On 31/01/2010 19:49, Geoffrey Reed wrote:
On 1/30/10 8:09 PM, "CSquared" <csquared3
at tx.rr.com> wrote:
> 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.
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....
I am really puzzled by this. The ACIA has no hardware reset line, but
it's very easy to send it a master reset command in software. In fact,
you have to do that to clear the hardware reset condition after a power
up, because the ACIA stays in the inactive/reset condition until you
program it.
Charlie, you weren't using GTE 68C50s, were you? They did have a few
weird bugs.
--
Pete Peter Turnbull
Network Manager
University of York