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psion/opl #1225, from psioncorp, 1153 chars, May 31 10:15 94
Comment to 1223. Comments. 
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FINDFIELD in fact has two bugs:

1. The flags% argument is documented incorrectly in that the nibbles of the lo-
w 
byte are in the opposite order. ie. the case dependent/independent value 0 or -
1 
must be multiplied by 16 (hex $00 or $10), while the direction value 0,1,2 or -
3 
should be used directly. The allowed values are therefore 0,1,2,3,16,17,18,19 -

(hex $00,$01,$02,$03,$10,$11,$12 and $13).

2. FINDFIELD actually does FIND unless the byte at address peekw($1c )+7 
happens to be zero! Therefore a temporary fix is to use:
pokeb(peekw($1c)+7),0
immediately before calling FINDFIELD.

NB pokeb peekw($1c)+7,0 must be called *immediately* before *every* 
call to FINDFIELD.This is because that address is a "scratch register" used by-
 
the OPL runtime for many things.

This also means, in fact, that you must not use procedures or functions of any-
 
kind for arguments to FINDFIELD because they could change that address. eg. 
pokeb ... :FINDFIELD(a$,s%:,GET,2) will fail. Always use constants, parameters-
, 
variables (array elements too), fields or arithmetical expressions based on 
these for FINDFIELD arguments.

Dave (psioncorp)