HP-21MX bootstrapping?

Brent Hilpert wrote: Yes, I saw this before. I don't have my cable wired the same as yours. I don't think my CSR/DSR/DCD go anyplace useful. Does your cable actually get you valid CSR? or are you just forcing it? ie: you connect to "U - +12V via 1k". I'll check the schematics, just have not yet. :) There are schematics for the B power supply on page 5-91 of: http://www.bitsavers.org/pdf/hp/2116/02116-9153_2116B_Vol2_Oct70.pdf You've seen that I presume? That's what I'm working off. Al was trying to track down an A version of Vol2 that he though he had, I've not heard back on it. I could really use this if someone out there has it. :) I was lead to believe that the C (perhaps only later C's?) used a switching power supply. I assumed, perhaps incorrectly, that there are different voltage outputs required for the A, B and C due to the different core memory designs. From what I understand: The A has 1 or 2 vertical 4kw stacks The B has 1 or 2 horizontal 8kw stacks The C has no stacks, but uses HP-2100[AS] compatible core cards Both the A and B can use a 2nd chassis to add 1 or 2 more stacks. The C can fit enough cards to take it to 32kw internally. Brent Hilpert wrote: Mine is labeled "HS TERMINAL" so I presume it's a D. I'll double check to be sure. I'll add more info on my notes page: http://rikers.org/wiki/HardwareNotes Thanx again for the help! -- Tim Riker - http://Rikers.org/ - TimR at Debian.org Embedded Linux Technologist - http://eLinux.org/ BZFlag maintainer - http://BZFlag.org/ - for fun!