If you're looking for the schematics on
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Inchworm ICD2 & Cricket Thermostat. I've had to move domains and transferring was a royal pain.I've not updated the site though, I want to put the PCB layout for the ICD2 compatable (easy to build and very basic VDD 5V and VPP ~12.5 which is plenty and generated using a common RS232 level converter)
I'm also a big fan of PICs and RS485, too it's not as common on computers as RS232.