Strange cartridge with 99% of the PCB surface occupied by chips and one epoxy-blob mapper.
//top-components.jpg
//bottom.jpgFirst look at the pcb reveals that /IRQ (pin 15) is not connected at all, so not a MMC3 single/multicart.
Second look shows that PPU/WE (pin 47) is also not connected, so not a CHR-RAM game.
//irq_ppunwe.pngEither NROM CHR-ROM multicart (probable) or MMC1 multicart (rather non probable as MMC1 is quite uncommon in epoxy). Though I never seen any mapper in epoxy being able to drive 6 memory chips directly.
Cartridge is not working at all and the very first thing game does is:After desoldering all chips and trying to rev-en board, you can notice more weirdness: tracks that go to nowhere, unconnected vias.. Designer was in hurry, doing some fast modification to existing board?
Even some of the ROM data pins not connected to anything at all. I was wondering how this cartridge was supposed to even work when it was new.
//tracks.pngThere are 4 PRG-ROM chips and 2 CHR-ROM chips. All ROM chips share the same /CE and /OE signal, so.. one half of the ROMs must have positive chip enable input (confirmed after reading in external programmer)So they had broken eproms with some data lines not working correctly and they designed special PCB for them? Crazy..
What about the mapper?Reading bare PCB with no chips soldered returns $f7 for $5800-$5fff.
Trying to write $ff at $5800 and then read back $5800-$5fff returns:
$ff $f7 $f7 $f7 $ff $f7 $f7 $f7 $ff $f7 $f7 $f7 $ff $f7 $f7 $f7 ....
so there are four memory cells ($5800/$5801/$5802/$5803), with only D3..D0 used. But beause of epoxy fault, D2..D0 is stuck to 1.
So looks like mapper 225.
After tryign to emulate in, shows a menu identical to 52 in 1 game, though with bugs and of course non-functional. Probably eproms are broken too.
http://krzysiobal.com/carts/?action=view&id=4
//scr.pngThis cartridge answers my mystery: why it is so uncommon to find two identical pirate-famicom PCBs and even many games, sharing the same mapper, exist on different PCB:
Looks like it was not a problem for designer to made new pcb project even if the game was not meant to be distributed in tens of copies.
//top-components.jpg
//bottom.jpg
Second look shows that PPU/WE (pin 47) is also not connected, so not a CHR-RAM game.
//irq_ppunwe.png
Cartridge is not working at all and the very first thing game does is:
Code:
FFF2: 8D 4F 98 STA $984F = #$30FFF5: FF UNDEFINEDFFF6: FF UNDEFINEDFFF7: FF UNDEFINEDFFF8: FF UNDEFINEDFFF9: FF UNDEFINEDFFFA: 7D 9F F2 ADC $F29F,X @ $F29F = #$8BFFFD: FF UNDEFINEDFFFE: 0A ASLFFFF: 80 UNDEFINEDEven some of the ROM data pins not connected to anything at all. I was wondering how this cartridge was supposed to even work when it was new.
//tracks.png
Code:
PRG-ROMU1 | SH19-B-I | /CE | D7..D4U2 | SH19-B-I 9048 | /CE | D3..D0U3 | SH19-C-I 9052 | +CE | D7..D4 | inconsistent reads of D3..0 in some cells U5 | SH19-C-I 9104 | +CE | D3..D0CHR-ROMU4 | SH19-A-I 9104 | /CE | D3..D0U6 | SH19-A-I 9103 | /CE | D7..D4 | inconsistent reads of D3..0 in some cells What about the mapper?
Code:
.----v----. CPU A9 -> | 01 40 | -- VCC CPU A10 -> | 02 39 | <- CPU A8 CPU A11 -> | 03 38 | <- CPU A7 CPU A12 -> | 04 37 | <- CPU A6 CPU A13 -> | 05 36 | <- CPU A5 CPU A14 -> | 06 35 | <- CPU A4 M2 -> | 07 34 | <- CPU A3 CPU R/W -> | 08 33 | <- CPU A2 CPU/RMS -> | 09 32 | <- CPU A1 PPU A10 -> | 10 31 | <- CPU A0 PRG A19 <- | 11 30 | <- PPU A11 PRG A18 <- | 12 29 | <- CPU D3 PRG A17 <- | 13 28 | <- CPU D2 PRG A16 <- | 14 27 | <- CPU D1 PRG A15 <- | 15 26 | <- CPU D0 CHR A18 <- | 16 25 | -> PRG/CE CHR A17 <- | 17 24 | -> CIR A10 CHR A16 <- | 18 23 | -> PRG A14 CHR A15 <- | 19 22 | -> CHR A15 GND -- | 20 21 | -> CHR A14 `---------`Trying to write $ff at $5800 and then read back $5800-$5fff returns:
$ff $f7 $f7 $f7 $ff $f7 $f7 $f7 $ff $f7 $f7 $f7 $ff $f7 $f7 $f7 ....
so there are four memory cells ($5800/$5801/$5802/$5803), with only D3..D0 used. But beause of epoxy fault, D2..D0 is stuck to 1.
So looks like mapper 225.
After tryign to emulate in, shows a menu identical to 52 in 1 game, though with bugs and of course non-functional. Probably eproms are broken too.
http://krzysiobal.com/carts/?action=view&id=4
//scr.png
Looks like it was not a problem for designer to made new pcb project even if the game was not meant to be distributed in tens of copies.
Statistics: Posted by krzysiobal — Fri Jun 07, 2024 7:13 am — Replies 0 — Views 140