Sony KV1311 CR monitor
Marty Goodman
BUT, there is a minor gotcha logistic involved in trying to make a cable
between it and the CoCo 3:
The Sony KV 1311 CR DOES NOT have provisions for separate postive horizontal
and vertical sync pulse inputs, of the sort the CoCo 3 provides. Instead,
it wants to see a negative combined H &V sync input.
This signal is easily provided by running the CoCo 3's H and V sync inputs
into the two inputs of a 74LS02 NOR gate, and taking the output of that NOR
gate as the signal to send to the Sony KV1311CR composite sync input.
The only gotcha really is that you need 5 volts to power the 74LS02 chip,
and this is NOT available on a stock Sony monitor's video connector, nor is
it available on a stock CoCo 3's video output connector.
I've used a variety of different solutions to this problem:
(1) Put the added 74LS02 chip INSIDE the CoCo 3, powering it from the CoCo
3's main 5 volt regulated power supply, and running the composite sync
output onto pin 10 of the CoCo 3's video connector (after DISCONNECTING pin
10 of the CoCo 3's video connector from the PIA chip... a function that was
intended to at some future date provide some sort of monitor recognition,
but never was actually implimented by Tandy in any firm or soft ware or
hardware.
(2) Go inside the Sony monitor and find a source of regulated +5 volts, then
send that to pins 1 and 2
of the 34 pin connector on the Sony.
Pins 1 and 2 are normally NOT CONNECTED on the Sony KV 1311 CR, but those
pins DO carry +5 volts on some other
Sony monitors from that period that use an otherwise identical pin assigment
on the 34 pin connector
to that used on the Sony KV 1311CR.
(3) Make a little adaptor box, with the 74LS02 in it, and power it via an
external source of regulated +5 volts from a +5 regulated wall xformer or a
9 volt xformer and a 78LS05 regulator.
Caution! Do NOT (as I initially did in an early run of such cables) try to
"steal" the needed 5 volts from the 5 volt line on the joystick connectors!
This will result in the joystick not having a full range of numbers for the
full range of throw of the stick, due to the use of a 100 ohm current
limiting resistor in the joystick connector circuit where the 5 volts is
supplied.
You COULD elect to use pin 10 of the video connector on the CoCo to bring
out 5 volts regulated (after first cutting the trace that connects it to a
PIA input).
Other tip: When making your cable, if you use ribbon cable, run a ground
wire between ALL signal lines... especially have ground wires on all sides
of the R,G, and B signal lines. And keep the cable length under 5 feet.
This will guarantee good signal quality on the monitor.
Here's that pin out for the Sony KV1311 CR connector (or at least the
relevant part of it):
(with notes on variations on some other Sony monitors that use the same 34
pin connector)
1,2 not connected (+5 volts on some other Sony models)
3 not connected (audio Right Channel input ground on some other Sony
models)
4 ground
5 not connected (remote control ground on some other models)
6 ground (composite video output on some other models)
7 ground (audio Left Channel input ground on some other models)
8 -16 ground
17 not connected
18 not connected (Ext / Int Sync switch mode switch on some other models)
19 not connected
20 not connected (Audio Right Channel signal input on some other models)
21 not connected (Analog / digital mode select. High (open) = analog
ground
Low (ground)= digital
This function is found NOT on th KV1311 but on some other Sony models)
22 not connected (remote control output on some other models)
23 composite video output
24 audio signal input (audio Left channel input on some other models)
25 Red analog video input
26 Green analog video input
27 Blue analog video input
28 not connected
29 fast blanking input
30 Composite Sync input (Horizontal or composite sync input on some other
Sony models)
31 not connected (Vertical Sync input on some OTHER Sony models)
32 not connected (half blanking input on some other Sony monitors)
33 RGB / Normal select input high (5 volts) = RGB input selected
low (ground)
composite video input selected
34 audio select high (5 volts) audio is accepted from the 34 pin RGB multi
input vide connector
low (ground) audio is accepted from the RCA
Audio Input jacks on the monitor.
Note that pin numbering on this connector has all pins in one row be ODD,
all pins in the OTHER row
be EVEN. This is quite different from how pins are numbered on a DB type
connector!!! On DB connectors
pin numbering goes 1,2,3,4,5, etc... down one row, and continues on the next
row. But on THIS dual row type connector, pin numbering goes 1,3,5,9 etc.
on one row and 2,4,6,8, etc. on the other row.
Example of an "other" Sony model with the extra pin functions: KX-1901
"Profeel" Sony Trinatron component TV
Obviously the pins you critically want to use are the R,G, and B analog
video inputs, grounds, composite sync pins, and (if you want to be slick)
the audio input and the audio input site select pin tied high... and perhaps
the RGB / composite select pin, too (for if you don't tie that pin high, you
must push in the RGB select button on the TV set in order for the analog RGB
cable to work)
THERE you are! Pretty much all of the info I have on those inputs. Good
luck!
Happy tinkering!
---marty