Some Questions About Homebrew Hardware

[TROGDOR]

Hi all,

 

I have some questions about the parts used for making homebrews. Why are older used components generally used for homebrews rather than new components? I have a systems engineering background, so I understand that there are legacy concerns when designing carts, the most important issues being a match on voltage levels (many newer components are 3.3v or 1.8v, which won't be compatible with the Atari's older 5v standard.), and also cycle time and setup/hold concerns (new chips will operate at higher speeds, which may not be compatible with the slower cycle time and setup/hold timing expected by the Atari 2600.)

 

I'm guessing Albert and others have already done research into using newer parts, and found some reason why they can't be used. I've been wondering about this for some time, but I was prompted to ask when I saw Albert's request for SARA SuperChip carts for use in new homebrews. Are there any newer RAM chips that would match the spec for the SuperChip?

 

Another thing I'm curious about is could AtariAge reduce costs by standardizing on one or two cart designs? Rather than offering 4k, 8k, 16k and other size carts, just buy a larger quantity of the largest EEPROM size, and then don't use the extra EEPROM space if you don't need it for your particular game. Same goes for the RAM. Rather than looking for an exact match for 128 bytes of RAM, it may be cheaper to go with a larger RAM as long as it matches the specs for the Atari. Game designers could decide to limit themselves to only 128 bytes of RAM if they wanted their game to have the same constraints as a SuperChip game, even though the cart would actually have, say, 2K RAM available in a particular bank. It would depend on unit pricing, but it seems larger volume purchases would make up for any price difference in the physical capacity of the chips.

[mos6507]

The Harmony Cart is intended to do away with the legacy parts by using an ARM chip as a one-time-programmable multicart.