[Coco] Nitr0S-9 question

[Becker, Gary]

If anyone is interested, I have put the source code for version 14 of
OS9gen on my web site.

http://www.geocities.com/gary_L_becker/os9gen.asm

It limits the read and write size of the volume bit map to 768 bytes. I
found that something overwrites some bytes in the last 256 bytes of the
1024 byte sector buffer, so I limit it to 768. This can handle track
sizes of

768 BYTES * 8 SCTORS/BYTE / TRACK 68 = 90 SECTORS/TRACK

I am including this version with the release of CoCo3FPGA.

Gary

-----Original Message-----
From: coco-bounces at maltedmedia.com [mailto:coco-bounces at maltedmedia.com]
On Behalf Of Becker, Gary
Sent: Wednesday, August 15, 2007 6:46 PM
To: CoCoList for Color Computer Enthusiasts
Subject: Re: [Coco] Nitr0S-9 question (and thanks)

I modified os9gen with these two changes.

-----
         ldy   <lsn0+DD.MAP,u	get number of bytes in device's bitmap
*new code
         cmpy  #1024
         bcs   less                 DD.MPA is less than 1024
         ldy   #1024
less
*end of new code
         lda   <devpath
         os9   I$Read   
-----
         ldy   <lsn0+DD.MAP,u	get number of bytes in device's bitmap
*new code
         cmpy  #1024
         bcs   less2                DD.MPA is less than 1024
         ldy   #1024
less2
*end of new code
         lda   <devpath
         os9   I$Write  		write out the bitmap
-----

Now I can gen the 132 meg drive image. There are still some issues with
os9gen. This fix only limits the reading and writing of the allocation
bit map to the first 1024 bytes. If the number of sectors in each track
is large enough, the boot track could be beyond this range and some bad
things could happen. Maybe I will fix these issues sometime.

Thanks to everyone for getting me over this hump.

Gary Becker




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