Kaypro 2 - 06-04.TIFF

&nPE SIGNALS 'ID AID IN ~ (81-1UJ-n)
The examples of correct signals shown below do rnt represent all of the
signals on a Kaypro mainboard, since most signals will be simple high-low
toggles. A group of video signals (~0 through ~3) are included as
illustrations of the timing relationships between the various video signals.
Note that only ~ of the I/O signals on U5? will be low at any given time.
State of the machine: The d<X>r of drive A is open: the machine is waiting to
boot.
The signal measurements were made using a Tektronix oscilloscope, model 2213.
It has a bandwidth of OC-60 MHz, sensitivity of 2mV/em, a sweep delay of 0.1
microseconds to 1 second, and a graticule display measuring 8 x 10 em.
Signal Ml from pin 27 of the CRT (U63) was triggered on. This signal is shown
in the top half of each display and was channelL Ground for the signals
shown on channel 2 was established at first graticule line above the bottom of
the display.
Each square of the representation is the equivalent of one square em on the
graticule. The scope was set for ?V/div. for all figures, an1 was set for .5
micro-secs/div. for all figures EXCEPT' figure 6, which was taken using 1
micro-secs/div.
Figure 1: Pin 6 of U63, 2.5MHz clock signal.
Figure 2: Pin 24 of U82, lMHz clock signal.
Figure
3:
pin
3 of U6, ~0.
Figure 4:
pin 4 of U6,
~l.
Figure 5:
Pin 5 of U6,
~2.
Figure
6:
pin 6 of U6,
~3.
6-4