Neil, I surprised you needed those patches. It’s a long time since I fired up that board but I do remember It worked fine without patches like that. It worked fine as is – at least with the simple monitor in ROM I wrote. Fabio how about you? I wondering if it’s something to do with your ROM addressing. Is that an Apple ROM? John From: n8vem...@googlegroups.com [mailto:n8vem...@googlegroups.com] On Behalf Of nbreeden I have the "S-100 6502 CPU VERSION 01" board - assuming this is the same board you have then I may be able to help. My board required major rework to get running. I eventually ported the Apple I (Apple I, not the Apple II) Woz Monitor and BASIC to run on this board (I converted them to console style I/O). Some of my notes are at http://n8vem-sbc.pbworks.com/w/browse/#view=ViewFolder¶m=Neil%20Breeden. I'm digging to see if I can find the rest of them. There was a significant layout error that resulted in D0..D7 being reveresed; in the photo you will see a group of 8 wrap wires I used to patch around the issue. -Neil -- |