17 Oct
2007
17 Oct
'07
6:18 a.m.
Christian Corti wrote:
On Tue, 16 Oct 2007, Alexandre Souza wrote:
Ehmm, you've replied to a posting that has apparently never appeared
on the list, at least it didn't arrive here... Who was the original
poster?
Anyway the machine's not working as it halted at $01F6, or did you
(->original poster) halt the machine with internal HALT switch? The
routine around 01F6 (specifically 01EE-01FA) is POST 'G' "Keyboard
Test". It enables interrupt 3 and busy waits for a short time:
; --- Test G ---
; Keyboard Test
01EE 8BC7 LBI R11, #'G'
01F0 7B50 MOVB (R5)+, R11
01F2 1440 CTRL $4, #$40 ; enable int.3 and
typamatic
01F4 AF00 ADD R15, #$01
01F6 CF04 SS R15
01F8 F005 BRA $01F4 ; small delay
01FA 1442 CTRL $4, #$42 ; disable typamatic
Christian
It was a response to my post (which took almost 2 days to show up for
whatever reason :)). I know the machine's not working, it has several
hardware issues -- the most apparent being the monitor :). There's also
a keyboard issue (which is why it's halted in the pic) -- it seems to
think there's a stuck key when there isn't (I've disassembled and
cleaned the keyboard, etc...) -- if I swap in the keyboard (apologies to
Tony) from my 5110 this goes away. The last issue is a ROS error, which
I'm betting will be very tough to solve, given the odd (proprietary?)
packaging of the ROS chips. (Again, if I swap ROS boards from my 5110,
this goes away and the machine works OK, minus the monitor issue.)
Thanks,
- Josh
But
I'd like to see what I can do about the monitor. The picture
exhibits a strange behavior that I can't say I've seen before. The
horizontal retrace seems to "fold" over itself in the middle (like
the electron gun is doing a "loop" in the center of the screen for
each line). I've taken a (terrible) picture of the fault and put it
at: http://yahozna.dyndns.org/scratch/5120disp.jpg). The picture's
also a bit jumpy. I've tinkered a bit with the various adjustments
on the CRT's PCB but it doesn't make any appreciable difference.
Have phun on the horizontal circuit caps. There is one shorted or
with a huge loss probably on the yoke line. 