From: Greg King (gngking_at_erols.com)
Date: 2002-11-21 11:38:02
-----Original Message----- From: William Levak Date: Wednesday, November 20, 2002 12:41 AM Subject: Re: LOAD command (Was: Disk drive questions) > > On Mon, 18 Nov 2002, Marko [iso-8859-1] Mäkelä wrote: > > > On Sun, Nov 17, 2002 at 11:10:29PM -0500, William Levak wrote: > > > Even a simple LOAD or SAVE uses the command channel, although you normally > > > don't see it from BASIC. > > > > Are you sure of this? I thought LOAD would be equivalent to OPEN1,8,0,"FILE" > > and SAVE to OPEN1,8,1,"FILE". I may remember the secondary addresses wrong. > > You're right. I did some tests, and the command channel is not affected. > Apparently, all the result information comes from the status byte. When a drive cannot open a file successfully, it refuses to move that file's data. LOAD attempts to read the first byte (load-address), then it looks at the STATUS variable. If LOAD sees the read-time-out flag, then it knows that the file could not be found. SAVE, on the other hand, has a bug (I wonder how many people noticed this): it blindly sends the data to the drive -- it does not care whether or not the drive accepts that data! If you try to save a large file, then you might wait a long time before you learn that the command did not work. Message was sent through the cbm-hackers mailing list
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