Ah, for those of you who have Win2000/XP, Gencyst has a hard time running, IF you can even get it running...I've been unsuccessful in all attempts to force gencyst to run. Unfortunately, Gencyst had the best dumps, and now I can't use it cause of stupid WinXP. I found out recently that the Emulator 'Gens' has support for debugging, looking at the current code, the graphics in the VRAM, the variable and memory contents, processor status, etc... This is fine and dandy, but there is no reference to ANY commands for the debugger, whatsoever in all the Gens Documentation. To find out some more information about the debugger, I did my customary Testing procedures and slammed both hands on the keyboard and looked to see if the screen changed. After many failed attempts, I downloaded the Gens source and looked at that. My luck changed. Here we go! For Gens (2.11) Debugger Commands: When viewing the Genesis VDP: You'll see a whole bunch of squares that make out-of-order pictures and pallete colors. I'm not quite sure how the Sprite List and it's values work... [*] - Changes the current pallete. Changes are seen in the VDP memory display [-] - Scrolls down the VDP Memory Display to reveal more tiles! [+] - Scrolls up the VDP memory display to reveal tiles already seen! [x] - toggles between the DEBUG and the playing screen When Viewing the Genesis 68000 status: You'll see the code that is currently being executed as well at the next 16 or so lines waiting in line. You'll also see the status of several parts of the 68k processor, as well as all of the values of the registers, the flags, and the contents of the memory. [T] - Execute next instruction. [next few lines are good to get through loops and stuff] [Y] - executes next 10 lines of code - executes next 100 lines of code - executes next 1000 lines of code [O] - executes next 10000 lines of code [P] - executes next 100000 lines of code [F] = subtract 0x8 from memory start address [D] = subtract 0x40 from memory start address = subtract 0x200 from memory start address [R] = add 0x8 from memory start address [E] = add 0x40 from memory start address [W] = add 0x200 from memory start address In all debug screens: [X] - toggles debug screen and play screen [Space] - switches between each debug screen [68k, z80, VDP] There are a couple other commands, but they don't really do much. Those ones above are the most important if you want to see what goes on. There is an addition to the Gens Debugger, that allows you to set Breakpoints. You need to go to the Developer's page at Sourceforge.net. Just search for Gens. You'll find it. Optionally, for those of you who don't know who to read 68k or z80 assembly, you can use the VDP to look at sprites. If you go to any level in S1, you can see the Goggle Box in all the levels in the VDP debug screen. Let me know if this guide has or will be of any help to you rom programmers. Okay. I'm off!