Some new Sega CD Boot ROMs

Andlabs sent me a copy of the No-Intro Sega CD Boot ROM archive as of yesterday, and it has three new ROMs that were previously not available on Sega Retro:

• Mega CD 1.00l (Japan/NTSC): This is now the earliest known Boot ROM. (Previously, 1.00p was the earliest.)
• Mega CD 1.00S (Japan/NTSC): This was previously only available in the Japan/PAL (Asia) region.
• Sega CD 1.00 (USA): I thought the US Model 1 boot ROM was numbered 1.10 because it had a different CD player interface than both EU and JP. Guess I was wrong. 1.00 looks identical to 1.10 on the surface (same CD player, same startup theme), but there's probably some low-level differences.

All three of these ROMs are now available on the Sega Mega CD page on Sega Retro.

 

Some random notes:

The following Japan/NTSC Boot ROMs will work on Japan/PAL:

• Mega CD 1.00l
• Mega CD 2 2.00c

The following Japan/NTSC Boot ROMs will not work on Japan/PAL (error message):

• Mega CD 1.00p
• Mega CD 1.00S
• Wondermega 1.00
• Wondermega M2 2.00

And the only currently-dumped Japan/PAL ROM, 1.00S, seems to work for Japan/NTSC.

I seem to remember that J/NTSC 1.00p *used* to work as J/PAL, but I may be remembering J/PAL 1.00S instead. (J/PAL 1.00s is what's marked as "1.00" in GoodGen, whereas J/NTSC 1.00p is "1.01".)

EDIT: Okay, now this is getting weird. 1.00S (J/PAL) works if the console setting is EU, but not if it's set to US. I'll have to retest all the ROMs and make a matrix of what's supported and what's not.

 

I finished testing all of the No-Intro ROMs for MD system region compatibility, and here's the results.

Regions: J = Japan, A = Asia, U = USA, E = Europe
Systems: MCD = Mega CD, SCD = Sega CD, MLD = Pioneer LaserActive (Mega LD), SWM = Wondermega / X'Eye

An "X" in a given box indicates the ROM works with an MD from that region.
Note that this does not affect the game regions supported. For example, Japanese ROMs will only work with Japanese games, regardless of the MD region support.

Code (Text):

1. +--------------+---+---+---+---+
2. |   Boot ROM   | J | A | U | E |
3. +--------------+---+---+---+---+
4. | MCD(J) 1.00l | X | X | X | X |
5. | MCD(J) 1.00p | X |   |   |   |
6. | MCD(J) 1.00S | X |   |   |   |
7. | MCD(A) 1.00S | X | X |   | X |
8. | SCD(U) 1.00  |   |   | X |   |
9. | SCD(U) 1.10  |   |   | X |   |
10. | MCD(E) 1.00  |   |   |   | X |
11. +--------------+---------------+
12. | MCD(J) 2.00c | X | X | X | X |
13. | SCD(U) 2.00  |   |   | X |   |
14. | MCD(E) 2.00  |   |   |   | X |
15. | SCD(2) 2.00W |   |   | X |   |
16. | MCD(2) 2.00W |   |   |   | X |
17. +--------------+---------------+
18. | SCD(U) 2.11X |   |   | X |   |
19. | CDX(U) 2.21X |   |   | X |   |
20. +--------------+---------------+
21. | MLD(J) 0.98  | X |   |   |   |
22. | MLD(U) 0.98  |   |   | X |   |
23. | MLD(U) 1.04  |   |   | X |   |
24. +--------------+---------------+
25. | SWM(J) 1.00W | X |   |   |   |
26. | SWM(J) 2.00  | X |   |   |   |
27. | SWM(U) 2.00  | X | X | X | X |
28. +--------------+---+---+---+---+

Interesting note: MCD(J) 1.00l doesn't even have the "ERROR!" text present in the ROM, whereas all the others do. I'm guessing they didn't implement the system region lockout in 1.00l, but for the other ones, it was likely caused by a typo in the ROM build configuration.