[LispM] Further Developments

[Brad Parker]

On 9/18/18 1:09 PM, Daniel Seagraves wrote:
> I have 5 memory boards, one is marked bad, a TV, something marked 
> “TEST 1” that goes to the disk ports, an unmarked board that I assume 
> is the xbus master since it’s connected to the processor, and a unibus 
> board marked IOB that has a bunch of stuff on it.
>
sounds like you have all the cards you need.  the IOB is where the 
keyboard and mouse go.  I assume "test 1" is the disk controller.

I think all of the slots are xbus, which is "unibus like", but not 
really unibus as I recall.  There was a unibus interface but I think it 
was really just a 16 bit parallel port.  You should be able to drive 
that from anything - you don't need a pdp-11.  I forget what that port 
was called (it has a name) but it was used in the "two machine lash up" 
which was used to bring up new machines and diagnose broken ones.  I 
emulated it in my fpga using a serial port and a serial protocol and 
then talked to it from a unix box, which was helpful.

I have some C code which drives that port and does basic stuff like 
single step and memory i/o.  It could be useful as initial diagnostics 
(like "do the A & M memories work).  The PROM does some basic tests 
which are good - if you pass those you know the memories work and the 
ALU us working as well...  You should be able to single step just from 
the board itself and watch the PC on the LED's.  On a good day you will 
end up in a loop waiting for the disk controller to come ready.

the "TV" is obviously the display board.  that part will be fun I think :-)

Brad