RQDX3 as third controller under RT-11

From: Jerome Fine <jhfine_at_idirect.com>
Date: Sun Aug 22 22:56:06 1999

>Zane H. Healy wrote:

> OK, it looks like I figured out why I've not been able to get the RX50's on
> my PDP-11/73 working, dead RQDX3. Of course it's my only one that can
> handle RX33's, thankfully I'm more interested in RX50's.
> Anyway, I've got a problem, and part of it might be what a mutant beast
> this system is. If I have DU7: set to one of the drives on the RX50 the
> system crashes after 1 minute (I actually timed this, and it was so close
> to 1 minute it was disturbing). I've not tried any other combo's of
> setting the RX50 in the system, but don't see why that would matter.
> The thing really wierd about this system, and one of the main reasons I
> call it a mutant beast is the following:
> Controller CSR Vector Purpose
> Viking QDT 172150 154 Both Hard Drives are on this board
> WQESD 160334 150 Bootstrap (that's all it does)
> RQDX3 160354 144 RX50
> DU0: is set UNIT=0, PART=0, PORT=0 (Boot Disk)
> DU1: is set UNIT=1, PART=0, PORT=0 (Backup Boot Disk)
> DU2: is set UNIT=0, PART=1, PORT=0
> DU3: is set UNIT=0, PART=2, PORT=0
> DU4: is set UNIT=1, PART=1, PORT=0
> DU5: is set UNIT=1, PART=2, PORT=0
> DU6: is set UNIT=0, PART=3, PORT=0
> DU7: is set UNIT=0, PART=0, PORT=2
> After one minute, I get the following:
> .
> 134606
> _at_
> I think it's always at 134606, but the minds a little fuzzy at the moment,
> I'm working on this while working on problems at work, and it's just a
> little late. Anyone have any ideas? My plan is to normally have DU7: set
> to PART=3 of UNIT=1, and only switch it to the RX50 when I need to use a
> floppy drive.

Jerome Fine replies:

It is really difficult to say why you are getting a crash at 134606. It
may be because of the "BAD" RQDX3, but I just don't know and
really don't have a clue.

I do have one suggestion. Why not have 2 MSCP device drivers?
I know that might seem a bit silly when you don't really need the
extra partitions (or do you - I thought that the you were using large
ESDI drives on the Viking QDT). One point I agree with is
that when you are using DEC MSCP device drivers that can't
even do a software boot (Sorry Megan - I just don't understand
why DEC would leave out ONE instruction in the secondary
boot program that is written into block zero) of non-zero partitions,
you have used DU0: and DU1: with their respective UNITs and
PART=0 both times which allows either to be hardware booted.

I suggest instead:
RQDX3,2,1 (which ever you use that actually works) = 172150/154
Viking QDT = 160334/150
WQESD = 160354/144 (not that you will actually set the VECTOR)

Then place the hard drives on the Viking QDT controller on a
device driver called VI: (I used to call my Sigma device driver
SI:) and keep the DU: device driver just for the RX50.
BUT, don't forget that a simple copy of DU(X).SYS to
VI(X).SYS is not sufficient. There are also a number of
locations that must modified:
(a) SET VI: CSR=160334 SET VI: VECTOR=150
(b) wherever DU appears as .RAD50, change it to VI
You can set up the VI(X).SYS on the hard drives along
with the DU(X).SYS, but you will have some trouble in
switching to the above suggested CSR/VECTOR settings
unless you can get a bootable RX50 on the RQDX3,2,1
If you can, and you can produce the necessary VI(X).SYS,
on the RX50 (you will also need SIPP to make the (b)
changes, and you can get everything to work correctly
with the new hardware and software set-up, then copy the
VI(X).SYS to the hard drives on the Viking controller.
Then as a test, boot the hard drives on the Viking controller
as a software boot using: "BOOT VI0:RT11FB"
That will be a software boot for those hard drives and will
test that everything works. If possible, have the hard drives
under WRITE PROTECT (and first make a backup of the
RX50 and WRITE PROTECT it so you can't lose it).
Once you get that far, the final step (without WP) is to:
either from the hard drive itself or from the RX50
(the latter might be a bit safer). After that, the WQESD
(I presume you are using a dual 11/73 M8192 without
hardware BOOT ROMs) should allow you to directly
boot the Viking hard drives if you specify the correct
controller: "B DUB1" if I remember the syntax.

If you need help setting up the VI(X).SYS, please ask.
If you rarely use the RX50 (I only use the RX50 to transfer
stuff to and from the PC using PUTR from John Wilson),
then you need not load DU: in any case.

The above stuff was done from memory and I may have
omitted minor points and been mistaken on others. But,
I have successfully run the following MSCP device drivers:
DU(X).SYS = 172150/154 RQDX2 with RD53/RX50
QR(X).SYS = 172140/144 RQDX3 Q=dual
VR(X).SYS = 172130/134 RQDX2,1 V=quad,2nd
HI(X).SYS = 160334/130 Hitachi ESDI drives
SE(X).SYS = 160434/140 Seagate ESDI drives
all at once and been able to boot from all of them.

Finally, if anyone is interested (so far no one has been and
at this point it would be a while before I could respond),
I can supply a DU(X).SYS for V5.4G and prior which
will boot non-zero partitions.

> In the mean time, I think I'll have to give that Codar clock a try.

They are fun to use, but probably not really worth the effort.
But at this point, there is only fun left - so go for it. I think
that Tim has also modified the code so it can be Y2K
compliant. When I fixed the software for a different
version, I found that the year in the TOY rolled over
from 99 to zero. So it was a simple matter to:
       Cmp #99.,Year ;Branch if 20th century
       Bhis $10 ; is present
       Add #100.,Year ;Switch to 21st century
But I would check just in case for your model.

Sincerely yours,

Jerome Fine
Received on Sun Aug 22 1999 - 22:56:06 BST

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