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tjboldt / Apple2-IO-RPi

Apple II expansion card using a Raspberry Pi for I/O
MIT License
123 stars 13 forks source link

SOIC PCB version #42

Closed bfranske closed 1 month ago

bfranske commented 2 years ago

Is your feature request related to a problem? Yes, DIP parts (especially 74LS245 and AT28C64B) are out of stock from many suppliers with very long lead times.

Describe the solution you'd like SOIC footprint version of the PCB

tjboldt commented 2 years ago

Indeed it seems that components are increasingly difficult to source. I'm working on a hybrid board that will take either DIP or SOIC so any chip can be of either package type depending on availability.

pmansell20 commented 2 years ago

Just built 2 of these, no 74LS245 DIP in stock anywhere, so used 74HCT245, no issues on ROM 1 IIGS or Laser 128EX so far. The T in the IC part no is important, HCT parts have switching thresholds similar to LS (that's what the data sheets say anyway).

FWIW No problems to get the AT28C64B DIP in Australia - element14 show them in stock (although they take a couple of days to come into the local warehouse). But there's not a lot of them.

In any case thanks for the easy storage solution for the II's.

Hubidrei commented 2 years ago

So i could source all components but the 74LVC374, only found them on Mouser but shipping is too expensive. So i now tried with 74AC374. They seem to work in my BASIS108, will have to do more long time tests.

tjboldt commented 1 month ago

Note that there is a SOIC version of the A2Pico card which is now compatible with this project.

https://github.com/rallepalaveev/a2pico/tree/main/A2Pico.v2.7