CODE PICK
HL POPqq,
chkPS,
( x2 )
L SLAr, H RLr,
SP ADDHLss,
C (HL) LDrr,
HL INCss,
B (HL) LDrr,
( check PS range before returning )
EXDEHL,
HL PS_ADDR LDddnn,
DE SUBHLss,
CC L2 @ JPccnn, ( abortUnderflow-B298 )
BC PUSHqq,
;CODE