Talk:Mask ROM pinout: Difference between revisions
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(Created page with "I have two questions regarding to this : 1) Does anyone have the pinout for SLxROM and TLxROM boards ? Such boards were apparently rarely/never used in PAL games so I can't d...") |
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I have | == SLxROM, TLxROM == | ||
Does anyone have the pinout for SLxROM and TLxROM boards ? Such boards were apparently rarely/never used in PAL games so I can't do much about it, unless I pay more than $30 to import USA games. | |||
—[[User:Bregalad]] ([[User talk:Bregalad|talk]]) 04:34, 08 February 2014 (MST) | |||
: The pictures on NesCartDB show the SL3ROM, SL1ROM, and TL1ROM boards are using ordinary 28-pin 128KiB mask ROMs for CHR, combining PPU A13 and PPU /RD with a 74'32 (*-TL1ROM, NES-SL1ROM, NES-SL3ROM) or a one-transistor A≤B gate (HVC-SL1ROM). | |||
: The pictures on NesCartDB of SLRROM and SL2ROM similarly only indicate parts with typical pinouts: they have a standard 32-pin 128KiB mask ROM for CHR. | |||
: Only one copy of game, without photos, claims to have a TL2ROM board, which I'm going to declare a typo until further evidence arrives. —[[User:Lidnariq|Lidnariq]] ([[User talk:Lidnariq|talk]]) 12:57, 8 February 2014 (MST) | |||
== Higher CHR lines == | |||
Apparently, the unused high address lines of PRG and CHR mask ROMs must be connected to VCC, but this was vital only on PRG ROMs as the CHR-ROM are not required to be enabled for booting, before the first mapper write. | |||
So, does games which don't use all their available CHR-space uses '1' for the unused bits ? For instance, a 32kb CHR-ROM MMC1 game should use either CHR bank range 8-15 or 24-31 instead of using 0-7 which would happen naturally, in order to set A15 to '1'. Does commercial games do this ?—[[User:Bregalad]] ([[User talk:Bregalad|talk]]) 04:34, 08 February 2014 (MST) | |||
So, does games which don't use all their available CHR-space uses '1' for the unused bits ? For instance, a 32kb CHR-ROM MMC1 game should use either CHR bank range 8-15 or 24-31 instead of using 0-7 which would happen naturally, in order to set A15 to '1'. Does commercial games do this ? | : No, most commercial games more often use the lowest mirror (although sometimes a random mirror) of undersized ROMs. I'm not clear where the "must be" comment came from. —[[User:Lidnariq|Lidnariq]] ([[User talk:Lidnariq|talk]]) 12:57, 8 February 2014 (MST) | ||
Revision as of 19:57, 8 February 2014
SLxROM, TLxROM
Does anyone have the pinout for SLxROM and TLxROM boards ? Such boards were apparently rarely/never used in PAL games so I can't do much about it, unless I pay more than $30 to import USA games. —User:Bregalad (talk) 04:34, 08 February 2014 (MST)
- The pictures on NesCartDB show the SL3ROM, SL1ROM, and TL1ROM boards are using ordinary 28-pin 128KiB mask ROMs for CHR, combining PPU A13 and PPU /RD with a 74'32 (*-TL1ROM, NES-SL1ROM, NES-SL3ROM) or a one-transistor A≤B gate (HVC-SL1ROM).
- The pictures on NesCartDB of SLRROM and SL2ROM similarly only indicate parts with typical pinouts: they have a standard 32-pin 128KiB mask ROM for CHR.
- Only one copy of game, without photos, claims to have a TL2ROM board, which I'm going to declare a typo until further evidence arrives. —Lidnariq (talk) 12:57, 8 February 2014 (MST)
Higher CHR lines
Apparently, the unused high address lines of PRG and CHR mask ROMs must be connected to VCC, but this was vital only on PRG ROMs as the CHR-ROM are not required to be enabled for booting, before the first mapper write. So, does games which don't use all their available CHR-space uses '1' for the unused bits ? For instance, a 32kb CHR-ROM MMC1 game should use either CHR bank range 8-15 or 24-31 instead of using 0-7 which would happen naturally, in order to set A15 to '1'. Does commercial games do this ?—User:Bregalad (talk) 04:34, 08 February 2014 (MST)
