INES Mapper 133: Difference between revisions
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(why did I ever say that /ROMSEL wasn't part of the decoding logic? that's not what Санчез said) |
(try to distinguish between "select register" by the CPU and "select register" by the feedback path) |
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| Line 7: | Line 7: | ||
$4100: [.... .PCC] - Select 32 KiB PRG bank and 8 KiB CHR bank | $4100: [.... .PCC] - Select 32 KiB PRG bank and 8 KiB CHR bank | ||
<hr> | <hr> | ||
Another physical release instead wired a [[iNES Mapper 206|Namco 108]] clone in an inscrutably complex way: | Another [//forums.nesdev.org/viewtopic.php?t=16827 physical release] instead wired a [[iNES Mapper 206|Namco 108]] clone in an inscrutably complex way: | ||
Mask: $E001 | Mask: $E001 | ||
$8000: [..B. .B.B] - Select register | $8000: [..B. .B.B] - Select register for writing | ||
$8001: [...X XPCC] - Write value to register | $8001: [...X XPCC] - Write value to register | ||
| |||| | | |||| | ||
| Line 17: | Line 17: | ||
+-+------ analog feedback path | +-+------ analog feedback path | ||
Four of the registers produce an analog feedback path through the 108's CHR | Four of the registers produce an analog feedback path through the 108's CHR registers: | ||
{| class="tabular" | {| class="tabular" | ||
! XX bits !! | ! XX bits !! if this register was selected by the XX bits, switch to using contents of register | ||
|- | |- | ||
| $00 || | | $00 || $04 | ||
|- | |- | ||
| $08 || | | $08 || $24 | ||
|- | |- | ||
| $10 || | | $10 || $01 | ||
|- | |- | ||
| $18 || | | $18 || $21 | ||
|} | |} | ||
Revision as of 02:06, 23 December 2017
GoodNES allocated iNES Mapper 133 for the Sachen unlicensed game "Jovial Race". It's almost identical to NINA-06.
Санчез, however, allocated Jovial Race to iNES Mapper 150. Either way, its UNIF MAPR is UNL-SA-72008.
Mask: $E100 $4100: [.... .PCC] - Select 32 KiB PRG bank and 8 KiB CHR bank
Another physical release instead wired a Namco 108 clone in an inscrutably complex way:
Mask: $E001
$8000: [..B. .B.B] - Select register for writing
$8001: [...X XPCC] - Write value to register
| ||||
| ||++--- select 8 KiB CHR bank
| |+----- select 32 KiB PRG bank
+-+------ analog feedback path
Four of the registers produce an analog feedback path through the 108's CHR registers:
| XX bits | if this register was selected by the XX bits, switch to using contents of register |
|---|---|
| $00 | $04 |
| $08 | $24 |
| $10 | $01 |
| $18 | $21 |
If this feedback path doesn't settle on one specific register, then the selected banks will rapidly switch between all the registers specified by the feedback path, and the 108 clone will get hot.
See also:
