[Coco] dir options on coco

Robert Gault robert.gault at att.net
Sun Nov 28 22:40:09 EST 2010

Little John wrote:
> This reminded me of an experiment I did recently. I fired up the Vcc
> emulator with RGBDOS active (your emulator version). Then I entered:
> which saved the "virtual" ROM to a virtual disk. I used the mess
> winimage tool to extract it. Used a hex editor to remove the first five
> bytes (preamble) and saved it back. I didnt bother removing the
> postamble - my eprom programmer truncates the image to 8K upon loading
> anyway... I burned it into a 2764 and stuck it in my disto mini
> controller. It seemed to work fine. Of course I wouldn't recommend this
> for serious use - obviously it has emulator specific changes, but still
> - it was fun to play around with. Having said that, if you like RGBDOS,
> it's a good investment to head over to cloud9 and buy HDBDOS.
> -JohnT-

For those who might wonder about the advisability of Little John's experiment, 
there won't be any problems for floppy disk use. You won't be able to use a hard 
drive because the routines (which were scsi) were removed and changed to work 
with specific emulators. I believe that MESS and VCC can use the same RGBDOS ROM 
but the JVC / Collyer emulator uses different hard drive I/O.

That being said you would want to make sure that the floppy drive table matched 
your system. The table at $D89D with a stock listing is 1, 2, 4, $40. If you use 
double sided drives the table usually is 1, 2, $41, $42. You should change the 
table as needed before burning an EPROM.

There are many advantages to using RGBDOS/HDBDOS, one of which is auto-paused 
directory listings. You also get repeat keys, commands like RUNM"filename" which 
combines LOADM and EXEC, and much more. You can see the command syntax at:
Look for HDBDOS documentation.

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