The original 8748, 8751, and 8755 had Erasable Programmable Read-Only Memory (EPROM) inside, which, if you intended to use it, had to be programmed and, if you wanted to change the program, erased.

Erasure was done with an ultraviolet lamp of about 2537 Angstrom wavelength, IIRC, but programming was done in accordance with a published parallel programming specification. The EPROM in the 8748 was 1kx8, the one in the 8749, was 2kx8, the one in the 8755 was 2kx8, and the 8751 had 4kx8, all UV erasable, IF IT WAS IN THE WINDOWED CERAMIC PACKAGE. the 87 prefix indicates EPROM inside. There were 8655's and other 86xx's which were plastic packaged one-time-programmables (OTP's) which would, of course, not be eraseable. I did, and may still, have a few windowed ceramic packaged 8641's which are somewhat different from 8748 but have more or less the same instruction set, though their features are different. These, despite their number, were reprogrammable after being erased.

The spec's on how to program any of these devices would be found in the first-release databooks and datasheets, but might not be in the later ones. Manufacturers quickly figured out that releasing programming spec's to end users led to endless technical support requests, hence, no longer release that information to end users.

Many commercially available programming devices support the old 5-volt-only EPROMS and these families of devices as well. They're not terribly difficult or complicated to program, and I've seen low-cost (<$100) programmers that would handle 8741/48/49 and 8751/52, as well as 8755.

If you have these quartz-windowed-ceramic-packaged parts, and the means to erase them, then you might want to program them. I'm not recommending you attempt to build a programmer, however. For you, a beginning hardware designer/builder, it will be a challenge, and you may, at least, want to wait before tackling that task. All these devices aside from the 8755 can be applied in some way without using the internal EPROM. If you're determined to use the internal EPROM, you'll need a proven programmer. Before you buy one, I'd suggest you learn to use these devices without programming them. If you already have a programmer of some sort with a 40-pin socket, you may find it can do the job already.

RE