[comp.sys.apple] ALPE jerkiness

AWCTTYPA@UIAMVS.BITNET ("David A. Lyons") (10/31/88)

>Date:         Wed, 26 Oct 88 14:37:00 GMT
>From:         RICH <jordan%lvvm6.span@SDS.SDSC.EDU>
>Subject:      ALPE

>First, has there been any upgrade to the ALPE software on the Apple since
>AppleFest San Francisco?

It's been updated at least a cople of times since spring, if that's
that question (I can't remember for sure which AppleFest was where).

>I used it there and was somewhat underwhelmed [...] by the slowness
>and 'jerkiness' of the menus and text output.  While reading text
>messages, it would 'blip' a section of text to the screen, then
>pause, then 'blip' another section.

The jerkiness is definitely there (why? see below), but I *don't*
agree that it's slower than other services, if that's what you're
implying.  It may seem that way at first, since if you see, activity
only at, say, 1-second intervals while reading a message.  Now, I
haven't done actual benchmarks on this, but I don't think it's
significantly slower than the traditional approach--it even has
advantages (just a sec).

>From appearances, it looked like everything coming in was buffered
>in a smallish (128 byte or so?) buffer, and only put to the screen
>when the buffer filled.  To me at least the appearance was very
>annoying and distracting. Personally, I'd really rather have the data
>sent to the screen as it comes in (streaming mode).

128 bytes sounds about right to me, altho I don't have any specs for
the protocol being used.  (It's conceivable that the packets vary in
size--I don't know.)

It's *not* just a buffering scheme--it's actually a protocol where
"packets" of information are sent; error checking is done on each
packet, so you never get phone-line noise in your messages.  But
message chunks are not the only kind of packet!  Remember Flashnotes
(real-time messages), chat sessions, upload/downloads, requests to
Identify and Locate other users, and the little "banners" that it can
send across your screen.  Many of these things can be mixed
together--for example, you can be in the middle of a chat *and*
reading/writing mail in the post office *and* sending/reading
Flashnotes all at the same time.

I don't find the jerkiness annoying.  Note that for all but very
short messages, the jerkiness goes off the end of your scrolling
window.  You don't have to wait for the whole message to be received
to start reading it--you can scroll both ways while it's coming in.
As long as it's a few lines ahead of you (once the window fills up),
you won't see any jerkiness.

Now, if they would just fix it so I could read/write messages in the
forums while uploading & downloading things, I'd be Really Happy....

>                            Rich
><jordan%lvva.span@sds.sdsc.edu>
>BIX:    richjordan (Rarely there)
>GEnie:    BARRACUDA

--David A. Lyons              bitnet: awcttypa@uiamvs
  DAL Systems                 CompuServe:  72177,3233
  P.O. Box 287                GEnie mail:    D.LYONS2
  North Liberty, IA 52317     AppleLinkPE: Dave Lyons