31 Jan
2010
31 Jan
'10
9:13 p.m.
Geoffrey Reed wrote:
On 1/30/10 8:09 PM, "CSquared" <csquared3 at tx.rr.com> wrote:
I'm sure that would have worked. We did something similar a few years
ago so the software could reset external (non-plug-in) modems where an
I/O line controlled a small relay whose contacts were in series with the
low voltage modem power. That worked quite well.
Back when I was coping with the ACIA's I was in a working environment
where the hardware guys were sometimes not too eager to listen to the
software guys input, to be ultra polite about it. :) This was a new
board design, and they were not about to respin the board to solve what
they probably considered to be a software problem. So, we just sort of
lived with it. Once the system was pretty well debugged and tested I
think it was not so much of an issue. I really don't recall by now how
the ACIA's would get into a state where only a reset could get them
unstuck. It's just been way too many years and way too many other
projects between then and now, but I do remember it being a bit of a
pain. ISTR that particular project was scuttled before it ever made
into production, so we never found out whether it would be a problem in
the field or not.
Later,
Charlie C.
Ah yes, 6850 and ACIA, thanks for the memory jog.
I had completely
forgotten both of those. I can't remember now precisely why I felt the
need to reset the ACIA with a software controlled line, but ISTR I
*really* needed to occasionally, and a power cycle was the only way. I
do remember the little system had several of the ACIA's attached to one
6809 and I controlled a number of unique hardware devices that way. I
got to do some 68000 stuff a few years later and liked it quite well
too, though that was using C - my very first C as a matter of fact,
along about 1986 or 1987.
Later,
Charlie C.
Hmmm, possibly It is because I am more of a hardware guy anymore than a
software guy, but couldn't you make an adapter pcb for the ACIA chip, that
had a relay and a few other componants on it, like a 555 set as a timer, and
when the 555 is triggered, it would power off your acia for a preset amount
of time by tripping the relay so the VCC pin no longer gets voltage, then at
the end of the timing cycle it returns the relay to normal position and the
acia comes back on and you set baud, etc....