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After completing the above set-up procedure, you are ready
to enter and run programs on your COSMAC VIP.
The COSMAC VIP operating system, explained in the
next section, permits you to load programs into memory
from the hex keyboard, verify them, and record them
on cassettes for later reuse.
1. Getting Started 7
What You See
You must now decide on the video display for your
computer. The video pad at the back right comer of the
COSMAC VIP card provides a video signal which you
can connect directly to the high-impedance input of most
standard video monitors. The horizontal sync frequency
is 15,720 Hz and the vertical sync frequency is 60 Hz.
One solution to your video display need is a commercial
video monitor having a suitable input -- not rf or antenna
input. Another option is your TV receiver used with a
relatively inexpensive FCC-approved modulator. Do not
use a standard TV receiver with the VIP output connected
to the VHF or UHF antenna terminals. Do not use
transformerless TV receivers.
Turning It On
After attaching a suitable video display, apply power.
Make sure the RUN switch is in the down (or reset)
position. Hold hex key C down while you flip the RUN
switch up. You should hear a tone with key
C pressed and the Q light should be on. When you release
key C the tone and Q light should both go off. (The tone
occurs whenever the Q light is on.) You should now see a
random pattern of small square spots on the display. Push
hex keys 8008 in sequence and you should see 8008 at
the bottom left of the screen and 64 at the lower right.
Adjust your display controls for the best picture (white
spots on a-black background). You can experiment with
changing the values of RI, R2, and R4 on the COSMAC
VIP card to improve picture quality although this step
shouldn't be necessary. Certain modulators work better
with an R4 of 1 kilohm instead of 200 ohms. If you don't
get a video picture refer to Section VII for
troubleshooting hints.