RCA COSMAC Operator's Manual page 51

CARD NEST AND SIGNAL-NAMING CONVENTIONS (cont'd)
The following signal naming conventions are observed in
the backplane wiring schedule and on the detailed module
logic diagrams, all in the Appendix:
An 'N' following a signal name indicates a low (GND)
assertion signal.
EXAMPLE: CLEAR-N (equivalent to
CLEAR)
A
'pI
following a signal name indicates a high (VDD)
assertion signal.
EXAMPLE: MWR-P
An 'NI' following a signal name indicates a buffered
'N' signaL
EXAMPLE: TPA-N powers up to TPA-Nl
*
A 'PI' following a signal name indicates a buffered
'pI
signaL
The backplane wlrlng plan of Appendix D indicates the follow-
ing types of connection: ·unused pins, pins interconnected by
printed wiring, pins interconnected by a wirewrap, and pins
not connected on the backplane but which have meaning
defined by the plugged-in module. A blank entry defines an
unused pin. Unbracketed names indicate signals interconnected
by printed wiring. Bracketed names indicate wire-wrap inter-
connected signals. Names bracketed by asterisks indicate
signals not interconnected on the backplane (defined only
by the plugged-in module). Ground, GND, is wirewrapped as
well as printed. In all cases, identically named signals
are interconnected. The backplane was laid out so that signal
flow is horizontal, i.e., wherever possible the printed wiring
connects identical pins on different connectors. Note that
almost all of the printed signal interconnections are made
on the exposed side of the backplane. If the user wishes to
modify the backplane wiring for some reason, he can scratch
out. undesired connections and wrap or solder his own.
*
Enhanced current drive, delayed but logically equivalent.
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