19 Apr
2011
19 Apr
'11
4:51 p.m.
On 4/19/11 12:54 PM, Ian King wrote:
I hope my experience is helpful for someone out
there.... -- Ian
Thanks for writing your experiences up, Ian. The shop at PARC had special stuff set up to
make
troubleshooting systems easier. The Alto is challenging to debug since it is a very
integrated
design, and there isn't anything obvious during the initial boot process to tell you
if the
system is stone dead or if one of the peripherals is acting up. The most common points of
failure in my experience have been in the display and disk subsystems. Well, that's
not strictly
true, I've seen lots of control store and power supply failures as well. But, once you
get them
to pass diagnostics and run Smalltalk, they seem pretty solid. I had thought about
building
something with blinkenlights to plug onto the wirewrapped backplane to watch the data bus
and
task lines, but never got around to it. I have slowly been working on the USB ethernet and
disk
simulator projects, which is something I need if we find the time to restore a couple at
CHM.