Busses vs no busses

From: allisonp_at_world.std.com <(allisonp_at_world.std.com)>
Date: Tue May 9 07:29:27 2000

> When asked once why I prefer the Q-bus 11's and Vaxen my answer is
> always because I can get lots of I/O to do neat things for those busses.
> (I'm writing a program for the PDP-8 to control an LED sign using a
> couple of 12bit parallel i/o cards. )

Now that's a cool hack. I nelieve one of the stadiums used a PDP-8 to
control a graphic scoreboard.

> be no slots. I thought that the bus was dead until I realized that USB
> has the same bandwidth as Q-bus and FireWire has much better bandwidth.
> So presumably we'll see some interesting I/O devices that use these
> busses in the future.

As the speed of the bus increases and the ability to contain the bus
interface in fewer chips increases the number of wires needed tends to go
down. Obviously two wires are easier to handle, terminate and connect
than 100. What also occurs is the simpler the bus the more sophisticated
the bus interface required, higher levels of integration feed that. It's
evolotionary. Think of USB and firewire as network buses and the devices
to connect them to things like printers and disks as "bridges".

Still, some buses will be hard fo the hobbiest to deal with due to the
specialzed logic needed.

Allison
Received on Tue May 09 2000 - 07:29:27 BST