As you may know already, regular ColecoVision cartridges are limited to 32
kilobytes of ROM data. This, along with the ColecoVision's single kilobyte
of RAM, severely limits the kinds of games that can be coded for the
console. Titles like Gateway to Apshai are probably the most elaborate games
you're going to see within these harsh hardware limits.
However, 20+ years after the commercial death of the ColecoVision, Opcode
Games is proud to introduce a solution to the ColecoVision's 32-kilobyte ROM
limit: The MegaCart! This piece of hardware designed by Bryan Edewaard,
which fits into a regular ColecoVision cartridge shell, implements
bankswitching schemes that go far beyond 32K. There are several variations
of the MegaCart: 128K, 256K, 512K and 1024K (yes, a full megabyte!).
Frequently asked questions about the MegaCart:
Q: Why is there no 64K variation of the
MegaCart? A: The PCB architecture doesn't really support it. If a game fits
inside 64K, a 128K MegaCart will have to be used, which means a lot of
available space on the MegaCart will remain unused.
Q: I am a homebrew programmer. Could I
purchase blank MegaCarts for my own games? A: The MegaCart is not our exclusive property, it's Bryan Edewaard's
creation. He streamlined the MegaCart PCB to make it as cheap to produce as
possible, and all a programmer needs to add is an EPROM chip with software
encoded into it (you can buy such EPROMs from several places). Bryan is
ready to sell exemplaries of his MegaCart PCB for a reasonable price, so
you only need to seek him out and ask him about it.
Q: What kind of equipment do I need to encode
game data into the MegaCart? A: Any 40-pin EPROM burner should do the job nicely, as far as the
ColecoVision software is concerned. It's really not that different from a
regular ColecoVision PCB/EPROM setup.
Q: Are there any plans to make a MegaCart
model that offers extra RAM? A: While it's not technically impossible, such a MegaCart would be
far more expensive to produce. Also, the ColecoVision console was not
designed to handle extra RAM incorporated in game cartridges, which means
programming games that use such extra RAM would be very complicated. Our
solution to add extra RAM to the ColecoVision is the
Opgrade Module.
Q: Can you describe the bankswitching method
used in the MegaCart? A: Without getting into too much detail, we can tell you that the ROM
addressing space is divided into two chunks of 16K, and one of these chunks
can be switched at any time. Therefore, no matter what MegaCart model is
used, only 32K can be adressed at any one time by the software, and the
programmer must design his/her games with this constraint in mind.
Q: Which game releases from Opcode Games use
(or will use) the MegaCart? A: Most of the games we want to release on the ColecoVision require
more than 32K of ROM space, so those will necessarily make use of the
MegaCart. To say the MegaCart will play a major role in the future of Opcode
Games is definately not an exagerated statement. The first game to use the
MegaCart will be Pac-Man Collection.
