System ROM: Difference between revisions

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== CD/CDZ BIOS ==
== CD/CDZ BIOS ==
=== RAM locations ===
*$10FD80: ?
*$10FD83: Nationality (JP:0, EN:1, EU:2, goes up to 6 ?)


[[File:cd2_bios.jpg|right|thumb|SP1 BIOS ROM on a CDM3-2 board.]]
[[File:cd2_bios.jpg|right|thumb|SP1 BIOS ROM on a CDM3-2 board.]]


512kB (1MB ?). One chip that contains [[Z80]] and [[68k]] programs, PCM sound, and graphics data which are copied to the corresponding [[DRAM|DRAMs]] at boot time.
1MiB chip that contains [[Z80]] and [[68k]] programs, PCM sound, and graphics which are copied to the corresponding [[DRAM|DRAMs]] at boot time.


Graphic visualisation of a CDZ BIOS dump, with separated data blocks (larger size available):<br>
Graphic visualisation of a CDZ BIOS dump, with separated data blocks (larger size available):<br>

Revision as of 23:33, 13 February 2011

BIOSes are ROMs containing the initial program executed by NeoGeo systems. They are present in all hardware types.

AES BIOS

Toshiba EP0 BIOS ROM found on an AES board

128kB. NEO-EP0.

MVS BIOS

Toshiba SP-S2 BIOS ROM on a 1FZS MVS slot.

128kB. SP-S2. Different names according to nationality.

CD/CDZ BIOS

RAM locations

  • $10FD80: ?
  • $10FD83: Nationality (JP:0, EN:1, EU:2, goes up to 6 ?)
File:Cd2 bios.jpg
SP1 BIOS ROM on a CDM3-2 board.

1MiB chip that contains Z80 and 68k programs, PCM sound, and graphics which are copied to the corresponding DRAMs at boot time.

Graphic visualisation of a CDZ BIOS dump, with separated data blocks (larger size available):
File:Cdzbiosgfx.png

File:Brd spj.jpg
SPJ Japanese BIOS on a ROM-only arcade board. Picture courtesy of [MVS-Scans].