Matthew & Xiaolaba,

I've attached the circuit diagram.

The particular resistor values are as-used, it was assembled from bench sweepings, so it is basically whatever I had that was the right order of magnitude. They are non-critical.

You may like to add small capacitances to the other serial input lines (SxI) after the resistors as I needed to add for the clock signal. It is not mandatory as the signals are stable by the time the clock edge occurs, but it can't hurt either.

There is no reason why you couldn't use NPNs instead of 2N7000 MOSFETs, again I had some laying in the junk on the bench so I used them instead of digging in the transistor bins.

Regards,

Alan

Any chance you could post up your schematic? I'm especially interested in how you controlled the high voltage lines for the reset pin. Thanks much for posting your code and photos, this will be a big help to me very shortly!

hello Alan,

call out of you did is useful.

however, dig into the source code of hv-programmer.c

there are few hints could be used to re-produce the hardward as refer to the LPT port mapping from your source code

VCC = 0x80, bit 7

RESET = 0x40, bit 6

SDO = 0x08, bit 3

SCL = 0x04, bit 2

SII = 0x02, bit 1

SDI = 0x01, bit 0

In case you are able to share a complete circuity, it will be much better.

appreciates that and this useful info.

have a good day.