Preferred Way of Developing to Genesis Hardware

oofwill · Post by **oofwill** » Thu Sep 06, 2012 9:16 pm

Thanks for explaination!

I always thought that "decoding address" as you call it was in fact bankswitching.

It's several times difficult for a person who don't really know electronics to understand what you're talking about, but i'm learning day after day thanks to this forum

Chilly Willy · Post by **Chilly Willy** » Thu Sep 06, 2012 9:47 pm

Eke wrote:
Some 3 - 4 MB games use bank switching as well (World Series 95, Mortal Kombat 3, etc). WS95 is a 3 MB game, so I'm assuming the board takes 2 2MB eproms. Would you be able to use that with 4 MB eproms or no?
What you call bankswitching is a simple address decoding logic which select ROM chip upon address lines asserted by the console. There are no ROM banks but different chips and no switching but simple chip selection so technically it's not bankswitching

Bankswitching is when a single memory mapped area can be assigned to different ROM pages and this is usually handled by more complex logic or dedicated hardware.

That's what I thought. Plenty of carts select different rom chips depending on the address so that you can use smaller (cheaper) roms, but it's rom SELECTION, not bank switching.

djcouchycouch · Post by **djcouchycouch** » Thu Sep 06, 2012 11:31 pm

Bank switching is when you take your money out of a financial institution and put it in another.

elusive · Post by **elusive** » Fri Sep 07, 2012 2:24 pm

Chilly Willy wrote:
Eke wrote:
Some 3 - 4 MB games use bank switching as well (World Series 95, Mortal Kombat 3, etc). WS95 is a 3 MB game, so I'm assuming the board takes 2 2MB eproms. Would you be able to use that with 4 MB eproms or no?
What you call bankswitching is a simple address decoding logic which select ROM chip upon address lines asserted by the console. There are no ROM banks but different chips and no switching but simple chip selection so technically it's not bankswitching

Bankswitching is when a single memory mapped area can be assigned to different ROM pages and this is usually handled by more complex logic or dedicated hardware.
That's what I thought. Plenty of carts select different rom chips depending on the address so that you can use smaller (cheaper) roms, but it's rom SELECTION, not bank switching.

My mistake

I thought it was bank switching with those carts. Thanks for clearing that up

jarrodparkes · Post by **jarrodparkes** » Fri Sep 07, 2012 3:08 pm

Just wanted to give everyone an update:

Because of cost limitations (although my birthday is quickly approaching

), I have gone the route with the Sega CD Transfer. I have not been able to test if my cable works yet, but I did create my own DB25 to DB9 cable which I thought was a fun little project for someone just getting into the lower level way of thinking about things. Anyways, I'll open up a new topic as things progress, and will probably also explore the various programming carts out there.

Thanks again everyone and God Bless.