Designed a working 272K bankswitched board.

[jbanes]

The board I designed for MULE takes up to 512K. I'm sitting on a huge stack of them since I had 200 made.

Impressive! Though I'm curious, why didn't they all sell? I never knew about a 5200 M.U.L.E. until now, and my interest is piqued.

[Bryan]

Impressive! Though I'm curious, why didn't they all sell? I never knew about a 5200 M.U.L.E. until now, and my interest is piqued.

 

Well, I only made about 48 of them, then decided there wasn't enough interest to make all 75 (which would have reqired me to track down more donor carts). I've thought of making another small run in the future.

 

-Bry

[CPUWIZ]

The board I designed for MULE takes up to 512K. I'm sitting on a huge stack of them since I had 200 made.

 

 

 

-Bry

 

I thought it was a 64K board, cool.

 

RE: Stack: Precisely why I am not even gonna bother with my board.

[supercat]

Basically, you have to have one bank be fixed, unless you want to 1) add a reset circuit to the cartridge and 2) require the programmer to download trampoline code to RAM. (okay, you could do two bank zones, but that would make the mapper way too complicated) Why use two EPROMs when you can use just one?

 

Why do you need a fixed bank? Explain to me any difference between the following:

(bbbb is 4-bit banking latch)
01aa aaaa aaaa aaaa maps to EPROM at address (bbb b0aa aaaa aaaa aaaa)
10aa aaaa aaaa aaaa maps to EPROM at address (111 11aa aaaa aaaa aaaa)
except for the above, EEPROM addresses of the form (xxx x1xx xxxx xxxx xxxx) are unused

and

(bbbb is 4-bit banking latch)
01aa aaaa aaaa aaaa maps to EPROM at address (bbb b0aa aaaa aaaa aaaa)
10aa aaaa aaaa aaaa maps to EPROM at address (bbb b1aa aaaa aaaa aaaa) 
 all of which should be programmed the same code as (111 11aa aaaa aaaa aaaa)