Submitted by Steve Fewell
Set A to #&40. This is the OSFIND (&FFCE) option to open a file for input access only.
Call routine &AAE9 (part of OPENUP) to obtain the filename and place it in the SWA (or issue 'Type mismatch' error if
a String value was not found), Append a '<cr>' character to the end of the SWA (so that the filename is correctly
terminated for the OSFIND routine's requirements), Set X and Y to point to the SWA (&0600), call OSFIND (&FFCE)
to open the file, and return the opened file's channel number in the IWA.
|AADF||@||169 064||A9 40||LDA#&40|
|AAE1||128 006||80 06||BRA 6 --> &AAE9 Get filename, call OSFIND to open the filename specified in the SWA & set IWA to channel#|