Technical Considerations for Buying Used Computers

Purchasing an older, used computer can offer some benefits. They are less expensive, tend to use less electricity, and may be more compact or quieter than newer computers. Some have features not available on most newer computers, such as built-in TV video output, the ability to install two or three disk drives, or storage of system configuration data without using a battery. When looking for a useful older computer, be sure that it has an appropriate disk drive, keyboard, accessory ports, and video output for your purposes.

Most computers you will find today have a standard 1.44MB 3.5" disk drive. However, some older (pre-1995) computers came with 720K 3.5" disk drives installed, and may or may not be capable of accepting a 1.44MB drive. 720K 3.5" disks can be read and written to by computers with 1.44MB drives, but a computer with a 720K drive cannot read 1.44MB disks. A computer of this type can still be very useful (I'm using one right now to type this article, although I will need to use a newer computer to put it online), but you should not purchase one which doesn't come with a supply of 720K disks. Some early Zenith computers have 720K 3.5" disk drives, and so does the Tandy 1000 TL/3, SL/2 and RL. The 1000 RLX and RSX were sold with 1.44MB drives.

Another part to consider is the keyboard and keyboard port. If the keyboard is built-in or uses a standard PS/2 port, this probably isn't a concern for you. However, if the computer uses a large, round DIN-style keyboard jack (fairly recent computers have these, including some units with Pentium II processors) you should avoid purchasing it without a keyboard included. Otherwise you will need to find an appropriate used keyboard or adapter. Most Tandy 1000 series computers use non-standard keyboards and ports, so it is generally not a good idea to purchase a Tandy 1000 with no keyboard included. If you presently use a USB keyboard, you will have to buy a standard PS/2 keyboard to use with an older computer lacking USB ports. The same applies to your mouse or trackball.