Reports have appeared of problems with HyperCard sending sounds over a
network. The sounds break up badly when they arrive at a workstation.
This includes sounds accessed from CD-ROM. Also, network performance slows
noticeably when sounds are being transmitted.
Some people have guessed that the breakup of the sound is due to clipping
of packets, but this is not the case. If packets were being clipped, there
would be no sound played at all. When AppleTalk receives an incomplete
packet, it throws the packet away and requests a retry. If the packet is
thrown away, HyperCard would never know the packet had been sent.
The breakup is due to the sounds being shipped in packets. In tests, the
sound starting and stopping correlates to the beginning and the ending of
packets. This is especially true with longer sounds, such as musical
passages.
Applications used across the network need to take into account the limits
of the network. Other performance difficulties have appeared in other
applications not designed for network access. Ethernet speed may solve
this particular issue. However, to achieve the best performance, an
application needs to be designed for the network environment. Long,
digitized sounds being transmitted over the network are less than ideal for
network-application design.
One approach to using long music passages in HyperCard is to keep the music
passages on local storage. HyperCard looks first for the requested
resource in the stack, next it looks in the Home card, then in HyperCard
itself, and finally in the system. If the required sounds are installed in
a local Home stack, the breaking up of the sound does not happen. If these
sounds are stored locally, you must remove them from the stack residing on
the server. Because HyperCard looks at the current stack first, the sounds
in the server stack are used, unless removed.
If the applications have not been optimized for multiuser network access, a
drop in network performance would not be unusual. Additionally, the
AppleCD SC has a slower access time than the typical hard drive that is
used as an AppleShare server.