Difference between revisions of "Sega Mega-CD/Boot ROM"

Revision as of 14:49, 19 December 2019

Back to: Sega Mega-CD.

The original Japanese Mega-CD boot ROM, version 1.00.

All variants of the Sega Mega-CD come pre-installed with a boot ROM - a menu interface which appears when the console is given power. While a Sega Mega Drive cartridge can boot almost instantaneously, CD-ROMs require verification and loading, which depending on the quality of the disc or drive, can take several seconds. In addition to help drive the CD-ROM, the Mega-CD's boot ROM informs the user that console is in Mega-CD mode, and cruically gives them something more interesting to look at than a blank screen.

Over time, many slightly different boot ROMs were developed by Sega (or its partners), either for localisation purposes, bug fixes or due to changes in hardware. The Wondermega for example has a different style of boot ROM to a standard Mega-CD, while the LaserActive has to accommodate the Mega LD format.

Functions

Most Mega-CD boot ROMs offer the same functionality - principly to run Mega-CD games. Most models can also play music CDs and Japanese models accept CD+G discs. As the Mega-CD also contains on-board memory for save games, the boot ROM allows users to manage data, either by removing save data they no longer need, or by transferring it to a CD BackUp RAM Cart. Later boot ROMs and the LaserActive cull some of these features, possibly as a cost-saving measure or limitations with the hardware.

On the Mega-CD, boot ROMs typically play a music track, while colourful Mega-CD and/or Sega logos dance around, demonstrating the system's rotation and scaling abilities. Boot ROM versions 2.00 and later support use of the Sega Mouse in control port 2, should users what to use that device to navigate the menus.

All of these features (and more) were also made available in the Sega Saturn and Sega Dreamcast, as well as most rival disc-based consoles.

Screenshots

Main screen

JP 1.00
US 1.00
EU 1.00
US 1.10
JP 2.00
US 2.00
EU 2.00
JP 2.11
US 2.21
EU 2.21
LaserActive 1.02
LaserActive 1.04
LaserActive 1.05
Wondermega 1.00
Wondermega 2.00
X'Eye 2.00

CD-ROM playback

JP 1.00
US 1.00
EU 1.00
JP 2.00-2.11
US/EU 2.00
Wondermega 1.00
Wondermega/X'Eye 2.00

Storage information

JP 1.00
US/EU 1.00-1.10
JP 2.00

Save data menu

JP 1.00
US/EU 1.00-1.10
JP 2.00

ROM dump status

System

Hash

Size

Build Date

Source

Comments

?

CRC32	8c3e3945
MD5
SHA-1

1993-03-29

LaserActive (NA) (0.98)

("Us lsr 930329.zip" does not exist) (info)

?

CRC32	9f5771d2
MD5
SHA-1

1993-03-29

LaserActive (Asia) (0.98)

("Jp lsr 930329.zip" does not exist) (info)

?

CRC32	3beb1ac2
MD5
SHA-1

Sega Mega-CD (Asia, NTSC) (1.00g)

("BIOS Mega CD Japan 1.00g.7z" does not exist) (info)

?

CRC32	f18dde5b
MD5
SHA-1

Sega Mega-CD (Asia, NTSC) (1.00l)

("BIOS Mega CD Japan 1.00l.md.zip" does not exist) (info)

?

CRC32	1d9756a3
MD5
SHA-1

Sega Mega-CD (Asia, NTSC) (1.00o)

("BIOS Mega CD Japan v1.00o.7z" does not exist) (info)

?

CRC32	9d2da8f2
MD5
SHA-1

1991-12-17

Sega Mega-CD (Asia, NTSC) (1.00p)

("Jp mcd1 911217.zip" does not exist) (info)

?

CRC32	79f85384
MD5
SHA-1

Sega Mega-CD (Asia, NTSC) (1.00s)

("BIOS Mega CD Japan 1.00S.md.zip" does not exist) (info)

?

CRC32	550f30bb
MD5
SHA-1

1991-12-28

Sega Mega-CD (Asia, PAL) (1.00s)

("Jp mcd1 911228.zip" does not exist) (info)

?

CRC32	d21fe71d
MD5
SHA-1

1992-02-06

Wondermega (Asia) (1.00w)

("Jp wmg 920206.zip" does not exist) (info)

?

CRC32	e7e3afe2
MD5
SHA-1

Sega CD (NA) (1.00)

("BIOS Sega CD USA 1.00.md.zip" does not exist) (info)

?

CRC32	529ac15a
MD5
SHA-1

1992-10-27

Sega Mega-CD (EU) (1.00)

("Eu mcd1 921027.zip" does not exist) (info)

?

CRC32	2ed602d7
MD5
SHA-1

1993-09-22

LaserActive (NA) (1.04)

("Us mld 930922.zip" does not exist) (info)

?

CRC32	b24b919d
MD5
SHA-1

1993-08-10

LaserActive (Asia) (1.05)

("Jp lsr 930810.zip" does not exist) (info)

?

CRC32	c6d10268
MD5
SHA-1

1992-10-11

Sega CD (NA) (1.10)

("Us scd1 921011.zip" does not exist) (info)

?

CRC32	4be18ff6
MD5
SHA-1

1992-05-01

Sega Mega-CD 2 (Asia) (1.11)

Japanese sample/prototype

("Jp mcd2 920501.zip" does not exist) (info)

Page

?

CRC32	8af65f58
MD5
SHA-1

1993-03-14

Sega CD (second model) (NA) (2.00)

("Us scd2 930314.zip" does not exist) (info)

?

CRC32	9f6f6276
MD5
SHA-1

1993-06-01

Sega CD (second model) (NA) (2.00w)

("Us scd2 930601.zip" does not exist) (info)

?

CRC32	dd6cc972
MD5
SHA-1

1992-12-22

Sega Mega-CD 2 (Asia) (2.00c)

("Jp mcd2 921222.zip" does not exist) (info)

?

CRC32	0507b590
MD5
SHA-1

1993-03-30

Sega Mega-CD II (EU) (2.00)

("Eu mcd2 930330.zip" does not exist) (info)

?

CRC32	4d5cb8da
MD5
SHA-1

1993-06-01

Sega Mega-CD II (EU) (2.00w)

("Eu mcd2 930601.zip" does not exist) (info)

?

CRC32	290f8e33
MD5
SHA-1

1993-12-27

X-Eye (NA) (2.00)

("Us xeye 931227.zip" does not exist) (info)

?

CRC32	2b19972f
MD5
SHA-1

Wondermega (Asia) (2.00)

^{[n 1]}

("Wondermega 2.00 Bios.zip" does not exist) (info)

?

CRC32	2e49d72c
MD5
SHA-1

1993-06-21

Sega Mega-CD (second model) (NA) (2.11)

("Us scd2 930621.zip" does not exist) (info)

?

CRC32	12154531
MD5
SHA-1

CSD-G1M (JP) (2.11c)

("Aiwa_CSD_GM1_Bios.zip" does not exist) (info)

?

CRC32	aacb851e
MD5
SHA-1

1993-09-16

Sega Multi-Mega (EU) (2.21x)

("Eu mmg 930916.zip" does not exist) (info)

?

CRC32	d48c44b5
MD5
SHA-1

1993-09-07

Sega Genesis CDX (NA) (2.21x)

("Us cdx 930907.zip" does not exist) (info)

Notes

↑ [The ZIP file contains two dumps, a "good" dump and a "bad" dump. The "bad" dump has an incorrect HINT vector, but is otherwise identical to the "good" dump. The CRC32 listed here is for the "good" dump. The ZIP file contains two dumps, a "good" dump and a "bad" dump. The "bad" dump has an incorrect HINT vector, but is otherwise identical to the "good" dump. The CRC32 listed here is for the "good" dump.]

References

Sega Mega-CD
Topics	Technical specifications \| History \| Magazine articles \| Promotional material
Hardware	Mega CD (Asia \| North America \| Western Europe \| Eastern Europe \| South America \| Australasia \| Africa) Sega Multi-Mega (Asia \| North America \| Europe \| South America \| Australasia) Wondermega \| LaserActive \| CSD-G1M
Misc. hardware	CD BackUp RAM Cart \| Mega-CD Karaoke \| Pro CDX
Development tools	SNASM Mega-CD \| PsyQ Mega-CD SDK \| PSY-Q CD Emulation System (Mega-CD)
Unreleased hardware	Game Genie

[The_ZIP_file_contains_two_dumps.2C_a_.22good.22_dump_and_a_.22bad.22_dump._The_.22bad.22_dump_has_an_incorrect_HINT_vector.2C_but_is_otherwise_identical_to_the_.22good.22_dump._The_CRC32_listed_here_is_for_the_.22good.22_dump.-1] [The ZIP file contains two dumps, a "good" dump and a "bad" dump. The "bad" dump has an incorrect HINT vector, but is otherwise identical to the "good" dump. The CRC32 listed here is for the "good" dump. The ZIP file contains two dumps, a "good" dump and a "bad" dump. The "bad" dump has an incorrect HINT vector, but is otherwise identical to the "good" dump. The CRC32 listed here is for the "good" dump.]

[n 1]

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 {{back}}
 [[File:BootROM MCD JP 1.00.png|right|320px|thumb|The original Japanese Mega-CD boot ROM, version 1.00.]]
-All variants of the [[Sega Mega-CD]] come pre-installed with a [[boot ROM]] - a menu interface which appears when the console is given power. While a [[Sega Mega Drive]] cartridge can boot almost instantaneously, CD-ROMs require verification and loading, which depending on the quality of the disc or drive, can take several seconds. In addition to help drive the CD-ROM, the Mega-CD's boot ROM informs the user that console is in Mega-CD mode, and cruically gives them something more interesting to look at than a blank screen.
+All variants of the [[Sega Mega-CD]] come pre-installed with a boot ROM - a menu interface which appears when the console is given power. While a [[Sega Mega Drive]] cartridge can boot almost instantaneously, CD-ROMs require verification and loading, which depending on the quality of the disc or drive, can take several seconds. In addition to help drive the CD-ROM, the Mega-CD's boot ROM informs the user that console is in Mega-CD mode, and cruically gives them something more interesting to look at than a blank screen.
 Over time, many slightly different boot ROMs were developed by [[Sega]] (or its partners), either for localisation purposes, bug fixes or due to changes in hardware. The [[Wondermega]] for example has a different style of boot ROM to a standard Mega-CD, while the [[LaserActive]] has to accommodate the [[Mega LD]] format.