I knocked up a schematic for the programmer:
And I tested the component values (for the 16v pulse):
The voltage/current is pushing it for the BC328 so it may be necessary to check output voltage before using the programmer in "anger".
Here is the schematic that I simulated:
I probably should add a pull down resistor on the base of T1 BC547.
Without the "bit" switch the output from the regulator would look like:
Best to let the dust settle on the design before I do a last check and knock up the PCB.
The minimum input voltage is 18.5v rather than 18v, and R2 should be increased from 180R to 200R.
Also worked out how to pull VCC to ground if it is a desired feature of the programmer.
I also "spat the dummy" with EasyEDA and have migrated to KiCAD.
Nearly as bad! How can you have a recommended install with no libraries.
It is a real headache for a novice to workout what libraries are required, where to put them, and how to link them in.
I will get there but why make it so *%#$^!? hard!
I don't actually have a need for this programmer so I will not be designing the PCB.
And Danny is keen to go the prototype path rather than the PCB path.