Here is a (shrinked) schematic describing the analog-input circuit of the early Jaguar-models.
Use "show image" of your browser to view the unshrinked image.
The following parts are missing on later Jaguar-models:
U16=ADC0844 (parts-side of the mainboard)
R110=10R (parts-side of the mainboard)
C93=10uF (parts-side of the mainboard)
C95=100nF (solder-side of the mainboard)
L4=FB (parts-side of the mainboard)
L5=FB (parts-side of the mainboard)
L22=FB (solder-side of the mainboard)
L23=FB (solder-side of the mainboard)
C93 is an electrolyt capacitor, L4, L5, L22 and L23 are FerriteBeads
In the following two pictures of both sides of the mainboard the space for the missing parts is marked by having it's colours inverted.
Sodelder side:
Missing parts: C95, L22 and L23
Parts side:
Missing parts: AU16, R110, C93, L4 and L5
Now after adding the parts:
Here is a view at an opened set of VCS paddles:
And here is a picture describing the details:
As said in the pictures, it is necessary to connect the GND signal to potentiometers.
And here is a schematic of the DSUB9-to-DSUB15HD-adapter:
And here is a test-program for the two Jaguar joypad-ports:
JANALOG.ABS shows two cursors which can be moved over a rectangle of 256*128 pixels. Additionally the values of the analog-input are output on the screen as HEX-values in the lower left corner for joypad-port1 and in the lower right corner for joypad-port2 (but only the lower 2 HEX-digits of these register-values are relevant!).
No ADC available
If you load my testprogram JANALOG.ABS on a Jaguar console which is not equipped with the ADC-circuit then it will read only 0xFF = 255dec and will position the 2 cursors therefore in the lower right corner of the green rectangle:
ADC available
If you load my testprogram JANALOG.ABS on a Jaguar console which is equipped with the ADC-circuit but without any analogue input device attached, then it will read only 0x00 = 0dec and will position the 2 cursors therefore in the upper left corner of the green rectangle:
If you now attach an analogue input device to one of the Jaguars Joypad-ports, you'll see that the corresponding cursor will move and and the register values for this port will change too, in this example i have attached a VCS-paddle to Joypad port1:
Update 20070714: JANALOG.ABS on CD
I have put JANALOG.ABS on an encrypted CD, you can find ZIP-files containing CDRecord-files, Nero or DiscJuggler-images (each ZIP about 2.3 MB in size) here: