11/45, sick or not?
jwest at classiccmp.org
Tue Jul 5 18:08:18 CDT 2005
I finally allocated another day to spend on the 11/45. Unfortunately, I must
say I'm not sure if it's sick or not, hopefully someone can help.
First, none of the blinking lights programs I've seen blink the lights. I
can store and retrieve the program correctly, but when I put 1000 on the
switches and hit load address then run, it goes into run mode but no lights
blink (with any display switch setting). Halt makes the processor halt.
Here's what I did:
1000 005000 start: clr r0
1002 005200 inc r0
1004 006100 loop: rol r0
1006 000005 reset
1010 000775 br loop
On this program I put 1000 in the switches, hit load address, then run.
Address lights constantly show 1010, Data lights are blank, and the Run
light is on. Data Paths setting shows 0, bus register setting shows 5, uaddr
Another test... if I store a 5007 (clr pc) in location 0 and start the
processor at location 0, the address lights show all 0's, the data lights
show 2, and the following lights are lit - pause, master, kernel. I also
tried this with location 0 set to 777 (br .) and get the exact same results.
More info... just after power up, the address lights show 20, the data
lights show 21043 (data paths). Master & Kernel are on. The uaddress setting
So... I decided to go back to basics and check all the power points at the
pins on the backplane. Here's what I found:
Since my machine only has regulators at B, C, D, E, and F, I suspect the 0
volt readings above are ok. All the 5 volt test points have a very clear .2v
sawtooth pattern (which looks fairly smooth at 5v). Since one manual says
the ripple limit is .15, and another manual says the ripple limit is .20, I
suspect I'm ok there. The ripple on -15, 16, and 9 I can't see any
And by the way... the cpu cardset was borrowed from another listmember and
tested before I received it so I don't think it's something wrong with the
cpu cardset itself.
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