It seems that way. One interesting aspect in this design, if I read it correctly, is that there isn't a "collision detect" function in the transceiver the way there is in the 10 Mb D/I/X Ethernet. Instead, the transceiver delivers "TRDATA" (received data) and "TROTHER" which is the XOR of received and transmit data. So it looks like TROTHER != 0 means collision. In the later Ethernet, collision is detected in the transceiver and signaled to the NIC with a signal that's stretched out as needed. For example, in the DELNI schematics (also on Bitsavers) you can see a state machine to do that -- unlike the combinatorial logic in this "dummy transceiver". I wonder how it was done in the 10Base5 transceivers; I have a vague memory that it's partly an analog process but that may be confusion. (I may be mixed up with the "packet voltmeter" -- an A/D project at DEC to build a device that would make a map of a coax segment by measuring the voltages of each station's packets using sensors at both cable ends.) paul