;PALASM Design to switch in PDP11 board as a slave

;---------------------------------- Declaration Segment ------------
TITLE    Slave Port Select for PDP11 Board
PATTERN  Non Latched
REVISION 1
AUTHOR   John Monahan
COMPANY
DATE     1/1/2017

CHIP PDP_GAL0  PALCE22V10       ;Select a GAL 22V10

;---------------------------------- PIN Declarations ---------------

PIN 1   PULSE_IN                ;CLK pin, input from pin 23 (PULSE_OUT)
PIN 2   A0                      ;Note these are actual S100 bus address lines (outside the 80486)
PIN 3   A1
PIN 4   A2
PIN 5   A3
PIN 6   A4
PIN 7   A5
PIN 8   A6
PIN 9   A7
PIN 10  A8
PIN 11  A9
Pin 12  GND

Pin 13  A10
Pin 14  A11
Pin 15  A12
Pin 16  A13
Pin 17  A14
Pin 18  A15
Pin 19  sINP                    ;S100 bus status Port IN line
Pin 20  pDBIN                   ;S100 bus port write
Pin 21  /RESET                  ;Active LOW reset pulse from S100 bus
Pin 22  TMAXPU                  ;Toggle bit to TMA 1-4 (inversed)
Pin 23  PULSE_OUT               ;Pulse to clock pin 1 input

;----------------------------------- Boolean Equation Segment ------

EQUATIONS

/PULSE_OUT   =       A0 * /A1 * A2 * A3 * /A4 * A5 * A6 * A7             ;Port EDH = 1110 1101
                  * /A8 * /A9 * /A10 * /A11 * /A12 * /A13 * /A14 * /A15
                  *  sINP * pDBIN
                  +  RESET  * TMAXPU                                     ;Clock LOW if HIGH with reset

TMAXPU       :=       /TMAXPU  * /RESET                                  ;Toggle
                  +   RESET