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Dr. Franken demo (GG) + Superman [Proto] (GG)
Post Posted: Wed Jul 20, 2011 8:49 am
Last edited by Bock on Tue Aug 02, 2011 6:54 am; edited 2 times in total
Long time no release!
After the Operation Taiwan rush (1 2 3) around new year I couldn't take the time to put up new releases (a lots of things happened and kept me busy!) but we're coming back full speed for the second half of the year and I'm happy to say I've got an indecent amount of new dumps to sort and release.

First of half a mistake I made earlier has to be addressed: when releasing build variations of Congo Bongo in January the labeling of version was incorrect.
INCORRECT BOO SHAME FAIL
        SG1 - 5a24c7cf - Congo Bongo [v0]
        SG1 - f7eb94c5 - Congo Bongo [v0] (TW)
        SG1 - 5eb48a20 - Congo Bongo [v1]

CORRECT WIN SUCCESS
        SG1 - 5eb48a20 - Congo Bongo [v0]
        SG1 - 5a24c7cf - Congo Bongo [v1]     
        SG1 - f7eb94c5 - Congo Bongo [v1] (TW)

I was slightly suspicious of it when releasing the dump but it slipped. Later on studying other SG-1000 boxing variations and in particular with the help of Z80 detective Paul Baker we confirmed the right order. For information, the [v0] is the Japanese release in a big box with a 3800 yens price printed on the box. Pricing information was removed in later releases.

For the more technically inclined of you, Paul's reverse engineering report about the difference between both builds will be posted shortly



Now to make up with this we have a none other than an unreleased game demo to offer you! Dr. Franken [Demo] for the Game Gear. Originally developed by Motivetime Ltd., released on the Game B*y among other systems, here we've got an early demo build of what could have been a full fledged gloriously colored version of the game!

The lovely pitch here (courtesy of our friends at Lost Levels) is that you play Dr Franken in pajama in a quest to -quoting- FIND THE SCATTERED REMAINS OF YOUR DEAD GIRLFRIEND. Unfortunately the demo is rather short and has no audio so the scattered remains will have to wait some more. We can hazard that the demo was created as a pitch to get the full game development approved.


We also got a second prototype for you today: Superman - The Man of Steel [Proto] for the Game Gear, that we could obtain from the same source as Dr. Franken. It is unknown what are the exact differences between this build and the final one but it looks like a beta-ish build and reasonably close to final. Superman may have telescopic vision but from a player point of the view the game camera, fast movement speed and reduced screen size makes it impossible to see anything. Only for super players.

Have fun and see you soon for more!
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Temporary Transitional Attachment Fairy
Post Posted: Wed Jul 20, 2011 8:51 am
This message will auto destruct itself someday.
congo_bongo-v1-sg.zip (12.51 KB)
superman-gg-proto.zip (88.07 KB)

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Post Posted: Wed Jul 20, 2011 8:55 am
Here's Paul report on Congo Bongo.
Note that [v0] and [v1] in this post refer to the *old, incorrect versioning order*, so [v0] in the post become [v1] after correction, and vice-versa.

Hi Omar,

I started writing a long forum post explaining what I've learned about
the the [v0] and [v1] dumps of Congo Bongo, and asking for some help
investigating further, when I came across something which may solve the
ordering problem:

The two ROMs differ in a single function, which begins at offset $0aba.
The changed code begins at offset $0b01:

Congo Bongo [v0], CRC32: 5a24c7cf
        ld      a,(ix+#04)
        cp      (ix+#07)
        ret     z

        ld      a,#8b
        ld      (#c1e6),a
        ld      a,(ix+#07)
        ld      (ix+#04),a
        ret     

Congo Bongo [v1], CRC32: 5eb48a20
        ld      a,(ix+#03)
        cp      (iy+#00)
        ret     z

        cp      (iy+#01)
        ret     z

        ld      a,c
        cp      #03
        jr      c,l0b19
        ld      a,(iy+#01)
        ld      (ix+#03),a
        jr      l0b1f

l0b19:  ld      a,(iy+#00)
        ld      (ix+#03),a

l0b1f:  ld      a,#8b
        ld      (#c1e6),a
        ret     

This code is executed when a snake (as found on stage 2) "sees" the
player - that is, when the player comes within 8 pixels of the snake
either horizontally or vertically. In this situation, the snake "chases"
the player. The purpose of the code above seems to be to determine
whether or not a "new" chase is being started ([v0] seems to do this by
looking for a change in direction, [v1] by looking for a change in X or
Y coordinate). If a new chase is indeed beginning, the write to $c1e6
causes a (vaguely) snake-like sound effect to play.

(Further information: The code is run independently for each snake in
the level - for the snake which is towards the top of the screen at the
start of the stage, ix=$c15d and iy=$c0c9. For the other snake, ix=$c165
and iy=$c0cd. What iy points to is straightforward - (iy+#00) contains
the snake's Y coordinate and (iy+#01) contains its X coordinate.
Unfortunately the information pointed to by ix is far more opaque - all
I can say is that (ix+#07) seems to indicate a direction (1 = down, 2 =
up, 3 = right, 4 = left). Thus the "cp #03; jr, c" in the code in [v1]
is intended to distinguish between horizontal and vertical.)

However, the function at $0aba is only called from two places -
functions beginning at $0b79 and $0b89:

l0b79:  ld      a,(ix+#03)
        cp      (iy+#00)
        call    z,l0aba
        ...

l0b89:  ld      a,(ix+#03)
        cp      (iy+#01)
        call    z,l0aba
        ...

So, the function at $0aba is only called if (ix+#03) is equal to either
(iy+#00) or (iy+#01). But in [v1], the code at $0b01 returns if either
of these conditions is true! In other words, the majority of the [v1]
code snippet above never runs - indeed I've never heard the snake-like
sound effect when testing [v1].

This looks like a bug in [v1], and it appears that [v0] fixes the bug by
simplifying the logic. This gives us some evidence regarding the order
of the builds - unfortunately it implies the order is the opposite to
the current labelling.

Thanks

Paul
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Post Posted: Wed Jul 20, 2011 3:42 pm
As always, thanks again Bock!
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Congo Bongo Panic
Post Posted: Wed Jul 20, 2011 5:34 pm
Holy cartridges dumping gods, while browsing my unsorted dumps from Operation Japan World Dumping Tour i found i had yet another dump for Congo Bongo which may predate the current ones..
Which means that v0 might become v1 and v1 might become v2.... but wait until we've sorted that out. Sorry for the confusion, labeling Roms with no header is tricky :)
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Post Posted: Fri Jul 22, 2011 3:38 pm
Nice find about Congo Bongo! I really love this kind of tech talk.
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Post Posted: Tue Aug 02, 2011 7:26 am
New Congo Bongo dump released here:
http://www.smspower.org/forums/viewtopic.php?t=13218
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