View Full Version : Compupro DISK3 and Quantum Q540 hard drive

June 30th, 2015, 09:55 AM
I have a recently acquired Compupro 8/16 with quite a few S100 cards. My current configuration is an 8085/88 cpu, DISK1 floppy controller with one NEC1165 DSDD 8" drive, System Support I, Interfacer 4, RAM22 256k, (2) 512k M drive cards. The system successfully boots CP/M 2.2 and CP/M 86 and creates a 1024k M drive. I also have a DISK3 hard disk controller which I modified by adding 3 7805 regulators since my Compupro chassis is an earlier version. I have a Quantum Q540 hard drive and MFM cables which I verified function on an old IBM PC with WD1002 MFM controller. The hard drive formatted and booted MSDOS just fine. Now I am attempting to add the DISK3 and Quantum to my Compupro. I have the Q540 jumpered as DS1 (the choices are DS1-4 or A for all). My MFM cables are straight thru (non-twisted). I have an original labeled Compupro DISK3 formatter 8" floppy. When I run DISK.COM from cpm22 or DISK3.CMD from cpm86 using the command: DISK3 Q540 ALL it verifies the parameter settings are correct and when I type Y it hangs. Also when I initially boot my Compupro, the LED on the front of the Q540 turns on and stays on. I know from using it in the IBM PC that it is the drive select light which is only on for R/W access. I don't think the light should stay on continuously. Anyone familiar with the operation of the DISK3 Q540 combo? I know it's a long shot whether any "old-timers" are still around and reading this. I know my 5v regulators are producing the correct voltage. I have an S100 extender board, a 100MHz oscilloscope, voltmeter and 20+ years experience using both as a senior electronics technician. I can troubleshoot waveforms but no experience with S100 bus architecture. My experience was mostly consumer electronics and analog circuits. Any suggestions?

Larry G