From the CLK connection on the computer control 1
board. With some digging, I think I've got the clock running, but it is too slow.
There is one dominant problem I need to tackle. The power supply has a 0.4v p-p ripple at
125Hz. Theres a filter capacitor that I think needs to be swapped out.
The main clock and T2 signals appear to have massive jitter. Looks like I forgot to take
pictures of that.
As for my oscilloscope: it's a Tektronix mainframe scope, 100MHz bandwidth, dual
trace.
Sent from my iPad
On 2012-07-22, at 10:24 PM, Robert Borsuk <rborsuk at colourfull.com> wrote:
On Jul 22, 2012, at 5:37 PM, Paul Anderson wrote:
I'm currently working on restoring a NRI 832
computer trainer. I finally got my oscilloscope on it. It looks like the clock isn't
running. You can see the waveform in this video. I tried both the fast(250kHz) and
slow(2Hz) clock. I'm just seeing noise from the power supply.
http://www.youtube.com/watch?v=RBV4QgQHq98
Sent from my iPhone
Hey Paul,
I got the schematic open, where were you measuring the clock signal from?
Rob
Robert Borsuk
rborsuk at
colourfull.com
Colourfull Creations
http://www.colourfull.com