Inside-out mouse
CD-ROM drives: 2x versus 3x versus 4x
Upgrading to Enhanced IDE
Memory mishmash
Squinting in the great outdoors
The perils of PCI
Monitors and measurements
Prepare to plug and play
Instant OverDrive upgrades
CD-ROMs and Enhanced IDE performance
Q My problem is that I wish to use a digitiser tablet with AutoSketch for Windows. The reason for requiring a digitiser tablet is my need to transfer information from a map into a MS-Word document. My current technique is to mount a transparent copy of the map features in front of the computer screen and trace it with the mouse cursor; not an ideal method.
I understand that Windows in its basic form does not accept digitiser signals, but perhaps there is some software that will add this feature to Windows. The digitiser that I had in mind is a Genius 1212, ie a 12" square drawing area, if my memory is correct.
The cost of purchasing AutoCad (for DOS) and the required learning outweighs my need.
- M Possingham, Marden, SA
A As far as I know, the Genius digitiser has the software to simulate a mouse under Windows, and should work well with AutoSketch - but ask the dealer to make sure. Another method you may like to consider is scanning.
Simple hand-held monochrome scanners should be cheap enough. Yes, they do produce a bitmapped image and not a vector-based one of the AutoSketch type, but if it's necessary to have such an image, there are several software packages that will convert the image (I know CorelDraw does).
Q I'm not sure how fast a CD-ROM drive really needs to be. I've heard that double-speed should be the minimum, but what practical advantage do triple-speed or even quad-speed drives provide? Is the faster speed worth the extra money?
- Bill Fulton, CompuServe
A The bottom line is this: With most of today's CD-ROMs, quad-speed drives don't improve performance noticeably over that of double-speed drives; at best they drop 10 to 20 per cent fewer frames during video playback. Nonetheless, you should still buy a quad-speed drive if you can afford it, even though double-speed models cost less than half as much.
Here's why: as more and more applications are optimised to take advantage of quad-speed drives, the more those drives will be able to show off their speed. On the other hand, nobody is optimising applications for triple-speed drives, making them a complete waste of money.
By the time you read this, not only will more optimised applications be available, but you should be able to buy a quad-speed drive for about half what one cost six months ago. Quad is the new standard, and I strongly suggest you buy into it.
Q I'm thinking of buying a second IDE hard drive, and I like the prices I've seen on 540Mb Enhanced IDE models. But my system doesn't support Enhanced IDE, which means I wouldn't get the speed benefits - and I'd lose 12Mb of disk space, since standard IDE tops out at 528Mb. Do I need to buy an Enhanced IDE interface card, upgrade my BIOS, or what?
- Abraham Phantazein, Berkeley, California
A If your system has a flash BIOS - one that can be reprogrammed - your system manufacturer may have a free BIOS upgrade, available via a BBS, that supports Enhanced IDE. You download the file, run a simple upgrade routine, and immediately gain Enhanced IDE support (along with possible other benefits, such as Plug and Play support). Alternatively, some companies will send you upgrades on disk for a nominal fee.
Enhanced IDE's main perks are support for disks larger than 528Mb; the ability to connect four IDE devices; and support for speed-enhancing techniques, such as read/write multiple and Programmable I/O Mode 3 or 4. If your new BIOS has Enhanced IDE support, you'll break the 528Mb barrier and get support for at least four IDE drives. But you won't get the speed increase. And there's no way you can really hook up four drives without using two IDE connectors (you can put two drives on each connector).
Third-party BIOS upgrades can be tricky. If you want to attempt a chip upgrade, start by running your system setup routine and writing down all of the essential configuration information - paying special attention to the hard disk parameters. Then remove the old chips with a chip puller (a pair of tongs you can get from any electronics store) and plug in the new chips. If your configuration information goes south when you plug in the new BIOS, re-enter the settings manually.
A better route is to buy an Enhanced IDE interface card. GSI Model 18, an ISA card, supports drives up to 8.2Gb and provides the read/write multiple speed enhancement. A VL bus extension to this card should be available by the time you read this. The extension provides Programmable I/O Modes 3 and 4 - speed enhancements available only for local bus systems. However, the additional throughput that Enhanced IDE offers will probably be noticeable only in multimedia applications.
Q I have a 486DX-33 system with four 1Mb 30-pin SIMMs. I have four SIMM slots left, and I'd like to upgrade to 8Mb by buying a single 4Mb SIMM. However, I see all kinds of 4Mb SIMMs advertised - 4x9, 4x8, 4x3, and so on. What kind of memory should I buy?
- Steve Arnold, Internet
A You may well ask, since the way that memory is advertised is utterly confusing. First, the bad news: because your system uses 30-pin SIMMs, you can't upgrade using a single SIMM. The 486 is a 32-bit CPU, and 30-pin SIMMs are eight bits wide, so you need to upgrade your SIMMs four at a time - that is, you must install another four 1Mb SIMMs to reach 8Mb. If you ever want to upgrade again after that, you'll need to replace one bank of 1Mb SIMMs with four 4Mb SIMMs, creating a whopping grand total of 20Mb.
As to what kind of memory you need, you've already established the basics: your system takes 30-pin SIMMs instead of 72-pin SIMMs (the latter can be added one at a time, by the way). Now you need to check your system manual to see whether your PC requires parity memory and, if so, how fast that memory must be.
Parity memory includes an extra bit per byte, which some systems use to check for memory errors. You'll see 1Mb parity SIMMs advertised as 1x9, because they're 1Mb with a 9-bit path (eight bits for data and one for parity). If your system uses nonparity memory, buy a 1x8 SIMM, which lacks the bit for parity checking. And what exactly is a 1x3 SIMM? It's a 9-bit parity SIMM with only three chips on it (1x9 SIMMs have nine chips, but just to confound you, 1x8 SIMMs have either eight or nine).
As for speed, the vast majority of systems now take either 70ns (nanosecond) or 80ns memory; PCs that take 60ns or 100ns SIMMs are pretty rare. Just match the memory speed of the SIMMs you buy with the speed listed in your system manual. Remember that buying faster memory than your system requires won't help - in fact, it's been known to cause errors.
Q I used to take my laptop outside to work in the open air. Then I upgraded to a notebook with a dual-scan colour LCD screen with rich, bright colours - indoors, that is. Outside, I can't even see the screen. Is there a screen colour combination that works best in daylight? What type of colour screen has the highest visibility outdoors?
- Bruce Ammerman, Internet
A Colour LCD (liquid crystal display) screens are dimmer than black-and-white ones, because the backlighting must pass through colour filters and because the screen creates colours by turning off some subpixels and leaving others on (there are three subpixels - red, green, and blue - for every pixel in a 640 by 480 colour image). The highest-contrast combination is black and white, since white turns on all the subpixels and black turns them all off.
No matter what you do, though, your dual-scan colour screen will still be too dim to use outdoors. Even an active-matrix colour LCD - the brightest and most expensive colour notebook screen that you can buy - isn't usable outside, except maybe deep in the forest on a cloudy day. The backlighting behind a colour screen simply can't compete with daylight.
Your best bet for outdoor computing is what you probably used before: an old-fashioned reflective screen, which relies on ambient light instead of backlighting (just like a digital watch). Unfortunately, these aren't available in colour, and only handheld PCs still offer them.
Q Are PCI systems safe to buy? A couple of people who bought PCI systems told me they'd had problems that were very difficult to fix.
- Tad Jones, Junction City, Oregon
A Like many new technologies, PCI (Peripheral Component Interconnect, the souped-up expansion bus found in nearly all Pentium systems) got off to a rocky start. In many instances, PCI systems and expansion boards simply wouldn't work together, causing system crashes and lockups that could be cured only by removing the offending device. Smart buyers made sure that the system manufacturer had successfully tested their PCI peripherals - and that a money-back guarantee was part of the bargain.
Fortunately, PCI's compatibility problems were solved more than a year ago with the introduction of the PCI 2.0 spec (we're up to revision 2.1 at this writing). If both board and system are of this vintage, everything should work. Any new PCI hardware you buy today will almost certainly be PCI 2.0 or later, but ask your salesperson to make sure. The money-back guarantee is always a good idea.
Q Last month I ordered a PC with a 15-inch monitor. When I received the system, however, the screen measured slightly less than 14 inches diagonally. Am I missing something here?
- Mike Johnson, Bingham Canyon, Utah
A Exaggerating monitor size is standard practice throughout the industry. The manufacturer tells you that the CRT (cathode ray tube) measures 15 inches diagonally, but the bezel surrounding it covers part of the screen. The advertised sizes are thus technically correct, but the world would be a better place if monitor manufacturers identified their wares by the diagonal measurement of the usable screen area and didn't count the hidden part. There's so much hype out there. (See Jan's introduction.)
Q If I buy Plug and Play expansion boards now, will they work in a system without Windows 95? (In case you're wondering, I'm not interested in trying Intel's complicated Plug and Play software for DOS and Windows.)
- Amelia Atenus, Plano, Texas
A Without either Windows 95 or Intel's Plug and Play utility, or More PC Tools, your system can't automatically configure Plug and Play expansion boards. However, it's still worthwhile to buy Plug and Play hardware now in preparation for Windows 95, which will almost certainly make hardware configuration much simpler than it is today.
Although Plug and Play promises to do away with switches and jumpers altogether, most current Plug and Play expansion boards come with a special jumper that enables you to switch between Plug and Play and standard operating mode. So when Windows 95 finally arrives, you simply move the jumper and enjoy the benefits of automatic hardware configuration.
Q On the motherboard of my Compaq ProLinea 486SX-25, I found a jumper that selects the clock speed. If I were to move the jumper from the 25MHz position to the 33MHz position and install a 33/66MHz OverDrive chip, would I have a DX2-66? It can't be that simple, can it?
- Phil McCole, Nantucket, Massachusetts
A Well, as a matter of fact, it is. I couldn't have described the process better myself.
CD-ROMs and Enhanced IDE performance
Q You have written that IDE "can transfer data only as fast as the slowest device allows, and your CD-ROM drive is much slower than your hard disk." Pardon me? A week ago I opened up my 486DX2-66V and installed a new double-speed IDE CD-ROM drive, the NEC V2i, on the same ribbon cable as my hard disk. Funny thing, though - I haven't noticed any slowdown. Am I missing something here?
- Walt Crawford, Mountain View, California
A No, but I missed two things. First, I should have specified that "fast as the slowest device" relates only to local bus IDE interfaces and Enhanced IDE drives. This still applies to your system, which has a VESA local bus. Second, I neglected to explain exactly what "fast" and "slow" mean in this context. It all has to do with the main speed benefit of Enhanced IDE: programmable I/O Mode 3 (or, more recently, Mode 4).
For example, if one drive supports the old-fashioned PIO Mode 2 and the other supports the much faster PIO Mode 3, then both devices will run in Mode 2, because the interface must talk to all devices on the same channel in the same mode (all higher modes are backward compatible). When I wrote the column, all CD-ROM drives were Mode 1 or 2. Recently, a number of IDE CD-ROM drives arrived that support Mode 3, including the NEC drive you mentioned. Sorry for misleading you or any other readers.
Eric Knorr