11/45, sick or not?
rigdonj at cfl.rr.com
Mon Jul 25 17:18:08 CDT 2005
Are you sure that the lights aren't blinking too fast to see? Perhaps you
can hang a logic probe (with a pulse extender) on one of the lights to be
At 06:08 PM 7/5/05 -0500, you wrote:
>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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