[Coco] Determining OS-9 Floppy Type

[Bob Devries]

Gene,
I believe that Andrew is trying to tdo this on a PeeCee, so the dmode 
command ain't gonna help him much.

--
Regards, Bob Devries, Dalby, Queensland, Australia

Isaiah 50:4 The sovereign Lord has given me
the capacity to be his spokesman,
so that I know how to help the weary.

website: http://www.home.gil.com.au/~bdevasl
my blog: http://bdevries.invigorated.org/

----- Original Message ----- 
From: "Gene Heskett" <gene.heskett at verizon.net>
To: <coco at maltedmedia.com>
Cc: "Andrew" <keeper63 at cox.net>
Sent: Sunday, May 27, 2007 2:12 PM
Subject: Re: [Coco] Determining OS-9 Floppy Type


> On Saturday 26 May 2007, Andrew wrote:
>>As you all know, I am doing a floppy disk conversion project for Carey,
>>to rescue a bunch of data from some old floppies, and convert it into
>>images which can be read under emulation. I have already completed the
>>DECB subset of floppies, and I am beginning to tackle the OS-9 subset.
>>
>>However, I am running into a snag. When I worked on the DECB subset, I
>>was able to determine what kind of disks the OS-9 floppy sides were
>>(some of the floppies were "mixed" - one side being DECB, the other
>>OS-9) by inference:
>>
>>Since under OS-9 there are only 35 track SSDD device descriptors and 40
>>track DSDD descriptors (but no 40 track SSDD descriptors), if there was
>>readable OS-9 data on one side of a floppy and the other was DECB
>>formatted (and there were two index holes punched in the floppy jacket),
>>then it could only be a 35 track SSDD floppy side.
>>
>>However, I can't make that inference now since a 35 track SSDD floppy
>>(with a single index hole) looks the same physically as a 40 track DSDD
>>floppy (which also has a single index hole). Unless it is labeled as a
>>certain format, I am not sure how to tell which is which.
>>
>>Can anyone tell me what the best way of determining whether an OS-9
>>formatted floppy is a 35 track SSDD floppy or a 40 track DSDD floppy?
>>Whether the method uses DECB, OS-9, or DOS, it doesn't matter. However,
>>I don't have access to a Windows machine with a 5.25 floppy drive, so
>>that method is out.
>>
>>I need to know this information so I can make a proper backup and
>>recovery image of the floppy (btw - what would be the best way for me to
>>create a DSK image of a 40 track DSDD OS-9 floppy under DOS?). Is there
>>a way to take an image with each side using RETRIEVE.EXE and then
>>combining them somehow? Or, is there something like RETRIEVE.EXE, that
>>runs on DOS, that will do this?
>>
>>Or - could I run a program under DECB in the emulator that took each
>>side image and then directly wrote it to a third image using DSKI$ and
>>DSKO$? Or perhaps in a similar manner use OS-9 on the emulator to pull
>>and combine each image?
>>
>>Hmm - this conversion effort for the OS-9 floppies has gotten hairy
>>quickly. Any and all answers will be appreciated - I don't plan on doing
>>anything until I have a working answer from someone(s) out there, or no
>>answer is forthcoming and I have to cobble something together myself.
>>
>
> Andrew, for os9 there is a very handy utility, called 'dmode'.  With it 
> you
> can adjust a spare descriptor (/d1?) in your bootfile so that it can read
> virtually any format the drive itself can handle.
>
> The arguments you want are 'sid' and 'cyl' which stands for the number of
> sides, and the cylinders/tracks the disk might have.  Note that the value
> for 'cyl' is stated in hexidecimal, so a 40 track disk is 28 in hex, and 
> an
> 80 track disk is 50 hex.
>
>>Thank you in advance...
>>
>>-- Andrew L. Ayers
>>    Glendale, Arizona
>>
>>--
>>Coco mailing list
>>Coco at maltedmedia.com
>>http://five.pairlist.net/mailman/listinfo/coco
>
>
>
> -- 
> Cheers, Gene
> "There are four boxes to be used in defense of liberty:
> soap, ballot, jury, and ammo. Please use in that order."
> -Ed Howdershelt (Author)
> system-independent, adj.:
> Works equally poorly on all systems.
>
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