Hi guys, I'm trying to track down a copy of the schematics (if any still exist) for the DMA Data LSI used in the AT&T Unix PC (aka the AT&T 3B1 or AT&T 7300). The Technical Reference Manual scans which were posted here earlier include the DMA Address LSI, but not the DMA Data LSI. Unfortunately about 80% of the DMA logic is in.... *drumroll*... the Data LSI. The Address LSI is basically a glorified presettable up-counter. These should be in the AT&T UNIX PC Technical Reference Manual, if anyone has a copy kicking around. I already have the DMA Address LSI, Video LSI, 512k Motherboard, 1MB Motherboard and 2MB Motherboard schematics. Thanks, -- Phil. classiccmp at philpem.me.uk http://www.philpem.me.uk/