Feeding the Dragon ecosystem

A forum for members to discuss this site, offer suggestions for improvement etc.
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rolfmichelsen
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Re: Feeding the Dragon ecosystem

Post by rolfmichelsen »

Taking on my own challenge, I've added documentation of the CAS file format.

-- Rolf
sixxie
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Re: Feeding the Dragon ecosystem

Post by sixxie »

Added some disk image formats (though shied away from completely describing DMK and just left a link). Tweaked some of the earlier headings to s/DMK/JVC/.

I wonder if it's right to document the CAS format as *being* the Dragon's blocked tape format - the CAS itself is usually just treated as a raw stream of bits with each 0 indicating a cycle of 1200Hz and each 1 indicating a cycle of 2400Hz. Custom loaders would lead to a CAS file not looking like it's in the right "format".

Also might be worth a note about its limitations: no way of indicating silence, or different cycle lengths. My old custom loaders sped things up a touch by reducing the cycle lengths. Here's an example: CoCo port of Impossiball! (gzipped WAV, you'll need to gunzip it).
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snarkhunter
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Re: Feeding the Dragon ecosystem

Post by snarkhunter »

A number of years ago (must have been circa year 2K), I did receive some invaluable help from a colleague of mine, who owns a real menagerie of old computers. We met at the office on a Saturday, and he had brought one of his old PCs having a dual drive (i.e. 5.25" & 3.5" floppies). Most of my personal collection of Dragon disks was then converted to ".vdk" files using "VCOPY". Some would resist the conversion process, but I then assumed they had a number of bad sectors (which is not so surprising when it comes to magnetic media that had remained unused for nearly 15 years).

Of course, the most interesting disks from my collection have now been posted to the archive. I do have a very few extra ones available but, as previously stated, the most interesting content on those is a multi-disk French RPG game ("Graal Quest") that I assume would be useless to most active Dragon users since it's all in French! But should anyone ever want it nonetheless, I guess I still could try to search my archive of ".vdk" files and add it to the collection. It was a genuine disk-based game, mainly running in PMode3 (if I remember well, but I'm not 100% sure about this now).

Otherwise, most of my "useable" games and utilities disks have somehow been posted.

Just to summarize things, getting ".vdk" files from genuine Dragon disks is very easy, as long as one has access to a "dual-floppy" PC.


Kind regards,
Lionel
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rolfmichelsen
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Re: Feeding the Dragon ecosystem

Post by rolfmichelsen »

sixxie wrote:Added some disk image formats (though shied away from completely describing DMK and just left a link). Tweaked some of the earlier headings to s/DMK/JVC/.
Great stuff :D
sixxie wrote:I wonder if it's right to document the CAS format as *being* the Dragon's blocked tape format - the CAS itself is usually just treated as a raw stream of bits with each 0 indicating a cycle of 1200Hz and each 1 indicating a cycle of 2400Hz. Custom loaders would lead to a CAS file not looking like it's in the right "format".
I modified the CAS entry slightly, trying to address some of your very valid concerns. Obviously, feel free to add details, comments, limitations as well. After all, that's what a wiki is all about...

-- Rolf
dlinsley
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Location: Seattle, USA (formerly Chester-le-Street, UK)

Re: Feeding the Dragon ecosystem

Post by dlinsley »

There's a great tool that works even in Vista (maybe Win7 too) if you have an old 1.2M floppy drive: http://www.omniflop.com

I last used it ~ 18 months ago and had success reading disks, IIRC, in DMK format into XRoar. I promised to send Simon some more stuff for the achive back then too, but then work + my 6m old daughter (at the time) took over! I'm hoping to be more active from now on.

Cheers,
David.
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