![]() The index starts at zero when the floppy side is changed, so I needed my earlier notes to create a table of the addresses where the floppy side data is located. So, in short, the index is $01de00 - 2*1de = 01da44 $1de is the number of sectors (sector $100 bytes), and if we lose 2 bytes/sector, that has to be subtracted from the original address somehow. There are only 16 bits of meaningful data. The problem was that the loader asked for data from $01de00. The game asks for data via certain indexes which turned out to be the address for the data. rel file starts at, so I could write some loader code to jump into the correct index when side2 is needed and so on.Īlter Ego has its data spread across 6 floppy sides, and when I had combined all of the data, I had a whopping 823kbytes of female and 844k of male data. All I had to do was just remove the header in front of each file and make notes about the index the next. rel files and combined them into an ide64 compatible format. After some investigation, it's just a bunch of regular looking sectors with only $fd bytes of actual data in them. I also realized that I don't have a clue what a. A pointer to the next sector is included in the accessed sector, so it keeps reading until everything has been read. The drive gets the seek command from the c64, loads some tables and finds the wanted sector from the floppy. I spent quite some time reverse-engineering the code and figuring out how it worked. Too bad that those are not even a challenge when you have an emulator and breakpoints, so getting readable code was quite simple. Straight away I stumbled into some not-so-hacker-friendly code involving encryption. rel files, as it seemed to use a custom loader instead of the kernal routines. The first part of the quest was to find the floppy routines to understand how the game accessed those. I chose the female version, because back in the 80s I didn't have it, so why not take a peek now? The Male and Female versions ought to be the same anyway? So after finishing several of my unfinished projects, I finally started to look into the code for Alter Ego Female version. Many other multi-floppy games had been ported already, but no one had provided this title. But it didn't work, and there was no fix for it either. When I first got my IDE64, one of the first games I would have wanted to play from it was Alter Ego. Grue of Beyond Force, Extend, KasettilameritĪlter Ego Male / Female For IDE64 fix by Grue
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