XRoar and DSK files images of discs 720K long

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pser1
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XRoar and DSK files images of discs 720K long

Post by pser1 »

Hi Ciaran,
we cannot open DSK files converted from VDK files that are discs 720k long.
The VDK work flawlessly in XRoar, but the DSK, that are exactly the same file without the header,
always return IV ERROR when entering DIR

Is there any constraint that doesnt' admit DSK files longer that 182k?

cheers
pere
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robcfg
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Re: XRoar and DSK files images of discs 720K long

Post by robcfg »

Hi Pere!

Can you attach a dsk file that you don't get to load?
pser1
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Re: XRoar and DSK files images of discs 720K long

Post by pser1 »

Hi Robert,
sorry I didn't attach it first time!
Here you will find a 720k disc in both formats:
VDK, this one loads and works flawlessly in XRoar
DSK, that gives IV ERROR when issuing a DIR command

cheers
pere
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720K-Disc.ZIP
(426.34 KiB) Downloaded 252 times
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robcfg
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Re: XRoar and DSK files images of discs 720K long

Post by robcfg »

Tried it and get the same error as you.

This is a case for sixxie :mrgreen:
pser1
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Re: XRoar and DSK files images of discs 720K long

Post by pser1 »

Yes, Robert
I think so ...
These DSK files work with the CoCo-SDC because it seems that the firmware reads the length of the disc file
and based on that information calculates the kind of disc, and so knows where the directory begins.
If not done and assumed it will begin at sector number 321, it will fail with any DSK longer than 182k
as is the case ...

So, please help, Ciaran!!

cheers
pere
sixxie
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Re: XRoar and DSK files images of discs 720K long

Post by sixxie »

Ah, I took a bunch of heuristics out when I made it look into OS-9 structure for disk geometry - they were the only "problem disks" I'd encountered. The issue is that JVC disks without a header are supposed to default to single-sided. However, 160 track disks don't make much sense, so I guess I could stick that particular check back in!

In the meantime, if you prepend these two bytes to the image, XRoar will recognise them as header information and treat it as a double-sided disk: $12, $02
pser1
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Re: XRoar and DSK files images of discs 720K long

Post by pser1 »

Hi Ciaran,
I think that nobody needs urgently a patch for that. We have the VDK file as well and it works without problems.
But when people wants to use these files in the CoCo-SDC, they need to convert them into DSK because, by now,
there you only can use VDK with headers exactly 12 bytes long. And when they contain a disc name, they are longer
than that ... so they cut the header with the VDK2DSK I had uploaded in the thread: A DOSPlus extender for DW4 and SDC.

In case you want to make any change to solve that problem, people are using discs 180k, 360k and 720k long
thanks in advance

cheers
pere
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