From: Greg King (gngking_at_erols.com)
Date: 2004-02-14 10:29:35
From: Christian Johansson; on Date: Saturday, February 07, 2004, 05:33 PM > I just noticed that if I, in assembly, first send one disk drive command > to the disk drive, e.g. "U1 3 0 1 0", and I then, immediately after the > carriage return, send another disk drive command, such as "B-P 3 0", > both commands fail. The drive light starts to flash, and if I read out > the error channel, it says "30 SYNTAX ERROR". If I just send one of the > disk drive commands, it works well. Why is this? Must there be a pause > between the commands, for it to work, or do I perhaps have to call UNLSN > followed by LISTN between the commands, or do something else to get it > to work? (For my application, I found that the B-P command was > superfluous; so, I could just leave it out. But, I would still like to > know how to do it.) Yes, it is UNLSN that actually executes a DOS command. In fact, the DOS ignores a carriage-return that is at the end of the command; you do not need to send that character. Position-commands are an exception: the record-number might contain chr$(13); so, you do need to add a carriage-return to the end of those commands. Then, DOS will ignore the carriage-return, and keep the chr$(13). Message was sent through the cbm-hackers mailing list
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