Try typing in
the MSCP bootstrap.
Why? The RX02/DSD440 is a DY: device, not DU:
I think he simply meant the size of the code, and I'll agree without
having tried... ;-)
The standard
RX02 bootstrap uses UNIT=0, so it may need to
be modified to use UNIT=1 for DY1:, however that stuff is not
accessible to me right now. Does anyone have the release
notes for RT-11? It may be there.
I've had it online for a long time, at
http://www.dunnington.u-net.com/public/ODT/Listings/RXV21BootD
I recently made a minor correction (almost all the DEC printed copies have
several errors). It's a Unit 0 bootstrap, but changing the word at
locations 001036 from 407 to 427 should make it work for Unit 1. At least,
I think so; I used it recently and I think that's what I did.
Darn! - I disassembled the whole stuff manually yesterday evening!
However, that's exactly what I found. I had two corrections marked in my
copy of the manual (one is obvious, as there is one digit too much, the
other becomes obvious when you see the ADD R5,R2 that follows).
Non-obvious is that only two sectors (1 and 3) need to be read: the code
in the manual continues up to sector 7 (constant in word 2124, or in
your copy, at 1124), in steps of 2 (BTW, why are even sectors skipped?).
The most non-obvious error is using the word at location 1132 either as
a HALT instruction (when aborting bootstrap due to an error detected by
one of the BMIs) or as a constant to load into R0 (when finishing
bootstrap and passing control to address zero, for which a CLR PC is an
excellent JMP @#0 replacement). My copy of the LSI-11 manual had this
completely wrong - it would fail to abort properly.
Starting the bootstrap might be easiest with a 1000G (or in the original
copy, 2000G). one command shorter than setting R7 to 1000 and then
<P>roceeding.
I found sources that looked like loading R0 with either zero (when
booting from DY1) or one (when booting from DY0). Anybody know if /
which secondary bootstrap uses this value?
Good luck!
Andreas
--
Andreas Freiherr
Vishay Semiconductor GmbH, Heilbronn, Germany
http://www.vishay.com
