If you don't have any complex math formula's in the program, you can reduce the number of T?_Save variables.

From ReEnterPBP.bas...
T1_Save VAR WORD
T2_Save VAR WORD
T3_Save VAR WORD
T4_Save VAR WORD

Start with T4. Comment it out and recompile. If no error, try T3, etc.

Then try ...
RS1_Save VAR BYTE
RS2_Save VAR BYTE

Might save a few bytes of RAM.

Just remember to un-comment them if you write a program for another chip.

DT