Thanks. I guess my description was more late-night short hand than I had intended. The “test” system consists of the following: SSM serial card, CompuPro RAM17, CompuPro Disk 1 and the S100-Computers Z80 Master card. The floppy drives are YE-Data YD380 (from the IBM-PC/AT) which can be used in place of 8” drives in these systems (with the proper modifications to two signals). These drives work well and are reliable, plus you get something like 800k of storage.
The CPU is running at 4MHz with the 2MHz bus clock enabled. This is the same general configuration as my IMSAI (same speeds) but my IMSAI uses a TDL Z80 card.
The ROM code and all hardware is identical between the systems. The only thing different is the CPU card. I’ve even swapped things around to eliminate the memory board, floppy controller, or floppy drive, as being the problem. That’s how I arrived at something on the Z80 Master card as being the issue.
I just thought about this — I have wait states enabled on the Z80 card. I have to try disabling them. I didn’t have time to do that last night.
From: Crusty OMO <crus...@hotmail.com>
Reply-To: S100-Post <n8vem...@googlegroups.com>
Date: Wednesday, November 27, 2013 at 1:25 AM
To: S100-Post <n8vem...@googlegroups.com>
Subject: RE: [N8VEM-S100:2059] Using Z80 board with older S100 boards
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