Troubleshooting RX02

From: Vintage Computer Festival <>
Date: Fri Feb 4 17:46:55 2005

On Fri, 4 Feb 2005, Ethan Dicks wrote:

> On Fri, 4 Feb 2005 15:12:35 -0800 (PST), Vintage Computer Festival
> <> wrote:
> > Well, as far as I can tell, the DSD and MXV11 are pretty much drop in
> > replacements for the equivalent DEC controllers. They work on the same
> > address vector and same interrupt, and are supposed to be 100% compatible.
> Yes... there are no funny drivers, no funny treatments, etc...
> *except*... sometimes, some of these cards provide boot code, and I
> don't know without looking them up, which ones do and do not. Once
> the OS is coming up, though, you are right... they are 100%
> compatible.

I've got the manuals for both cards, and both have boot PROMs. I think I
see what the problem might be, which you refer to below...

> I suppose it's possible... ah... refresh and floppy boot... you should
> definitely check your floppy controller for boot code... none of the
> DEC floppy controllers come with boot code,
> so things can be a little different when you have 3rd-party cards...
> one has to know the caveats when going off the 100% DEC path. Back in
> the day, many people did just that, but they picked certain cards for
> price and performance (mostly price) if they weren't prepared to pay
> what DEC was asking for certain things. Consultants who were widely
> versed in such things used to get lots of money for that kind of
> knowledge and flexibility.
> There's no reason to expect that you are having anything more than a
> conflict or a corrupt floppy or something simple. Unfortunately, it
> doesn't sound as if you have the gear set up to confirm what's on the
> floppies you have - only the unit you are testing in the first place.

I now have something like 6 boot floppies, and none are coming up.
Coupled with my experience with floppies and how hardy they can be, I have
no reason to believe that all are bad.

> Perhaps... or maybe there's a way to disable the boot code on the
> M9400 (don't have my books in front of me). In any case, you should
> confirm that you have one copy of boot ROMs in the memory map, or zero
> (and type in a bootstrap via ODT)

Yep, I now realize that. I'll look into the M9400 and see how to go about
disabling the boot code. If not, I'll just put the clock/calendar card
back in, as I believe that provides termination but has no boot PROMs.

> One could _write_ some test programs, but they would take a long time
> to type in and verify - an autoloader like we wrote in FORTRAN to
> force-feed programs via ODT would be much handier for this. When
> interfaces were simpler to boot (RK11, etc.), toggle-in boots and
> paper tape diagnostics were small enough to be viable. Programmed-I/O
> devices like the RX11 need a lot more code to make work, but it could
> be done.

I verified that at least the first 17 bytes of memory are working by
poking bytes throughout that range and reading them back (via ODT).

Anyway, I think I'm close now...

Sellam Ismail                                        Vintage Computer Festival
International Man of Intrigue and Danger      
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Received on Fri Feb 04 2005 - 17:46:55 GMT

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