Search found 1037 matches

by krzysiobal
Tue Mar 26, 2024 3:50 pm
Forum: Reproduction
Topic: Repro freezing and screen garbage
Replies: 2
Views: 163

Re: Repro freezing and screen garbage

1. Be sure that the ROM occupies whole memory (if it is less that the size of it, mirror it across whole memory)
2. Check if PGM/WE lines of the memories are tried to VCC
3. Check if the game requires RAM and repro-cartridge provides it.
by krzysiobal
Mon Mar 18, 2024 8:50 am
Forum: NES Hardware and Flash Equipment
Topic: ELI5: What can the NES HUB do?
Replies: 2
Views: 468

Re: ELI5: What can the NES HUB do?

Same question as `what you can connect to cartridge port` or `joypad port`. Anything your imagination can bring. 1) I don't see any potential in the expansion port because from the CPU bus it has only data pins, but no R/W, no M2, no address pins - you don't know what is going on the bus except $401...
by krzysiobal
Tue Mar 12, 2024 10:00 am
Forum: NES Hardware and Flash Equipment
Topic: Strange multicart
Replies: 4
Views: 444

Re: Strange multicart

$6000.A1 | $6000.A0 | PRG A18 | PRG A17 | CHR A18 | CHR A17 0 | 0 | 0 | 0 | 0 | M 0 | 1 | 1 | 1 | 0 | 1 1 | 0 | 0 | 1 | 1 | 1 1 | 1 | 1 | M | 1 | 0 M - bit comes from MMC3
by krzysiobal
Tue Mar 12, 2024 12:28 am
Forum: NESdev
Topic: Final Fight 3 (mapper 90), get rid of multiplier, issues
Replies: 12
Views: 3095

Re: Final Fight 3 (mapper 90), get rid of multiplier, issues

Pinout of the mapper chip confirms it is mapper #90.
Interestingly, PRG CHIP has pinout of regular 8bit DIL32 EPROM, while CHR has 8/16bit 27320-like EPROM.
by krzysiobal
Sun Mar 10, 2024 12:05 am
Forum: NES Hardware and Flash Equipment
Topic: Boot Up delay solution to prevent slowly configuration from FPGA.
Replies: 6
Views: 494

Re: Boot Up delay solution to prevent slowly configuration from FPGA.

always @(negedge m2) You can't do it on falling edge, because ROM CHIP (or you FPGA) will not have enough time to drive its data output before CPU wants to sample it. Generally you can't also do it on rising edge, because /ROMSEL is not stable yet and you wont be able to distinguish between $4C4C a...
by krzysiobal
Sat Mar 09, 2024 3:51 am
Forum: NES Hardware and Flash Equipment
Topic: Boot Up delay solution to prevent slowly configuration from FPGA.
Replies: 6
Views: 494

Re: Boot Up delay solution to prevent slowly configuration from FPGA.

Tragically, there is no great way to handle this. The least bad option we've come up with is to stuff the CPU's data bus with an endless stream of $4C or $6C, which will keep the CPU doing something safe until the FPGA can take over (and recover from this) Yeah exactly, pull-up the CPU data bus wit...
by krzysiobal
Thu Mar 07, 2024 1:52 pm
Forum: NES Hardware and Flash Equipment
Topic: Fishing simulator with undumped game: King Fishing
Replies: 3
Views: 1592

Re: Fishing simulator with undumped game: King Fishing

Incredible, thank you!! I think you might be correct with RX1 and RX2 being related to the tilt sensors. I've found it to be consistent in multiple emulators that it's constantly pulling the line left. When enabling an expansion port peripheral, the tilt control commands (casting the line, moving t...
by krzysiobal
Wed Mar 06, 2024 3:00 pm
Forum: NES Hardware and Flash Equipment
Topic: Fishing simulator with undumped game: King Fishing
Replies: 3
Views: 1592

Fishing simulator with undumped game: King Fishing

Fishing simulator with undumped game: King Fishing I got recently an interesting plug&play famiclone: fishing simulator with undumped game: King Fishing. Shell It contains four-direction volant joypad and four buttons: * POWER, * RESET, * ESC (A button), * START (B button). https://obrazki.elekt...
by krzysiobal
Mon Mar 04, 2024 9:09 am
Forum: NES Hardware and Flash Equipment
Topic: AUX on the Yobo Gameware FC2
Replies: 7
Views: 531

Re: AUX on the Yobo Gameware FC2

Are FC/SNES cartridge ports accessed just like in regular console, or are they only used to dump the game and emulate it, just like in Retron 5?
If that's the latter, maybe you can use the AUX port to plug-in pendrive with software update.
by krzysiobal
Sun Mar 03, 2024 12:51 am
Forum: NES Hardware and Flash Equipment
Topic: MMC1 free implementation on CPLD released
Replies: 39
Views: 22202

Re: MMC1 free implementation on CPLD released

I still maintain my viewpoint that the MMC1 implemented by 64 macro cells is only a simplified subset, and it does not support IRQ (definitely), SUROM (perhaps), SZROM, SOROM, SXROM, SJROM, or/and SKROM. ??? MMC1 is just a 24-pin chip and can be fully implemented in 64 macrocell chip. All those S*R...
by krzysiobal
Wed Feb 28, 2024 12:54 pm
Forum: NES Hardware and Flash Equipment
Topic: Weird 15 in 1 Cartridge
Replies: 13
Views: 994

Re: Weird 15 in 1 Cartridge

Since this pin is stuck on Vcc, I did try a pull-down resistor, in the hope that it solves the problem. Now every byte has D3 (D6 after rearrangement) stuck to 0. Last hope is to to check if the reason for D3 being held at 1 is because of some internal short inside memory. If it is that case, memor...
by krzysiobal
Tue Feb 27, 2024 12:17 am
Forum: NES Hardware and Flash Equipment
Topic: Weird 15 in 1 Cartridge
Replies: 13
Views: 994

Re: Weird 15 in 1 Cartridge

The address and data pins are in the wrong order. I was able to rearrange 15C.BIN to get something that looks like the correct CHR, but it doesn't match the board layout or krzysiobal's schematic, so I'm not sure what's going on... Why do you think so? After rearranging the data & address lines...
by krzysiobal
Fri Feb 23, 2024 4:42 am
Forum: NES Hardware and Flash Equipment
Topic: Weird 15 in 1 Cartridge
Replies: 13
Views: 994

Re: Weird 15 in 1 Cartridge

sch.png 1. Those resistors are pull-ups to VCC, not pull-downs to GND! 2. interesting about the 330R resistors. Because both ROM data lines are all shuffled and the resistors connect not only the 3012A ROM but also 74161 latch, I suspect they are placed as an alternative way of further shuffling th...
by krzysiobal
Mon Feb 19, 2024 1:48 pm
Forum: NES Hardware and Flash Equipment
Topic: Famicom freezing...
Replies: 4
Views: 360

Re: Famicom freezing...

Yes, OAM part of your PPU might be broken and so the sprites are not displayed and sprite 0 hit does not trigger correctly.
by krzysiobal
Mon Feb 19, 2024 1:47 pm
Forum: NES Hardware and Flash Equipment
Topic: Everdrive N8 not working on HVC-CPU
Replies: 4
Views: 451

Re: Everdrive N8 not working on HVC-CPU

Ask the creator of everdrive. We do not know how exactly everdrive works, does it capture address/bus signals after certain delay with respect to M2 clock or what. Some old famicom revisions have CPU with different duty cycle and M2 behaviour, I had a 168-in-1 (mapper 015) multicart that could not e...