M8207 anyone? - test-drb@ccmp.vtda.org

10 Aug 2000

From: Chuck McManis &lt;cmcmanis(a)mcmanis.com&gt;

...
 At 09:27 PM 8/9/00 -0400, Allison wrote:
>Read up on parallel ports for PC first, the M8027 WILL NOT be sufficient.
...
 >Most parallel ports ahve enough bidirectional lines
and the 8bit data is
...
  bidirectional
(only the old XT ports aren't). 
I have, and they are, _if_ they are CENTRONICs compatible. There are 11
output bits and 6 input bits. When you have such a port on your PC (and
even PC/AT and some 386 machines had them) you could use them in "nybble"
...
 mode. In this mode four of the 8 data bits are outputs,
Busy/SLCT/Paper 

Stiill it's of no help to you as the DEC cards (LAV and LPV-11s) are
useable
for centronics but, are data products interface as such you have only one
programable ouput bit (D8) and three input lines (busy, online, error).
The done bit reflects the status of the transfer (ack recieved in
response
to strobe).

The M7941s are general ports with 16 out and 16 plus strobe and req
lines.
You have to  deal with the fact that the lines are seperate and not
inheirently
bidirectional.

The DRV11J with 64lines may be more resonable to work with.

Allison