...just procrastinating!

But thanks to Isa I decided to get back to work. I haven't been updating this feed for some time, but that doesn't mean, that I've been doing nothing (well... sorta). 

When I found out that my modification of the DW6k's bit map (aka patch structure) will corrupt SysEx messages, I knew that there's no turning back from some heavier firmware modifications. All I need to do is to write a function which assembles bigger values out of two bits available in almost each byte of patch data. Not quite a rocket science, just some shifts and masking (this is what assembly is all about:)), but must be precisely injected into the existing code. Doing it the old way (i.e. run the code in the emulator, set some break- and watchpoints, decipher what it does, comment, wash, rinse, repeat) is highly inefficient as it requires lots of patience and concentration. What I needed was a way to graphically represent the code including calls and conditionals. There's a brilliant program called IDA Pro, but unfortunately is way too expensive. OK, I thought - maybe I don't need it with its all bells and whistles. At one point I considered writing a piece of software which parses the source file and exports it to Graphviz format, but then I decided to spent comparable amount of time to do something better. Do you know radare2? It's an open source reverse engineering suite which supports multiple processor architectures. As for upd7810, if you can write a module for it it will run just fine:) And that's what I've been doing for some time. I've re-used some code from MAME (didn't have to type in all opcodes by hand), but I didn't manage to get it fully working (disassembly works fine, but the analyzer gets crazy on branching instructions). And that's what I'm gonna do now.