[Coco] Crunch?

[Stephen H. Fischer]

Hi,

No can do!!

1. There cannot be any DECB Data file restrictions.

2. There cannot be any restriction on where a file is placed on a DECB disk.

Think of the case where a binary DECB data file is an OS-9 floppy contents.

The file is placed into Sector 0.

That would be a DECB disk even though it looks like an OS-9 disk. (with DECB
FNT added)

It might work initially as both a DECB and OS-9 disk.

1. There cannot be any restriction on an OS-9 file contents.

2. There cannot be any restriction on where a file is placed on a OS-9 disk.

A OS-9 file might be a valid DECB FNT contents.

This OS-9 file might end up in the correct place for an DECB FNT.

This is harder to make one that would work for both initially.

The only foolproof way to fix this is to build a time machine and go back
and tell Jeff about this problem and have him require a header on all files,
something that I remember one emulator tried to do.

And then insure that all programs follow this requirement.

Jeff knew nothing about OS-9 existence initially so he cannot be blamed.

I think he was made aware of OS-9 only after the CoCo 3 emulator was first
released.

SHF



"Bob Devries" <devries.bob-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org> wrote in
message news:D613D6721C32430DA56224BBC25AB18A at master...
> Maybe someone (we as a group?) can come up with a sure-fire way to
> differentiate between an RSDOS disk and an OS-9 disk?
>
> Lets start by listing the obvious similarities and differences.
>
> I'll head off by suggesting that Track 17 sector 1 of an RSDOS disk is all
> $FF, since it should not be used. (of course, someone could shoot me down
> in flames here.... )
>
> Also, the directory entries on sectors 3 and following of track 17 do fit
> a certain pattern, especially those bytes which denote the file type, and
> ascii flag.
>
> Anyone else care to add to this?
>
> --
> 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.
>
> my blog: http://bdevries.invigorated.org/
>
> ----- Original Message ----- 
> From: "Willard Goosey" <goosey-jbiyUuBjK3C+51mZqJFLXQ at public.gmane.org>
> To: "CoCoList for Color Computer Enthusiasts"
> <coco-uNHYcr1XS/wmlAP/+Wk3EA at public.gmane.org>
> Sent: Thursday, June 04, 2009 9:48 AM
> Subject: Re: [Coco] Crunch?
>
>
>> On Wed, Jun 03, 2009 at 04:35:28PM -0600, Darren A wrote:
>>>I think it is seeing the data in track 0
>>> sector 1 and deciding that it must be an OS-9 disk (even though it
>>> isn't). It then uses that information to setup an incorrect disk
>>> geometry.
>>
>> Can't handle virtual disks with data in the first sector of the disk?
>>
>> That's bad.  I mean, I've seen lots of broken software, but DAMN!
>>
>> Willard
>> -- 
>> Willard Goosey  goosey-GCsgzf5TmRs at public.gmane.org
>> Socorro, New Mexico, USA
>> I search my heart and find Cimmeria, land of Darkness and the Night.
>>  -- R.E. Howard