Qbus HDLC controller -- a "what is it" board - test-drb@ccmp.vtda.org

21 Sep 2001

Here's something else from my junk box that somebody might know what to do
with:

Four half-width Qbus boards, built by Applied Computer Consultants, Santa
Barbara, CA. It looks like a DEC compatible DMA board and a three-board
Z80-based standalone HDLC controller that sucks power off the Qbus.

1: this one attaches to the Qbus, and is called MDMA. Contains four AM2901
bit slices, a row of microcode ROMs, some logic, and a ribbon cable
connector on the front edge. I'd venture a guess that this might be a clone
of some DMA board Digital made.

2: this, and the remaining boards, get only power from the backplane. This
board has two Zilog DMA's and a bunch of 74LS buffers, latches, and logic,
all in sockets. Name: XQCP-I, serial number 235. It has a ribbon cable to
the next board. My guess is this is a DMA board that lets the standalone uC
talk to the PDP-11's DMA board.

3: a memory board. Contains 8 ROM sockets, 4 of them populated. ROM labels
are marked IF-11Q/HDLC. Also 16 TMS4116-20L DRAMs. Name: XQCP-M, serial
number 230. There is yet another ribbon cable connecting it to the next
board.

4: CPU board. Zilog Z80-A, two more DMAs, an SIO/2, a CTC, and a little
logic, all in sockets. Name: XQCP-P, serial number 240. There are two narrow
ribbon cables on the front edge.

There is no documentation, and I'll never have time to fool with it. If you
want it, send me an email, and we'll draw straws in a couple days to see who
gets it.

--
Jonathan Engdahl???????????????? Rockwell Automation
Principal Research Engineer????? 24800 Tungsten Road
Advanced Technology????????????? Euclid, OH 44117, USA
Euclid Labs????????????????????? engdahl(a)cle.ab.com  216-266-6409