[Coco] TC-9
Frank Swygert
farna at att.net
Tue Jul 8 12:20:57 EDT 2008
Is there a reason for having a drop in GIME replacement for the CC3?
It's not like the GIMEs are especially susceptible to blowing like the
6809...
At this point having RS-DOS compatibility is pretty much a moot point.
Very little done there, and there are still plenty CC3s (and 2s) to be
had cheap enough. Buy a spare if you're worried about parts in the
future, just like us old car guys do (parts cars). I did like the ease
of programming in DECB, but everyone claims Basic09 is just as easy once
you learn it. I never thought so, it was closer to C programming to me,
but then I never really learned anything but line number BASIC.
The NitrOS-9 machine sounds promising though! Use the 6809 core in an
FPGA running at a higher speed (10+ MHz) instead of one of the slower
68K processors and it should run as fast as one of the slower 68Ks. Then
use a GIME compatible MMU and video (no need for composite?) just to
make the system compatible with OS-9 programs -- at least so they would
need only minor tweaks to run right. That would give you a nice software
base to work with and a good number of people who might be interested in
development work. There aren't a lot of OS-9 68K programs out there, and
they are usually expensive. Might have to have a software or hardware
"throttle" for the processor for some of the programs to work, but if
things like Dynacalc will run with only a few patches that would be a
great help!
RS-DOS compatibility just requires way to much work -- you may as well
put the entire CC3 in a FPGA and only have a few enhancements, like the
upgrades that are currently available all built in (support for 2MB, and
IDE or CF/SD card, real serial port, and modern floppy controller --
maybe use on of the PC integrated I/O chips?). Change the monitor to a
standard RGB rather than the analog, and use a standard PC keyboard. But
as far as enhancements, that would require re-writing DECB. Integrating
512K BASIC might be doable, but most of the enhancements would only be
usable under OS-9. That being the case, a machine that only runs OS-9
(Nitros) would be a better way to go, and if someone wants to implement
a 512K CC3 in FPGA (like the C=64) there's no need to go with a lot of
enhancements, just make it compatible with readily available peripherals
-- replace the printer port with a USB port even if you have to use
circuitry like one of the USB to serial (or parallel) cables do and it
can only be used as a printer port. Actually, I think that would be very
difficult, as the printers are now dumb and rely on a driver and the
host processor. I suppose a rather generic driver could be integrated,
but would likely take another FPGA with processor to go between the CC3
circuitry and the printer, and when the printer driver becomes obsolete
so would the entire machine.
--
Frank Swygert
Publisher, "American Motors Cars"
Magazine (AMC)
For all AMC enthusiasts
http://farna.home.att.net/AMC.html
(free download available!)
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