From: Greg King (gngking_at_erols.com)
Date: 2003-06-10 12:40:40
-----Original Message----- From: Baltissen, R (Ruud) Date: Saturday, June 07, 2003, 03:13 AM > > Hallo Marko, > > > I remember seeing a piece of code that tells a printer to > > LISTEN and a disk drive to TALK, in order to print a file > > while the computer could do something else. > > Quite simple if two drives are concerned: > -- you tell the TALKER what file to send > -- you tell the LISTENER what file to receive > -- you tell the LISTENER to start to LISTEN > -- you tell the TALKER to start to talk A fifth step is needed: -- you "disconnect" from the bus. The General Purpose Instrument Bus allows multiple controllers. They (and other devices) have three modes: listen, talk, and idle. But, Commodore's version allows only one controller (the computer); it never idles! That program "fakes" the idle-mode. It sets the IEC's output-buffers so that they let the lines float (high). That step stops the computer from interfering with the transfer between those devices. Message was sent through the cbm-hackers mailing list
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