Thomas, need data! What Z80 board do you have. Is it the V2a (recent version) Does the Z80 monitor sign on, do you see the initial “#” character on the screen. If so how does the memory map look. Can you display RAM at E000H, is it RAM or ROM Can you even get the IDE ROM to sign on, if so how far. Will the IDE ROM work at say 1000H in RAM when Reassembled Likewise for the Z80 Monitor. These basic types of tests with the answers are required before anybody can realistically help you. The V2a board decodes the A12 address line so the Z80 should be in the upper half of your EPROM the IDE stuff in the lower. Make sure your prom burner is not erasing one while writing the other. Check and display the initial final EEPROM contents before using it Good luck John From: n8vem...@googlegroups.com [mailto:n8vem...@googlegroups.com] Hi John, Thomas, Could this be the problem: from S100computers.com: "Note if you decide to use a EEPROM such as a Samsung MK28C64A 8KX8, you have to place it at an 8 K boundary. So in high RAM this would be at E000H. If you want to use E000H-FFFFH for your monitor then that's fine." Rick Bromagem From: John Monahan <mo...@vitasoft.org> Dave has become the de facto IDE board guy so I’ll let him answer, but where are your disk RAM buffer variables etc. stored. The Z80 monitor will try and find the top of RAM for the stack. It always puts out a “#” character as the very first thing it does to indicate it’s alive. Without a description of exactly what you mean by “but not together” it’s not possible to really help. Please describe symptoms in detail. John From: n8vem...@googlegroups.com [mailto:n8vem...@googlegroups.com] On Behalf Of Thomas Owen Hello Everyone, -- -- -- |