DL11 M7800

Henk Gooijen henk.gooijen at hotmail.com
Wed Jun 15 12:12:55 CDT 2016

-----Oorspronkelijk bericht----- 
From: william degnan 
Sent: Wednesday, June 15, 2016 5:35 PM 
To: cctech 
Subject: DL11 M7800 

OK.  I must be missing something here

Does anyone have a M7800 (DL11) set for 9600 b N71 or N81 jumper'd with the
default address for use as a serial terminal interface?  I understand the
other jumpers on the card, but the address and vector jumpers confuse me.
I can't seem to find a table or a "here is the default for console" or I
don't get it. I have the manual, I want I believe 777560, but I cannot find
"table 5-2" referred to in my copy of the manual.  Can someone give me a
couple of examples "if you have Ax Ay Az connected then that represents
address ------- .

I am looking at the manual and web sites on the subject and I think for use
as a simple serial terminal interface I need to jumper "in" *A9, A7, A5,
A4, A3* ... correct?  Vector jumpers *V6, V7 "*in" .  Just curious if
anyone can help me specifically not indirectly what I need, super thanks in


Doing this from memory ... I actually configured an M7800 for console
a week ago! But I left my notes in the "museum", 9 km away. I could get
it on Saturday ...
Anyway, I did it using the doc from bitsavers, so it is not too hard:

The gotcha: for address jumpers a jumper installed makes it a "0",
whereas a jumper installed for the vector makes it a "1". I found it
pretty confusing, seeing how many scribbled remarks I made on paper :-/
Console address is 777560. The last "0" is A0-A1-A2, and these do not
have jumpers. So A5-A4-A3 sets the "6", A8-A7-A6 sets the "5", and
A10-A9 sets the low two bits of the "7". (there is no A11).
Console vector is 060. Same story. V2-V1-V0 is not available, so you
only have to set the "6" (V5-V4 jumpered).

To get 9600 Bd, check the crystal. It has to be the frequency listed
in the 4th column in the documentation, else 9600 is not selectable.
Note that there are two tiny rotary switches on the board. One to set
the transmit baudrate, the other the receive baudrate.

Testing is easy too. Just LOAD ADDR 777564, then EXAM. If all is correct
you will see 0200 (transmit buffer emtpy flag set). Press EXAM again.
The "address" is now set to 777566 (transmit buffer). Toggle 073, then
DEP. If all is right, you will get a "3" in the terminal.

- Henk

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