On Thu, Jan 14, 2016 at 11:49 AM, Mike Stein <[email protected]> wrote:
> 'Stealing power' (AKA parasitic power) from the control lines is a fairly > common technique in the RS-232 gadget world: > > http://www.epanorama.net/circuits/rspower.html > > I think in the case of the TPDD it was used in the LapDos cable to power a > *real* CMOS TTL<>RS-232 converter IC to connect to the higher voltage > levels of a PC; the kludge in the M100 cable would not be adequate. > > m > > > Well I've used a real TPDD cable with a real TPDD and USB -> RS232 ports. It works. I don't remember whether I've ever tried it with an actual PC serial port. -- John.
