1) There are three main differences between Apple's previous Token Ring
card and this one:
- Transmission speed
The old card supported only 4 Mbps transmission, and the new card
supports both 4 and 16 Mbps.
- On-board memory capacity
The old card came with 512K RAM on the card, but there was no
expansion capability. The new card comes with 512K standard,
expandable to 1 or 2.5MB.
- Token Ring technology
The old card used the Texas Instruments TMS380 Token Ring chip set.
The new card uses the industry-standard IBM Token-Ring chip set.
2) There's no upgrade program at this time.
3) Both of the cards are based on IEEE 802.5 standards for Token Ring, and
will therefore work in all standard Token Ring environments. You can
use multiple protocol stacks with the cards, including SNA and
AppleTalk. In fact, because both cards are based on the Macintosh
Coprocessor Platform architecture, you can run multiple network
protocols simultaneously. Still, some customers found the name
TokenTalk confusing, thinking that the card only supported AppleTalk
protocols. We have changed the name to reflect the broad range of
applications possible with the card, and to complement its standards-
based design.
4) That depends on your network configuration. We find that in low-traffic
situations, the increase in throughput is not astronomical. Generally,
this is because the bottleneck is not how much information can be
transferred over the wire, but how much can be processed in and out of
the Macintosh. As the total amount of traffic on the ring increases,
the capacity of the network becomes more important and 16Mbps token ring
begins to perform better than 4Mbps Token Ring.
Operation at 16 Mbps also provides a feature called "Early Token
Release," whereby more than one frame may exist on the ring at once.
This provides an additional improvement in throughput, especially on
large rings carrying a significant number of small frames.