Herb Lin <LIN@Mit-Mc.ARPA> (12/28/84)
a report to netland about the Macrotech dual processor board, (with an 80286 (10 MHz) and a Z-80 (8 MHz) advertised as a "drop in replacement" for the Compupro dual processor board (8085/8088). It isn't. No doubt it does adequately with certain configurations, but with mine, it does not. The symptom of difficulty is that when I boot my system (a Compupro System 8/16 C) running MPM 8-16 (Gifford Computer Systems), the system does not boot properly (but only intermittently). It sometimes takes me a few pushes of the reset button to even start the system; then, sometimes, the system seems unable to find the right INIT files. Sometimes, it finds the files, but then branches off into some strange part of the code. It has never entirely failed to work, and these troubles seem to happen only when I am doing my boot. Once the system has booted properly, it appears to operate properly after that. The problem has been diagnosed as an interaction problem between the processor board and my hard disk controller board, a Morrow HDCA, that probably results from timing problems. Gifford has offered to refund in full the cost of the dual processor board; they have also suggested that I upgrade my hard disk controller to a COMPUPRO Disk 2 board. They have explicitly refused to develop a fix to my problem. Since I would really like Z-80 capability for my 8 bit processor, can anyone make suggestions to me? tnx.
CSTROM@SIMTEL20.ARPA (12/29/84)
Have you spoken to the people at Macrotech? It is possible that the hard disk controller you have is incompatible because of timing problems, but I cannot say for sure. I don't recall hearing of the MI-286 operating with the Morrow controller, but it does indeed operate with the Konan and CompuPro controllers. The technical suppoert people at Macrotech are _very_ cooperative and will go out of their way to try to assist you. The MI-286 board buys much more than 8-bit Z80 operation - the speed improvement over the 8085/88 board is impressive. Don't give up just yet! -Charlie
"Jerry E. Pournelle" <POURNE@mit-mc.ARPA> (12/30/84)
see my report on Macrotech board in January BYTE. It is a very good board. Now all I need is a BIOS that lets me use my memory-map video with it. JEP