Search found 152 matches
- Sun Feb 14, 2010 4:35 am
- Forum: Megadrive/Genesis
- Topic: Z80 clocking
- Replies: 7
- Views: 5727
Waitstates will slightly corrupt DAC samples, as the DAC relies entirely on software timing for output of data. If you've ever played a PAL C64 SID tune on NTSC by only calling the music player 5 out of every 6 frames, you may have heard this type of error. I expect the audible error to be worse whe...
- Sun Feb 14, 2010 3:53 am
- Forum: Megadrive/Genesis
- Topic: Benefits between SMD and BIN Format
- Replies: 5
- Views: 5028
Although you can find a lot of roms named *.smd, they are really in bin format renamed to *.smd extension. Not always. Sometimes such ROMs are actually SMD format (which can be confirmed by attempting to use them as BIN files, or by loading them in a hex editor). SMD should die as a distribution fo...
- Sun Feb 14, 2010 3:39 am
- Forum: Megadrive/Genesis
- Topic: Help with Copier RAM Test
- Replies: 16
- Views: 13334
I'm not sure on the hardware differences between the SMD and the DPF, but Charles MacDonald's smdutil includes a facility to do a RAM test on the copier, which he does by uploading Z80 code and executing it. Perhaps this code could be modified to handle the full range of the DPF and any hardware dif...
- Wed Jan 13, 2010 8:13 pm
- Forum: Megadrive/Genesis
- Topic: Regarding Flight
- Replies: 4
- Views: 3867
ROM is not reserved at all, you can use any ROM data to feed any I/O chip. VRAM is partially reserved - while tile data can go pretty much anywhere, you have to assign certain ranges of VRAM to the nametables, sprite tables, and horizontal scroll RAM. Those ranges are not hardcoded, however, and you...
- Sun Dec 27, 2009 9:43 pm
- Forum: Demos
- Topic: MD xmas post card
- Replies: 6
- Views: 5434
- Sun Dec 27, 2009 3:03 am
- Forum: Demos
- Topic: MD xmas post card
- Replies: 6
- Views: 5434
- Sat Dec 26, 2009 8:58 pm
- Forum: Demos
- Topic: MD xmas post card
- Replies: 6
- Views: 5434
- Tue Dec 22, 2009 5:18 am
- Forum: Megadrive/Genesis
- Topic: Super Magic Drive research thread
- Replies: 133
- Views: 278420
Ok, Charles got in touch with me and sent me his smdutil, and I dumped my unit's BIOS. Here's the binary . In the ROM is the following text: *** MAGIC DOS V4 *** PRODUCT MANAGER: LMM, DEBUG ENGINEER: JUS, BIOS PROGRAMMER: JSI, ALL RIGHTS RESERVED, COPYRIGHT 1992 BY JSI, CHINA COACH COMPANY LTD., FRO...
- Mon Dec 21, 2009 2:31 am
- Forum: Megadrive/Genesis
- Topic: Stable interrupt discussion
- Replies: 3
- Views: 3325
- Fri Dec 18, 2009 8:24 am
- Forum: Megadrive/Genesis
- Topic: Super Magic Drive research thread
- Replies: 133
- Views: 278420
Hm, the more I look at this, the more I think this just loads the "upgrade" into RAM temporarily, rather than doing any sort of permanent upgrade. Here's the entirety of the code at $0200, before a shitton of FF bytes and the actual ROM: ROM:0000 ld hl, 0A000h ROM:0003 ld de, 0C000h ROM:0006 ld bc, ...
- Fri Dec 18, 2009 6:53 am
- Forum: Megadrive/Genesis
- Topic: Super Magic Drive research thread
- Replies: 133
- Views: 278420
Super Magic Drive research thread
In a quest to get a working MS-DOS setup for my SMD800, I came across a few interesting things, and a need for a tool that I cannot find. First of all, does anyone have a copy of Charles MacDonald's SMDUTIL? The link on his website is 404, and I can not find it anywhere (have done about two solid ho...
- Wed Dec 16, 2009 8:15 pm
- Forum: Megadrive/Genesis
- Topic: Sega Channel
- Replies: 13
- Views: 10129
I don't think anyone's going to want to help you on this until you make an effort to try and learn the basics on your own. It's very rare that someone comes in, says "I have this idea", and people jump on board. Sometimes group projects do exist, but usually the ones who come up with such ideas alre...
- Sat Dec 12, 2009 4:33 am
- Forum: Megadrive/Genesis
- Topic: Neo Myth Menu beta
- Replies: 36
- Views: 21488
INTs have to be disabled while the Neo Myth is doing its thing since often the exception table at 0 disappears depending on the mode the Neo Myth is in. However, I think setting a variable that's updated during the vertical blank int during those times the ints are on should be doable. I'll see if ...