IC tester
Hello. I am considering using my BS2 as an IC tester, and I was wondering if there is anyone who has done something like this already. The IC's are the TTL 7400 series. In particular, I'm looking for a template or standard parameters that's already been established, to at least give me a start.
Comments
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·· This could be done.· I built one of these back in 1992 that worked on all the primary logic chips, such as 7400 through 7410.· I don’t think I ever implemented counters or decoding chips such as the 7447.· In any event, you would need an I/O expander to properly do this.· Back then I used the 8255PIA on the Z80, but there are a few chips that work with I2C for the BS2.· You will need resistors on pretty much all I/O lines.· These resistors will have to be adjusted so that improper connections results in minimal current draw but still allow the pins to source/sink enough power to make the chip/gates operate.· I hope this gives you some starting guidelines.· Take care.
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Chris Savage
Parallax Tech Support