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TL;DR: What functionality or convenience is gained by having these offsets be negative values from the base address? It provided easy access to two lists that can be extended independently in future versions with a single pointer. The Long Read: A single pointer can only point a single memory location (yes, sound obvious, but stay with me). So at first ...


14

Splitting the ROM is not the same as byte-swapping the ROM. Amiga ROMs are usually split so that odd locations and even locations are stored in separate chips. This is because the 68000 has a 16-bit databus (i.e., it can fetch data 16 bits at a time), and the ROMs are normally 8 bits wide. The solution is to use two ROMs, so that one can contain the even ...


8

I'm not familiar with Amiga specifically, but, in the general case as you'd see with something like tools for manipulating ROMs of console cartridges: The system being dumped will typically return more than 8 bits at a time. (The 16-bit data bus OmarL mentioned), which means that the resulting values can be stored in little-endian or big-endian format. (For ...


5

The only thing CurrentDir() does is change the lock in your process structure that is used as the process' current directory, and return the old value. So, it is the return value of Lock() applied to the directory you want to use that needs to be checked. If this is a valid/successful lock pointer, then you can be assured that it will become your current ...


3

The simple answer is don’t build your relocation tables by disassembling the code, use the relocation tables already built in tools like Remus and Capitoline. The more complex answer and the process I use to create the tables is by breaking down the Kickstart ROM into individual modules using the ROMHEADER and LIBHEADER structures, the program kickinfo does ...


2

Kickstart switchers tended to either be physical switch driven (i.e. install a toggle switch on the case) or smartly drove themselves off of signals it could grab off the motherboard. The traces suggest that the jumpers might be for ROM size since it looks like it might just loop around a high address line when closed (i.e. would be for a 256KB ROM like KS1....


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