ralphw@ius2.cs.cmu.edu (Ralph Hyre) (08/04/87)
References:
Is a 16K Coco (presumably without extended ROM) worth $40 (new)?
Is there any hope I can add on enough (memory, mainly - probably through
the expansion connector) to run OS-9 level 2 without exceeding the cost
of a CoCo 3 system or other OS-9 capable system in the process?
If I have to buy the extended ROM I'm looking at $39 extra, I have some 64k
RAM chips lying around, does somebody make an expansion box for the CoCo that
plugs in and gives a disk interface [I figure I can get bare floppy drives
and such pretty cheap, as long as I can get the interface from somebody],
more memory (DAT-compatible 512k?), serial/parallel, etc?
My memory is fuzzy, can I do machine language from BASIC without the
extended ROM? (I could live with cassettes and the bit-banger serial port
for some months if necessary - I'm hoping to make a quick-and-dirty
communications processor out of the thing, if I can tie the bit-banger to
the interrupt line or do hardware handshaking it might work, but I'd rather
get real hardware.)
If I can get a REAL MULTITASKING system for $200 for hardware (machine+disk)
and $100 for software I'd be REAL HAPPY.
--
- Ralph W. Hyre, Jr.
Internet: ralphw@ius2.cs.cmu.edu Phone:(412)268-{2847,3275} CMU-{BUGS,DARK}
Amateur Packet Radio: N3FGW@W2XO, or c/o W3VC, CMU Radio Club, Pittsburgh, PAronald@csuchico.UUCP (08/10/87)
In article <1248@ius2.cs.cmu.edu>, ralphw@ius2.cs.cmu.edu (Ralph Hyre) writes: > Is a 16K Coco (presumably without extended ROM) worth $40 (new)? > Is there any hope I can add on enough (memory, mainly - probably through > the expansion connector) to run OS-9 level 2 without exceeding the cost > of a CoCo 3 system or other OS-9 capable system in the process? $40? Sure, if you just wanted to play the ROMPAK games. OS-9 Level II requires just too much in the way of specialized memory management hardware to be cost effective. You could upgrade to the current CoCo 2 and run OS-9 Level I. > If I have to buy the extended ROM I'm looking at $39 extra, I have some 64k > RAM chips lying around, does somebody make an expansion box for the CoCo that > plugs in and gives a disk interface [I figure I can get bare floppy drives > and such pretty cheap, as long as I can get the interface from somebody], > more memory (DAT-compatible 512k?), serial/parallel, etc? It would end up costing you as much as the new CoCo 3 ($169 in the new ads in Rainbow magazine)! > My memory is fuzzy, can I do machine language from BASIC without the > extended ROM? (I could live with cassettes and the bit-banger serial port > for some months if necessary - I'm hoping to make a quick-and-dirty > communications processor out of the thing, if I can tie the bit-banger to > the interrupt line or do hardware handshaking it might work, but I'd rather > get real hardware.) Yes. > If I can get a REAL MULTITASKING system for $200 for hardware (machine+disk) > and $100 for software I'd be REAL HAPPY. OS-9 on the Color Computer is not a true multitasking system due to lack of DMA and the NMI kludge of the disk controller. Too many interrupts can (and do) get lost. I'm hoping the CoCo 4 (if Tandy ever gets off its ass) will break away from the old CoCo mode and use the real 6809 hardware like the 6829 (with 8 of them you can manage two megabytes of memory, or one meg and memory protection!), DMA, and maybe even *gulp* multiple processors! -- Ronald Cole | uucp: ihnp4!csun!csuchic!ronald AT&T 3B5 System Administrator | PhoneNet: ronald@csuchico.edu @ the #_1_ party school in the nation: | voice (916) 895-4635 California State University, Chico "It's O.K." -Hal Landon Jr., Eraserhead
knudsen@ihwpt.ATT.COM (mike knudsen) (08/12/87)
> OS-9 on the Color Computer is not a true multitasking system due to lack of > DMA and the NMI kludge of the disk controller. Too many interrupts can (and > do) get lost. I'm hoping the CoCo 4 (if Tandy ever gets off its ass) will > break away from the old CoCo mode and use the real 6809 hardware like the > 6829 (with 8 of them you can manage two megabytes of memory, or one meg and > memory protection!), DMA, and maybe even *gulp* multiple processors! > Ronald Cole | uucp: ihnp4!csun!csuchic!ronald Both Levels 1 and 2 OS9 can be made into true multitasking systems (edit one file while compiling another and printing yet a 3rd), IF you buy one of the two new floppy disk controllers coming out of Canada -- either Sardis Technologies in British Columbia or DISTO in Quebec (anyone in Alberta want to cover the middle?) Both of these cache up at least a sector at a time and transfer by nice simple software loops that don't block interrupts or do any other non-Ivy_League gaucheries. The 8K of RAM in the Sardis may someday be expanded by software into a real cache of the sort being discussed on this net. These new controllers cost about $150 US each. Whatever you do, don't buy a Radio Shack controller, since 3rd-party clones at least as good are available as low as $65 (see _The Rainbow_ mag.). The Shack's disk drives are also a ripoff. $170 Coco III $ 65 Disk controller $ 90 one DSDD-40 drive $ 80 OS9 Level 2 $ 70 case, power supply & cable for drive ---- $475 + your TV set or $90 mono monitor PS: Motorolas's old MMU chips (6829) waste a clock cycle on every RAM access. Tandy's new custom GIME chip does not. I posted months ago about how easily Tandy could extend the GIME to 2 Meg. Let's not wish Tandy back to obsolete off-shelf chips. -- Mike J Knudsen ...ihnp4!ihwpt!knudsen Bell Labs(AT&T) Delphi: RAGTIMER CIS: <memory failure, too many digits> "Just say NO to MS-DOS!"
ronald@csuchico.EDU (Ronald Cole) (08/20/87)
Mike, In article <1902@ihwpt.ATT.COM>, knudsen@ihwpt.ATT.COM (mike knudsen) writes: > Both Levels 1 and 2 OS9 can be made into true multitasking systems > (edit one file while compiling another and printing yet a 3rd), > IF you buy one of the two new floppy disk controllers coming out > of Canada -- either Sardis Technologies in British Columbia or > DISTO in Quebec (anyone in Alberta want to cover the middle?) Ok, so I didn't give a complete example. I agree OS-9 is a true multitasking operating system, but it is crippled on a Color Computer. OS-9 expects IRQ to be the way that I/O devices are interfaced. But does Tandy bring IRQ to the MultiPak? Noooooo! Well, we could use the CART line to get to the FIRQ line and do in software what should have been done in hardware (a more reasonable Tandy approach), but only one slot can be attached to the CART line at a time. Double-whammy!! The only reasonable super-kludge is to make a super i/o board that "does all" from one slot (leaving the others free for "Robot Battle" and other such crud). > Both of these cache up at least a sector at a time and transfer > by nice simple software loops that don't block interrupts or do any > other non-Ivy_League gaucheries. The 8K of RAM in the Sardis may > someday be expanded by software into a real cache of the sort being > discussed on this net. I, personally, would have just designed DMA into the new CoCo 3 and solved all these kludgy solutions once and for all! > PS: Motorolas's old MMU chips (6829) waste a clock cycle on every > RAM access. Tandy's new custom GIME chip does not. > I posted months ago about how easily Tandy could extend the GIME > to 2 Meg. Let's not wish Tandy back to obsolete off-shelf chips. Ok, for the sake of speed, you have me there. I see that you also rag on Tandy; they kinda "half-ass" things, don't they. If they would concentrate on making the CoCo g_o_o_d_ and not c_h_e_e_p_, they would sell just as many units. Still, multiple processors in a CoCo 4 would still be a +. ;^} -- Ronald Cole | uucp: ihnp4!csun!csuchic!ronald AT&T 3B5 System Administrator | PhoneNet: ronald@csuchico.edu @ the #_1_ party school in the nation: | voice (916) 895-4635 California State University, Chico "It's O.K." -Hal Landon Jr., Eraserhead