Hi Martin! Thanks! Yes, the SD circuitry is quite different from the last prototype and is incompatible with the last version of the N8 prototype software. Sorry for the confusion! One of the changes from the last prototype to the production board was to the SD socket circuitry. It is quite different and will require a fix to the software to implement an SD reader. David was helping with the prototype and suggested a new approach using the CSIO pins to drive the SD much more efficiently. As I recall, he wrote some SD reader code for his modified N8 prototype and maybe he would comment further on the new design. I think it is on the wiki and is explained in the ZIP file: http://n8vem-sbc.pbworks.com/w/file/46685735/N8-v04-10-10-11-DG.zip I very much appreciate you taking the time to help with the N8 project. Thanks and have a nice day! From: n8...@googlegroups.com [mailto:n8...@googlegroups.com] On Behalf Of MartinL I just finished my N8VEM 2312. I have working CP/M 2.2c using ROM v2.0 B13 (RomWBW-WWarthen-120711T1101). I can format RAM disk and copy to it from ROM with verification. The same for FDC – working OK. SD card does not seem to be working. Is there any testing utility, such as PPIDETST? Similar for TMS9918 and AY38910. Are there any testing utilities or program sources, so I do not have to write it from scratch? I tried MSX BIOS, but no success. Screen is just white rectangle. Best regards Martin -- |