Troubleshooting RX02

From: Vintage Computer Festival <>
Date: Fri Feb 4 17:12:35 2005

On Fri, 4 Feb 2005, Ethan Dicks wrote:

> In terms of what you are dealing with, I have to say that I don't
> remember ever having to poke through bootstrap code with an 11/03...
> but my stuff is frequently 100% DEC, with the occasional Emulex card
> or Systems Industries interface... If I were to sit down and build an
> 11/03, I'd throw in the CPU, a memory card, a DLV11J (for console),
> and a real RXV11 and real RX01, and top it off with a BDV11 bootstrap
> and terminator... From there, I'd expect that if I had a known,
> bootable RX01, I would see an RT-11 prompt. I didn't speak up
> because I don't have much experience with the DSD drives, nor the
> MXV11.

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.

Is it possible my bus isn't terminated properly? I've got a M9400-YA at
as the last device in the bus, which is supposed to provide "120-ohm
terminators with refresh & floppy boot".

I have considered going with 100% DEC but I can't find an RXV21. Besides,
all the hardware I'm playing with worked at one point, and worked well.
The only changes I've made is putting the DSD controller in place of the
MXV21, and replacing a clock/calendar/terminator board with the M9400.
Maybe I should put the clock/calendar back in and see if that fixes

> Also... I tended to play with RL(V)11-based systems more than any
> other interface, due to the price/performance point of the RL01 and
> RL02 drives at the time I was personally and professionally fiddling
> with this stuff on a daily basis... if you were having an RLV11
> problem, I could be of much more assistance than helping with a 3rd
> party-floppy controller problem with boot code of unknown provenance.
> I do have floppy-only PDP-11s, but I haven't experienced any pitfalls
> with setting them up, and your symptoms are unfamiliar to me.

Well, I always do get stuck with the stupid problems. There's got to be
something higher level going on here. Are there any general diagnostic
type things I can do? Any code I can type in through the ODT console to
test out various things?

Sellam Ismail                                        Vintage Computer Festival
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Received on Fri Feb 04 2005 - 17:12:35 GMT

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