[Color Computer] Re: [Coco] DSK images to coco

George Ramsower yahoo at dvdplayersonly.com
Mon May 2 15:19:18 EDT 2005

<snip, snip, cut, snip>
> > stock OS-9 disk in it after booting the new disk, I get error 249 when
> > trying to access it. Both systems (Nitro and non Nitro)are using 80
> > 3.5 disks.
> Use dmode to check how the drive descriptor is set up. Make sure that
> the /d0 (if that is what is used) in the booted version matches the
> properties of the older OS-9 disk. Error 249 is wrong format if I
> remember correctly.
 I was in a hurry and didn't check that. Tonight I will.

> >  Also....
> >
> >   That's only about 800 baud.
> >
>  ><snip>
> True but writing to the Coco hard drive must be contributing to the
> slowdown.

 I still average about 240 cps on downloads to the coco, using a hard drive
for storage. A floppy would slow it down a lot, but not to 80 cps. I think
possibly, the null modem cable is the culprit. At 19.2 kb, there will be
lots of errors and retries. I would try it again at 1200 or 2400 to see if
it speeds up. This will prove if RTS, CTS, DTR, DSR are needed.
 Sending data to a coco at 19.2 just won't work, at least not without some
handshaking between the computers. I gave up speeds over 4800 with all the
signal lines working.
 The coco can SEND data at a faster rate kuz wherever it's sending it to
today, is most likely fast enough to receive it. I've found that the coco is
still limited on how fast it can send data. If I use 9600baud, it doesn't
send much faster than 4800, or about 450 cps average. The packet bursts seem
to go quicker, but this little guy still has to group them up to send them.

 Once I get Nitros9 where I want it, I'll try again to see how fast the 6809
can work. I don't have a 6309 to play with. I suppose I need to get a couple
of those buggers to try.


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