The CHR$(n) function is incorrectly documented:
"To convert a number n into its corresponding ASCII character. n must be a numeric constant (0 to 255)"
The range of n is limited to 1..255. This limitation is consistent with most variants of BASIC. The value of &H00 is used to mark the end of a string in many versions of BASIC. Your documentation for ASC(x$,n) hints that this is the case for TBASIC.
If n is set to a value of 0, it will break the simulator in TRiLOGI V 6.40 build 02.
The following code will compiles w/o error but fails during simulation. No error message is issued by the simulator, but the 2nd line of code is not executed (A is not set to 255).
A$ = chr$(0) ' illegal value for chr$()
A = 255 ' this line of code does not execute
Just add it to your list of small things.
Gary D.