Search found 32 matches
- Sat Feb 03, 2024 3:30 am
- Forum: SNESdev
- Topic: SRAM doesn't working with NPN and flash S29GL064
- Replies: 20
- Views: 1187
Re: SRAM doesn't working with NPN and flash S29GL064
OK, let me know if you want le review your design. You can send me information in PM if you like.
- Fri Feb 02, 2024 4:52 pm
- Forum: SNESdev
- Topic: SRAM doesn't working with NPN and flash S29GL064
- Replies: 20
- Views: 1187
Re: SRAM doesn't working with NPN and flash S29GL064
Yes, it'll need to be tidied up a bit. What PCB are you working from by the way?
- Fri Feb 02, 2024 7:55 am
- Forum: SNESdev
- Topic: SRAM doesn't working with NPN and flash S29GL064
- Replies: 20
- Views: 1187
Re: SRAM doesn't working with NPN and flash S29GL064
Don't worry, it should be correct. A15 for LoROM is always high when accessing the ROM and that's why output Y3 is driven low. When ever LoROM is not accessed, i.e. A15 = 0, then it gives access to the SRAM. What game are you using at the moment? I can check the memory allocation to make sure it mat...
- Fri Feb 02, 2024 6:52 am
- Forum: SNESdev
- Topic: SRAM doesn't working with NPN and flash S29GL064
- Replies: 20
- Views: 1187
Re: SRAM doesn't working with NPN and flash S29GL064
No, VCC to SRAM is between R4 and R5 on my schematics. If you used it where you suggested, R4 would limit current too much for the chip to operate. Also forgot to mention, that placing VCC to SRAM where you suggested would actually unpower the chip when the transistor conducts which will make you lo...
- Fri Feb 02, 2024 1:01 am
- Forum: SNESdev
- Topic: SRAM doesn't working with NPN and flash S29GL064
- Replies: 20
- Views: 1187
Re: SRAM doesn't working with NPN and flash S29GL064
Start with getting LoROM working and then we'll look at the HiROM configuration.
- Thu Feb 01, 2024 11:11 pm
- Forum: SNESdev
- Topic: SRAM doesn't working with NPN and flash S29GL064
- Replies: 20
- Views: 1187
Re: SRAM doesn't working with NPN and flash S29GL064
Yes, pin 15 should be connected to 1y0 (pin 4) and not 1y2 (pin 6). That's the mistake.
- Thu Feb 01, 2024 2:07 pm
- Forum: SNESdev
- Topic: Max sprites on-screen using the following approach . . .
- Replies: 9
- Views: 935
Re: Max sprites on-screen using the following approach . . .
You reach the 128 object table limit after 32 pixels i.e. 4 rows of 8x8px sprites. Then, you would need to turn off rendering to write a vertical offset on each objectif in the table using dma as it would be the simplest and fastest way of doing it and then reenable rendering. Dma will write 1365/8 ...
- Thu Feb 01, 2024 1:20 pm
- Forum: SNESdev
- Topic: SRAM doesn't working with NPN and flash S29GL064
- Replies: 20
- Views: 1187
Re: SRAM doesn't working with NPN and flash S29GL064
Try changing R1 to 33k. You also missed a pull-up resistor on the emitter connected to 5v (and not vcc2). I think you can also use 33k there.
- Thu Feb 01, 2024 6:23 am
- Forum: SNESdev
- Topic: SRAM doesn't working with NPN and flash S29GL064
- Replies: 20
- Views: 1187
Re: SRAM doesn't working with NPN and flash S29GL064
Would you mind sharing your schematics to be sure?
- Wed Nov 01, 2023 3:54 pm
- Forum: SNESdev
- Topic: S-SCPU Schematics
- Replies: 5
- Views: 2287
Re: S-SCPU Schematics
Panic's over, it looks like my schematics were correct after all. I have reorganised the simulation to closer match the schematics and have seen the expect behaviour found in available documentation. Note added to my schematics: "Simulation shows that when VBLANK ends, HDMA will enable HDMA cha...
- Mon Oct 30, 2023 11:17 am
- Forum: SNESdev
- Topic: S-SCPU Schematics
- Replies: 5
- Views: 2287
Re: S-SCPU Schematics
Hi all, just to let you know that significant progress has been made on the schematics and most of it seems to make sense. However, I have come unstuck with regards to the HDMA section. I must have a made a mistake as the HDMA does not switch between table reads and data transfers (which ever comes ...
- Wed Jun 14, 2023 11:32 am
- Forum: SNESdev
- Topic: S-SCPU Schematics
- Replies: 5
- Views: 2287
Re: S-SCPU Schematics
Thanks for this. I knew someone would have done this already but didn't know where to look.
- Wed Jun 14, 2023 2:26 am
- Forum: SNESdev
- Topic: S-SCPU Schematics
- Replies: 5
- Views: 2287
S-SCPU Schematics
I have started the reverse engineering of the SNES CPU. Most gates have been identified and portions of the chips have been converted to schematics. Some registers and functions have been tidied up but some are a bit scattered at the moment but this is still is work in progress. The DMA section look...
- Thu Jan 19, 2023 8:34 am
- Forum: SNESdev
- Topic: CRT monitor vs. CRT TV (also SNES region modding)
- Replies: 25
- Views: 1954
Re: Two Ship mode 5 hires + interlaced comparison
A lot of people (myself included) like to use a PVM rather than a TV for this purpose. They're normally multi-sync for NTSC and PAL, have lots of tuning options, multiple inputs, and often RGB. They also tend to have a convenient cube shape. Otherwise old TVs are more common and cheaper, especially...
- Thu Jan 19, 2023 1:48 am
- Forum: SNESdev
- Topic: CRT monitor vs. CRT TV (also SNES region modding)
- Replies: 25
- Views: 1954
Re: Two Ship mode 5 hires + interlaced comparison
Thank you @linariq. It looks like I need to find a CRT monitor, then. Note that CRT monitors and CRT TVs are completely different, so ideally, you'd want a CRT TV (if you already have a real console) to test real 15 kHz interlacing. Yes, this is actually what I meant; a CRT TV like in the olden day...