🚀 go-pugleaf

In article <1992Apr9.223816.1466@panix.com> schuster@panix.com
(Michael Schuster) writes:

   I've noticed on the specs of the Trantor parallel port-to-SCSI adaptor that
   writes (i.e. output from the parallel port) are twice as fast as reads
   ("input" via the parallel port). Does this mean the "input" is kludged?

In a word, yes.  If you eyeball the pinout for the printer port pinout
you will notice that there are 8 dedicated output lines, (DATA 0-7)
and 4 dedicated input lines (BUSY, PAPER OUT, etc.)  So your SCSI
gizmo must be using the 8 output lines for writing and the 4 input
lines for reading.  Many computers, but not all, can use the 8 data
lines bidirectionally.  Some of software for the devices made for
printer ports test this when they are initialized and use it that way
if possible, otherwise they fall back to the 8 out and 4 in
configuration.

- Jim
--
J.V. Pieronek                           Internet: jvp@ll.mit.edu
Massachusetts Institute of Technology   (617) 981-3468
Lincoln Laboratory                      These are my opinions, not the Lab's.