Search found 230 matches

by mickagame
Sat Jul 11, 2015 6:11 am
Forum: Megadrive/Genesis
Topic: Question About Sonic 2
Replies: 4
Views: 1763

Thanks for your answer. I would like to understand the utility of Z80 interrupt that is asserted every frame durng one line.
Perhaps this is noob question but i'm sjust starting adding audio part in my emulator.
by mickagame
Fri Jul 10, 2015 4:38 pm
Forum: Megadrive/Genesis
Topic: Question About Sonic 2
Replies: 4
Views: 1763

Question About Sonic 2

Does anyone knows if Sonic 2 Z80 access M68K memory via bank space mecanism? Or all datas are loaded in Z80 Memory?

I'm currently testing The Z80 part in my emulator.
Does exist some Z80 test rom?
by mickagame
Fri Jun 26, 2015 6:49 pm
Forum: Exodus
Topic: Exodus 2.0 + Open Source Release
Replies: 105
Views: 42287

Hi Nemesis.
Super Street Fighter 2 show a red screen at start.
Does Exodus can support it?
by mickagame
Sun Jun 07, 2015 6:34 pm
Forum: Hardware
Topic: I/O Ports read upper byte
Replies: 1
Views: 4462

I/O Ports read upper byte

Does anyone knows what happens when reading higher byte of I/O ports?
In doc they said that in case of byte access only lower byte is meaningful (mean odd adress).
by mickagame
Fri May 29, 2015 1:02 pm
Forum: Hardware
Topic: Does Memory Chip have endianness?
Replies: 3
Views: 4981

I think whatever th access m68000 do (word or byte) the 68000 always do word access. Lds and uds complete the access. In exemple i take the m68000 do word access and because uds is set (access to addr 0x000000 so msb) the CPU takes only thé msb of the word and put in register. That s my point of vie...
by mickagame
Fri May 29, 2015 6:16 am
Forum: Hardware
Topic: Does Memory Chip have endianness?
Replies: 3
Views: 4981

Does Memory Chip have endianness?

Writing my genesis emulator i'm asking myself question about memory Chip. Does a memory chip is made to take part or in MSB or LSB system? If i take the example of M68000. If I write 0x1100 at 0x000000, the processor waiting that : - If I read data at 0x000000 it return 0x11 (MSB) - If I read data a...
by mickagame
Tue May 26, 2015 7:51 pm
Forum: Video Display Processor
Topic: Understanding VDP
Replies: 10
Views: 6138

It make sens !!!
by mickagame
Mon May 25, 2015 9:26 pm
Forum: Video Display Processor
Topic: Understanding VDP
Replies: 10
Views: 6138

Why thé 68k will hang? The read will be perform when write will be finish?
by mickagame
Mon May 25, 2015 9:42 am
Forum: Video Display Processor
Topic: Understanding VDP
Replies: 10
Views: 6138

Thanks for your help if i need i will ask u :-)

If i read VRAM from 68K bus and that FIFO is not empty
=> The read isn't performed until the FIFO is empty.

So the DTACK signal from 68k bus remain high until the data become available (so the 68K is locked)? Or there's another mecanism involved?
by mickagame
Mon May 25, 2015 6:09 am
Forum: Video Display Processor
Topic: Understanding VDP
Replies: 10
Views: 6138

Ok that's more clear :-)
I will try to look in exodus see how nemesis implements this.
Thank u !
by mickagame
Sun May 24, 2015 9:32 pm
Forum: Video Display Processor
Topic: Understanding VDP
Replies: 10
Views: 6138

Thanks for this informations ! I would need more details about how the FIFO is filled. For example when i write data to VRAM : 1) Data is writed to data port 2) The FIFO is immediately written with this data? 3) Next external slot the VDP take the data from FIFO and write to VRAM If my step 2) is co...
by mickagame
Sun May 24, 2015 7:30 pm
Forum: Video Display Processor
Topic: Understanding VDP
Replies: 10
Views: 6138

Understanding VDP

Reading the documentation of Nemesis I understand that VDP access to VRAM are divided in slots. There are slots called "external slots access". When performing DMA The DMA use these slots to access VRAM? There is a link between these slots and the VDP FIFO? I work actually on a VDP core at slot leve...
by mickagame
Sat May 02, 2015 1:01 pm
Forum: Exodus
Topic: Exodus 2.0 + Open Source Release
Replies: 105
Views: 42287

If u want play games with emulator 100% compatibility i told u play With retroarch and genesis plus core. Is perfect !
by mickagame
Fri May 01, 2015 5:50 am
Forum: Exodus
Topic: Exodus 2.0 + Open Source Release
Replies: 105
Views: 42287

Nemesis.
I've just build successfully Exodus but all files (exe, dll ...) are build in the root directory of the project instead of the build directory.
by mickagame
Thu Apr 30, 2015 8:43 pm
Forum: Exodus
Topic: Exodus 2.0 + Open Source Release
Replies: 105
Views: 42287

Thanks !!!!!!!!!!!!!!!!! Help me very much !