AW: [pups] 2.11BSD disklabel-programm

Pete Turnbull pete at
Mon Jan 21 00:57:33 AEST 2002

On Jan 20,  2:05, lothar felten wrote:

> mine is about 40 inch high, 19 inch wide and
> as deep as
> the rl02 is. the "microcomputer interfaces
> 1983-84" shows
> some pictures of boxes: is might be the
> BA11-S

Sounds like you have what was a standard PDP-11/23 (or maybe 11/23+) system
in an office-type cabinet (H9642 or equivalent), with an RL02 in the top, a
stiffener panel, BA11-N or BA11-S box, a second RL02, and two blanking
plates at the bottom.  Sometimes people moved the second RL02 down 3U and
put one blanking plate or an expansion box between the BA11 and the RL02.
 As far as I remember, the only significant difference between a BA11-N and
a BA11-S is an uprated power supply, and a 22-bit backplane instead of an
18-bit one (but you can upgrade the 18-bit ones).

> on the backplane i found H9276-A.
> i don´t know what -A means, but it should be
> a Q22/CD
> so no serpentine?

Correct.  There is a very similar backplane H9275-A which is all
serpentine, but not in a standard 11/23 box, as far as I remember.  H9276-A
is for a BA11-S.  BA11-N uses H9273.

> now i´ve got the numbers here:
> CPU:   M8190-AE      KDJ11-B
> MEM:   M7551-CC      MSVC11-QC
> RL02:  M8061
> DELQA: M7516
> RQDX3: M7555
> DEQNA: M7546

OK.  That should be fine, so long as there are no gaps in the A/B slots
(left side of backplane as you look into it from the back of the machine)
between the cards.

The original 11/23+ probably had an RQDX1 or RQDX2, and possibly an RLV11,
and certainly different memory.

> hmmm, this is really confusing, since i have
> AE can it take an FPU? maybe it has a fpu? what
> does the fpu look like?

The -AE means it's a later board, should be 18MHz, and should not only be
FPU-capable, it should actually have the FPJ-11 chip on it.  -AD is the
same thing without the FPJ-11 fitted (it still does floating point ops,
just more slowly).  If not, you'll probably find it easier to get a
replacement board with an FPU already on it, rather than get the FPU chip
on it's own.

> > However, the biggest difference between 11/83 and 11/73 is whether
> > memory is used as QBus memory, or PMI memory, which is faster. the
> so i should put in first memory then cpu.

To get the best performance, yes.  It won't double the speed, or anything
like that, but it will go a bit faster.

> well it´s a BA11-S i suppose by now.

If it's an H9276 backplane and H7861 PSU, yes.

> a weird pdp.

Not quite factory-standard :-)   But none the less good.

Pete						Peter Turnbull
						Network Manager
						University of York

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