Help Screen

Issue: November 1995
Section: Hardware
Pages: 167-172


Contents

Video capture
The best CPU upgrade
Problems installing serial card
Slave to the hard drive
Keeping an eye on the PC market


Video capture

Q I'd like to take pictures from TV and turn them into small posters. What equipment will allow me to do this?

- Jeff Craighead

A For still pictures only, the Video View card from Video Associates Labs, distributed by Lako Vision, is a good choice. The PAL video system used in Australia takes two frames of video to create a high-resolution image. It draws every second line of frame 1, then goes through and draws the in-between lines supplied by frame 2. Standard video cards capture only frame 1, which gives a low-resolution result. The Video View card captures both frames and interpolates them to achieve high resolution. The Video View card costs $1,599.

Standard video capture cards achieve a low resolution of 388 by 244 pixels. They start relatively cheaply, with the Creative Labs Video Blaster costing about $700, and then rise to about $1,000 as general quality increases. These cards can't record back onto videotape - a card to capture low-resolution video and play back to tape costs about $1,260.

For the best picture, consider buying a laser disc player and taking your pictures from laser discs in the CAV format. A laser disc produces a sharper image than a VCR, and CAV laser discs provide extremely clear freeze-frames. (Most laser discs are in the CLV format and don't provide freeze-frames at all, except on very expensive machines.)

Also, avoid action sequences, and keep those posters small. With a maximum resolution of 640 by 480, the images are going to look pretty grainy even on an A4 sheet.

Keep in mind that use of these images is bound by copyright laws. They're fine for personal use, but if you want to reproduce them in a publication or post them on-line, you must obtain permission from their owners.

The best CPU upgrade

Q Which CPU should I use to upgrade my DX2-66 system: a DX4-100 or the new Pentium OverDrive? If you suggest the latter, should I buy the 63MHz or 83MHz version? And who makes the better chip: AMD or Intel?

- Antonio Chiang

A Your best upgrade from a DX2-66, if you're just swapping chips, is a DX4-100. As of this writing, the Pentium OverDrive for systems with 33MHz buses, such as your DX2-66, is not yet available. This forthcoming chip is the 83MHz version you mention, the only Pentium OverDrive that will work in your system. And if our tests of Intel's Pentium OverDrive 63 - designed for systems with 25MHz buses - are any guide, the 83MHz version will not be a good deal.

At best, a Pentium OverDrive 83 will likely provide 66MHz Pentium performance.

If your DX2 system doesn't support write-back memory caching - and only a minority of DX2 systems do - you should expect considerably slower performance, probably something equivalent to a DX4-100. Intel's DX4 OverDrive 100 sells for $350 as I write this, while the Pentium OverDrive 63 will probably sell for about $800. So, save yourself some money and buy a DX4-100.

Which DX4-100? AMD's chip has an 8K internal cache, while Intel's has a 16K cache, so you'll get better performance from Intel's version, although how much better depends on your applications. Our tests indicated about 30 per cent smoother video from a system with an Intel DX4-100 than from an otherwise identical system with an AMD DX4-100. In normal business applications, the differences are less dramatic, usually in the 5 to 20 per cent range.

AMD chips cost less, but in this case I recommend spending the extra money, and not only for speed purposes. Intel supports its DX4 OverDrives directly, while AMD leaves warranty and support up to the reseller. (When you buy any upgrade product, always make sure you get a money-back guarantee.) Also, the speed boost from DX2-66 to DX4-100 may not be as apparent as you expect. To get satisfaction, I recommend going for the faster chip.

The best upgrade of all for a DX2-66 is a motherboard swap to a 90MHz (or faster) Pentium, which would give you a huge speed boost. I recommend this upgrade only if you know what you're doing - how to reinstall your disk drives, connect cables, troubleshoot problems and so on - or are willing to pay someone to do it. If this sounds good to you, look for a PCI motherboard with 256K of secondary cache, a built-in Enhanced IDE interface, and a Plug and Play flash BIOS from a name-brand vendor (such as AMI, Phoenix, Award or Quadtel).

Problems installing serial card

Q Recently I purchased an X-2233 Serial Card IBM/XT/AT from Dick Smith Electronics. I installed it myself. When I restarted my PC and connected my NetComm E7F fax modem to this new card, I could not get it to function. Is there a problem with my jumper settings on the new serial card? Could you have a look at my MSD report and let me know?

- John Hallinan

A John, installing hardware is one of the most frustrating aspects of owning a PC. The trick in dealing with machines is to let them know who's boss. You really are more intelligent than them, and in the final analysis, they don't have access to your power switch. You just have to be systematic.

Just about all hardware problems are due to resource conflicts. These occur when devices try to share hardware features called IRQs (interrupt requests), which let the devices communicate with the processor. They can also occur when devices share I/O addresses, which let the processor exchange information with the devices.

While you supplied your Microsoft Diagnostics, you didn't supply details of the jumper settings you had chosen on your card; however, your MSD report indicates that your new card is sharing IRQs with your old serial card. If the new card is set up for COM 3 and COM 4, and you're using your modem on COM 3, then it's going to conflict with the mouse on COM 1.

If your old serial ports are on a removable expansion card, remove it and see if the new one works. If your old serial ports are built into your motherboard, there might be a way to disable them - refer to your motherboard documentation to find out.

If the new port works after disabling the old ones, the problem is probably due to a conflict between IRQs, which is unbelievably common due to the primitive and limited design of the PC. It only has 16 IRQ lines, which have to handle all your hardware devices, including the built-in ones.

If the problem is due to IRQ conflict, you may be able to solve it by changing jumpers on your new serial card to set the IRQs to unused values. Installing hardware will involve much frustrating experimentation of this kind until the Plug and Play standard is widespread. Also, do you need four ports?

Slave to the hard drive

Q A few months ago I bought a Quantum Maverick (540Mb) hard disk which I set up to run as a slave disk to a Western Digital Caviar 2200 hard disk (203Mb). I was using this setup to make it easy to transfer files to and from the older Caviar drive until I was happy with the location of all my files. This worked beautifully.

The next part of the plan was to install the Maverick in a computer of its own and run it as the C: drive. However, I cannot find the correct arrangement of the jumper settings that will allow it to run as a single drive or master drive. Do you have any ideas? Incidentally, the computer shop in which I bought the drive is in Brisbane and I am now in Melbourne, which makes it difficult to pop over for advice. My motherboard has an AMD 486 chip and I run MS DOS 6.22.

The BIOS has no problem recognising the hard disk when autodetect is used, but as soon as the bootup sequence reaches the point where it would normally say LOADING MSDOS it stops and refuses to progress further. To make things more confusing (for me at least), if I boot from a floppy drive in A:, the start-up sequence proceeds quite normally, but then I have to switch to C: to make further use of the computer.

- Peter Dawson

A Peter, your geographical isolation from the point of purchase need not be a difficulty in the great global virtual village. Quantum has its own World Wide Web page, and it contains not only specifications and jumper settings but full diagrams. The only thing missing is a 3-D virtual reality walk-through of the setup process. I hope these details help.

I'm not altogether sure your problem is jumper settings though. It sounds like the system is trying to boot from the disk but isn't finding a Primary DOS partition or is missing the necessary system files. When you did your original format of the Quantum Maverick disk, did you create a primary DOS partition using the Fdisk command? To check, go to the DOS prompt, run Fdisk and select Option 4, Display Partition Information (see below).

If you do have a Primary DOS partition, did you put the DOS system files on the disk? You can do this when you format the disk with the format command format /s. You can also do it later. Boot from a DOS floppy and use the sys command: sys c:. The format command /s option or the sys command copy the hidden MS-DOS system files, io.sys and msdos.sys to your drive, as well as the MS-DOS command interpreter.

If you don't have a primary DOS partition, it sadly appears that you're going to have to reformat the disk from scratch and all your file transferring is as footprints in the sands of time.

Keeping an eye on the PC market

Q I own a medium-sized optometry practice and am interested in buying a good computer. Basically, I'm computer illiterate and have been shopping around for months without getting anywhere. I'm confused with sales talk from computer salesmen. Different people tell me different things!

I have been given a quote for an Optima Pentium P5-90 (about $3,100 without the extras, but with Windows 95 and DOS 6.22). Another quote is for a Compucon Pentium 90 PCI/ISA ($3,500 to $4,000). Please advise me as to what is the best buy today in terms of value. My budget is $2,500 to $3,500 excluding a printer.

- Ian O'Shea

A In Help Screen we can't advise on which brand you should purchase, for reasons which become obvious when you consider that our magazine carries advertisements. In our PC reviews and Top 10 articles, we supply benchmarking results and pricing information to help you with your choice. The simple answer is that, as with any other shopping, when you're buying a computer you try to compromise between meeting your current needs, allowing for future growth, and living within your budget.

In general, if you're buying a computer for standard home or office use today, you need at least 8Mb of memory and a 450Mb hard drive. The operating system and the current word processors, spreadsheets and other standard business software demand lots of memory and space.

If you want to run Windows 95 and make the best of the new features, such as the Microsoft Network, you need 12Mb or 16Mb of memory. To allow for future growth, you should also ensure that memory is installed in a configuration that allows you to add more memory easily, without throwing away what you have already. Ask the salesperson what is involved if you want to upgrade to 20Mb or 32Mb of memory. You'll also last longer without an upgrade if you get a gigabyte or more of hard drive space.

For good performance, you need VL or PCI bus slots and expansion cards. To make the best of Windows 95, you need a Plug and Play motherboard and Plug and Play expansion cards. Make sure you ask the salesperson about this and get a straight answer. Older machines without Plug and Play support are obsolete.

A Pentium 90 or 100 system with 16Mb of memory is a good choice. If you don't require a sound card and CD-ROM drive, you can get this PC for under $3,500. However, I wouldn't recommend that anyone buy a computer without a CD-ROM drive and sound support - too much good stuff is available on CD-ROM, and operating systems, office suites and many other software packages are much easier to install from CD. With luck you could get a multimedia kit included in the price of the PC.

Get a system with Windows 95 installed. If you can, get a printer with it and insist that the shop install and troubleshoot all the hardware with the operating system. If possible, get them to install your software as well. Ensure that everything's running before you get it home - ask to see it running in the shop. The same advice applies to Windows 3.1, but I wouldn't advise any new purchaser to get a system configured with DOS 6 and Windows 3.1. Windows 95 is a better choice for almost anybody buying a new machine.

- Eric Knorr and Neale Morison

Thanks to Spiro Hionis, our Test Centre guru, and Harris Computer Superstore and Harvey Norman Computer Superstore for prices and technical assistance.


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