30 Jan
2010
30 Jan
'10
8:09 p.m.
Henk Gooijen wrote:
From: "CSquared" <csquared3 at
tx.rr.com>
Sent: Saturday, January 30, 2010 4:20 AM
To: "General Discussion: On-Topic Posts Only" <cctech at classiccmp.org>
Subject: Re: 6809 SBC
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.
When I moved from the 6800 to the 6809 (in
assembly language - *many*
years ago) I was sort of astounded and at the same time very pleased
by the way many of the little subroutines I had written for the 6800
became one instruction in the 6809. I think it will always be my
favorite 8-bit CPU. My only annoyance at the time was the fact that
there was no way for the software to reset the companion UART chip,
whose number I've completely forgotten by now. 6821 maybe???
Later,
Charlie Carothers
I am somewhat a Motorola-guy, so a bit biased :-) Of the 8 bit CPUs the
6809 indeed would be my favorite. The 6821 PIA (parallel I/O) has the RST*
pin, the 6850 ACIA (serial I/O) does not.
- Henk.