Univac I memory tank

If anyone has a Diehl Combitron or one of the NCR versions. I'd love to have one. I used one years ago while working for UofMiami. I used it because it could be programmed and did square root. I can't pay what one is worth but would still love to have one. Dwight ________________________________ From: cctalk <cctalk-bounces at classiccmp.org> on behalf of Christian Corti via cctalk <cctalk at classiccmp.org> Sent: Thursday, March 16, 2017 2:22:27 AM To: General Discussion: On-Topic and Off-Topic Posts Subject: Re: Univac I memory tank On Wed, 15 Mar 2017, dwight wrote: I can tell you exactly what the Diehl Combitron does; I have a running bachelor thesis for a student who is developing an emulator and assembler for that machine, and we have also disassembled (but not yet understood) the firmware (contained on the metal tape) of the machine. In fact, it uses two magnetostrictive delay lines, one is called the R delay line containing 219 bits plus one external in a flip-flop. The other is called the M delay line with a total of 10889+1 bits. The main clock of the machine is 1 MHz thus a bit time (called P) is 1 ?s. The R line holds four words ? 55 bits, one in the I phase P bits time, one in the I phase /P bits time, one in the /I phase P bits time and one in the /I phase /P bits time. The instructions are always fetched from the I phase /P bits and executed in the /I phase. The M line holds a total of 99 P words and 99 /P words. The phase between P and /P changes every M cycle During the loading phase (e.g. at power on or after a 'e1' order) the R line is filled with the contents coming from tape and then executed. Usually the code just transfers the other three words of the R line somewhere into the M line and restarts the loading phase for the next block. After loading the last block a fill instruction "jumps" to the entry point of the firmware. The fill instruction transfers four words Christian