Jay, Mike, John, Thanks for the helpful information. It just dawned onto me that these were "write once" PROMs, not modern EEPROMs. Duh. So you get one shot at doing it right... The Data I/Os on ebay seem to be quite a bit more than $100 right now, I'll keep looking. I guess none of the modern ebay Chinese ones would do? Also where can you get the blanks? Any modern equivalents here too? Marc ------------------------- Jay West wrote: The Data I/O 29B works perfectly for those old fusable link proms. John Robertson wrote: One can pick up a Data I/O 29B and Unipak II off eBay starting around $100USD (ish). There is a very good support group on yahoo groups: https://groups.yahoo.com/neo/groups/Data_IO_EPROM Mike Loewen wrote: I used a Data I/O 29B programmer to burn the PROMs, with a Unipak 2B. The blank PROMs were variously Signetics N82S141, MMI 6341-1 and National 74S474. Along with the 12821A HP-IB board, you also need a Boot Loader PROM, 12992H (12992-80004). The boot loader PROM is a Signetics N82S129 or equivalent. For installation information about the firmware PROMs, see manual 12791-90001 (HP 1000 M/E/F-Series Firmware Installation and Reference Manual). For boot loader information, see manual 12792-90001 (HP 12992 Loader ROMs Installation Manual). ------------------------