Getting a Sun Ultra 5 To Work

Some of those 'universal' switching adapters (or patchboards) had the problem that you couldn't strap 2 signals at ne end of the cable withoug it goign to soemthign at the other end. In particlar doing things like looping cak RTS to CTS and each end with no connection to the otehr end was impossible YEasr ago I made a universal RS232 adapter. It used a lot of DIP switches and a pair of DB25 conenctors. From waht I rememebr : A DPDt swithc did the obvios staright/cross connection of TxD and RxD. There were 4 off 4-way DIP switches associated with each connector and 4 further switches linking them. The following circuit was built 4 times : RTS --/ o----+ +---/ o---RTS CTS --/ o----+ +---/ o---CTS DSR --/ o----+-----/ o------+---/ o---DSR DTR --/ o----+ +---/ o---DTR These circuits could be used to link any handshake line at one end to any line at the other end, or, bu openning the middle switch to loop back handshake lines at one or othre end. Or of course to do things like DTR at one end driving DSR and CTS at the other end. I think I added a couple more swtiches to link the DCD line on each conenctor to the DSR line o tne hsame connetor. It worked wrll, and I nevr found a device that couldn't be got to work using it. On the toerh hand, working out the settings of 40 switches took as long (if not longer) than soldering up a custom cable... -tony