# 16V8 for I/O number zero (U37)

Device 16V8 #In combinitorial mode

input
    SYNC:1,      # Sync from CPU
    PH2:2,       # Phase2 from CPU
    PINT:3,      # Processing interrupt from CPU
    T3IOR:4,     # From CPU GAL, flags I/O read cycle in progress
    T3IOW:5,     # From CPU GAL, flags I/O write cycle in progress
                 # Input 6 not currently used
    A11:7,       # Address bus
    A10:8,       # Address bus
    A9:9,        # Address bus
                 # Input 11 not currently used

temp
    adr_0, adr_1, adr_2, adr_3, adr_4, adr_5

output
                 # Output 12 not currently used
    Reset.L:13,  # Master reset
    DBG1.L:14,   # Write-read debug latch-1
    DBG0.L:15,   # Write-read debug latch-0
                 # Output 16 not used
                 # Output 17 not used
    SYS.L:18,    # Read the system latch
    KBD.L:19,    # Write-read the keyboard                  
 
implementation

adr_0 equ !A11 & !A10 & !A9
adr_1 equ !A11 & !A10 &  A9
adr_2 equ !A11 &  A10 & !A9
adr_3 equ !A11 &  A10 &  A9
adr_4 equ  A11 & !A10 & !A9
adr_5 equ  A11 & !A10 &  A9

KBD     equ     Adr_0 & SYNC & T3IOR
SYS     equ     Adr_1 & SYNC & T3IOR

DBG0    equ     Adr_4 & SYNC & T3IOR
DBG1    equ     Adr_5 & SYNC & T3IOR


# If we are processing an interrupt then it's RESET time
RESET     equ  PINT