15 Jul
2012
15 Jul
'12
6:21 p.m.
Thanks Tony. I did some more research. The info on
http://www.pdp-11.nl/peripherals/comm/interface/dl11w-info.html was
particularly useful and I have determined which of the two M7856
boards in the machine is configured as the system console.
I need to check the cable wiring to ensure it is configured for EIA
serial IO (the attached cable has a molex connector rather than a DB25
or DB9) and I will give it a try.
I did power up the machine with a minimum set of boards installed.
The KY11-LB front panel came up, address 000000, Run and DC OK leds
on. Some of the front panel button work. I can load an address into
the address register and read it back but the buttons on the right
side are very stiff and do nothing or provide the wrong digit. Will
need to pull the front panel off and have a look at the keyboard but
it certainly seems that the controller card for the front panel is
working.
Before I pull the front panel apart I will get a terminal connected to
the system console port and see if the console emulator comes up.
That should tell me if the CPU is running.
Regards
Andrew
On Mon, Jul 16, 2012 at 8:51 AM, Tony Duell <ard at p850ug1.demon.co.uk> wrote:
I am also
looking to confirm my understanding of the M9301 card. I
Basiclaly, the M9301 contains a small amount of ROM containing a PDP11
machine code program to provide the ocnsole emulator and device
bootstraps. The PDP11/04 CPU on its own will not talk to a terminal at
power-up, it'll just execute machine instructions. Of course, if said
intructions are a program that acesses the terminal port then the system
talks to the terminal. And that's what happens here.
have read the maintenance and operators manual
for the M9301. I think
it is saying that the Console Emulator startup message from the M9301
and the console emulator commands will be available on the terminal...
which I take to mean the terminal connected to the M7856 in this
machine. Am I understanding that right.
It'll display the output and take the conoslue emulator commands from a
terminal (conented to a DL11-something-or-other card) at the standard
console terminal address, which IIRC is octal 777560 yo 777566. Note that
hardware addresses are 18 bits lont (even on a machine without an MMU)
and that word addresses are always even. The DL11 port takes up 4 word
addresss, for thee receive control/status register (CSR, it's a term
you'll come across time and again), the receive data register, the
transmit CSR and the transmit data register.
Progrm adresses, are, of course, always 16 bits long. On a machine with
out an MMU (like the 11/04), program addresses 000000 to 157777 are left
unchanged (The extra 2 bits for the 18 bit address are set to 0), while
160000 to 177777 are converted to 760000 to 777777 The latter range of
addresses (4K words) are gernally used for I/O devices, not memory.
Now, the M7856 is certainyl a possible terminal itnerfce card for this,
but the address can be set by DIP swithces on said board, so it's not
certain that' sthe right one. It wuld be perverse in the extreme _not_ to
have a DL11 at the normal conosle terminal address, but if you get noting
on the connected terminal, checkign the address would not be a bad idea
-tony