Julie, the full diagram of the CPU section is here:-
http://www.zimmers.net/anonftp/pub/c...N/320349-1.gif
The diagrams for the rest of the circuit / machine are here:-
http://www.zimmers.net/anonftp/pub/c...ers/pet/2001N/
Rather than 1 74LS245 (which would be reasonable to expect) the machine instead uses another pair of 244s as data bus buffers. However (in contrast to what I said in #362) these buffers only buffer the data bus feed to certain areas including the expansion port and circuit diagram sheets 5 and 8. The CPU data bus connections to other parts of the machine (circuit diagram sheets 2,3,4) appear to be direct.