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KXJ11-CA - can anything be done with this CPU?

C

Crawford

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Folks,

So I found my old stash of DEC boards, and there is a KXJ11-CA board, which looks like the sister to the PDP-11/53 CPU. I think it was an instance of ebay 'click first, read later'. Oh well.

So I have the bitsaver docs for this board, but they seem to fail to mention: What is this board for? They say it's a peripheral processor - OK, but for what in particular? Can this operate as a main CPU in a system, or just as a slave processor in a MicroVax or PDP? With a full-blown J-11 onboard it should be able to do *something*.

Looking for some insights .. Thanks,
 
The KXJ11-CA is a follow-on / upgrade of the KXT11-CA SBC. It's intended more as an I/O processor than as a QBUS master. So while it's interesting, it's not really the kind of PDP-11 CPU relative it seems you wanted. It was intended for heavy-duty "roll your own" interfaces, and to my knowledge was never used as a DEC product based on the module.

In fact, I'm the only one I know of who has it's KXT11-CA predecessor - which I've not yet put to use either.

So... you were hoping it was an 11/53 kinda thing?
 
Chris,

Yeah, I was in the market for a PDP based on the J11 chip (53,73, 83). I guess I bought it thinking it was one of those (lack of up-front research) on my part. Later I got a DECserver 500 cpu and converted it to a PDP-11/53 with Lou's coaching.

So this thing does have 24 lines of parallel I/O so it could possibly drive an ATA/IDE drive... and the RQDX3 has a T11 that runs MSCP on one side and an MFM disk chip on the other. Could be a project here (but I have a long list of those.

Thanks for the info!

? ; - )
 
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I still use a KXT11 at work. We use it as a dedicated high-speed parallel communications controller for the PDP-11. We used MicroPower Pascal to write software for it which can be downloaded via a driver from the main PDP-11. The on-board firmware allows for this type of boot as standard. I believe (although I have never done it myself) that you can write your code, PROM it and exchange for the standard devices that come with the card to make a dedicated stand-alone device.

The device does support DMA transfers to and from main memory (shared with the main PDP-11 processor) and some form of interrupt handshake - although (to my knowledge) you can't use the card as a stand-alone processor to run (say) RT-11 or RSX-11.

Dave
 
Dave,

Oh, dear. The first language I truly loved was Pascal - UCSD on dec and cp/m, then digital research mt+ on cp/m.

I hope Micropower Pascal is available somewhere...

? ; - )
 
LOL - I had occasion to put a concurrent UCSD P-System interpreter for an 1802 on ROM. Think I still have those sources - typed them in manually from a printout.

Never got around to doing the experiment of cross-compiling on a PDP-11 for an 1802 target. Maybe someday. :rolleyes:
 
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