Date   : Fri, 03 Feb 1984 1240-:00PST
From   : Ted Shapin <BEC.SHAPIN@USC-ECL.ARPA>
Subject: The problem with LISTST

Digital Research made an error in their manual in describing what LISTST
should do.

"The value 00 is returned in A if the list device in not ready to accept
a character and 0FFH if a character can be sent to the printer. A 00 [!] value
should be returned if LISTST is not implemented."

An application program cannot know whether the BIOS implemented LISTST or
not.  If the application program uses this BIOS entry point and assumes it
is implemented according to DRI's instructions, it will loop forever waiting
for a 0FFH if tha BIOS doesn't implement LISTST and returns a 00.

I do my checking for printer ready in the LIST code which outputs a character.

It sounds like Lifeboaat may have done a similar thing and perhaps there is
a bug in the LIST routine.
Ted.