Buying an Old IBM PC or Compatible on eBay or in Person - tips

Buying old computers is always a bit of a gamble, as is buying used items made so long ago. As long as you go into buying mode with the expectation that things may go well or not so well, you'll be best prepared for the results.

So you browse eBay or Craigslist, or go to a boot sale or Ham swap meet. There is an old IBM or compatible computer you're interested in. Here are some tips that may help you in the buying evaluation process.

1. Is it running? - Likely "no way to test" as few rarely have all the parts, period correct display, etc. Here is a list of running conditions:

• No power applied
• Powered up, fan spins on power supply
• Computer beeps on power up
• Hard disk and/or floppy sounds
• Some display says it "boots" to BASIC
• Some display says it shows errors or boots MS or PC-DOS

Each level down is better than the last. If there is a hard disk and it boots to DOS, that's best. Boots from floppy second, and so on. This gives you confidence in the motherboard, power supply, disk controllers, etc. More confidence in working hardware = more valuable (to you - always keep this info to yourself).

2. Exterior Visual Inspection - Why is this #2? Because #1 provides more information at first inspection.

Look at the pictures, or if you're lucky in person. Case condition counts - are there screws holding things, items loose, accessories if any.

Important: Look at the rear panel. See what add-in cards you can see from the outside. It's a really good indicator of what comes with the machine. And sellers most often have no clue and don't price up with "good cards" inside, full memory, or a coprocessor. This is the first IBM PC/AT I bought. The price was good and I was intrigued at the cards:

The left connectors look like a standard 9-pin serial and parallel port. The far right looks like a display card with parallel port. The second from the left is a 10-Base T network card and the third card could be a display but that would make two. So definitely more than bare bones here. That with two floppy drives had me intrigued. 

If you have few ports, that may be a sign the machine is a bit less desirable - the best thing is to get an...

3. Interior Inspection - this isn't always possible, try to see inside if at all possible. Many auction listings have interior pictures. 

Here you can see a lot of good info: It's a later model AT from the 512K System board. It has a Seagate ST-225 hard drive, half height, no 80287 coprocessor and lots more interesting card info. The most valuable cards are memory. The cards are, from the left, the floppy/hard drive controller, standard, IBM serial/parallel adapter, common, an IBM 128k memory board (brings memory to 640K, good!) the 10-Base T network card, an IBM Token Ring network adapter, and the far card was a dual board strange beast, which turned out to be a Wyse 700 display card, pricey in the day. 

Wow, this is better than average. The extra memory is the main bonus. Unfortunately the card doesn't hold more than 128k. The network cards are not immediately useful and the rare display card not immediately useful either (but commands $90 to $150 on eBay).

So the inspection lets you know how much bang for the buck you get. Add this to the info in previous steps.

NOTE: Unless it boots with hard drive access via a display, never assume the hard drive works. Most often they have died due to age or transit. The red light might come on, it doesn't count really. This is not a huge deal breaker as there are solutions to use memory cards holding much more instead. But a working hard drive is excellent, one with application software more so. Floppies can also not be working with dirty and/or misaligned heads. This is all about 40 year old hardware.

4. Cleanliness - if it's cleaner than not, that's great. Also if it doesn't smell like cigarette smoke or says "smoke free environment" that's good too. I had one machine that had an old insect infestation, yuck.

Ready to Decide

Ok, based on the information you have, you then need to decide if you want it. You don't want to show much emotion to the seller. Of there is a process to offer a price, you can start lower than their price. Then again, if you see lots you like, you might just want to pay their price, if reasonable. 

Know that you'll need a keyboard, display, cabling often to be able to check it out, those all cost extra, usually from other buyers. Factor that into your budget. I usually look to buy a used VGA card and hook it to a more modern LCD display with VGA connection. Keyboards can be very expensive especially for genuine IBM, but some knock-offs can be reasonable. On this machine, I got the seller to throw one in for free.

Then you use the methods for haggling and buying familiar to most people. Don't like it, don't buy it. If you find some utility, look to pay what is useful to you, which may be less than they want. If they want too much, there are likely others out there. If you see something rare about the machine, factor that into your price.

Usually there is enough stock on the market to have a pick. At the time this is being written, a drought on IBM PC/AT machines appears over and they are selling for around $300 US just the system unit. But not all machines are the same, hence the review. Also price rises depending on #1 - if it's running. Don't expect a $300 machine that boots to DOS 6.22 with a ton of software and memory. If you can find one, it's a true bargain.

Shipping

Buying in person saves money. Unfortunately these computers are heavy and shipping can be costly. If an auction says shipping free (or at a low cost), factor that as a positive. If shipping is too much, you might want to pass. And likely if the hard drives with my two PC/ATs ever worked, the harsh shipping that likely ensued trashed them. 

The buyer could park the drive heads or pack the drive in a secure box but that would be very rare and command more money as most will not do such.

Good Luck

The chance can be fun and can be frustrated. I ended up getting a second AT that had some different features than the first and the parts complement each other - like a 1.44MB floppy, an extended memory card with 128K and room for more, a coprocessor, a clock/port card. So I could use all the best parts for my build. But the hard drives in both machines failed, different reasons. And the floppies had some issues.

I hope you find some satisfaction in the hunt and digging into your finds.

From minuszero.net - some tips on language used on auction sites:

"Extremely rare"

Example:  I would list one of my toenail clippings as extremely rare, because only my clippings contain my DNA.

"Includes a certificate of authenticity"

Useful for proving the authenticity of an item that you are selling.
For example, I provide a Certificate of Authenticity with every "Genuine Loch Ness Monster's Tooth" that I sell.

"Pulled from a working system"

working  =  I turned the system on, and I either heard the power supply fan turning, or I saw a light somewhere turn on.  No smoke was evident.

"It was working the last time I powered it on"

Meaning #1:	It does not work now.  I will say that it it worked the last time I powered it on.  When the buyer complains, I will say that it was working 5 years ago, and must have deteriorated in that time.
Meaning #2:	I have no idea how to tell if it is working or not.  But, I think there's a good chance that it is working.  I do not want to list it as untested because that will put a lot of people off.  I will list it as, "It was working the last time I powered it on", and take my chances.