Talking to DEC disks controllers with non-DEC hardware(was

From: Tony Duell <ard_at_p850ug1.demon.co.uk>
Date: Thu Jun 5 15:56:01 2003

> Neat. I also have a DW11-B (and the DDV11B backplane to go with it).

I haev the 2 halves in separate cabinets. The Unibus (quad height) board
is in the 11/45's BA11-F, the Qbus (dual height) board is in the
backplane of the MINC chassis, with a couple of 40 way ribbon cables
linking them. Works fine (but then it's DEC, so it would :-))

> When I got it, it only had an IBV11 in it. I haven't bothered to use
> something like an RLV11 with it because I have more than one RL11.

When I started puitting this machine together, I didn't have an RL11. The
RLV11 and RL01s came with the MINC, and one reason for this set-up was to
get RL drives on the 11/45. Now I have a couple of real RL11s. I really
should reconfigure it one day...

Incidentally, I once repaired a DEC gamma-11, which is a medical imaging
display system. It's an 11/34 with a VS60 in it, and lots of custom I/O
cards. Some of those are Q-bus. There was a 5.25" expanison box with 2
quad backplanes in it. One was Unibus, the other Qbus, and there was a
DW11-B linking them. Made me do a double-take when I first pulled it out!

> I don't know what I'd call my "main" PDP-11 system at the moment. The
> one I have spent the most accumulated time on is a PDP-11/23 in a
> (modified) BA-11N, with 512KB of RAM, an RLV11, LPV11, RXV21 and
> a third-party 512x512 graphic board. I used it to earn my living in

That reminds me. I must get the I2S displays running again (512*512*30
bits (or 24 bits), with some local intellegence...)

> The other -11 that I've put some time and effort into is an 11/24
> w/KT-24, a few megs of RAM, RL11, that I've installed 2.9BSD onto.

I never much cared for the 11/24. Having the CPU in a few custom LSI
chips spoils the fun. I must have another go with the 11/44, though...

>
> > For hardware hacking, I find the Unibus to be simpler. I also have more
> > 'exotic' controllers for that bus..
>
> True. Me, too... disk, tape, DEC comms, abundant COMBOARDs, etc.

I got a boatload of comms cards in a clearout. DUP11s, DMC11s, DMR11s, a
KMC11, etc. Even a couple of DX11s (not, that's not a typo for RX11).
Pity I've not nothing to connect the latter to.

> It's also not cheap... End-to-end, it cost more than nearly all of my

Ah....

[...]

> to attach to the aforementioned PDP-11/23). There are side benefits,
> though; I'm getting plenty of SMT practice assembling the IOB-6120.

SMT assemnly/rework has never really bothered me. The first chip I did
was a bit nerve-wracking, but I soon got used to it...

-tony
Received on Thu Jun 05 2003 - 15:56:01 BST