Compuprint 10200 Programmer Manual - Manual (Page 220)

Interfaces
216
Reverse Idle Phase: Set high in response to PtrClk (nAck) low pulse to re-enter reverse data
transfer phase. Is set high with 1284 Active (nSelectIn) being set low, the
1284 idle phase is being aborted and the interface returns to Compatibility
Mode.
Peripheral Logic High (+ 5V)
Set high to indicate that all other signals sourced by the printer are in valid state. Set low to indicate the
printer is off.
n.a. (nInit)
Compatibility Mode: Pulsed low in conjunction with 1284 Active low to reset the interface and
force to return to Compatibility Mode idle phase.
Negotiation Phase: Set HIGH.
Reverse Data Transfer
Phase: Set HIGH.