I am making some minor changes to this circuit now in the hope that it realises the potential for the IV-17 SS to be an experimenter's kit too.
I will be a adding a couple of blocking diodes and a transistor switch which will allow the microcontroller to be run from a backup battery while being disconnected from the 35V supply and heaters by the transistor switch, therefore the backup battery does not need to try to power those things.
My idea is to make available complete hardware kits with unprogrammed controllers, to give kit builders the optino to code their own devices.
The pic control board will then include the backup battery connections, a 32.768kHz crystal on the pic's Timer 1 clock pins, a 35V supply and/or an equivalent area on the pcb populated with a prototyping pad matrix in case somebody wants to make their power supply.
Access to 4 analogue,4 digital and the serial port pins is made through PCB pads.
In doing this I think I have opened up the scope for experimenters to play around with these tubes by producing a 4 tube assembly which is very easy to program. I can make use of DIP pics instead of SOIC pics to facilitate quick program changes and testing without having to increase the size of the PCB.
Smartsocket code can then be supplied seperately on a 'plug in' basis in the form of preprogrammed DIP pic.
The first run of prototype boards has gone well, although there are only 5 pairs available. if anyone would like to obtain one of these first kits (without the backup battery mod) I will be selling them with a kit of parts very soon.
Thanks for your interest and support