From: Marko Mäkelä (marko.makela_at_hut.fi)
Date: 2004-05-26 18:24:18
On Wed, May 26, 2004 at 09:14:00AM -0500, Jim Brain wrote: > True, my command can be repeated: > > LISTEN 4 > LISTEN 5 > LISTEN 8 > etc. True. I confused your LISTEN directive with the LISTEN command of the serial bus. But I still think that it's cleaner to list all device numbers in a single atomic command. > I'm still trying to decipher your protocol. How does it deal with a > resynchronization of the serial line (to prevent interpreting commands > as data or vice versa? In my protocol, $00 is the escape command. A $00 data byte is escaped as $00 $00. If an ATN interrupt arrives, it'll send some $00 xx escape (see the comments). There are also $00 xx responses for indicating EOI, end of ATN transmission, or talk-attention turn around. > I also want to support higher level commands (get file, let the AVR deal > with the IEC commands) I didn't want to do that, because I thought you would need a custom application on the other end of the serial line anyway. Besides, the Flash ROM of the 2313 was getting a little tight (especially if support for burst mode transfers or JiffyDOS is going to be added later). It would be a different matter if all protocols for the cassette port were removed. Of course, as you have a bigger controller, the design constraints are different. > I've got routines working, and I have a state diagram (had to generate > one for my state machine in the AVR. Could you represent the diagram in an easily editable format? I'd start with the input language of GraphViz, but maybe someone knows a better approach that has been implemented in an open source or free software tool. Marko Message was sent through the cbm-hackers mailing list
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