8-bit acorn hardware • Re: Speech by D.E Talker for the BBC Micro

Out of interest how/what are you using to view the contents of the ROM

The Tweak hex editor, and MAME's unidasm for disassembly (with a script to update labels automatically). The Advanced User Guide is a useful reference.

I found another D.E.TALKER chip in my collection and that seems to read better using the GQ-4x4
It's in this zip file and saved as talker2.bin and talker2.hex

Yep, that looks a lot happier! In that zip file, detalker.bin is v2.20 with a few bit errors, and detalker2.bin is v2.30 apparently intact (i.e. a better read of the detalker.bin in your previous post).

I've attached a partial disassembly of detalker2.bin. The routine that drives the hardware is:
So writing a byte to &A000 clocks it into the SP0256-AL2 (so I guess ALD is toggled automatically), and reading &A001 gives you SBY in bit 6. From v1.00 it also appears that reading &A000 returns &FF.

The same routine appears in the v1.00 image, except that the sta had been replaced with jmp $9000 to call the Sweet-Talker-ish code instead. I've attached a "reconstructed" v1.00 where I've put the sta back in, which should in theory work if the hardware's emulated correctly. (I've also zeroed out the now-unused second half and changed the copyright message, to avoid confusion with the real v1.00 if it ever shows up...)

Detalker_v1.00_reconstructed.rom

detalker2.lst-v1.txt

Statistics: Posted by atsampson — Wed Jan 21, 2026 10:26 pm

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