Since the Prop-1 and Prop-2 both use flavors of PBASIC, most conversions are pretty easy. Use these guidelines to make sure you don't miss anything.
1) Change your directives:
' {$STAMP BS1}
' {$PBASIC 1.0}
becomes...
' {$STAMP BS2}
' {$PBASIC 2.5}
2) Change SYMBOL to PIN, CON, or VAR
Instead of:
SYMBOL Trigger = PIN7
... use:
Trigger PIN 7
Instead of:
SYMBOL IsOn = 1
... use:
IsOn CON 1
Instead of:
SYMBOL secs = B2
... use:
secs VAR Byte
... and remember that you have Bit, Nib (4 bits), Byte, and Word variables.
3) PBASIC 2.5 add nice features like IF-THEN-ELSE and DO-LOOP that minimize user-created labels. Here's one example:
Instead of:
Run_Timer:
IF tix = 0 THEN Timer_Done
PAUSE 100
tix = tix - 1
GOTO Run_Timer
Timer_Done:
RETURN
... you can use:
Run_Timer:
DO WHILE tix > 0
PAUSE 100
tix = tix - 1
LOOP
RETURN
4) Functions with parameter lists use square brackets, [ ], in PBASIC 2.5.
5) SERIN and SEROUT are more flexible and require the biggest changes as there are no built-in baud constants. These, however, can be built into code like this:
T2400 CON 396
T38K4 CON 6
Open CON $8000
Baud CON Open + T38K4