Search found 32 matches
- Sun Apr 07, 2019 5:16 am
- Forum: SNESdev
- Topic: Mesen-S - SNES Emulator
- Replies: 370
- Views: 180703
Re: Mesen-S - SNES Emulator
Alien Vs Predator There are 2 V-IRQ interrupts by frame: 16 and 209 scanlines. On line 209 every first IRQ handler is ending on line ~210. On line 225 run NMI handler. Снимок.PNG On line 209 every second IRQ handler is ending on line ~238-245 (i.e. in VBlank), NMI handler does not start and one fram...
- Thu Apr 04, 2019 8:39 am
- Forum: SNESdev
- Topic: Mesen-S - SNES Emulator
- Replies: 370
- Views: 180703
Re: Mesen-S - SNES Emulator
I checked Mesen-S on my problem games and some games have the same issues that I had on my FPGA SNES :) . 1. Wild Guns, flickering TSB $66 must be executed before runs NMI handler. Снимок.PNG https://board.zsnes.com/phpBB3/viewtopic.php?p=77276&sid=bf8f0333cabdc554baa99bf8b3946eb4#p77276 2. Robo Cop...
- Tue Feb 12, 2019 10:16 am
- Forum: SNESdev
- Topic: Internal OAM address sprite evaluation
- Replies: 17
- Views: 15195
Re: Internal OAM address sprite evaluation
Found interesting information about Uniracers.
I made a temporary patch PPU and now Uniracers works well, but need rework sprites engine for correct work.
I made a temporary patch PPU and now Uniracers works well, but need rework sprites engine for correct work.
- Wed Oct 03, 2018 10:31 pm
- Forum: SNESdev
- Topic: Window color gradient with hdma?
- Replies: 8
- Views: 5242
- Sun Aug 19, 2018 1:29 am
- Forum: SNESdev
- Topic: More detail on SNES PPU tile-to-pixel pipeline/compositing?
- Replies: 3
- Views: 4465
Re: More detail on SNES PPU tile-to-pixel pipeline/compositi
Mode 7 also uses double-pumped for get two results of the multiplication or uses two separate multipliers?tepples wrote:This priority encoder is double-pumped, meaning it can return two results per pixel
Thanks, very helpful information.
- Sat Aug 04, 2018 6:56 am
- Forum: SNESdev
- Topic: SDD1 FGPA implementation
- Replies: 58
- Views: 37383
- Fri Aug 03, 2018 2:40 am
- Forum: SNESdev
- Topic: SDD1 FGPA implementation
- Replies: 58
- Views: 37383
Re: SDD1 FGPA implementation
To determine Internal Operation cycle I use VDA and VPA, maybe it wrong.magno wrote:Because some instruction have an Internal Operation cycle whilst RWB is '1', so CPU_RD would go low even if no read cycle is executing.
- Fri Aug 03, 2018 2:17 am
- Forum: SNESdev
- Topic: SDD1 FGPA implementation
- Replies: 58
- Views: 37383
Re: SDD1 FGPA implementation
Why do you think that CPU_RD is decoded from address and not just RWB? I think it something like ~(RWB & PHI2).magno wrote:tDECOD is combinational propagation delay to decode CPU_RD from full address (bank + offset) and RWB signal.
- Thu Aug 02, 2018 9:40 pm
- Forum: SNESdev
- Topic: SDD1 FGPA implementation
- Replies: 58
- Views: 37383
Re: SDD1 FGPA implementation
According to the logical analyzer traces from this post (LISTING8.txt) CPU_RD/CPU_WR is 3/3 and 3/5 master cycles long when work CPU and 4/4 when work DMA.
- Thu Aug 02, 2018 12:18 pm
- Forum: SNESdev
- Topic: SDD1 FGPA implementation
- Replies: 58
- Views: 37383
Re: SDD1 FGPA implementation
I read all this information in the W65C816S datasheet from Western Digital (year 2010); table 4-2 has the timings for 5Vcc (even if the column say "14MHz", those timings apply because they are related to Vcc, not the maximum frequency). Figure 5-1 shows the bank latching circuit, the one I think SN...
- Thu Aug 02, 2018 11:15 am
- Forum: SNESdev
- Topic: SDD1 FGPA implementation
- Replies: 58
- Views: 37383
Re: SDD1 FGPA implementation
Thanks magno, you are the only one who gives very useful information. I have little experience in this. Address bank appears on data bus at most 33ns after PHI2 falling edge (your signals are rising-edge-aligned, but I think the correct is falling-edge as in PHI2). This byte is latched and after lat...
- Thu Aug 02, 2018 7:24 am
- Forum: SNESdev
- Topic: SDD1 FGPA implementation
- Replies: 58
- Views: 37383
Re: SDD1 FGPA implementation
SFA2 instead PHA PLA uses:tepples wrote:Could the S-DD1 be prefetching the PHA during the $4801 write cycle and the PLA during the "internal operation" cycles of PHA?
Code: Select all
STA $00
STA $00Code: Select all
LDY $00
LDY $00- Thu Aug 02, 2018 6:51 am
- Forum: SNESdev
- Topic: SDD1 FGPA implementation
- Replies: 58
- Views: 37383
Re: SDD1 FGPA implementation
Can so you will understand that I mean
- Thu Aug 02, 2018 4:45 am
- Forum: SNESdev
- Topic: SDD1 FGPA implementation
- Replies: 58
- Views: 37383
Re: SDD1 FGPA implementation
How did you resolve finally SNES CPU / SDD1 core collision after writing to $4801? SDD1 accesses ROM when both CPURD and CPUWR in high level, it takes 3 master cycles always . Thus, one CPU cycle is one ROM reading for SDD1. After writing to $4801 and before starting DMA are 9-10 CPU cycles. I use ...
- Wed Aug 01, 2018 4:16 am
- Forum: SNESdev
- Topic: SDD1 FGPA implementation
- Replies: 58
- Views: 37383
Re: SDD1 FGPA implementation
Great!! It would be nice there were some open-sorce projects for SNES FPGA implementation. It could be use for homebrew, getting the most of SNES system, adding features... In the future I want to do something like hardware debugger via USB. Scheme of my board is applied. Maybe there is something I...