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Old 11th Oct 2019, 8:48 pm   #13
circuitryboy
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Join Date: Jun 2012
Location: Bristol, UK.
Posts: 115
Default Re: A Simple Programmer for TESLA "MH74S-" bipolar PROMs

Yes, my MK14 was upgraded early on into a more useful device. With the Monitor in EPROM and simple extra address decoding,
the PCB layout allowed the PROM positions to be converted to 2114s. And similar conversion for a pair of the 2111s.

The TESLA programmer was based on the SoC circuit and I only altered the minimum to suit the other PROM.
Now the programming protocol is proven (fortunately quite similar to National SemiC's, compared with the multiple-voltages
requirements of other pin-compatibles) the circuit can be refined/replaced. (I have changed the 74LS125s to a DM81LS97.)

Your suggestion of compressing the input data could be useful approach for someone working with a 'standard' MK14.
The TESLA Promblower code (I have yet to try) has 2byte length for source-data so duplicating the Monitor in one pass will
be one of the tests. Code includes a 3mS cooldown after each bit is blown.
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