Re: Not possible to send two disk drive commands after each other

From: William Levak (wlevak_at_cyberspace.org)
Date: 2004-02-08 01:30:14

On Sat, 7 Feb 2004, Christian Johansson wrote:

> Hi!
> 
> 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.)

I have noticed that even in BASIC, some commands require that you read the
error channel afterword, or the next command is not executed correctly.  I
don't remember which ones, at the moment.


       Message was sent through the cbm-hackers mailing list

Archive generated by hypermail pre-2.1.8.