M9301-YB Bootstrap/Terminator ROM dumps / listings?

Josh Dersch derschjo at gmail.com
Wed Apr 29 18:11:17 CDT 2015

On Wed, Apr 29, 2015 at 3:58 PM, Noel Chiappa <jnc at mercury.lcs.mit.edu>

>     > From: Jorg Hoppe
>     > I also have a spare DL11-W to offer
> Josh, if you want a second serial line, it's best to use a regular DL11
> (M7800), not a DL11-W. (M7800s are available on eBay, for pretty modest
> amounts.) The reason is that each DL11-W presents a load on the line clock
> signal (from the power supply), even if the line clock on the second board
> is
> disabled; several Dl11-W's, and the line clock signal may get overloaded.

That's good to know, thanks.  I do have a spare DL11 in my stash of spare
boards, I just need to find it, it appears to have gotten misplaced during
my house move last year.  Not sure if it's a -W or not.

>     > From: Josh Dersch
>     > I need to scare up a second SLU so I can get an emulated TU-58 hooked
>     > up to try booting XXDP
> I'm not sure any M9301 variant supports the TU-58? Some are set up to boot
> over the console serial line, though. (I haven't yet checked the code, so I
> don't know whether you need to feed it the absolute loader first, or if it
> will just take .LDA files directly.)

I'm now running off of a M9312, and there is a TU-58 boot PROM for that
(see here: http://ak6dn.dyndns.org/PDP-11/M9312/).  I believe I have a set
of compatible PROMs and I'll probably try that tonight, if I can find the
time (and the DL11 :)).

> And I just realized you're working with a -YB, and I've been dis-assembling
> the -YA! Fat lot of use that would have been! Oh well, I assume the code is
> fairly similar, I'll do the -YB next. (Anyone have a dump, to start me
> off?)
>     > comparing the diagnostic/console PROM listings to what I have
> Where were those from? Thanks in advance...

See the link above.  I was assuming that the console emulator code was at
least *similar* to that on the YB, I never did find actual listings for the
YB.  (At any rate, the code at the entry point in my ROM is an invalid
instruction so that's evidence enough for me...)

>     > From: Henk Gooijen
>     > I could be wrong, but ISTR that in the first few words of a ROM are
> the
>     > two capitals of the boot device that the PROM supports.
> Not in the M9301-YA, in either bank.

This appears to be true for the M9312 from what I've read.

- Josh

>         Noel

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