DL11 M7800

william degnan billdegnan at gmail.com
Wed Jun 15 16:29:07 CDT 2016

On Wed, Jun 15, 2016 at 1:12 PM, Henk Gooijen <henk.gooijen at hotmail.com>

> -----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
> advance.
> Thanks
> Bill
> ---------
> 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:
> http://bitsavers.informatik.uni-stuttgart.de/pdf/dec/unibus/EK-DL11-TM-003_DL11_Asynchronous_Line_Interface_Manual_Sep75.pdf
> 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

This further helps my understanding.  Problem is, the card is bad.  Knowing
it's probably jumpered correctly (assuming I have everything right, which
is a big assumption) I will check the 1488/89 drivers, etc. to see what's
wrong with the card.

I have a working M7856 serial card so I know the terminal is ok, CPU is not
farting out, etc.  I have a pdp 11/40 with 16K core and M9312
ROM/Terminator that I am working on.  Making some progress lately.
@ BillDeg:
Web: vintagecomputer.net
Twitter: @billdeg <https://twitter.com/billdeg>
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