PDA

View Full Version : Any clue what this is?



soeter04
7th February 2015, 21:51
Howdy,

Does anybody have a clue what this is or does?
Seems to plug into a control port of the C64, and exposed what looks like a RCA plug...

https://dl.dropboxusercontent.com/u/15717744/amibay2014/GS_ADD9/sellc64misc2/IMG_7444.JPG


https://dl.dropboxusercontent.com/u/15717744/amibay2014/GS_ADD9/sellc64misc2/IMG_7446.JPG


https://dl.dropboxusercontent.com/u/15717744/amibay2014/GS_ADD9/sellc64misc2/IMG_7447.JPG


https://dl.dropboxusercontent.com/u/15717744/amibay2014/GS_ADD9/sellc64misc2/IMG_7448.JPG

hese
7th February 2015, 22:16
Does anybody have a clue what this is or does?
Some kind of suicide device? (judging by how the RCA plug is rigged)

rootboy
8th February 2015, 04:34
Homemade?

After fooling around trying to draw up the schematic I came to the conclusion that schematic programs suck in general, others in particular.

That said, your jack is wired to a LM324 Quad op-amp, and your jack is blocking my view, but it looks like all four amps might be wired up.

The output of the op-amps feeds the hex inverter and then gets summed up in the quad NAND gate. There is a precision resistor next to the trim pot, it may be used to set the trigger level to the op-amps.

Anything analog coming out of the op-amps is going to be converted to digital once it hits the inverter. And the 9 pin connector is using far too many connections to make it an audio device.

Maybe a poor man's analog to digital converter?

Beegle
8th February 2015, 05:53
An external sound device ( la Covox Speech Thing) but homemade for the C64?

rootboy
8th February 2015, 07:52
Pinout-wise, it looks like it's made to work with a C64 joystick port (notice that the power comes in on pins 7&8 ). The four identical resistors near the trim pot suggest a R2R A/D network. It only is inputting on pins 1&2, which supports the A/D theory. The adjustable pot makes me think that it is intended as a ham radio interface for rtty or CW.

soeter04
8th February 2015, 08:33
Some kind of suicide device? (judging by how the RCA plug is rigged)
:D i did cut my finger on the damn thing..

- - - Updated - - -


Homemade?
I would friggin' hope so. Imagine something coming out of a factory looking like that :D

Thanks for your help lads, now at least i can label the item before it goes into the 'likely useless' box o' goodies

SaviorX
8th February 2015, 08:34
maybe it's just me, but it appears as though the person who made it completely disregarded the fact that the RCA plug itself is metal....

rootboy
8th February 2015, 09:04
I'm guessing that at one time it was pointing straight up. One would hope so at least.

- - - Updated - - -



Some kind of suicide device? (judging by how the RCA plug is rigged)
:D i did cut my finger on the damn thing..

Happens to me all of the time... :)

- - - Updated - - -


Homemade?

I would friggin' hope so. Imagine something coming out of a factory looking like that :D

Thanks for your help lads, now at least i can label the item before it goes into the 'likely useless' box o' goodies

If you are curious, and have a C64 handy, you could try it out using the earphone jack from a radio and a simple program that reads the status of the joystick port. But you are probably right in labeling it "likely useless".