of computer.
- {SHIFT--} -DB(5){SHIFT--} 11 {SHIFT--}
- {SHIFT--} -DB(6){SHIFT--} 12 {SHIFT--}
- {SHIFT--} -DB(7){SHIFT--} 13 {SHIFT--}
- {SHIFT--} -DB(P){SHIFT--} 20 {SHIFT--}
- {SHIFT--} GND {SHIFT--} 7,9,14 {SHIFT--}
- {SHIFT--} GND {SHIFT--}16,18,24 {SHIFT--}
- {SHIFT--} -ATN {SHIFT--} 17 {SHIFT--}
- {SHIFT--} BSY {SHIFT--} 6 {SHIFT--}
- {SHIFT--} -ACK {SHIFT--} 5 {SHIFT--}
- {SHIFT--} -RST {SHIFT--} 4 {SHIFT--}
- {SHIFT--} -MSG {SHIFT--} 2 {SHIFT--}
- {SHIFT--} -SEL {SHIFT--} 19 {SHIFT--}
- {SHIFT--} -C/D {SHIFT--} 15 {SHIFT--}
- {SHIFT--} -REQ {SHIFT--} 1 {SHIFT--}
- {SHIFT--} -I/O {SHIFT--} 3 {SHIFT--}
- +-----------------+
- Pin 25 is NOT CONNECTED
-
-
-
- --
- --/* Gary A. Field - WA1GRC, Wang Labs M/S 019-72B, 1 Industrial Ave
- Lowell, MA 01851-5161, (508) 967-2514, email: garyf@wiis.wang.com, EST5EDT
- A waist is a terrible thing
-
-