22 Nov
2006
22 Nov
'06
1:22 p.m.
From: "Al Kossow" <aek at bitsavers.org>
Sure. The TC08 is a Posibus Data Break device, though, and that's 72 pins
right there. There are 67 indicators, 15 connections to the drive, and 41
connections to various non-digital (think Gxxx and such) interfaces, for a
total of 195 "pins".
I also believe the Posibus itself is amenable to multiplexing, with some
latching drivers. There's some work to be done to get the thing down to
a reasonable pin budget for a non-BGA chip, though :-).
These issues come up if you try to push the CPU into an FPGA, too. All
the ones I've seen replace all the cool vintage intefaces with a screen
and a keyboard :-(.
For the TC08
and similar devices, the issue really comes down to
the Posibus interface and the Blinkenlights. Both are key features
of the TC08, and both are very pin-hungry.
Lights can be serially multiplexed to an external holding register / light
driver on the panel. A TC08 on an omnibus card would be useful too.
Nah, you just need yet more Posibus and Data Break cards for your
Omnibus machines :-).
I like Posibus because it works with more of the -8's, and can be
built without hard-to-find receivers and drivers.
Vince