On Tuesday, July 14, 2015 at 11:54:21 AM UTC-7, monahanz wrote:Those IDE boards are in fact a very simple boards. Essentially you are just talking to a 8255 three port chip. If you cannot write, you need to determine where the log jam is. Using a simple logic probe determine if the chip CS* lines is going low with a write. If WR* is going low etc. Single step through a simple continuous write loop in RAM. Eg:-
These three screen captures are from my Owon DS7102V connected to pin 23 of GAL 1. The test computer is a IDE/CF v3 card in a CCS Z80 running it's ROM monitor. Similar results were obtained from A CompuPro ZPU running DDT under CP/M. I don't specifically remember seeing the ?glitches? when I ran this simple test on an Altair when I began this theread.