According to Jeff Kell:
>
[stuff deleted]
>
> There are THREE "modes" of terminal I/O on MPE/iX:
>    * Block mode (you truly read a line or screen with no interrupt other than
>      break possible,
>    * Line mode, where you read "x" characters (where x > 1) with provisions
>      for break, end-of-record, subsystem break (ctl-Y), certain line editing
>      characters (ctl-H, ctl-X, some escape sequences, break, ctl-Y, etc).
>    * Character mode, where every character is processed by the application,
>      or essentially FREADs of 1 byte at a time.
>
> In the latter case, yes, you can significantly impact an MPE/iX system.
> In the center case, the DTC pre-processing has eliminated much of the host
> overhead traditionally associated with block mode.  Block mode may still
> offer the best solution (I haven't extensively benchmarked it) but line mode
> is no slouch on an MPE/iX box.  This may break down further when host-based
> incoming telnet comes into play, but for now, it is fine.  Likewise for VT
> connections, where the DTC intelligence is extended to the VT client.
>
> I don't know how the original "Uniface" system operates, but unless it is
> truly character mode by the latter strict definition, it should not be an
> overly relavant factor in your performance, as compared to the other possible
> bottlenecks you may be facing.
>
> [\] Jeff Kell, [log in to unmask]
>
 
Cognos has done a good job with Quick (with version 7!) of combining
line-mode and character mode to get very good performance.
 
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Richard Gambrell        | Internet: [log in to unmask]
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