[comp.sys.apple] ProDOS and BASIC

dalea@fai.UUCP (Dale M. Arends) (11/20/86)

In article
 <8611192224.AA09960@ucbvax.Berkeley.EDU> LMLARS01@ULKYVX.BITNET writes:
---
>The number of files you can have open in ProDOS is essentially limited
>only by memory.  Each open file has a 1K buffer associated with it.
>It sounds to me like your problem is that you didn't issue the READ
>command right before your GET or INPUT statement.  Remember that ProDOS
>commands sort of cancel each other.  A READ cancels a subsequent WRITE
>and vice-versa.  Both are killed by any other ProDOS command.
>
>                                               Lee
>                                               LMLARS01@ULKYVX.BITNET

Actually, ProDOS can handle up to eight open files at a time. You are 
correct in saying that the READ or WRITE statement needs to preceed EACH
GET or INPUT (or PRINT) to the file but only if the preceeding file access
was to a different file.  The CONTROL-D in the READ or WRITE statement is
what closes access to a file and flags a different path.  This allows a
program to have I/O to files and keyboard/screen without having to close
the open files.  Simply do a

	PRINT D$: REM D$ is a CONTROL-D

to tell ProDOS not to output to files.  The next READ or WRITE will again
access the files open.

-- 
--
		Dale M. Arends  (Fujitsu America Inc., San Jose, Calif.)
		seismo!amdahl!fai!dalea  -or-  ihnp4!pesnta!fai!dalea

The opinions expressed herein do not necessarily reflect those of my employer.
They are entirely my own if they make sense and I disavow them if they don't.