It is possible to control either the STMISOL or the STM200 with a TTL pulse from a parallel port or other device. For example, if you raise one of the digital output lines of the parallel port from 0 to 5 Volts for 50 msec and connect it with the ground from the parallel port to the 3.5mm input of the STMISOL/STM200, the stimulator will output a pulse. The following output would occur under the example conditions of 0 to 5 volts for 50 msec. 

• For the STM200: a 50 msec pulse at whatever voltage is currently set on the front panel
• For the STMISOL: a 50 msec pulse at 100 V (if used in voltage mode) or 50ma for 50 msec (if used in current mode)

Connection order:

25 pin Parallel port via 25 pin printer port cable (you will need to determine what connectors should be MALE/FEMALE on each end of the cable based on the exact components you are using) 

to

Parallel port splitter (optional so you can still use the parallel port for other tasks)

Example(picture taken from http://www.cablesandconnectors.com/PIX/CC-082.pdf):