From welland Sat Nov 28 03:38:51 1987 Date: Sat, 28 Nov 87 03:38:48 est From: welland (Bob Welland) To: daveh Subject: 68020 progress Status: R Dave: It's 3:30 am, friday. We just got DMA going (with Unix) ! The "stray interrupt" problem also went away. The problem was that when a DMA device tried to get hold of the bus it got the Physical Bus but NOT the Logical Bus. This resulted in the 68020 hanging around (waiting for the Physical Bus to be freed up) with its data and control lines asserted. This causes big problems if the 68020 is trying to write while the DMA device is trying to read. In any event we fixed that up (lots of jumpers but no new chips) and it seems to work. I don't think that this has any bearing on the "B2000" problems but it might ... think about it ... strange things can happen when you try to get control of the bus (the B2000 does this when it is trying to become BOSS ...). In any event much progress is being made. We should keep this quiet from Henry Cejtin and Rico Tudor till monday so we can profit most from their skepticism (Al Gelato's ice cream ... I can almost taste it already). A tired Bob Welland