[Coco] HDBDOS - Floppy/DSKINI Mod

Mon Jan 19 21:31:34 EST 2015

Chad,

It is possible to hide some code right after the DOSIN2 routine and
shorten some of the FCB's to keep the ROM size correct as well as
modifying the DSKINI routine that creates the raw track buffer before
it is written.  Can replace the CLRA and the following LDA with a NOP
& LBSR to a new sub routine at that space after DOSIN2.

I am currently working on a patch for HDBDOS at the moment.  First
tests seem good and the ROM size is correct.

My first routine used up almost all of the free byte space after the
DOSIN2 routine, but thanks to William Astle that code has been
shortened by a few bytes.

The routine actually checks for the SIDE 1/DRIVE 3 select bit.  So if
that is actually active then the side 1 value will be used while
building the track buffer.  This idea is also thanks to William Astle.

I am still doing some tests right now. Once I am ok with it I will
talk with Tormod and can get this pushed to the repo.

So just hold tight and will post a reply once it is tested working and pushed.

On Mon, Jan 19, 2015 at 8:03 PM, Chad H <chadbh74 at hotmail.com> wrote:
> Note to CoCo 3 users:
>
> I don't have a CoCo 3, I have a CoCo 2 so I thought there were no issues here but I tried loading the .ROM in the M.E.S.S. emulator for a CoCo 3 and it always hanged.  I tried loading for a CoCo 1 and that works.  I was perplexed as I thought the CoCo 3 could handle larger ROM's than the CoCo 1/2 (up to 32K right?)  I guess you have to do something special in the ROM to get that to work though with the MMU of the CoCo 3.  I found a Memory Map for the CoCo 3 that shows the following...
>
> $C000-$DFFF     Disk Basic Interpreter  (i.e. Cartridge ROM / 8K space same as CoCo 1/2)
> $E000-$FFFF  Super Basic, GIME regs, I/O, Interupts
>
> IF this is the case then it explains why my ROM's won't work in a CoCo 3 as they cross the 8K boundary.  According to the same document, the CoCo 2 map shows by comparison ...
>
> $C000-$DFFF     Cartridge ROM Space
> $E000-$FEFF     Unused
> $FF00-$FFFF     I/O, machine configuration, reset vectors
>
> The CoCo 2 has the extra space from $E000-FEFF available that the ROM could run into.  That’s 7.5K of space.  Hopefully someone will figure out how to use the MMU features to 'map in' larger than 8K ROM's on the CoCo 3 at some point
>
> - Chad
>
>
> -----Original Message-----
> From: Coco [mailto:coco-bounces at maltedmedia.com] On Behalf Of Chad H
> Sent: Monday, January 19, 2015 2:48 PM
> To: 'CoCoList for Color Computer Enthusiasts'
> Subject: [Coco] HDBDOS - Floppy/DSKINI Mod
>
> Ok this for those guys like myself that still are heavy Floppy Drive users.
> I would hope that those responsible for maintaining the OFFICIAL HDBDOS/ToolShed repository consider implementing the DSKINI patch on any future revisions.  I know not everyone uses floppy drives with HDBDOS, but this patch could save frustrations for those that might use RETRIEVE and other imaging tools.
>
>
>
>   Modifications:                                ** Unofficial ROM !! **
>
> .          Checks AUTOEXEC.BAS from real floppy instead of DW/Hard Drive.
>
> .         DSKINI routine patched to work flawlessly with utilities such as
> the latest RETRIEVE.EXE
>
>
>
>
>
> This includes the .ROM's and the modified HDBDOS.ASM source as well as a .RTF document listing the changes made for review.
>
>
>
> http://tinyurl.com/p8rewfd   ** Unofficial ROM !! **
>
>
>
> Unfortunately, the changes have made most of these ROM's greater than 8,192 bytes which means they will not fit inside your 2764 EPROM and will require atleast a 27128 EPROM to work.
>
>
>
> 01/17/2015  03:31 PM             8,192 bas13.rom
>
> 01/17/2015  03:31 PM            32,768 coco3.rom
>
> 01/17/2015  03:31 PM             8,192 disk11.rom
>
> 01/17/2015  03:31 PM             8,192 extbas11.rom
>
> 01/19/2015  01:25 PM             8,226 hdbchs.rom
>
> 01/19/2015  01:25 PM             8,254 hdbd4n1.rom
>
> 01/19/2015  01:25 PM             8,254 hdbdhdii.rom
>
> 01/19/2015  01:25 PM             8,112 hdbdw3arduino.rom
>
> 01/19/2015  01:25 PM             8,113 hdbdw3bc3.rom
>
> 01/19/2015  01:25 PM             8,104 hdbdw3bck.rom
>
> 01/19/2015  01:25 PM             8,180 hdbdw3cc1.rom
>
> 01/19/2015  01:25 PM             8,224 hdbdw3cc2.rom
>
> 01/19/2015  01:25 PM             8,233 hdbdw3cc3.rom
>
> 01/19/2015  01:25 PM             8,101 hdbdw3jc2.rom
>
> 01/19/2015  01:25 PM             8,110 hdbdw3jc3.rom
>
> 01/19/2015  01:25 PM             8,299 hdbdw4cc2.rom
>
> 01/19/2015  01:25 PM             8,308 hdbdw4cc3.rom
>
> 01/19/2015  01:25 PM             8,255 hdbkenton.rom
>
> 01/19/2015  01:25 PM             8,130 hdblba.rom
>
> 01/19/2015  01:25 PM             8,255 hdblrtech.rom
>
> 01/19/2015  01:25 PM             8,251 hdbtc3.rom
>
>
>
> -          Chad
>
>
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