fyi, here are the lines that the Q-BUS exposes on its 25 pin D-Sub connector:
GROUND +5V (In or Out depending upon the Power Source Select jumper) /ENABLE : Input, active low, default=1 (interface disabled) /WRITE : Tri-state output, active low (indicates a write to the currently selected port; byte appears on D0-D7) /READ : Tri-state output, active low (indicates that a read from the currently selected port is in progress; byte read from D0-D7) /SELECT : Tri-state output, active low (indicates a peripheral address is being selected; address appears on A0-A7 and remains until the next SELECT) /CONTROL : Tri-state output, active low (indicates a write to the Interface Control Register; eight control bits appear as a byte on D0-D7) D0 - D7 : Bi-directional, tri-state buffered data bus (requires terminating pull-ups on one of the attached peripherals) A0 - A7 : Tri-state, buffered peripheral address bus (address is latched and held when /SELECT goes low) Note: All I/O and control lines are disconnected if /ENABLE goes high. The info above may be of use to anyone who has other ROM-port peripherals so that we can avoid clashes and hopefully ensure some kind of compatibility between systems. Adrian <http://www.memorylanecomputing.com> www.memorylanecomputing.com _______________________________________________ QL-Users Mailing List http://www.q-v-d.demon.co.uk/smsqe.htm
