User:MintChoctopus/Sandbox

This page details one or more prototype versions of MintChoctopus.

Two Prototypes of the Sega Master System BIOS are known to exist, both of them originating from demonstration units from SEGA of America.

File: SMS_Prototype_M404_BIOS.zip (2.3KB) (info)

File: Sms_prototype_v1.0-proto-bios-sms.zip (3.7KB) (info)

M404 Prototype

This prototype is documented on Hidden Palace.

The boot screen is completely different than later versions, with an animated SEGA logo coming in from the bottom of the screen and the MASTER SYSTEM logo coming in from the right side.
Both the Sega logo and the MASTER SYSTEM logos differ from the final.
The BIOS checks for the strings COPYRIGHTSEGA and COPYRIGHT SEGA at $f7e0.
Due to the different strings checked, only two games can run on this version of the BIOS: the Japanese version of Fantasy Zone and Choplifter.
No region checking is done on the inserted cartridge/card.
No sound engine is present.

M404 Prototype	Final (v1.3)

(Source: SMS Power!)

This prototype is documented on Hidden Palace.

To do:

The final boot screen is present, but not animated.
The sound engine is present, but never called. Due to this, the BIOS is completely silent.
The jingle found in v1.3 and later is present, but different.
Snail Maze is not present, but the music is there.
There is no code to handle the reset button.
The Sega and Master System logos are stored uncompressed. In v1.3 and later, they are stored using the same compression method used in Phantasy Star.
Starting with this version, the BIOS checks for the string TMR SEGA at $7ff0, $3ff0 and $1ff0 in order to check if a cartridge/card is inserted.
The instructions screen in v1.3 is not present. If no cartridge/card is inserted, the BIOS will show a screen similar to the software error screen in the final, with a flashing question mark. If there is a software error, the system will display CHECK SUM ERROR before the question mark.

v1.0 Protoype	Final (v4.4)

(Source: SMS Power!)