The BBC and Master Computer Public Domain Library

B181 Load Variable & Push its value and address details to the BASIC Stack

Submitted by Steve Fewell

Description:

If the Variable type (location &2C) is less than #&05 (i.e. an Integer value) then retain the Variable's parameter
block (&2A-&2C) by temporarily storing the IWA value in locations &37-&3A.

Call routine &B1A0 to load the variable's value into either the IWA, FWA or SWA (depending on the variable type).
Store the 6502 flags on the 6502 stack (to retain the variable type details).

Call routine &BC22 to push the variable's value to the BASIC stack.
Retrieve the 6502 flags from the 6502 stack.

If the 6502 flags indicate that the variable is not a String (Zero flag not set) or a Floating-Point value (negative flag
not set), then it must be an Integer, so call &AA80 to restore the variable parameter block (&2A-&2C),
i.e. the IWA, from the zero-page locations &37-&3A.

Call routine &BC26 to push the IWA value to the BASIC Stack - this ensures that the variable's address and type
details are stored immediately after the variable's value - this enables the values to be matched back to the original
variable's once the subroutine has been executed.

Disassembly for the Load Variable & Push its value and address details to the BASIC Stack routine