The BBC and Master Computer Public Domain Library

BEBD BPUT

Submitted by Steve Fewell

Description:

Call routine &BA3E to copy BASIC Text pointer A address to BASIC text pointer B, Check that the next character is '#'
('Missing #' error if not), set Y to the number after the '#' (the file channel number).
Store A (the file channel number, as &BA3E sets A to a copy of Y) to the 6502 stack.

Call routine &96AC to check for a comma ',' (issuing an error if not found), and get the Integer result of the
expression after the comma (issuing 'Type mismatch' error if a String value was found). The IWA now contains the ASCII
code of the character required to be output to the file.

Call &9B96 to check for the end of statement (at BASIC Text Pointer B). If the next character after the BPUT
parameter value is not ':', '<cr>' or 'ELSE-token' then issue 'Syntax error', as the statement was not terminated
correctly.

Retrieve Y (the channel number) from the 6502 stack.
Set A to the LSB value of the IWA (location &2A; i.e. the ASCII code of the character to output to the file).
Call the Operating system OSBPUT routine (&FFD4) to carry out the file operation.
Jump to &9005 to execute the next BASIC statement in the program/command line.

Disassembly for the BPUT routine