[Coco] Questions about drivewire3/hdbdos

[Aaron Wolfe]

DW4 sort of does that.  Every drive on the DW server side allows
specifying an optional offset and optional size limit.
At Robert Gault's suggestion I added a simple dropdown for choosing
the offset that matches the LSN for any particular drive # inside an
image, so you don't have to multiple by 630 each time.

This allows one to mount any "DRIVE n" inside a 256 disk image file
into any drive number, and since each of the 256 drives can use a
different source file, you can effectively map one (or dozens) of
disks from one 256 disk image file and some others from another 256
disk image file.  Theoretically all 256 disks could come from
different images, and none need be matched to the actual physical
order of the disk inside the image file.

So.. yes you could have a shared drive of sorts, by mapping a common
file into a particular drive number.  You could also just map in the
specific sections of two files containing the source and destination,
etc.

Hope that makes some kind of sense... it really is simple, but it
feels like it isn't coming out very clearly.  Each drive has an LSN
offset so you can make LSN 0 for that drive refer to any arbitrary
sector inside that drives source image.  The size limit setting is
just there for safety, to ensure you don't write outside of the
intended "window".  Good for mounting OS9 partitions in the middle or
at the end of an image too.



On Mon, Mar 19, 2012 at 7:29 PM, Robert Hermanek
<rhermanek at centurytel.net> wrote:
> A little off this subject, but maybe of interest to the makers of the DW4
> server:  When I wrote my own (somewhat crude) DW server, I decided on an
> option of a shared drive.  So if I refer to the DRIVE #n command as choosing
> between "devices" 0 to 255, and the DRIVE n command selecting virtual
> floppies on said device, I then made an option where I could choose an
> arbirary disk number, such as 255, to reserve as a shared disk.  What this
> meant then was that regardless of what DRIVE # command you used, the shared
> disk always returned the same DSK image.  So you could do this:
>
> If "DRIVE 255" was shared, you could issue these commands:
>
> DRIVE #1
> BACKUP 10 to 255  (copies device #1, disk 10 to shared disk 255)
>
> DRIVE #2
> BACKUP 255 to 3 (copies shared disk 255 to device #2, disk 3)
>
> This allowed me to easily swap disk images between device #'s without
> worrying about ramdisk/etc, also was very handy as a general purpose "temp"
> disk...
>
> (And for all I know DW4 already has a feature like this, I have downloaded
> it and installed, it, but have not had time to look at it in depth yet...
> very nice though!)
>
> -Robert
>
> ----- Original Message ----- From: "Robert Gault" <robert.gault at att.net>
> To: "CoCoList for Color Computer Enthusiasts" <coco at maltedmedia.com>
> Sent: Monday, March 19, 2012 6:04 PM
>
> Subject: Re: [Coco] Questions about drivewire3/hdbdos
>
>
>> Bill wrote:
>>>
>>> Well, I thought I had it figured out.
>>>
>>> When I type DRIVE #1, it accesses the #1 drive. When I type DIR, I get a
>>> directory. But how do I load files into DRIVE #1, dir 1 or dir 2 or dir
>>> 3?
>>>
>>> (does that make sense?)
>>>
>>
>> Not really :)
>>
>> Bill, don't get confused between Drivewire3 and Drivewire4.
>> The first program assumes that each of the four slots is the equivalent of
>> a drive mounted on a scsi channel. There is no built-in HDBDOS command that
>> permits (under Disk Basic) copying between channels/slots. The only way that
>> can be done is to move files into memory, issue a DRIVE#n to change
>> channels, and then SAVE or SAVEM to the new disk.
>> The second program, has the feature HDBDOS Translation. This feature
>> permits emulating Drivewire3 (Translation=OFF) or having each DW slot 0-255
>> the equivalent of the "drives" on a HDBDOS formatted hard drive.
>>
>> Let's look at some examples which might make this easier to follow.
>> 1) Moving files between a real disk in a Coco drive0 and a Drivewire image
>> in slot0 by loading them into memory and then saving them.
>>   You access the real disk with DRIVEOFF and any commands to access
>> drive0. You access the DW disk with DRIVEON and any commands to access
>> drive0. This works with both DW3 and DW4.
>> 2) Copying files between two drives mounted in different DW slots.
>>   Issue DRIVE#n to select the drive. Load a file into memory. Issue
>> DRIVE#m to select the other drive. Save the file. This works for both DW3
>> and DW4.
>> 3) Moving files when they can't easily be stored in memory, ex. machine
>> language files. This applies to both 1) and 2) above.
>>   You can get the RAMdisk program from the Drivewire site. This program
>> makes drive3 a RAM disk which is active whether the floppies are on or off.
>> The program can be stored on either a real disk or a DW image.
>>   LOADM"RAMDISK" or whatever name it is saved as. Issue DRIVEON and
>> DSKINI3 to format the RAM disk. Use DRIVEON or DRIVEOFF to activate either
>> floppies or DW disks. Use either BACKUP0TO3 or COPY"file.ext:0"TO3 and then
>> after an appropriate DRIVEON or DRIVEOFF go from 3 to 0. This works with
>> both DW3 and DW4.
>>
>> 4) Moving files between DW disks.
>>   If you don't want to use the method in 3) you must use Drivewire4.
>>   Mount several images (single disks not hard drives) in the Drivewire
>> slots. Turn on HDBDOS Translation and issue DRIVEON. Now you can transfer
>> files between any of the drives with COPY or BACKUP.
>>
>> =======================
>> If you are not sure what you want to accomplish or can't describe it, the
>> above will seem confusing. It will not be when you can clearly state exactly
>> what you want to do, step by step.
>> If nothing else, if you want a step by step answer to a question, you must
>> present a step by step question. :)
>>
>>
>>
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