pTAL Conversion Guide

TAL Standard Routines
pTAL Conversion Guide—527302-002
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pTAL
pTAL
You can test $OVERFLOW only if overflow traps are disabled and only following an
assignment statement in which the final operator executed on the right side of the
assignment is one of the following operators or standard routines:
•
Negate (unary -), +, -, *, /,’/’
•
$DBL of an INT, FIXED, REAL, or REAL(64) value
•
$FLTR of a REAL(64) value
•
$FIX of a REAL or REAL(64) value
•
$FIXD
•
$FIXI
•
$FIXL
•
$FIXR of a REAL or REAL(64) value
•
$INT of a FIXED, REAL, or REAL(64) value
•
$INT of a FIXED, REAL, or REAL(64) value
•
$INTR of a FIXED, REAL, or REAL(64) value
•
$SCALE, for which: 1 <= exponent <= 4
For more information about overflow, see Section 20, Hardware Indicators.
$RP
$RP is a TAL routine for which pTAL has nothing similar.
$RP returns the current value of the TAL compiler’s internal RP counter (not the run-
time value of RP).
The RP counter is a value between 0 and 7 that is an index into an eight-element array
of 16-bit registers and defines the current top of the register stack.
$SWITCHES
$SWITCHES is a privileged TAL routine for which pTAL has nothing similar.
$SWITCHES returns the current setting of the SWITCH register.
VST017.vsd
$RP
VST020.vsd
$SWITCHES