[Coco] R+DOS/16 IDE support: I learned about the $052DDC offset the hard way.

Juan Castro jccyc1965 at gmail.com
Wed Apr 8 01:40:12 EDT 2015


It was less invasive and it was WRONG -- all file additions had been left out!

This one is much closer to being commit-worthy IMHO:
https://dl.dropboxusercontent.com/u/15643089/hdbdos-16krom-1.5-proposal.patch

What it does that MAY still raise eyebrows:
- Some black magic to reinsert the includes if you go to cocoroms/ and make
- If compiling the IDE+USELBA version, I use that voodoo sector offset
$052DDC, and 0 for all others
- IDE default port address is now $FF50
- Version has been bumped to 1.5R1
- When compiling the 16K versions, the OS name is R+DOS/16 instead of
HDB-DOS. Too much vanity?

A change in HSET MEM semantics:
- HSET MEM COPY copies ROM to RAM, leaves RAM active
- HSET MEM just switches to RAM, yeah, instant crash if you haven't a
functioning BASIC in RAM
- HRESET MEM switches to ROM.

Also, there's no DriveWire speed change anymore. I'll think about how
to reintroduce that in a polite way.

The compiled ROMs are in the link below -- each and every one of them
should be usable, with all its respective disk semantics intact, plus
my fluff. MiniIDE users, if you feel courageous enough to alter the
board's circuit to allow for a 16K ROM, feel free to dare. Caveat
emptor. Also, I'd like DriveWire users to test if printing still
works.

https://dl.dropboxusercontent.com/u/15643089/16kroms.zip

The good news? I didn't have to shorten any messages!

Juan Castro
Enviado do meu Olivetti Programma 101


On Sun, Apr 5, 2015 at 3:48 PM, Tormod Volden <lists.tormod at gmail.com> wrote:
> Hi Juan,
>
> Is 052DDC some kind of standard value? In case it maybe should be
> applied to HDB-DOS proper. Are there other common values?
>
> I looked through your patch and it it looks indeed less invasive than
> what I have seen before. But what changes in this patch require going
> to 16K?
>
> I am however inclined to keep HDB-DOS conservatively to 8KB and rather
> let people explore Brett's new DOS for everything that one can do with
> 16KB.
>
> Regards,
> Tormod
>
>
>
>
> On Sun, Apr 5, 2015 at 2:09 AM, Juan Castro <jccyc1965 at gmail.com> wrote:
>> I tried to use a compiled-from-sources 16 KB LBA HDB-DOS ROM with my
>> BASIC goodies in my MiniIDE, and got nothing. Then I remembered about
>> the FF70 port thing, changed it to FF50 -- nopw I got gibberish from
>> the disk instead of a lockup.
>>
>> I backtracked EVERY change in the ROM, one by one. At some point I
>> even thought the recent TFSIDE patch was the culprit. After taking
>> everything out (and burning some 20 EPROMs in the process). After much
>> disappointment, I got to a difference of 3 bytes between my compiled
>> ROM and the one that worked.
>>
>> Those bytes were 00 00 00 in my ROM, and 05 2D DC in the working ROM
>> that came with the MiniIDE. Yeah. Hard-coded sector offset.
>>
>> Now I FINALLY have a 16K HDB-DOS derivative for the CoCo 1/2 with the
>> BASIC enhancements I had before (except DW support) working on an IDE
>> interface. It should work in a Glenside IDE or a SuperIDE if you can
>> coax the hardware into seeing a 16K Disk ROM. Here's it:
>>
>> https://dl.dropboxusercontent.com/u/15643089/16k-hdblba.rom
>>
>> And below is the source patch. On its face, it's a less invasive patch
>> -- it just creates 16k ROMs and leaves disk support as-is. I imagine
>> ROM 16k-xxxxxx.rom should work pretty much as well as the plain 8k
>> xxxxxx.rom, for every xxxxxx.
>>
>> https://dl.dropboxusercontent.com/u/15643089/16k-ide-rom.patch
>>
>> Next challenge is to reintroduce DW support into an IDE ROM as an
>> add-on. That will be tricky, but, I imagine, less than introducing IDE
>> support into a DW ROM.
>>
>> Also, I didn't hack my MiniIDE; I used an MPI.
>>
>> Juan Castro
>> Enviado do meu Olivetti Programma 101
>>
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>
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