Wanted: M9312 RX01 bootstrap ROM

From: Ashley Carder <wacarder_at_usit.net>
Date: Thu Dec 16 17:50:25 2004

> > > > The fun wears off after the second or third time
> > > > of toggling in that code!
> > >
> > > Wouldn't VTserver also be a way out here?
> > >
> > > John A.
> >
> > Yeah, I could load up the bootstrap code in a PC file and run
> > VTServer and have it load and run the bootstrap file. But then
> > I'd have to have my PC hooked up as the console. I'm trying to
> > run my configuration using all 1970s vintage hardware and
> > peripherals.
> You could do what we did at Software Results in the late 1970s through
> the 1980s...
> we needed to downline feed a PDP-11 test bed with our product in it
> for test. We had a number of diagnostic programs, both for the
> embedded 68000 and the PDP-11 itself (tests like the DMA test required
> code running on both CPUs simultaneously). Note that this PDP-11 had
> *no* peripherals other than the console and our board under test, and
> no operating system, just ODT (an 11/04 for Unibus cards, an 11/03 for
> Qbus cards). We had this special console switch that one of the
> engineers built that would let us bank in a real VT100, the PDP-11
> console, and a port on our VAX. Under normal use, one would have the
> switches thrown such that the VT100 was either a PDP-11 console or a
> VAX terminal. One would go to the PDP-11, type a few ODT commands,
> switch to the VAX, run a special in-house FORTRAN program that would
> take a binary and convert it to ODT commands, pausing to let one flip
> switches, then... we would pick a _third_ setting of the switches to
> gate the VAX output to the PDP-11 input while gating the PDP-11 output
> to the VT100, allowing us to watch what was going on. So the VAX
> would 'toggle in' the test programs via ODT, saving us the hassle.
> AFAIK, the switch was pretty simple - common ground for all 3 serial
> ports, with a single-pole/double-throw switch on each Rx and Tx, with
> the common lead going to the PDP-11. Up/Up to connect the VT100 to
> the PDP-11, Down/Down to connect the VT100 to the VAX, and Up/Down to
> enter "load mode". We had two flavors of it - one was hand-made with
> switches from Radio Shack. A later version was two AB switch boxes,
> internally re-wired, but they used RJ-11 jacks, the same as all of our
> serial comms gear (we had Nevada Western patch panels, telco-cable
> adapters, DB25 hoods, Hydras, etc.) It doesn't matter _how_ you rig
> the switches mechanically, as long as they swap round Tx and Rx
> properly.
> This way, you can have a cable to a PC that could be used for booting
> (you could even run simh on it and feed it from a vintage OS ;-) and
> also to a real VT100 or VT52, etc.
> One could probably do something similar with 20mA, but with active and
> passive devices, it might take a bit of fiddling and an active circuit
> or two to keep two devices (the PDP-11 and the (VAX/PC/vtserver host)
> from both trying to drive the loop. If you are looking for a PCish
> 20mA interface, the original IBM 8-bit ISA serial board has both EIA
> drivers and a 20mA current loop.
> But with all that said, I understand about trying to keep it all
> vintage. The right boot PROM would solve a lot of hassles. I have an
> ancient Data I/O burner that we used to burn 6309s in (256x8) - I
> would be surprised if it couldn't handle the PROMs for an M9312, but
> a) I'm n ot home yet, and b) I wouldn't have any blanks. If you are
> still looking three or four months from now, and you can locate a
> blank or two, I'd be happy to burn one for you for free (you pay S&H
> both ways...) I can try to locate blanks for you if you like, but I
> couldn't guarantee I'd have any better luck finding them than you
> will.
> Cheers,
> -ethan
> P.S. - I may have just found a use for the extra serial ports on my
> SBC6120 - a PDP-11 bootstrap server... :-) Set the switches on the
> FP6120, throw the console switch on the -11 to 'load mode', then give
> the SBC6120 a kick and let it emit the necessary ODT commands...
> Would need a trivial app for OS/8, but I _have_ one written in VAX
> FORTRAN I could start with. Not sure how to read the switch register
> in FORTRAN, though. Might have to use the VT100 I/O stream.


Thanks for the great ideas on other ways to get data to the -11 from
other sources. 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.

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.

Happy Holidays!
Received on Thu Dec 16 2004 - 17:50:25 GMT

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