chip for the DAC ? and a suggestion .

[huze11]

firstly i would like to ask if i can find a chip that would output me correct voltages for the the ad725 instead of the 5% resistors that i can find for the DAC .
i can import chips , but importing accurate 1% resistors is quite harder .
i also want to ask if i can get a DAC chip that would generate me an analog signal between 0.3v and 1v

and the suggestion is , why not use a synchronous external RAM for the uzebox ?

[D3thAdd3r]

That could be cool if there was an all in 1 DAC that was cheap and accurate(and DIP).

On the ram I don't quite understand, do you mean use full ports for an address bus and a data bus? I don't think there would be any way for it to coexist with the current Uzebox design really unless you mean something else. It could be a cool derivative project.

[huze11]

yeah can we find such a DAC ?

and for the external RAM , i already did work at such a thing . u used an 128k external SRAM with an atmega644 , the data I/O port is connected to both the AVR and the main DAC , i managed to get it to a resolution of 480/224 (frame buffer in the RAM) i managed to write text and shapes to the screen , and it was relatively stable .

[huze11]

any response ?

[uze6666]

yeah can we find such a DAC ?

and for the external RAM , i already did work at such a thing . u used an 128k external SRAM with an atmega644 , the data I/O port is connected to both the AVR and the main DAC , i managed to get it to a resolution of 480/224 (frame buffer in the RAM) i managed to write text and shapes to the screen , and it was relatively stable .

I don't think there's some easy to use DAC that does exactly what you need. I'd just use resistors.

For the RAM, sure there's way to hack in external SRAM. I contemplated the idea when doing the original design but in the end it required to many components and went against the elegance of simplicity I wanted.