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

[Kip Koon]

Hi Juan,
I will try this out after I get back from the beach and get my PCBs built.  I'm looking forward to your rom!

Kip Koon
computerdoc at sc.rr.com
http://www.cocopedia.com/wiki/index.php/Kip_Koon



> -----Original Message-----
> From: Coco [mailto:coco-bounces at maltedmedia.com] On Behalf Of Juan Castro
> Sent: Saturday, April 04, 2015 8:09 PM
> To: CoCo List; Lista CoCo
> Subject: [Coco] R+DOS/16 IDE support: I learned about the $052DDC offset the hard way.
> 
> 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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