Driver for 24AAXXX EEPPROM mounted on karri's carts

[42bs]

31 minutes ago, LX.NET said:

Who is the owner of newcc65? It would be good to also have that in a public place (as stated in the dev-containers thread as well). Is that yours, @42bs and would you be willing to host it in your GitHub repo?

I think there is no "owner". My understandig is, that @karri took the one from my page and fixed/improved it. I did not even try to compile it for years.

[Nop90]

I reopen this old thread to inform the other developers that Dragonbox decided to produce, and soon also to sell, carts with a 24AA256 chip onboard (32KBytes of memory).

 

These cart will be used for the phisical release of Starblader. I got the news only today and now I'm changing the code of the game to support this chip.

 

This is an opportunity to start developing games that saves more data, I think that a new RPG game could benefit from this, but also other project, e.g. @LX.NET  could be interested to these carts to save more custom levels of Circuit Dude.

 

 

Edited March 26 by Nop90

[Nop90]

There Is a problem with Dragonbox carts, they decided to use A18 for the SCL line instead of A1 or A0.

 

Weird decision because this requires a more complex handling of IODIR and IODAT to drive the I2C line.

 

Does someone want to help me to customize the driver to support this configuration?

[42bs]

14 minutes ago, Nop90 said:

There Is a problem with Dragonbox carts, they decided to use A18 for the SCL line instead of A1 or A0.

 

Weird decision because this requires a more complex handling of IODIR and IODAT to drive the I2C line.

Do they use 2k blocks then? You need to select block 128 for SCL high and any < 128 for SCL low.

Block select routine is in the ROM, so should be easy do do.

 

[Nop90]

9 minutes ago, 42bs said:

Do they use 2k blocks then? You need to select block 128 for SCL high and any < 128 for SCL low.

Block select routine is in the ROM, so should be easy do do.

 

This is slow, i would initialize the higher 8 bits of the high part of the cart address with 01010101 then at every clock strobe I would shift in a 0 and then a 1.

This should be a better driving of the SCL line.

 

Ps: for me A18 is the highest address line, since Epyx jumped a number in the official documents, it's called A19 sometimes