Lloyd Robert Borrett

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The AT Waiting Game

by Lloyd Borrett
Today's Computers, PC Australia, May 1985

  Lloyd Borrett

Lloyd Borrett

When will l IBM AT be released? I am asked this question regularly, and unfortunately IBM Australia is playing this one so close to the chest that the answers I give are not at all precise. For all I know, by the time you read this the PC AT may well have been announced in Australia.

But it is unlikely. IBM is unlikely to make the PC AT available in Australia until it can guarantee continuity of supply. The last thing IBM needs is the same bad feelings and publicity generated with the premature release of the XT. No matter how much money you had, there was a time when you just could not buy the XT. It was not until IBM Australia got the Wangaratta assembly plant going that the XT became readily available in Australia.

IBM does not want history to repeat itself with the AT. Supplies of these units are so tight that there is a flourishing black market in the US, with second-hand units selling for far more than the original price. There is little chance of being able to guarantee supplies to Australia.

So when will we see it? When Wangaratta starts assembling the AT, or May-June, whichever comes first. Why May-June? The investment allowance on new business equipment runs out at the end of this financial year, and there will be a mad rush to make the most of it. IBM would need very good reasons not to make the most of this opportunity.

OK, let us assume you will be able to get your hands on an AT. Here are some of the factors to be considered in such a purchase.

First, forget about all of that bad press the AT has received in Australia. Most of it was ill informed, and the rest just sensationalised a few problems some users had early on in the US. They were reported as failures of the IBM 20¬megabyte fixed-disk drive. My sources, and personal experience, suggest the symptoms were problems with the fixed disk, but that the causes were errors in the DOS 3.0 operating system, especially the BACKUP and RESTORE programs.

Also, several programs written to run under DOS 2.0 corrupt the disk structure when used with DOS 3.0 on the PC AT. Many appear to be working fine, but on exiting the program and running CHKDSK the true story is revealed.

IBM has provided US dealers with corrected versions of DOS 3.0, and most producers of offending programs have released new versions. We are unlikely to see the offending version of DOS 3.0 here, but application programs should be verified as AT and DOS 3.0 compatible.

Second, there are shortages of key components - specifically, the IBM 512K and 128K memory expansion cards, and the 20-megabyte fixed-disk drives.

The base model of the AT, which doesn't have the 20-megabyte fixed-disk, is a lot easier to obtain, and it has become quite common for dealers and customers to buy the base model and add their own fixed-disk drives. The user benefits from this as the often-used half-height drives leave increased expansion capacity.

Third-party supplies of memory expansion boards are now becoming available in the US. AST Research has an enhancement card called Advantage!, which removes the need for IBM's 128K memory card as well as providing up to two serial ports, one parallel port, a games port, and three megabytes of parity-checked memory. It is to be hoped that Australian distributors will  not be slow in getting such cards out.

It is worth noting that most of the memory expansion cards offering more than a megabyte use 256K memory chips, which are not in common supply. The better cards allow the use of 64K chips, but have provision to use 256K chips for increased expansion.

Third, there are problems with the use of the 1.2-megabyte diskette drive that comes standard on the AT. The special high-capacity diskettes required are in short supply. That will change, but it will take time. This means that you face the odious task of backing up a 20-megabyte hard disk using more than 30 360K diskettes. No wonder tape backup units have become popular.

If you have PCs or XTs that you want to have share data via diskettes on the AT then you are in for more money. The high-capacity diskette drive can read and write to 360K format diskettes, but it cannot be guaranteed that the drives on the PC and XT will be able to read them. That makes addition of a 360K diskette drive to the AT almost a necessity.

As if that is not enough, the 360K diskette drives used in the AT use a different interface to those in the PC and XT. So if you want to add a third-party 360K diskette drive to your AT, make sure that it is compatible with the IBM version.

Already a lot of people are awaiting the AT; they need the added performance and capacity. Don't become one of those who rush in blindly, and thus pay extra while the suppliers learn the ropes.

The AT differs in many ways from the existing IBM models, and it will take most suppliers some time to come to grips with the implications of these changes. Take the time to seek out someone who has done the pioneering work and learn from them. Even then, as with all new technology, you may still have to do just a little trail blazing yourself.

Lloyd Borrett is support co-ordinator for HiSoft Australia, president of the Australian PC User Association, founder of the Melbourne PC User Group, and system operator of the PC Connection bulletin board.

Last modified: Saturday, 15 October 2011


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