I have recently been given a starturn -1985 manufacture- in a clearout at my school. The BBC computer and software have long disappeared and I don't think the lathe has actually ever been used at all -its as clean as a whistle ! Plugging in the machine only -the cooling fan starts up -but nothing else operates, presumably because the 37 pin connector is not connected to any driving/program commands from a computer. Can I drive the lathe manually ? using push to make switches to activate the X/Y stepper motors forward/reverse and spindle on/off (with the onboard potentiometer to control speed). I have experience of making stepper motor driver boards and understand the need for clock pulses/and direction high/low switching - is it possible to make an external control switchpad to control the functions - I would be glad to hear from anyone who could point me in the right direction.
CNC Expert
HI & welcome to the nut house 
Google Mach3 that's the software sorted
& search this form, I believe Davidmurry has posted his conversion, seems easy enough
Google Mach3 that's the software sorted
& search this form, I believe Davidmurry has posted his conversion, seems easy enough
Self Catering Lodges in Central France with covered pool & large grounds
www.la-coterie.com
www.la-coterie.com
CNC Expert
David-Thanks for the information - since posting my query I have gone through every wire on the control board using the electrical data sheets posted by denford and labelled their function. I found that the motor spindle control fuse was blown and now have the spindle turning under the potentiometer control. The next step is to gain manual control of the X/Y stepper motors. I have located the pulse and direction control terminals and wires coming from the 74LS38 nand gate/buffer on the relay board. Your detail on using the transistor gate to pullup/down the signal should provide me with the answer to gain manual control of the saddle and topslide - many thanks - will post back when successful.