[Coco] CoCo 3 patch question
flexser at fiu.edu
Mon Nov 24 22:40:54 EST 2008
If you put in a STA $FFDE to go to ROM mode, all the CoCo 3 patches
will disappear, which I would think would solve the problem.
On Mon, 24 Nov 2008, Roger Taylor wrote:
> Does anyone know if the CoCo patches the Disk ROM if it's available?
> The reason I ask is that I'm developing an embedded system EPROM
> which poses as Disk BASIC by having the "DK" bytes at the top. From
> M.E.S.S., a CoCo 1 or 2 boots into my ROM fine and shows a title
> screen, but from the CoCo 3 modes, my title text has about 5 or 6
> bytes of garbage in it, which tells me something is changing part of
> the area where my text is stored within the ROM.
> I tried starting my ROM with:
> fcc "DK"
> jmp Start
> fzb 256 (CCASM's way of filling with 256 0's)
> Start nop
> And this works in the emulator, but I'm not sure what OTHER bytes are
> altered by the CoCo 3 patch routines. This leads me to ask yet
> another question... how does the CoCo 3 (if it's patching Disk BASIC)
> deal with the other DOS brands?
> Anyway, I've created a nice ROM which turns a CoCo into an embedded
> server. It boots up hands-free-ready to accept MP3 cassette files or
> those sent by cocotape.exe from a PC, or a real tape deck, etc. As
> soon as the file is over, it executes. This allows the control
> program to be uploaded just by sending the audio stream into the CoCo
> once. If you hit RESET it runs the control program again (or last
> program uploaded) instead of resetting the CoCo back to a hard
> start. The control program can be a game or any other single-record
> ML tape file. I've been sending games to the remote CoCo for my kid
> to play and all he's doing is toggling the power button when he wants
> a new one sent. The game starts up automatically. Talk about
> nice. The serious side to this project is that no keyboard or
> monitor is required if the plans are to do an emedded project. Just
> send power to the CoCo board and run a cassette cable to an MP3
> player, select (I'll call it control.mp3) and walk away. Or connect
> a laptop speaker, type cocotape control.bin, and walk away.
> Roger Taylor
> Coco mailing list
> Coco at maltedmedia.com
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