14 Jan
2014
14 Jan
'14
10:28 a.m.
On Mon, Jan 13, 2014 at 09:40:46PM -0500, Ethan Dicks wrote:
On Mon, Jan 13, 2014 at 6:20 PM, Eric Smith
<spacewar at gmail.com> wrote:
> On Jan 13, 2014 3:11 PM, "Ryan Brooks" <ryan at hack.net> wrote:
>> I believe the 68HC000 can dynamic size down to 8-bits...
>
> Unfortunately the bus sizing feature is static, not dynamic, and is only on
> available on the 68HC001, 68EC000, and 68SEC000, but not the far more
> common 68HC000. The 68EC000 and 68SEC000 don't provide the /BGACK signal.
Of all of those, I only know a little about the
68EC000 but never worked with
it. ISTR hearing it was popular in washing machine controllers, but that
could be a fuzzy memory.
My fuzzy memory suggested that it might have been in the short-lived Amiga 600,
although the Internet isn't agreeing with me and I may be thinking of the
'EC020 that was used in the A1200. However, I can apparently buy a *new*
"accelerator" for the Amiga 500 that uses an overclocked 'EC000 part. (I
hope
they are a bit more reliable than the 14MHz 68010 I tried back in 1990, and
which was sent back within the week as Not Fit For Purpose.)
[...]
I haven't kept up with what's in production
and what is not. There are so
many MC68K-family CPUs out there that any project I'd tackle wouldn't make a
dent in the supply.
Although as a heads-up to anybody wanting to use those in retrocomputing
projects, some of them omit "difficult" instructions such as DBxx and so
won't
run legacy binaries.