11 Aug
2019
11 Aug
'19
6 p.m.
On 8/11/2019 7:01 PM, Jon Elson via cctech wrote:
On 08/11/2019 11:11 AM, W2HX via cctech wrote:
I just looked at the TC02 and the Qualstar, there are termination
resistor packs on each.? The Qualstar has a bunch of 74LS240 IC's near
the J1 and J2 pertec interface cables.? The TC02 has a bunch of 74LS374
chips near the J1 and J2 connectors.
This is where the electrical engineer could help.? How do you determine
how long a cable the 74LS240 can drive?
Doug
I seem to remember they were ribbon cables
with each odd/even pair twisted which probably meant one
active and one ground twisted together.
Or differential pairs.
No, both Pertec unformatted and Pertec formatted interfaces were TTL
single-ended.
Jon