UNIBUS transceiver was RE: have an extra M105 + M7821 unibus card?

vrs wrote: The bus driver/receiver voltage spec (absolute maximum voltage of 2.5V) of these parts is NOT suitable for UNIBUS/QBUS. These parts are designed for low voltage swing busses and may work in the short term on UNIBUS, but will eventually fail, as the UNIBUS termination voltage (static high level) is 3.5V, 1V over the abs max rating. I've looked at this problem a bit and the most suitable modern day (ie, still in active production) part I've found is the Am26S10C. TI now produces this older AMD part, and it is available in both 16DIP and 16SOIC. It is a quad part not unlike the DS8641. You can get them at Digikey for about US$1.35 each. Even in Pb-free packages. The 26S10 has 100ma OC drivers, and the bus receiver input threshold is in the 1.75-2.25V range, very close to UNIBUS specification. The only issue I see in using this part is that the specs of the output rise/fall time are sub 10ns transitions. This may cause problems with reflections, especially on UNIBUS systems with longer cables. Don