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

Latest revision as of 23:46, 7 August 2024

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 the console is in Mega-CD mode, and crucially 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 - principally 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 want 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

Audio CD 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
US/EU 2.00

Save data menu

JP 1.00
US/EU 1.00-1.10
JP 2.00
US/EU 2.00

Technical information

ROM dump status

System

Hash

Size

Build Date

Source

Comments

?

CRC32	8c3e3945
MD5
SHA-1

128kB

1993-03-29

LaserActive (NA) (1.02)

BIOS header lists version as 0.98

(74 kB) (info)

?

CRC32	9f5771d2
MD5
SHA-1

128kB

1993-03-29

LaserActive (Japan) (1.02)

BIOS header lists version as 0.98

(74 kB) (info)

?

CRC32	2ed602d7
MD5
SHA-1

128kB

1993-09-22

LaserActive (NA) (1.04)

(74 kB) (info)

?

CRC32	b24b919d
MD5
SHA-1

128kB

1993-08-10

LaserActive (Japan) (1.05)

(69 kB) (info)

?

CRC32	41af44c4
MD5	e99e30eeffee8201f9eb2c6e219b6fc2
SHA-1	f30d109d1c2f7c9feaf38600c65834261db73d1f

128kB

1991-11-14

Sega Mega-CD (Japan) (1.00c)

Found on prototype EPROM labeled "1.00c"

(80 kB) (info)

?

CRC32	3beb1ac2
MD5
SHA-1

Sega Mega-CD (Japan) (1.00 Rev B)

HAA-2910 EPR-14088B

(80 kB) (info)

?

CRC32	f18dde5b
MD5
SHA-1

Sega Mega-CD (Japan) (1.00 Rev C)

HAA-2910 EPR-14088C

(80 kB) (info)

?

CRC32	1d9756a3
MD5
SHA-1

128kB

Sega Mega-CD (Japan) (1.00 Rev D)

HAA-2910 EPR-14088D

(80 kB) (info)

?

CRC32	9d2da8f2
MD5
SHA-1

128kB

1991-12-17

Sega Mega-CD (Japan) (1.00 Rev E)

HAA-2910 EPR-14088E

(80 kB) (info)

?

CRC32	79f85384
MD5
SHA-1

Sega Mega-CD (Japan) (1.00 Rev H)

HAA-2910 EPR-14088H, MPR-14088H-T

(80 kB) (info)

?

CRC32	4be18ff6
MD5
SHA-1

1992-05-01

Sega Mega-CD (Japan) (1.11)

Dumped from Japanese model 2 sample/prototype

(81 kB) (info)

?

CRC32	550f30bb
MD5
SHA-1

128kB

1991-12-28

Sega Mega-CD (Asia) (1.00 Rev H)

(80 kB) (info)

?

CRC32	e7e3afe2
MD5
SHA-1	c5c24e6439a148b7f4c7ea269d09b7a23fe25075

128kB

Sega CD (NA) (1.00)

(85 kB) (info)

?

CRC32	c6d10268
MD5
SHA-1

128kB

1992-10-11

Sega CD (NA) (1.10 Rev B)

MK-1690 MPR-15045B-T

(85 kB) (info)

?

CRC32	529ac15a
MD5
SHA-1	f891e0ea651e2232af0c5c4cb46a0cae2ee8f356

128kB

1992-10-27

Sega Mega-CD (EU) (1.00)

MK-1690-18

(81 kB) (info)

?

CRC32	dd6cc972
MD5
SHA-1

1992-12-22

Sega Mega-CD 2 (Funai Model) (Japan) (2.00)

HAA-2912 MPR-15398-T

(79 kB) (info)

?

CRC32	8af65f58
MD5
SHA-1

1993-03-14

Sega CD 2 (Funai Model) (NA) (2.00)

MK4102 MPR-15511-T

(85 kB) (info)

?

CRC32	9f6f6276
MD5
SHA-1

1993-06-01

Sega CD 2 (Funai Model) (NA) (2.00 Rev A)

MK4102 MPR-15511A-T

(85 kB) (info)

?

CRC32	0507b590
MD5
SHA-1	7063192ae9f6b696c5b81bc8f0a9fe6f0c400e58

128kB

1993-03-30

Sega Mega-CD II (Funai Model) (EU) (2.00)

MK4102-50 MPR-15512-T

(83 kB) (info)

?

CRC32	4d5cb8da
MD5
SHA-1

128kB

1993-06-01

Sega Mega-CD II (Funai Model) (EU) (2.00 Rev A)

MK4102-50 MPR-15512A-T

(83 kB) (info)

?

CRC32	2e49d72c
MD5
SHA-1

1993-06-21

Sega CD 2 (Sony Model) (NA) (2.11)

MK-4102A MPR-15764-T

(86 kB) (info)

?

CRC32	c1aa217f
MD5
SHA-1

1993-06-21

Sega Mega-CD II (Sony Model) (EU) (2.11)

MK-4102A-50 MPR-15811-T

(84 kB) (info)

?

CRC32	d48c44b5
MD5
SHA-1

128kB

1993-09-07

Sega CDX (NA) (2.21x)

MK-4121 MPR-16139-T

(86 kB) (info)

?

CRC32	aacb851e
MD5
SHA-1

128kB

1993-09-16

Sega Multi-Mega (EU) (2.21x)

MK-4121-50 OPR-16140

(84 kB) (info)

?

CRC32	d21fe71d
MD5
SHA-1	3fc9358072f74bd24e3e297ea11b2bf15a7af891

128kB

1992-02-06

Sega Wondermega (Japan) (1.00)

HWM-5010 G301

(79 kB) (info)

?

CRC32	2b19972f
MD5
SHA-1

128kB

Victor Wondermega M2 (Japan) (2.00)

RG-M2 G303^{[fn 1]}

(81 kB) (info)

?

CRC32	290f8e33
MD5
SHA-1

128kB

1993-12-27

JVC X'Eye (NA) (2.00)

RG-M10BU G304

(80 kB) (info)

?

CRC32	12154531
MD5
SHA-1

128kB

Aiwa CSD-G1M (JP) (2.11)

MPR-15768-T

(80 kB) (info)

Footnotes

↑ 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.

[fn 1]

@@ Line 49: / Line 49: @@
 BootROM MCD US 1.00 Storage.png|US/EU 1.00-1.10
 BootROM MCD JP 2.00 Storage.png|JP 2.00
+BootROM MCD US 2.00 Storage.png|US/EU 2.00
 </gallery>
@@ Line 56: / Line 57: @@
 BootROM MCD US 1.00 Menu.png|US/EU 1.00-1.10
 BootROM MCD JP 2.00 Menu.png|JP 2.00
+BootROM MCD US 2.00 Menu.png|US/EU 2.00
 </gallery>

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

From Sega Retro

Latest revision as of 23:46, 7 August 2024

Contents

Functions

Screenshots

Main screen

Audio CD playback

Storage information

Save data menu

Technical information

ROM dump status

Footnotes

References