At 07:26 PM 7/24/98 -0500, you wrote: Originally, the Altair (S-100) bus did not define a need for termination of any kind. It was not until things on the bus started to speed up (using DMA and such) that anyone apparently thought about it. A number of companies started to put out terminator cards (active and passive) that just plugged in, and later some manufacturers (Gotbout being a notable example) began to incorporate (active) termination into their backplane boards. Can't hurt. I will say however, I do seem to recall seeing a board or two that would not run on a terminated bus, but that has been so long that I don't evem recall what it was. A note tho: if it is an active terminator, check the regulator voltages and filter caps on the board with no other boards in the machine. A bad terminator can introduce many more problems that it will solve. -jim --- jimw(a)agora.rdrop.com The Computer Garage - http://www.rdrop.com/~jimw Computer Garage Fax - (503) 646-0174