Search found 109 matches
- Fri Apr 09, 2021 5:46 am
- Forum: Megadrive/Genesis
- Topic: VDP FIFO and DMA questions
- Replies: 3
- Views: 51140
Re: VDP FIFO and DMA questions
This is *really* impressive information, thank you so much for sharing! But, wow, every time I ask a question, the answer is an additional ten layers of crazy deep to go down the rabbit hole ^-^; The pixel timings of 342/420 are easy enough to follow. ... what in the world are half-lines? o_O I coul...
- Fri Apr 09, 2021 2:12 am
- Forum: Megadrive/Genesis
- Topic: VDP FIFO and DMA questions
- Replies: 3
- Views: 51140
VDP FIFO and DMA questions
Been trying to implement all the knowledge here, hoping someone can help with some tricky points for me ^-^; First, DCLK/EDCLK. I get that EDCLK was a last-minute thing to stabilize H40 mode and that it makes some of the MCLK cycles longer. With either mode, you get 171 access cycles for H32 mode, a...
- Sun Apr 04, 2021 8:57 am
- Forum: Megadrive/Genesis
- Topic: Question on Golden Axe II
- Replies: 4
- Views: 111950
Re: Question on Golden Axe II
That was exactly it, thank you so very much!
This hardware is really giving me a lot of trouble it seems ^-^;
This hardware is really giving me a lot of trouble it seems ^-^;
- Sat Apr 03, 2021 11:00 am
- Forum: Megadrive/Genesis
- Topic: Question on Golden Axe II
- Replies: 4
- Views: 111950
Re: Question on Golden Axe II
Shoot, I do that too. auto VDP::writeDataPort(n16 data) -> void { io.commandPending = false; //DMA VRAM fill if(dma.io.wait) { dma.io.wait = false; dma.io.fill = data >> 8; //falls through to memory write //causes extra transfer to occur on VRAM fill operations } //VRAM write if(io.command.bit(0,3) ...
- Fri Apr 02, 2021 8:04 pm
- Forum: Megadrive/Genesis
- Topic: Question on Golden Axe II
- Replies: 4
- Views: 111950
Question on Golden Axe II
I notice my emulator is getting a garbled "Sega" logo screen, and partially garbled intro screen immediately after it. Looking at the trace, it loads d0 with #$ffffffe3, and then shortly after just starts spamming loop: move.l (a0)+,($c00000); dbf loop; instructions for big ~64K loops from ROM to VR...
- Fri Apr 02, 2021 4:35 am
- Forum: Super 32X
- Topic: Questions on emulating the 32X
- Replies: 14
- Views: 245480
Re: Questions on emulating the 32X
For whatever it's worth, I posted ares v119 with my 32X emulation source to https://ares.dev I really appreciate everyone's help here. If anyone wants to work on 32X for their emulator, I would be most happy to return the favor. Feel free to ping me with any questions and I'll try to answer them. Th...
- Thu Mar 25, 2021 10:30 am
- Forum: Super 32X
- Topic: Questions on emulating the 32X
- Replies: 14
- Views: 245480
Re: Questions on emulating the 32X
- a debugger (a must. 'definitely would pay for it) I have a pseudo-debugger. You can see, edit, and export any RAM contents, create trace logs (with optional masking and automatic loop elision) of all chips and their associated interrupts, certain debugging information like DMA requests (limited s...
- Thu Mar 25, 2021 5:42 am
- Forum: Super 32X
- Topic: Questions on emulating the 32X
- Replies: 14
- Views: 245480
Re: Questions on emulating the 32X
I found the key to most of my issues: I was failing to type-extend DMULS/DMULU first to 64-bits, so they were being truncated to 32-bits. With that fix, compatibility is now around 80-90% or so. Not bad! VDP outputs a signal called !YS which is active when nothing/backdrop color is being output Is t...
- Wed Mar 24, 2021 10:18 am
- Forum: Super 32X
- Topic: Questions on emulating the 32X
- Replies: 14
- Views: 245480
Re: Questions on emulating the 32X
Not having much luck with rendering. Take Amazing Spider-Man: Web of Fire. This is the Mega Drive layer: https://i.imgur.com/V8PrqN7.png And this is the Super 32X layer. https://i.imgur.com/ZwbZru6.png The combination is supposed to look like this: https://i.imgur.com/f6ggTiT.png Throughbit is never...
- Tue Mar 23, 2021 10:34 pm
- Forum: Super 32X
- Topic: Questions on emulating the 32X
- Replies: 14
- Views: 245480
Re: Questions on emulating the 32X
I figured out the bug with the HINT(2) tests, a dumb logic bug I made refactoring ^-^; I was incrementing the counter on both Hblank start and end by mistake. It is indeed HCOUNT of 5 == every 6th line. Thank you! Also, reading the HCOUNT register returns the set value and not the current counter, o...
- Mon Mar 22, 2021 11:32 am
- Forum: Super 32X
- Topic: Questions on emulating the 32X
- Replies: 14
- Views: 245480
Questions on emulating the 32X
Hi all, I started on a 32X emulator. It's far enough to run Chaotix, but not much else. https://near.sh/posts/20210318071942/chaotix.png Problem is, it's feature-complete. I implemented the VDP, PWM, FIFOs, DREQ, vector 4 address (0x70-0x73) as RAM, and the half of the SH7804 games use: full cache e...
- Wed Mar 10, 2021 2:51 pm
- Forum: Mega/SegaCD
- Topic: Popful Mail
- Replies: 17
- Views: 351809
Re: Popful Mail
Wow!! You are just a saint! <3 It does indeed fix the booting problem, thank you again! I went and audited every single io.cpp and io-external.cpp register after this one, but sadly didn't find any more fixes ^-^; I got nerd-sniped yesterday with the SVP, but I did take a look briefly at the sprite ...
- Mon Mar 08, 2021 7:03 am
- Forum: Mega/SegaCD
- Topic: Popful Mail
- Replies: 17
- Views: 351809
Re: Popful Mail
Now next challenge: let's find out why sprites are invisible in all existing Sega CD emulators during the intro of Radical Rex. This one has been puzzling me for quite some time now (sorry to hijack thread :oops: ) Please, by all means. I have a few more Popful Mail bugs, but I should at least spen...
- Fri Mar 05, 2021 6:56 pm
- Forum: Mega/SegaCD
- Topic: Popful Mail
- Replies: 17
- Views: 351809
Re: Popful Mail
Writing zero to the wordram control reg (from either side) does not affect 2M wordram assignment. Ishmael, thank you SO VERY MUCH !!!! https://i.imgur.com/CTa1rc9.png I can't tell you how happy this has made me. Definitely made my entire week. Really, really thank you so much! I really got lost thi...
- Thu Mar 04, 2021 2:25 am
- Forum: Mega/SegaCD
- Topic: Popful Mail
- Replies: 17
- Views: 351809
Re: Popful Mail
This has become my white whale ^-^; So I'm aware both Kega Fusion and Gens require the 'perfect sync' option to run this game. I've set my emulator to sync all components after each component steps by one cycle. I can confirm that's working by seeing my FPS drop from 204fps to 78fps. My 68K core's t...