Serial console problems on 11/34
ak6dn at mindspring.com
Wed Jun 21 13:16:36 CDT 2006
Julian Wolfe wrote:
> I have, what I now know for a fact is the correct lines set up on the serial
> console on my 11/34. the correct signals are coming out according to my
> tester box. However, I cannot respond to the prompt.
> I started with the diagnostic on the front panel, which says if I hit CLR
> 173024 LAD EXA I should get 173000. I don't. I get 127777. According to
> the manual there is something wrong with the M9301 or the switches are set
> wrong, and all the switches are ON. Do you guys know of anything else that
> could be the case? I do get different results whether or not I hook up the
> faston tabs going to the front panel or not - I get 177777 if I don't hook
> them up at address 173024.
Is is very straightforward to check the basic functionality of your console
interface from the front panel:
1) EXAM the console TXCSR at 777564; it should be 000200 indicating ready
2) DEP a character into the TXBUF at 777566; it should appear on your terminal
3) repeat step 2 until you are convinced the TX serial link is OK
1) EXAM the console RXCSR at 777560; it should be 000000 after init
(it may be 000200 if you sent some data from your terminal; in this
case EXAM 777562 to clear it out, or INIT the box from the front panel)
2) send ONE character from your terminal
3) EXAM RXCSR at 777560; it should be 000200 indicating data available
4) EXAM RXBUF at 777562; the low byte should be the character you sent
the upper byte should be ZERO for no errors; if nonzero then:
15=ERROR, 14=OVERRUN, 13=FRAMING, 12=PARITY error
if 15 is set (summary error) then one or more of 14:12 will be set
5) repeat steps 2-4 until you are convinced the RX serial link is OK
If all the above works your UNIBUS is (probably) OK and your console works.
If either of the above fails you have some debugging to do.
In bringing up some of my DL11-W serial cards I have found the logic works
but the DIP switch packs are notoriously unreliable. You may set the switch
rocker one way, but the internal switch contact is stuck, and not following
the rocker (you may think you configured the board switches, but not really).
In my experience with DL11-Ws I the first thing I now do is beep-out each DIP
switch in the OFF/ON state to make sure it is operating correctly (shorted or
open). If not, cycle the switch open/closed repeatedly until it works; I have
found most switches start to work again somewhere between 10 and 25 cycles.
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