3E+ RAM bug

[+Andrew Davie]

The reason some that 3E+ chess versions do not work on PlusCart/UnoCart is apparently because the 3E+ driver limits RAM 32 banks.

If so, this is incorrect.  3E+ handles up to 64 RAM banks (32KiB total).

 

[+Al_Nafuur]

5 hours ago, Andrew Davie said:

The reason some that 3E+ chess versions do not work on PlusCart/UnoCart is apparently because the 3E+ driver limits RAM 32 banks.

If so, this is incorrect.  3E+ handles up to 64 RAM banks (32KiB total).

 

the code don't lie:
https://gitlab.com/firmaplus/atari-2600-pluscart/-/blob/master/source/STM32firmware/PlusCart/Src/cartridge_emulation.c#L591

https://github.com/DirtyHairy/UnoCart-2600/blob/master/source/STM32firmware/Atari2600Cart/src/cartridge_3ep.c#L20

 

I'll fix that for the PlusCart in the next release(s)

 

[Thomas Jentzsch]

That one is much more obvious than the bug we had in Stella. I wonder were the 32 bank limit originally came from.

[+Al_Nafuur]

should be "fixed" in the new release:

 

[+Andrew Davie]

4 hours ago, Thomas Jentzsch said:

That one is much more obvious than the bug we had in Stella. I wonder were the 32 bank limit originally came from.

It's because we're used to thinking in 1K chunks, not 512 byte chunks.

So when 64K banks was "converted" to 32K actual RAM, at some point we/someone was still thinking 32 chunks of 1K to make 32K

And thus, when setting the number of banks, it was set to 32.

Pretty straightforward and easy to make error, I think.

 

[+Andrew Davie]

Have tested, and appears to be working well - thank you.