Submitted by Steve Fewell
Name: '$' address peek/poke operator
Starting Address: &98DC
Entry criteria: PTR B points to next character in command line.
Exit: The IWA contains the address (&2A, &2B).
&2C contains #&80 to indicate that a string is the variable type at the address.
Carry is set.
Increment the Text pointer B offset, to point to the next character of the command.
Get the integer value after the '$' operator and place the value in the IWA.
Note: As '$' is a 'peek/poke' operator, the expression handler is not used, as the address
value for the 'peek/poke' operation has the highest precedence.
BASIC does not allow an '$' function to be applied to a zero-page address, so if the
addess MSB (in &2B) is zero then generate the '$ range' error.
Otherwise, set &2C (the variable type at the address) to #&80 (to indicate a String),
set the carry flag (as the return value is a String) and exit.
|98DC||230 027||E6 1B||INC &1B|
|98DE||032 180 150||20 B4 96||JSR &96B4 Get Integer value at PTR B|
|98E1||+||165 043||A5 2B||LDA &2B|
|98E3||240 006||F0 06||BEQ 6 --> #&98EB $ range error|
|98E5||169 128||A9 80||LDA#&80|
|98E7||,||133 044||85 2C||STA &2C|