13 Dec
2005
13 Dec
'05
6:03 p.m.
Warning: I did not top post! There are further responses inline with the
reply. ;-)
=-=-=-=-=
Firstly, I'd like to mention that I've always wanted to build my own
homebrew 6809 system... altho I've been thinking of designing my own buss
system (around 80 pins or so) so other CPUs could be used if desired. I was
thinking of a multi-board system with a 6-7 socket backplane. I want it to
be educational to others (read: see-thru Lucite case & lotsa Blinkenlights!
;-) at the same time that I learn from it, too.
For a few reasons, S100 is not an option: I want the system smaller /
easily portable (I'm guesstimating in inches: 6x6x9, with an external 5V
only switcher), and I also want it to be easily buildable by a hobbyist.
Trying to dremel an S100 cardedge would seem to be quite a bit of work for
not a lot of gain - but square boards with a pair of 40-pin IDE connector
(for example) edge-soldered on would be pretty easy to do at home.
I do have a question:
Are there any 80-100 pin buss structures already in use I could copy that
might fit my bill? I'd rather do something that might be compatible with
something else out there if it's similar enough to what I want to accomplish.
I'm hoping to take lots of pictures & basically make the design free on the
web as I do this, mainly to show people if an idiot like me can make a
computer, so can you! ;-)
Oh, and for the record: Cubix looks *kewl*. ;-)
Rumor has it that Scott Stevens may have mentioned these words:
On Sun, 11 Dec 2005 20:15:48 +0000
"Dave Dunfield" <dave04a at dunfield.com> wrote:
> > I think cubix was a good idea, but this 15 years too late for
> > me as I
>
> What a co-incidence ... CUBIX is 20+ years old, so it should
> have been perfect :-)
And it's never too late for good ideas. ;-)
> > realize in hindsight that 128k of
> > memory - split code and data is needed for any real work.
Them's fightin' words. 64K w/OS-9 got me thru High school & my first year
of college, before I got my CoCo3 & 128K (later to 512K) but I still had a
maximum 64K code space - and that kept me working until the mid-90's. Other
than running (crawling) Autocad, my '386 was the 'toy' and my CoCo was the
workhorse. Once I got an EISA 486-66 server from my (then current)
employer, did I consider the CoCo my secondary machine.
> > This the crummy 8088 has but not the 6809.
>
> Funny, I've done LOTS of "real work" in <64k 8-bit CPUs. Even
> now a lot of my command line utilities are compiled in 64k
> "tiny" model (Referencing stuff known here, Anyone notice that
> ImageDisk, my Simulators and the various other transfer
> utilities that I've done are all .COM files) - I used to think
> 64k was lots of memory... and I still do!
Unless you're running Windows. ;-)
64K is a HECK of a lot of memory if your code is all in
assembly.
I've worked on projects where the limited program memory in the
micro, i.e. the 16K of program memory available on-chip, was a
godsend- it served as a brake on futher 'feature creep' requests
from the folks in marketing. ("yes, we can include new feature
'x' but it means doing away with the lookup table that feature 'j'
you requested last month uses.")
A few of those microcontrollers have 128K of flash on 'em now.
I want my CoCo on a chip! ;-)
Laterz,
Roger "Merch" Merchberger
--
Roger "Merch" Merchberger | "Profile, don't speculate."
SysAdmin, Iceberg Computers | Daniel J. Bernstein
zmerch at 30below.com |