Disk archival techniques

---------------Original Message: Date: Wed, 18 May 2005 14:21:03 -0500 From: "Randy McLaughlin" <cctalk at randy482.com> <snip> Using one manufacturer as an example - Cromemco used bipolar PROMs and made their own numbers - 749XX. This makes it confusing but easy to spot when seen. They would use the chips on multiple boards keeping the same programming by chipnumber i.e. 74901 could be used on a floppy controller or memory card and still be interchangeable (I just made up an example but I've seen common 749XX across different types of cards). Randy www.s100-manuals.com -------------Reply: As a matter of fact, I just dumped several Cromemco PROMs a while ago for archival use; what's the recommendation for 4 bit PROMs? 8 bits with hex F's in the upper nibble, or? And are we going to be able to find blank bipolar PROMS or PALs in 10 or 20 years? mike