Hello Mark, * On Sun, Feb 21, 2010 at 08:45:33AM -0500 Mark J. Reed wrote: > On Sun, Feb 21, 2010 at 7:44 AM, Ullrich von Bassewitz <uz@musoftware.de> wrote: [...] > > Ok, good point. But this means, just checking for zero is wrong. The code > > would have to check if $ba is less than eight and substitute 8 in this case. > > Right? > > If the value is below 8 (or above the maximum? Is there a ceiling on > the serial device number range for disk drives?), The serial device numbers on the bus can be 0-30. The higher bits are "FLAGS", and the device number 31 is used for special cases (UNTALK, UNLISTEN). The KERNAL only "automatically" uses the IEC bus for 4-30, though. Thus, for 0-3 to use the IEC bus, you have to use the IEC routines themselves (which do not have a KERNAL jumptable entry on VIC20 and older.) > all you know is that > the last operation wasn't to disk. Not even that. You can also build a disk on #4, #5, #6 or #7, for example. You cannot rely on the device number being unique for a device type. Regards, Spiro. -- Spiro R. Trikaliotis http://opencbm.sf.net/ http://www.trikaliotis.net/ http://www.viceteam.org/ ---------------------------------------------------------------------- To unsubscribe from the list send mail to majordomo@musoftware.de with the string "unsubscribe cc65" in the body(!) of the mail.Received on Sun Feb 21 17:56:36 2010
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