dyer@spdcc.UUCP (Steve Dyer) (03/24/86)
In pirating my AT for a memory board to put in my AT clone, I find now
that I cannot reboot the AT: I neglected to run SETUP from the diagnostic
disk first to resize the CMOS RAM's idea of how much memory I have.
Instead, the boot ROM sizes memory up to its new hi-water point, then
reports a 201-- memory error, then reports a memory size error, then
says "Run SETUP". However, although the diskette then runs as if to
boot from disk, the system then simply hangs. The behavior is identical
regardless of what copy of AT Diagnostics or DOS I load.
Short of taking down and opening up a perfectly well-running system to
temporarily snarf the memory board back, is there anything I can do?
I tried unplugging the battery from the board, but that seemed to have
no effect.
--
Steve Dyer
dyer@harvard.HARVARD.EDU
{bbncca,bbnccv,harvard,ima,ihnp4}!spdcc!dyerdyer@spdcc.UUCP (Steve Dyer) (03/25/86)
In article <227@spdcc.UUCP>, dyer@spdcc.UUCP (Steve Dyer) writes: > In pirating my AT for a memory board to put in my AT clone, I find now > that I cannot reboot the AT: I neglected to run SETUP from the diagnostic > disk first to resize the CMOS RAM's idea of how much memory I have. > Instead, the boot ROM sizes memory up to its new hi-water point, then > reports a 201-- memory error, then reports a memory size error, then > says "Run SETUP". However, although the diskette then runs as if to > boot from disk, the system then simply hangs. The behavior is identical > regardless of what copy of AT Diagnostics or DOS I load. I relate the solution that others might avoid similar problems in the future. It is sobering and surprising to realize how subtle the problems were, which had nothing to do with the amount of memory in the machine. I was given a set of hard disk cables by the clone dealer; as it turned out, I used the AT's original disk cables on the clone, because it had two hard drives, and the AT's cables have two connectors. This explains why the clone came up and worked. I used the spare cable which had only one connector on the AT (which has only one drive.) It turns out that the 'hanging' was the boot program waiting for the hard disk. The AT hard disk cable follows the IBM convention of TWISTING several conductor pairs on the ribbon cable for drive C. My single-drive cable was NOT twisted, hence the hanging. Things were further complicated by the fact that my hard disk was lacking a termination resistor (it had previously been used as a second drive) which also contributed to its misbehavior even after replacement of the correct cable. By unplugging the battery (and leaving it unplugged for > 5 minutes) I could get the diagnostic program to boot. Everything worked fine if the # of hard drives was set to 0, and it hung as described above if the number of hard drives was 1 or 2. This led me to the problems with the hard disk. -- Steve Dyer dyer@harvard.HARVARD.EDU {bbncca,bbnccv,harvard,ima,ihnp4}!spdcc!dyer
2212msr@whuts.UUCP (ROBIN) (03/27/86)
> In pirating my AT for a memory board to put in my AT clone, I find now > that I cannot reboot the AT: I neglected to run SETUP from the diagnostic > disk first to resize the CMOS RAM's idea of how much memory I have. > Instead, the boot ROM sizes memory up to its new hi-water point, then > reports a 201-- memory error, then reports a memory size error, then > says "Run SETUP". However, although the diskette then runs as if to > boot from disk, the system then simply hangs. The behavior is identical > regardless of what copy of AT Diagnostics or DOS I load. > > Short of taking down and opening up a perfectly well-running system to > temporarily snarf the memory board back, is there anything I can do? > I tried unplugging the battery from the board, but that seemed to have > no effect. > -- I did some swapping of memory boards on my AT and found that simply inserting the diagnostics disk (either one that comes with the machine or IBM's Adv. Diag.)and runnign setup was all that was required to overcome the error. My machine had been configured with 3M and in the swapping/experimenting process it was reconfigured numerous times with memory ranging from 512K to 3.5512K to 3.5M with no problems. Max Robin email:whuxg!2212msr
fetrow@entropy.UUCP (David Fetrow) (03/30/86)
> Gives an error and then the system just hangs
With disk drives at least the machine may hang for up to 5 minutes before
getting around to trying to finish the startup procedures! It is easy to
stare at a blank screen for 3 minutes, sob, and give up. Perhaps this "long"
hang happens on some memory errors as well?
--
- Dave Fetrow
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