Apple Disk II technical info / code disassembly

I have come across this French Apple II game:

Le mur de Berlin va sauter

It is apparently one of the very first video games to include a non-straight character. Though he is the bad guy, as was common back then, in am still interested in making an English translation for personal/historical reasons. There doesn't seem to be an English translation, despite "Emulator Games" claiming that they have an exclusive US English translation.

It is available as 2 disk images. I am familiar with 6502, but not familiar with Disk II, which is the old Apple floppy disk drive. Reading around online, people generally use CiderPress to extract files from Disk II images, then import the files into a disassembler such as 6502Bench. However, CiderPress tells me that the disk image is "Unadorned", which I believe means that it just runs in a raw fashion and it does not contain DOS or ProDOS or any individual files.

I am guessing that I can just treat the whole disk image as 1 raw file in 6502bench. What I do not know, and can't find with Google, is:

• The Disk II must start reading the disk from somewhere and copy it into RAM, then start executing from RAM.
• What part of the disk does it copy first? (i.e. does it copy from the beginning or end, etc?)
• Where does it copy it to, in terms of address space of the Apple II motherboard?
• Where is the entry point when it starts executing from RAM? Is there any sort of vector table, etc?

I can see where 6502Bench will automatically show me where calls are made to the Apple II's ROM for accessing the disk, requesting more data, etc. I think that once I understand a starting point, I will be able to follow those things in order to proceed. I want to be able to roughly disassemble it, change text, and reassemble. I am seeing that it likely uses ASCII format because I am seeing a lot of text with a hex editor, so it seems pretty approachable.

Statistics: Posted by Ben Boldt — Sun Dec 08, 2024 2:48 pm — Replies 2 — Views 122

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