I have the following available, both from HP: 'Data Systems Customer Support Handbook' dated Sep. 1980. Contains technical and support data for what appears to be a wide variety of early HP computer hardware, including what looks like source code for diagnostics (I just skimmed it -- didn't really read in detail). Here's a sample from the Table of Contents. Common Data 2114/15/16 2100 21MX-M and 21MX-E Power Supplies/Extenders Memories/Accessories Input/Output Parts Operating Systems I also have a binderful of user's guides for the HP9825A desktop system, circa March 1980, including: Operating and Programming 9872A Plotter Programming 98034A HPIB Interface - Installation and Service 98035A RTC - Installation and Operation Advanced Programming 98032A 16-bit Interface - Installation and Service Extended I/O Programming Matrix Programming General I/O Programming String Variable Programming 98036A Serial Interface - Installation and Service Systems Programming <Sheesh, what a load! The whole binderful weighs in at just over 9 pounds!) That's what I've got at the moment. Best offer (and I'm not looking for a fortune here, folks) plus mailing costs takes them! Thanks in advance. -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Bruce Lane, Owner and head honcho, Blue Feather Technologies http://www.bluefeathertech.com Amateur Radio:(WD6EOS) E-mail: kyrrin(a)bluefeathertech.com SysOp: The Dragon's Cave (Fido 1:343/272, 253-639-9905) "Our science can only describe an object, event, or living thing in our own human terms. It cannot, in any way, define any of them..."