QBus termination?

From: Vintage Computer Festival <vcf_at_siconic.com>
Date: Tue Feb 8 22:48:12 2005

On Tue, 8 Feb 2005, Pete Turnbull wrote:

> On Feb 8 2005, 8:29, Pete Turnbull wrote:
> > On Feb 7 2005, 19:04, Vintage Computer Festival wrote:
> >
> > > The M9400-YA does have boot PROMs. I've got one in this 11/23.
>
> > Anyway, you should only have one set of boot ROMs. I think you can
> > disable the bootstrap on an M9400, but offhand I don't know how.
>
> Ah, I do now. Take a look at
> http://www.fpns.net/willy/pdp11/boards.htm#REV11
>
> You want to make sure W4 is removed.

Hmmm. Can't tell exactly what's going on here but my board contains no
jumpers, just resistors. The resistor (or whatever was there) across W2
has been cut off. W4 has a brown thing that looks like a resistor but
with one black stripe around the body. Is that a straight-through
strapping type device?

At any rate, this would indicate that this thing has its boot PROMs
enabled, which confuses me, since this system came loaded with both this
card and the DSD-440 controller (which has its own boot PROMs).

I booted the system again and got the $ prompt. I tried some of the
commands the REV11 page above mentions. OD enters ODT (but breaks at
165246). XM (supposedly performs memory test) works; short pause before
returning to $ prompt. XC (supposed processor diagnostic) returns
immediately (which is supposed to be good).

However, RK (RK05 boot), AL and AR commands are not recognized. This is
with the MXV11 controller and with the DSD-440 controller. I'm not sure
then what boot controller I'm operating here.

-- 
Sellam Ismail                                        Vintage Computer Festival
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Received on Tue Feb 08 2005 - 22:48:12 GMT

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