Hello! W dniu 2011-01-27 10:23, Hársfalvi Levente pisze: > Here comes the possibly interesting part: anytime the > machine crashed, I could notice the corruption of a position of _each_ > memory page. (Ie. if address $xxab was hit, then each addresses of > $00ab, $01ab, $02ab, ..., $ffab were all corrupted... the low part of > the address was usually nonpredictable). This is pretty similar to > Michał's description of how the memory got corrupted in the 610. ...I > wouldn't draw conclusions at this point, however. After all that time, I > still don't know how/why all that happened... only, that it did. Well, that is a very interesting story! So you say that if an instruction at $xx21 was affected by a hardware problem, all memory locations at $xx21 would be corrupt. Now, let's apply this theory to our 8088 case... After careful isolation, I was able to determine that memory is corrupted after this call: 0040:0674 call far ptr 0F000h:0F003h Which is, of course, a call to IPC. Until then, no 8088 code is executed from memory locations 0xxx21h nor 0xxxA1h. But in the ROM code at 0F000h:0F003... yes, we have an instruction at location 0FF021h, and guess what it is? F000:F021 in al,21h Now that's a coincidence - an instruction at location 21 which accesses port 21! My bet is that this is the very instruction that corrupts the memory. Regards, Michau. Message was sent through the cbm-hackers mailing listReceived on 2011-01-27 11:00:09
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