WELTE@BUPHYC.BU.EDU (08/10/89)
I have a question concerning the two recently posted 1-meg upgrades for the 520 ST. How is the memory controller chip (U15 on the board) numbered? In the second of the two postings, the numbering was given as counterclockwise while looking at the bottom of the board. There are numbers on the TOP of the board (component side) which run counterclockwise. The problem I'm having is that when I follow the "bottom" convention (counter- clockwise while looking at the noncomponent side), then I can't get it to boot. If I use the numberings on the board (counterclockwise from component side), then the computer boots, but I still have only 512K. Hmm..... I am happy that the computer didn't smoke (yet!), but I think that the only thing wrong is where the busses are connected from pins 4 and 15 (x2) from the new chips. I checked everything else long before I put 'er back together. Thanks for your help.... Frank WeltE (WELTE@BUPHYC.BU.EDU on Bitnet)