Classic Computer Magazine Archive CREATIVE COMPUTING VOL. 11, NO. 5 / MAY 1985 / PAGE 82

Notes on the AT and hard disk systems; IBM images. Will Fastie.

It's bird! It's a plane! Well, it sounds like a plane, anyway. That is, my new computer sounds like a plane, and a loud jet plane at that. But I'm getting ahead of myself: this is the end of the story. Let's start at the beginning.

A little over a month ago, PC Tech Journal's first PC/AT arrived. About two weeks ago, it was installed on my desk, and my aging(!) XT was passed on to a new member of the staff. The beginning of the story is therefore about IBM's so-called Advanced Technology Personal Computer, aka the IBM PC/AT.

If you want to know everything there is to know about the AT (well, just about everything), take a look at the December issue of PC Tech Journal. The description here is from a different point of view: I'm pretending to be just an ordinary, mortal, end-user, installing my new computer. In fact, I try to be more than an end-user because I ask my local ComputerLand not to install or otherwise check out the equipment we buy from them. Instead, I like to open the boxes myself, see how IBM packages and what's actually in the box, and see just how hard it is to figure out what to do.

The AT is surprising in this way. I expected about the same level of difficulty normally associated with installation of a regular PC or XT, but the AT is simpler. Furthermore, IBM has included two charts, poster-like affairs that have the major points of installation called out along with pointers to the documentation for more complete explanations. The charts cover all the bases--at least in the context of the time frame in which the AT was announced (more on this in a minute).

IBM has cleverly packaged the documentation in an attempt to get the installer to look at it. The books (Guide to Operation, Installation and Setup, Basic) and the charts come in a separate box along with the power cord; the box is marked "Open this box first!" Yes, you can reach right past the books for the cord, but at least you see the books and charts and therefore might understand that they might be helpful. In fact, it is important to open at least the Guide to Operations because that is where the Diagnostics disk is found; it is a most important player in the setup of an AT.

Once the documents have been found, the charts guide you through the setup process. One chart has the necessary instructions for the installation of internal options (boards, etc.). At least one option, a display adapter, needs to be added, and the battery needs to be connected, so these instructions are important. The second chart has the basic setup instructions for cabling and startup.

A significant improvement over prior PCs exists on the AT. In short, the DIP switches on the system board have been removed and replaced by battery operated memory. There are only two physical switches that need be considered, one inside the unit and one outside. Inside, a slide switch is used to tell the system which type of display will be the default. I'm not sure why this couldn't have also been put in memory, and it did prove to be the only point of confusion I encountered during the setup; I installed neither the IBM Monochrome nor the IBM Color/Graphics (CGA) adapter, the only two options documented. Outside, a switch on the power supply comes set to 230 volts and must be reset to 115. I found that curious, because IBM told me that the plant in Boca Raton builds only for North America, so I would expect the default to be 115. ATs for Europe are built in Scotland.

My big installation confusion came over the IBM Enhanced Graphics Adapter. When the AT was announced, only the two original adapters were available from IBM, and the installation documentation reflects this fact. I was quite confused about how to set the internal switch, and neither the AT documents nor the pile of paper that came with the EGA could bail me out.

I finally decided that the EGA could be considered a color adapter, so I set the switch accordingly. I plan some further experimentation to determine the effect of the switch; as it stands now, most of the software I use thinks a color board is installed and uses color, even if I prefer otherwise.

Connecting the battery is simple, but a flashlight is helpful to find the pin connector on the system board. The plug on the little cable is keyed, which means that it will fit only one way. Once connected, you can forget about it until the battery dies. The battery itself is about the size of a Zippo cigarette lighter and is attached to the rear of the cabinet by a Velcro strip. The battery must be installed to set the system configuration properly.

Once everything is installed and cabled, the next step is to turn on the system and boot the diagnostics disk. It is a good idea to run the diagnostics, but the important part is the setup program. You will know you need to run SETUP, because when the AT boots, it complains if its configuration memory is empty. The SETUP program is simple to use and speaks English for the most part. You will need to collect some information (amount of memory installed, type of hard disk) but IBM has provided a checklist for recording these items; if you use the checklist when you are performing the installation, you will have everything you need for SETUP. A nice feature of the AT is its built-in clock/calendar, and SETUP is the vehicle for getting proper values of the time and date initialized.

After SETUP, every boot of the system will read the time, date, and configuration memory. The AT maintains compatibility with its other family members by storing the configuration in absolute memory location 0040:0010 (aka 410), so application programs should feel at home.

Now that your AT is ready to run, all that is left is to install DOS--version 3.0 (or later) required. I'm making the assumption that most ATs will have a fixed disk, so the process is to boot DOS from diskette, run FDISK, run FORMAT/S, and then add files to your disk as desired. Table 1 shows how I typically organize my directory structure, and Figure 1 is a listing of the AUTOEXEC.BAT file I use to get going.

EGA Confusion

My confusion with the Enhanced Graphics Adapter was enhanced by the mound of documentation that came with it. In a way, it is funny. Installation of the AT is really the simplest of any PC family member yet, but it is the most well supported with documents. Better some of the effort should have been spent on the EGA. In particular, one of those charts would have been very helpful. The chart could give the big picture by acting as a roadmap and explaining what each of the individual documents was for.

At the moment, each one says things like "I am package 4. If you haven't opened Package 1, do so first." Yeah, but why? What's it for? Worse, you need to use some packages if you have an AT and others if you have a PC or XT. It is just not clear enough, at least not for me.

IBM's overall documentation strategy is good, as far as I am concerned. However, it is incumbent on us, as users, to maintain the books over time. The EGA includes updates for the Guide to Operations, for example. Because there are different Guides for different PC models, I had some difficulty deciding what went where. Again, I wished for the roadmap.

Once inside the EGA documents, the installation went smoothly. It was more complicated than usual because the EGA can be equipped with piggy-back memory options and must be jumpered depending on the display to be used (EGA supports IBM Monochrome, Color, and Enhanced Color displays). In addition, a set of DIP-like switches, accessible from the outside, must be set; for the first time in my IBM memory, the on and off positions of a switch are not clearly marked.

One thing that caught me was a protector that IBM installs on the piggy-back pin connector of the EGA. Even though IBM includes a note about removing it, the protector looks like a female pin connector and is somewhat confusing. I would have gotten over this hump more quickly if the protector had been bright red instead of black, and IBM's note would have been clearer.

Hard Disk Fever

A couple of issues ago I talked about how I used my home system with electronic disk and how that strategy satisfied me even though I used an XT at work. I'm sorry to report that having an AT on my work desk has destroyed the harmony of my venerable PC.

Generally speaking, my RAM disk gave me performance similar to that of the XT. It did take some discipline on my part, but practice makes perfect. The AT, however, is a whole lot peppier than the XT. My personal PC seemed pretty pathetic by comparison. I became vulnerable. I weakened. I began to look at ads for hard disks. I began to consider the options. And then, it happened. Kamerman Labs lowered their price by $200, to $695, and I burned up the telephone lines getting my order to them.

The going price right now for ten megabytes of internal hard disk is $695, or less. Just about every mail order house has an offer in that price range. I'm satisfied with my purchase, and I thought I should tell you the basis upon which it was made and some of the other pertinent details.

To begin with, Kamerman is not the only choice. You should make your decision based on price and the reputation of the vendor. Also, look to see if the vendor you choose has other products. Some of the sellers of hard disk systems are in business right now only to take advantage of the price situation; next year, they might be selling pet rocks or hula hoops. A vendor with multiple products in the category (different sizes of hard disk, tape backup, external mount subsystems, etc.) is more likely to have a broader customer base and is thus more likely to be around when you need service. Ignore this advice if the price for the entire subsystem drops below $500: for that kind of money, you one fails.

You should also carefully consider the power situation. A standard PC delivers 65 watts, enough to power the hard disk if the system is not overpopulated with boards. If you have a full house, however, you should seriously consider additional power. I decided to buy an IBM XT power supply as a spare part from my dealer. I paid a premium ($215 VS. $79 up from third parties), but I was willing to do so because I carry an IBM service contract on my system unit (the only part so covered) and wanted to keep the system as IBM as possible. Replacing the PC power supply with either IBM's XT unit or other replacement is easy.

Installing the Kamerman Mega-flight was a little tedious but not complicated. It arrived with a half-height bezel mounted and a full-height bezel in the box. I needed the latter, and had to exchange them. That also required the addition of "legs" on the drive to get it to the proper mounting height; Kamerman supplies long bolts for this purpose. The cabling instructions are clear, and I had no trouble of note.

Kamerman's software for the installation process is quite good. Getting from a factory disk to an installed system was automatic, with the Kamerman program supervising the execution of the DOS programs FDISK and FORMAT. The system is ready to boot from the hard disk after this program runs.

A warning: before you take your system apart and remove disk drive B:, make copies of the Kamerman software as the manual suggests. I forgot, and it is a much slower process with only one floppy. Also, don't forget to set the system board switches to reflect one the system board switches to reflect one floppy so that DOS will behave properly if drive B: is ever mentioned again.

Most of the vendors of disk subsystems are using the same set of suppliers for the disk drive itself. This means that you can generally depend on the physical drive. The electronics are also moving in a common direction, with the controller chips coming from a small subset of manufacturers. I'd suggest only that you look for a one-year warranty on the whole subsystem and a return policy if, for any reason, you are unhappy with your purchase.

I did have to sacrifice something when the hard disk went in. I gave up my game port. I find myself wishing for an AST MegaPlus II instead of my original, gameportless MegaPlus, but maybe I'll solve the problem by buying an EGA to replace both my Monochrome and Color adapters; I'll pick up a slot in the process.

By the way, I had already upgraded my system with the new IBM ROM BIOS chip. If you have a PC whose serial number is smaller than 030060, you need the new chip if you want the system to boot from the hard disk. Every machine purchased after about April, 1983, has the new BIOS. Your dealer can help if you are uncertain.

Oh yeah, the end of the story. That XT power supply is noisy. Aurally, it can be heard across the basement; the original PC supply was much quieter. Electronically, it messes up the TV in my kitchen worse than the PC did; the PC garbled distant stations while the XT supply affects local stations on the low end of the VHF band.

Ah, progress.