Date : Thu, 18 Jun 1992 21:15:57 CDT
From : hanscom@eid.anl.gov (roger hanscom)
Subject: Re: WANTED: info on Cromemco TU-ART S-100 serial/parallel board
Steve Willoughby asks about Cromemco TU-ART board. I sent the following
reply via e-mail, but perhaps it is of general interest?
Steve -
I've got lots of TUART's, what do you need to know? The dip switch
is (top is your label "2--0", "ON" is to the right) interrupt mode,
address reversal, and then the base address for device A (A4 thru
A7) and same for device B. On the interrupt mode, 2 is for IM2 type
interrupts (Z-80), and 0 is for IM0 type interrupts (8080). The base
address, combined with the following table, addresses the TMS 5501
functions/registers.
A3-A0 Input Output
====== ======== ======
0 status register baud rate register
1 rcv data register tr data register
2 ---- command register
3 interrupt addr reg intr. mask register
4 dev. parallel port dev. parallel port
5 ----- timer 1
6 ------ timer 2
7 ------ timer 3
8 ------ timer 4
9 -------- timer 5
The address reversal bit (one can switch device addresses on the fly)
puts device addresses under software control when it's on, and under
hardware control when it's off via pin 1 of J2 and J3. Then grounding
this pin will reverse addresses. Don't ground pin 1 of J2 or J3 when
the TUART is in software mode (dip sw. #2 ON).
The TMS 5501's ought to act like vanilla devices, if you can find the
specs. on them. A word of warning: initialize both 5501's even if
you use only one. A half-arsed 5501 can generate bogus interrupts that
may/will drive you crazy.
I've got some TUART initialization code around here somewhere that I
might be able to send you --- I had it at my fingertips not 10 years
ago!! @:^) (just a little joke there!)
Good luck.
roger hanscom@astoria.eid.anl.gov