[Coco] .DSK Partition extract/inject tool?

[Bill Pierce]

Chad, I think that the whole 256 disk thing was inherited from the original RGBDOS for the Kenton Systems drives. That's where I first saw it used. A friend of mine had one of the first ones.
This is all controlled by HDBDOS not DW. DW doesn't care, it just reads sectors. This is why you cam make huge disks in DW.
 The multipartitioned VHD (OS9/RSDOS) was derived from that system as well. Also the descision to have OS9 first was probably due to the fact that with the first emulator that used VHD... Jeff Vavsour's Coco 3 emulator modded by John Collier, would only use the VHD for OS9. The RSDOS part was added later and was just appended to the OS9 vhd by Robert Gault (I believe, he'll correct me).
Part of the reason behind keeping the RSDOS disks at 256 was (I believe) to keep it an 8 bit value therefore allow small changes to DECB to make the Multidrive system work with most existing software or with just a few pokes like changing the Max drives allowed from $03 to $FF. To have added more drives would have carried it over into the 16 bit range and made for a COMPLETE rewrite of everything... including disk basic.
As I said, this actually started in the 80s and has stayed that way for compatability. This is why so very few alternate disk systems (JDOS, SDOS, MYDOS etc) with the exception of Art's ADos as he kept it tight and close to the original which is how HDBDOS was kept.
Also, to do some of the things you suggest would mean a much larger rom and that is talking a BIG rewrite.

Bill Pierce
My Music from the Tandy/Radio Shack Color Computer 2 & 3
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-----Original Message-----
From: Chad H <chadbh74 at hotmail.com>
To: 'CoCoList for Color Computer Enthusiasts' <coco at maltedmedia.com>
Sent: Tue, Sep 24, 2013 7:25 pm
Subject: Re: [Coco] .DSK Partition extract/inject tool?


What you call ".vhd" I'm already using as .DSK files, but same thing.  They
have 0-255 drive in one file.  I understand what your saying that you can
adjust the offset in DW4 thereby specifying which disk within the image to
use for that drive, but that's extra work.  I still don't understand why the
decision was made to use "OffSets" in multiples of 630 sectors.  DW4 is set
for ALL of the 0-255 disks to be 630 sectors as a standard right?  Then why
not make it so DW4 lets you choose a 0-255 disk to mount as a offset
instead?  Just a thought.

If I had a PC side utility that I could select one .VHD, and a specific
0-255 disk, then select a second .VHD with another 0-255 disk and instantly
transfer it over...that would be bypassing a lot of steps and calculations
too.

-----Original Message-----
From: coco-bounces at maltedmedia.com [mailto:coco-bounces at maltedmedia.com] On
Behalf Of Robert Gault
Sent: Monday, September 23, 2013 10:30 PM
To: CoCoList for Color Computer Enthusiasts
Subject: Re: [Coco] .DSK Partition extract/inject tool?

Chad H wrote:
> I was just wondering if there existed a tool in any Toolshed or 
> elsewhere that made it easy to take a single virtual disk (0-255) out 
> of a .DSK partition and inject it into another .DSK partition at a 
> specified virtual disk (0-255).  Anyone?
>

You really don't need a tool. The easiest method whether using HDBDOS or
RGBDOS is just to copy one of the .vhd Disk Basic disks to a single .dsk
image and then to a different .vhd image.
If you are using Drivewire4 and have read the documentation, you will see
that you can mount multiple .vhd image that have up to 256 Disk Basic drives
per vhd. 
You can then adjust the offsets individually for each DW4 drive and turn on
HDBDOS translation. That will permit using the BACKUP command of Disk Basic
to transfer any of the 0-255 drives from one .vhd image to another.

Are you asking about Drivewire usage or one of the other emulators, JVC,
MESS, or VCC? Techniques will differ.



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