8-bit acorn software: other • Re: Master MOS disassembly

After poking around a bit more, I've got a couple of updates to the addresses in https://mdfs.net/Info/Comp/BBC/SROMs/MegaROM.htm that I'm fairly confident about.

ROM bank 9 (DFS):

$8000 - $aeff : DFS 2.45 code
$af00 - $b7ff : MOS 3.50 code
$b800 - $bfff : ADFS 2.03 disk code

There's actually a bit of space free at the end of DFS 2.45 - but it'll be obvious when you're looking. It's a run of $ff bytes.

ROM bank 14 (VIEW):

$8000 - $bbbf : VIEW
$bbc4 - $bd80 : EDIT 1.50r Tube relocation bitmap
$bd9f - $bfff : BASIC 4r32 Tube relocation bitmap

I haven't disassembled VIEW, and I don't intend to, so I guessed at its region from staring at the hex dump. MOS 3.20 View ran to $ba00; another 450-odd bytes doesn't sound outlandish given the extra stuff in MOS 3.50.

--Tom

P.S. for investigating the Tube relocation bitmaps, I put together a Python script: https://github.com/tom-seddon/beeb/tree ... relocation - still needs work (needs a mode to create new bitmaps for your own ROMs; the set command needs some budget-/range-type options so you can insert bitmaps with confidence; etc., etc.) but it's proven useful enough as it stands

Statistics: Posted by tom_seddon — Thu Jan 25, 2024 1:39 am

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