Shurgart drive question

From: Dwight Elvey <elvey_at_hal.com>
Date: Wed May 24 13:19:40 2000

Hi
 I'm still working no my NIC-80. I'm having a data pattern
sensitive problem. I'm not yet sure if it is in the SA900
drive or in the controller. When looking at the drive,
there is a clock/data separator circuit. It uses two one shots.
One is for the next clock cycle after a one was read and
one is for the next clock cycle if there was no one read.
I understand the issues of this shifting of the read
data but I don't know how much these two one shots need
to be adjusted. The SA800 TTL board also has the same circuit.
I was hoping that someone with an old drive could put
a 'scope on these two one shots and determine the nominal
pulse widths they see? The test points are labled the same
on both the SA900 and SA800 series drives as TP21 and TP24.
They are negative going pulses.
Dwight
Received on Wed May 24 2000 - 13:19:40 BST