8-bit acorn software: classic games • Re: Chuckie Egg 2023

Hi again.

I'm going to have to point the finger at MAME's implementation, I'm afraid, given the number of combinations of hardware and emulators on which it does run.

My first guess is that the host is waiting for the parasite to send something that never arrives:

While "Initialising" is displayed on screen a few things happen including the parasite overwriting the Acorn ROM code and then issuing JMP ($FFFC) to set the new OS running. On real hardware that last step does not page the Acorn ROM back in but if that is happening in MAME the symptoms would be the same - Acorn sends the startup banner text in R1 in its reset routine whereas my host code is waiting for data in R4 from the replaced reset routine.

It could be something different of course but either way MAME isn't behaving the same as real hardware.

As for the disc image not being recognised in MAME, I can't think of anything that would cause that. There's nothing non-standard in the files.

Sorry I can't be more help with this.

Sam

Statistics: Posted by SamSkivington — Mon Jul 22, 2024 11:01 am

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