Wanted: M9312 RX01 bootstrap ROM

From: Ethan Dicks <ethan.dicks_at_gmail.com>
Date: Thu Dec 16 19:36:08 2004

On Thu, 16 Dec 2004 18:50:25 -0500, Ashley Carder <wacarder_at_usit.net> wrote:
> Thanks for the great ideas on other ways to get data to the -11 from
> other sources.

You are welcome. I hadn't heard anyone on the list make a similar
suggestion, and I know it was just the thing for our situation 25
years ago, so here it is.

> I have found an RX01 bootstrap ROM today and I should
> have it in a day or two, so I can install my RX01 drive, install the
> bootstrap rom on my M9312, install the M7846 RX11 controller, and
> then I'll be able to boot from the RX01 or my RK05s or RL01 or RL02s.

Nice. Of course, the bootstrap for the RK11 and RL11 are somewhat
trivial... I used to know off the top of my head what to do to boot an
RL11 in a couple of ODT commands - I _think_ it involved initiating
an INIT cycle via the FP (11/34), then entering an RL11 'command' with
the GO bit into the RL11 CSR, and since everything else had just been
zeroed, it would load block number zero into address 000000, which one
would then jump into.

I _think_ it went something like this...

deposit 201 (or 401) at 174400 (depending on how your ODT works, that may vary)
watch the 0/Ready light blink on your RL01/RL02
jump to 0

I suppose analysis of the _real_ RL11 boot routine would reveal lots,
but essentially, it's the same procedure, without checking and waiting
on status bits, because you, the human, are much slower than boot
code, so the act of typing things in manually serves to let the
operation complete before jumping to the boot block.
 
> I do think that I'll try to do some things along the lines of what
> you've described above. It sure does sound like it has some quite
> interesting possibilities having the console cable available to both
> the VT52 terminal as well as the PC serial port.

Sure... if you don't have the switches in a junk box, it's only a few
$$$ at a nearby Radio Shack and a few minutes with a soldering iron.
If you have a junky AB switch, one could even pull the rotary out of
it, replace it with two toggle switches and away you go (simpler to
use an older, wired switch box vs a newer one with a PCB, but either
kind could be made to work).

Just remember to have your loading program hang (wait for ^C perhaps?)
so the OS prompt doesn't get fed to ODT.

-ethan
Received on Thu Dec 16 2004 - 19:36:08 GMT