Needs correct VRAM DMA FILL implementation (read charles mc donald document)matich wrote:AamirM,
Have you ever thought of enabling the link cable support ?
PS:
"Contra Hard Corps" bug (ReGen 0.6).
-> See video <-
Search found 3131 matches
- Thu Mar 27, 2008 8:33 pm
- Forum: Regen
- Topic: Old Regen pages
- Replies: 547
- Views: 776456
- Thu Mar 27, 2008 8:30 pm
- Forum: Regen
- Topic: Old Regen pages
- Replies: 547
- Views: 776456
- Mon Mar 17, 2008 10:39 pm
- Forum: Sound
- Topic: 68000 ram access from z80 ?
- Replies: 41
- Views: 36883
Doing more intensive VDP access will cause Z80 to "slowdown" when it accesses ROM too. I guess this is when you fill the VDP FIFO, the next write to the VDP port will lock the 68000 (and then the bus) until it free a FIFO emplacement. On real hardware you can avoid that by testing the "FIFO full" f...
- Sun Mar 16, 2008 6:44 pm
- Forum: Sound
- Topic: 68000 ram access from z80 ?
- Replies: 41
- Views: 36883
Of course i was speaking of example where we use the 68000 BUS from Z80, but i assure you i never met any problems. I think it can happen but rarely in fact. Yes, but SEGA says it will give SOME people a problem SOMETIMES. If your stuff is aimed at a small group, you can probably ignore a lot of th...
- Sat Mar 15, 2008 8:38 pm
- Forum: Sound
- Topic: 68000 ram access from z80 ?
- Replies: 41
- Views: 36883
HOHOOOO... I never halt Z80 when reading control pads, and my sound engine doesn't go crazy then... I must be lucky or something. It works on my MD2 and on my MD1s without TMSS. Same here and honestly i'm happy we don't need that ! If you only run the Z80 on it's own memory and use the 68000 to tra...
- Sat Mar 15, 2008 4:43 pm
- Forum: Sound
- Topic: 68000 ram access from z80 ?
- Replies: 41
- Views: 36883
Well, there IS a bug in the real hardware associated with the Z80 accessing the 68000 bus: if the 68000 ever accesses $A100xx (the pads) without first requesting the Z80 bus, the Z80 will no longer be able to read/write the 68000 bus correctly. Apparently, the hardware cuts the Z80 cycles to the 68...
- Sat Mar 15, 2008 2:48 pm
- Forum: Sound
- Topic: 68000 ram access from z80 ?
- Replies: 41
- Views: 36883
Ok, i done all possible tests and i can confirm it is *not* possible to access 68k RAM from Z80. Any read from the Z80 return $FF and write doesn't work, they are simply ignored... I tested on each possible areas ($E00000 to $FF0000) and it gave always the same result. I tested on a PAL model 1 and ...
- Sat Mar 15, 2008 12:00 pm
- Forum: Sound
- Topic: 68000 ram access from z80 ?
- Replies: 41
- Views: 36883
Well, the addendum makes it sound like it's always, but it probably varies according to the exact revision of the chips used. It's possible it's even fixed on certain models. There's also that issue on bus requesting the Z80 during an interrupt. That combined with the $A100xx issue is something to ...
- Sat Mar 15, 2008 11:55 am
- Forum: Regen
- Topic: Old Regen pages
- Replies: 547
- Views: 776456
- Fri Mar 14, 2008 11:06 pm
- Forum: Sound
- Topic: 68000 ram access from z80 ?
- Replies: 41
- Views: 36883
Well, there IS a bug in the real hardware associated with the Z80 accessing the 68000 bus: if the 68000 ever accesses $A100xx (the pads) without first requesting the Z80 bus, the Z80 will no longer be able to read/write the 68000 bus correctly. Apparently, the hardware cuts the Z80 cycles to the 68...
- Fri Mar 14, 2008 3:47 pm
- Forum: Sound
- Topic: 68000 ram access from z80 ?
- Replies: 41
- Views: 36883
Hi, Steve Snake said(its also written in Charles MacDonalds's docs) that it was indeed possible on very early models. These were used for developing games. Later models would either lock-up or as in my case return 0xFF. I think only some models allowed it. stay safe, AamirM Yeah i remember that tal...
- Fri Mar 14, 2008 2:12 pm
- Forum: Sound
- Topic: 68000 ram access from z80 ?
- Replies: 41
- Views: 36883
68000 ram access from z80 ?
Lately i was playing with z80 and i done some 68k ram access test. it works perfectly on emulator but my attempts failed on real hardware. At least the z80 isn't able to modify the 68k ram. I've rarely saw any games doing that (except '777 casino' but with inexpected result, i guess devers did somet...
- Wed Mar 05, 2008 11:31 pm
- Forum: SGDK
- Topic: Sega Genesis Dev Kit (SGDK)
- Replies: 852
- Views: 1179069
It can sound stupid but are you not simply doing division by 0 exception (%0) ? This was first that I check. Of course not, especially in case %40 in code above. If not, do you checked the i_ldiv function in sega.s file ? as you don't have the base library you need manual implementation of 32 bits ...
- Thu Feb 21, 2008 8:54 pm
- Forum: Demos
- Topic: Mini demo / tech MD stuff posted by members :)
- Replies: 94
- Views: 81674
Can you wait for 3 minutes :( ? Unless you tell me a better way of testing how much RAM is available 8) ... Also I've just uploaded a new version, it should be a little faster in the initialization... 3mn for RAM checking ??? Can't you just test one byte each 256 bytes of the memory map ? If you ha...
- Thu Feb 21, 2008 8:51 pm
- Forum: Regen
- Topic: Old Regen pages
- Replies: 547
- Views: 776456
I think i'll have a look on the source code to understand how this is possible, i though the SVP couldn't be dumped ;) It's simple - SVP uses the first 128K of game ROM for it's code, so there was no need to dump anything :) ok, so the chip on the SVP board is a simple DSP without any internal rom ...