[jan-jaap]

According to the SGI Hardware FAQ, "some" IP4 boards will accept the 4MB SIMMs too. This will be my next experiment. I also have some VME ethernet boards I think I can only test in the Professional IRIS. Ideally, the IP4 will take the SIMMs and I'll put 64MB RAM in it, and still have 48MB left for the 4D/25. Then I'll fill the spare IP4 and IP10 with the 1MB SIMMs and store or sell the rest of them.

Fired up the Professional Series 4D/70 yesterday with a bank of Tosiba 4MB SIMMs installed. It puts a short message on the serial console:

Code:

Version 4D1-3.1 PROM IP4 OPT Thu Dec  8 16:12:10 PST 1988 SGI
Memory address pattern test from 0xA0000000 to 0xA02FFFFF

and then it freezes with code 4 on the hex status display. I've seen it get further with no memory or broken SIMMs installed.

For completeness sake I even tried with a bank of 4MB SIMMs that the 4D/25 doesn't like in the first bank. To my surprise, the system completed POST, but showed only 4MB RAM installed and soon after it froze up.

I think I'll settle for 16MB if RAM in the 4D/70.