PlayNet
Randell Jesup
This is a reply to an ancient message found via DejaNews.
Brian Heyboer <bjhe...@space.honeywell.com> writes:
>Brian Williams wrote:
>> I've been reading about this for some time, and.. can anyone tell me
>> WHY aMERICA oNLINE won't sell the software or the rights to run
>> Qlink?? What the hell are they scared of?!
>
>I can't tell you for sure, but I suspect they are afraid it will give
>away some of their security systems that are also used in the AOL
>software. Remember, there was a lot more on the Q-Link end than just
>the interface for the users. There was also their entire billing and
>password security system. There was also a "back door" of sorts where
>Q-Link menus and what-not could be updated via AOL.
AOL is in fact largely based on rewritten QLink (nee PlayNet)
code. Many of the algorithms are unchanged.
>Another possibility is that they cannot rather than will not. Q-Link
>licensed the software from Playnet and acquired the rights to it only
>after winning a lawsuit against the receiver of the bankrupt Playnet.
>They never did get all the source code and documentation the lawsuit
>gave them the rights to. So, they may not be able to either because the
>terms of the judgement don't allow it or they simply don't have it all.
In fact, they may not have the right to resell the technology;
it depends on what rights they got. (I suspect they eventually got all the
rights, though.)
They did, however, have all the source code and documentation
for the PlayNet system, at least as it was when they licensed it (we made
a number of mods later to PlayNet, some of which were activated and some
never were). I spent a number of days down there training various
programmers there on the design. One thing added after QLink (now AOL)
licensed PlayNet was a quite complete auditorium/panel/etc setup with
queuing, moderators, etc, run entirely via online messages (no client
software change required). This was complete and tested and finished
the week before PlayNet declared bankruptcy, so no one ever actually used
it. There were other things too, but I remember that because I was working
on it as PlayNet went under. Of course, they made their own mods
(initially mostly cosmetic, but they added lots of stuff later).
As must be obvious, I was one of the main (and last) programmers at
PlayNet. It's _really_ amusing to look at AOL today and say "I know why
users are limited to 10-character names.", and see many other elements of
the original PlayNet design unchanged (even though the reason for them is
LONG gone). For example, the 10-character name limit was largely based on
how many screen names we could display in the room header in chat within
4(?) 40-character lines on a C64 screen. Ditto the screen-name defaults (I
remember us sitting around BS'ing about how we'd handle that, and conflicts
- so now you have JoeS12345.) Online messages and how they popped up were
another Playnet idea (remember, the next-most-sophisticated system at the
time was Compuserve's ASCII "CB". Much has changed in AOL, of course, but
it's kind-of heartening to see just how well a design from 1984-85 for 64K
6502-based machines has held up over the years, at least in the broad
strokes.
The system (PlayNet and QLink) was actually quite sophisticated.
It was run by programs written in a multi-tasking state-machine language.
(Yes, your C64 was multi-tasking when doing this - N state-machine tasks
plus the "main" (basic/etc) task, which ran the game or whatever if needed.
Things like Online messages caused a new task to be started.) The
communications protocol was designed (by me) to error-correct the X.25
pad<->modem link, obey a limit on packet size (128?), and minimize the
number of packets (since we were charged both by the hour and the packet
back then). It used CRC error-checking (yes, in a C64), asymmetric
sliding-windows, piggybacked-acks, selective retransmit, etc. It may be
that this protocol continued (continues?) to be used in modified form in
AOL, from what an AOL engineer told me shortly after QuantumLink launched
AOL. I also wrote the fast-loader (which hid itself under the screen ram
when not in use, and used huffman compression of all files to help speed
loads) and other bits like the server side of the BBS (news-sort-of)
section (my original rejected design was much more like News; amusing since
I hadn't seen News at that point).
The server side ran (and runs) under Stratus VOS on Stratus fault-
tolerant hardware (originally at PlayNet a Stratus 200, with 8 12Mhz
68010's). The server-side software was (and may still be) written in PL/1
subset G, as was most of Stratus software of the era, including the OS (C
was introduced around the time PlayNet went under). The design of the
Playnet server software was specifically set up to make maximal use of
multiple servers connected by medium-speed links. For example, each chat
room was a separate process (if I remember correctly, or maybe each process
handled N rooms), and all the IPC was set up to use Virtual Circuits
(sort-of equivalent to sockets), so they didn't care whether the other end
was on the same system or not.
AOL still runs on Stratus hardware, and pushes it (and VC's etc)
to the limit I'm told. For a while they kept an old Stratus in the corner
of the machine room for C64 owners, as I'm sure you know.
It's also amusing to now see the explosion of networked games; many
ideas just now reaching the public are very similar to the stuff we built
prototypes of or sat around discussing back then.
If people really want, I suppose I could write up my view on the
soap opera of how PlayNet was, what happened, how AOL nee QLink nee CVC
got the software, etc.
--
Randell Jesup, Scala US R&D, Ex-Commodore-Amiga Engineer class of '94
Randel...@scala.com
#include <std/disclaimer>
Exon food: <offensive words no longer censored - thank you ACLU, EFF, etc>
CDKAISER
It would be really cool just to find out what *did* happen behind the
scenes at Qlink. I actually have some of the old PlayNet software hanging
around somewhere ;-)
By the way, I had no idea Scala was still around.
Still writing for the Amiga?
Cameron Kaiser
spe...@calvin.ptloma.edu
www.computerworkshops.home.ml.org
R. T. Cunningham
Yeah, and I'd like the hear the whole story behind the changes to the
Lynx program by Will Corley. I've been told it had to do with the
"Big Tops".