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NAOMI GD-ROM BIOS

Game Information
manufacturer Sega
year 2001
genre N/A
downloads 3
Screenshots
naomigd title
naomigd title
Download Details
split set naomigd.zip 3.22m
bios/device mie.zip 725.00b
bios/device jvs13551.zip 14.73k
merged set naomigd.7z 342.41k
standalone set naomigd.7z 350.74k
Game Details
Arcade System published 25 years ago:

NAOMI GD-ROM System (c) 2000 Sega Enterprises, Limited.

- TECHNICAL -

The GD-ROM upgrade is compatible with Naomi and Naomi 2 via the option port on the top of the board. It comes with a DIMM board, very similar to the ROM board on a normal NAOMI cartridge, but has RAM instead of ROMS.

RAM board Uses normal PC type DIMM's, so upgrading memory is not a problem, and relativly cheap.

The GD Rom system has a very clever way of getting around the loading delay time. When the game is initially installed, the GD ROM loads its content into the Naomi RAM. Once this is completed, the GD ROM goes into standby unless the RAM gets corupted or the game gets shut off for 72 hours or more. This does two things,

1) Eliminates loading delays completely, (after initial power up.)
2) Minimizes the on/off cycles of the GD ROM drive and greatly increasing the life of this mechanical device.

From Sega R+D - "We learned a lesson watching our coin-op competitors go through hardware hell. Many have been using off-board storage devices for years - hard drives, CD's, etc. with great success in increased content but at a tremendous cost in realiablity. These storage devices simply could not withstand the constant on/off cycling a coin-op application demands. Add to that the dirt and smoke a game has to put up with on location vs. a normal computer application and you can see how this was a problem waiting to happen"

The GD-Rom system uses an electronic "key" that plugs into the DIMM module to act as an activator, to prevent people just copying the GD-Roms, visible on the top right of the pictures. A different key is supplied with every game.

There is a well founded rumor that Sega may use this system for having multigame cabinets like the neogeo multi systems, as the GR-Rom can store a LOT of data....

- CONTRIBUTE -

Edit this entry: https://www.arcade-history.com/?&page=detail&id=48276&o=2
Driver Details
source sega/naomi.cpp
status preliminary
emulation preliminary
savestate unsupported
graphics imperfect
sound imperfect
Screen Details
display screen
type raster
orientation horizontal
width 640px
height 480px
refresh 61.7mhz
Input Details
player 1
type joy
buttons 6
directions 8
player 2
type joy
buttons 6
directions 8
Chipset Details
name Hitachi SH7091
clock 190.73mhz
name ARM7 (little)
clock 2.69mhz
name Zilog Z80
clock 15.26mhz
name Toshiba TMP90PH44
clock 9.54mhz
name Motorola MC68000
clock 9.54mhz
name Speaker
clock N/A
name Speaker
clock N/A
name Yamaha AICA
clock 21.53mhz
ROM Details
name size crc
epr-21576e.ic27 2.00m 08c0add7
epr-21576g.ic27 2.00m d2a1c6bf
epr-21576h.ic27 2.00m d4895685
epr-21578h.ic27 2.00m 7b452946
epr-21578g.ic27 2.00m 55413214
epr-21578e.ic27 2.00m 087f09a3
epr-21577h.ic27 2.00m fdf17452
epr-21577g.ic27 2.00m 25f64af7
epr-21577e.ic27 2.00m cf36e97b
main_eeprom.bin 128.00b fea29cbb
x76f100_eeprom.bin 132.00b 3ea24b6a