Specifications

181
Syntax:
CHAIN "[drivename:]programfilename"
Parameter:
"[drivename:]programfilename"
A string expression.
Description:
CHAIN transfers control to a program specified by "[drivename:]program-
filename
". That is, it terminates the current running program (1st program) and
closes all of the files being opened. Then, it initializes environments for the chained-
to user program (2nd program) specified by "
[drivename:]programfile-
name
" and executes it.
• [drivename:] is used in conventional BHT series. In the BHT-100 series, it is
merely for the compatibility with their specifications. The
drivename may be A:
or B:, but it will be ignored.
•
"[drivename:]programfilename" is an executable object program
compiled by the Compiler and has the extension .PD3, as shown below. The
extension .PD3 cannot be omitted.
CHAIN "prog1.PD3"
• You should download an executable object program (2nd program) to the BHT
before the
CHAIN statement is executed.
• You can pass variables from the current program to the chained-to program (2nd
program) with the
COMMON statement.
• User-defined fonts loaded by the
APLOAD or KPLOAD statement and the setting
values assigned by the KEY statement or COUNTRY$ function remain effective in
chained-to programs.
• The
ON ERROR GOTO statement cannot trap run-time error 07h (which means
"Insufficient memory space") happened during initialization of environments for
chained-to programs.
Flow control statement
CHAIN
Transfers control to another program.