Programming instructions

DIVIDE SUBROUTINE

/PDP-4 ones complement divide subroutine

/calling sequence: /lac high order dividend

/jms divide

/lac low order dividend

/lac divisor

/return; quot. in AC, rem. in dvd. if high dividend is

/greater than divisor, no divide takes place and L=>l. Time = 3.1 ms

divide, 0

spa + cl1 - opr

cma + cml - opr

dac dvd

xct i divide

spl

cma

dac quo

jms dv5

dv5, 0 /remainder has sign of dividend

isz divide

xct i divide

sma +cml - opr

cma + cml- opr

jms dv4

dv4, 0

cll

tad (1

dac dvs

tad dvd

isz divide

spl

jmp i divide

lac (-22

dac dvl

jmp dv2

dv3,

lac dvd

ral

dac dvd

tad dvs

spl

dac dvd