Search found 815 matches

by krzysiobal
Wed Nov 25, 2020 12:50 pm
Forum: Other Retro Dev
Topic: DOS VGA Tricks
Replies: 26
Views: 554

Re: DOS VGA Tricks

This will be about tricks in text mode. 0) As far as I remember, DOS can offer 3 video modes for text display: * 8x16 characters (most typically used) * 8x14 characters (used quite rarely, for example - in the BIOS start screen (when EPA Pollution Preventer logo is shown) * 8x8 characters 1) There i...
by krzysiobal
Fri Nov 20, 2020 12:27 am
Forum: Reproduction
Topic: triying to make a rockman 6 unique harassment!
Replies: 2
Views: 169

Re: triying to make a rockman 6 unique harassment!

Sprites are not displayed at all. This game uses $0000-$0fff for background tiles and $1000-$1fff for sprites, so PPU-A12 is used for distinguishion. But if there was problem with that line, garbage tiles would be displayed instead of sprites, not empty ones. IRQ - not used in boss selection screen....
by krzysiobal
Thu Nov 19, 2020 4:41 am
Forum: NES Hardware and Flash Equipment
Topic: Super Mario Bros (2 players hack) repro hell
Replies: 3
Views: 309

Super Mario Bros (2 players hack) repro hell

I wanted to make a cartridge version of `Mario 2 Players hack` at ultimately low cost. --------------------- Some background overview, skip that if you're lazy ---------------------- Normally for that purpose I use my universal EPM240 based PCB that: + can mimic almost many mapper, with PRG-ROM/RAM,...
by krzysiobal
Fri Nov 13, 2020 8:31 am
Forum: General Stuff
Topic: Why did SNES Japan-only games have much better graphics than localized games?
Replies: 23
Views: 2580

Re: Why did SNES Japan-only games have much better graphics than localized games?

I always wondered the same. Doki Doki Yuuenchi vs Trolls in Crazyland https://obrazki.elektroda.pl/7368204400_1605281362.png https://obrazki.elektroda.pl/6338799100_1605281364.png Wanpaku Kokkun no Gourmet World vs Panic Restaurant https://obrazki.elektroda.pl/6838127500_1605281370.png https://obraz...
by krzysiobal
Thu Nov 12, 2020 1:27 pm
Forum: NES Hardware and Flash Equipment
Topic: Micro Genius IQ501 - console with PAL to SECAM converter
Replies: 1
Views: 477

Micro Genius IQ501 - console with PAL to SECAM converter

I get this console for fixing because it suffered from blinking horizontal bars. My first idea was that the crystal resonator got jitter, but after opening it I couldn't believe what was inside.. a piggyback board with PAL to SECAM converter. This console must have been developed for French or easte...
by krzysiobal
Thu Nov 12, 2020 10:34 am
Forum: NES Hardware and Flash Equipment
Topic: Diagnosing faulty Famicom
Replies: 18
Views: 1220

Re: Diagnosing faulty Famicom

Solid gray screen is a sign that something wrong is either with CPU, with its RAM or address decoder 74139. You can sniff it's M2, pin 11 and see if pin11 is high when M2 is low, if the PPU/CE and RAM/CE get low sometimes. If PPU breaks, it stop generating video signal at all. You can always try to ...
by krzysiobal
Thu Nov 12, 2020 9:01 am
Forum: NES Hardware and Flash Equipment
Topic: Diagnosing faulty Famicom
Replies: 18
Views: 1220

Re: Diagnosing faulty Famicom

Is the supply voltage OK? (~4.75-5.1V?)
You can get the Dendy PPU/CPU replacecement for around 1$ each.
by krzysiobal
Wed Nov 11, 2020 6:00 pm
Forum: NESdev
Topic: Mmc1a versus 1b2 etc
Replies: 16
Views: 5030

Re: Mmc1a versus 1b2 etc

Try adding resistors
* Between M2 and GND
* Between CPU R/W and +5V
Around 1k-10k should be ok
by krzysiobal
Wed Nov 11, 2020 3:12 pm
Forum: NES Hardware and Flash Equipment
Topic: Diagnosing faulty Famicom
Replies: 18
Views: 1220

Re: Diagnosing faulty Famicom

Check if all pins between CPU and PPU (D0..D7, A0..A2, R/W) are correct, not shorted to each other or to GND/VCC
by krzysiobal
Wed Nov 11, 2020 10:59 am
Forum: NES Hardware and Flash Equipment
Topic: Diagnosing faulty Famicom
Replies: 18
Views: 1220

Re: Diagnosing faulty Famicom

None of the inverters is mandatory for the work of console. Without U8 you won't be able to use any of player 2 pins ($4017 D4-D0) Without U7 you won't be able to use any of player 1 pins ($4017 D2/D1/D0) and additionally there will be no sound and the image will be garbled like in your first photo,...
by krzysiobal
Wed Nov 11, 2020 7:10 am
Forum: NES Hardware and Flash Equipment
Topic: Diagnosing faulty Famicom
Replies: 18
Views: 1220

Re: Diagnosing faulty Famicom

Check on the scope pins 12 and 11 of U7 if the latter is indeed inverted and has 0/5V logic evels.
by krzysiobal
Wed Nov 11, 2020 6:39 am
Forum: NES Hardware and Flash Equipment
Topic: Diagnosing faulty Famicom
Replies: 18
Views: 1220

Re: Diagnosing faulty Famicom

Could be. Try borrowing the second 74368's and puttin it in place of first to see if it changes. Looking at the diagram it seems that U7 also buffers player 1 controller input, and that works perfectly, so I might be wrong. Broken chip /= completely dead. Some gates might be OK, some might malfunct...
by krzysiobal
Wed Nov 11, 2020 5:17 am
Forum: NES Hardware and Flash Equipment
Topic: Diagnosing faulty Famicom
Replies: 18
Views: 1220

Re: Diagnosing faulty Famicom

Could be. Try borrowing the second 74368's and puttin it in place of first to see if it changes.
by krzysiobal
Tue Nov 10, 2020 11:35 am
Forum: NES Hardware and Flash Equipment
Topic: Diagnosing faulty Famicom
Replies: 18
Views: 1220

Re: Diagnosing faulty Famicom

Broken VRAM or broken CIRAM /CS to PPU /A13 connection . Thanks. For now I'm not touching the console, I'll check the traces in case the seller partially refunds me. For now I'm hoping he'll just refund me, even though he's pulling the "it was working perfectly when I shipped it" crap If I were you...
by krzysiobal
Tue Nov 10, 2020 7:57 am
Forum: NES Hardware and Flash Equipment
Topic: Diagnosing faulty Famicom
Replies: 18
Views: 1220

Re: Diagnosing faulty Famicom

Broken VRAM or broken CIRAM /CS to PPU /A13 connection .