>
>The sticky bit would be that the 3000's terminal I/O is essentially
>one-way-at-a-time: if the terminal device doesn't have a read request
>posted, then most data sent from the attached device will be discarded
>(the exceptions being break and subsystem break indications). And
>trying to do anything else with the terminal device will involve
>aborting the read request, doing the something else, and starting a new
>read request.
>
>If the OPTO22 protocol can work around this, you're probably OK.
>Otherwise, you will probably need to build a front-end processor of
>some sort.
>
>If you have questions, feel free to ask, but my COBOL is rustier than
>my SPL, and so I will probably present terminal I/O examples in the
>latter with heavy [ab]use of MPE intrinsics.
>
With the exception of a few watchdog functions (which I wouldn't be using
anyway), all OPTO22 communications are done through polling. So, that
shouldn't be too big a hurdle.
Since I've never done any terminal I/O programming on the 3000, I decided to
start with the 9000 which is much more familiar. Once I have a proof of
concept running, I can port it back to the older box.
SteveRob
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Received on Tue Jun 26 2001 - 13:09:19 BST