Hans, First, congratulations on this terrific progress! Second, a stop at 22 is probably an unexpected CAL (opcode of 0), which would do an effective JMS 20, pick up the instruction at 21 (probably a HLT to catch the CAL), and then halt with an apparent PC = 22. Take a look at M[20], it should have the PC+1 of the CAL. /Bob -----Original Message----- From: Hans B Pufal To: classiccmp; aek(a)spies.com; Bob Supnik Sent: 12/1/01 12:59 PM Subject: PDP-9 lives I am very happy to be able to announce that the PDP-9 that we have been working on for quite some time finally began talking to the world again today. We had gotten memory and processor operational, then had to fix a memory fault which developed. TTY I/O posed some problems but finally today it spoke and we could reply. We ran the only two test routines we have on paper tape: the extended memory test and the TTY test. There appears to be some issue with the TTY since part 1 test halts after a while with PC=22, no mention of that in the test writeup! TTY test part 2 runs without error. Anyways, we plan on completeing checkout on this system, fix a couple of burnt our indicator bulbs and get the punch up before starting on the second system we have. That one has a dual dectapes, then we can read the 100 or so tapes trhat came with the system, and run some real software ;-) I'd be interested in knowing the status of other pdp-9's. Regards -- hbp for ACONIT, Grenoble France