Re: Covox Voice Master

Interesting, someone said it was joystick port but user port is good too 
:-) There definitely was a joystick port sampler for the c64.

Yes please for pictures.

On 12/10/2016 16:01, Steve Gray wrote:
> Sorry for jumping in late. I own an original Covox Voice Master like this:
> http://www.commodorespain.es/wp-content/uploads/2014/10/Voice-Master.jpg
>
> It connects to the user port. I have it open right now. There are two chips: ADC0804LCN and LM324N. So obviously an analog to digital converter and amplifier. The other components are normal resistors, capacitors, diodes and transistors. The pcb is single-sided. It looks like I hacked it long ago for some reason. The user port connector was removed, some traces cut, and wires added. I'm guessing I must have tried modifying it for use on the Amiga. Anyway, if anyone is interested in pics let me know.
> Steve
>
>        From: Gerrit Heitsch <gerrit@laosinh.s.bawue.de>
>   To: cbm-hackers@musoftware.de
>   Sent: Wednesday, October 12, 2016 10:29 AM
>   Subject: Re: Covox Voice Master
>     
> On 10/12/2016 03:54 AM, Terry Raymond wrote:
>> Hi Gerrit,
>>
>> Are you referring to the actual data pins that solder in or are socketed.
>> the transistor is way small though?
> I'm talking about the structure on the die shot I supplied.
>
> If you put pinout of SID and die shot side by side, you can easily tell
> which pads are what.
>
>
>> I was looking at the larger 3 squares at the bottom, wow .
> The squares are the pads where the bonding wires are connected. The
> drivers on the pads of the data lines are the large comb like structures
> next to them. The ADC pads have something similiar, but MUCH smaller.
>
>
>
>> Is the SID wafer about the size of a match head about,  just amazing so much
>> could fit on a small wafer, SID on Steroids  :)
> The die is about 4 x 4 mm if I remember right.
>
>    Gerrit
>
>
>
>
>
>> Terry Raymond
>>
>> On Tuesday, October 11, 2016, Gerrit Heitsch <gerrit@laosinh.s.bawue.de
>> <mailto:gerrit@laosinh.s.bawue.de>> wrote:
>>
>>      On 10/11/2016 06:10 PM, Jim Brain wrote:
>>
>>
>>          The SID POT ADC circuitry needs to drag the line hard to ground
>>          for 256
>>          cycles.  NMOS would easily handle this, but it must be a pretty
>>          hefty
>>          transistor to ensure it can overcome the current coming from the
>>          paddle
>>          resistor.  I don't see such a transistor on the 6581 die shots,
>>          but it
>>          must be there.  What should I look for?
>>
>>
>>      When looking at
>>
>>      http://mail.lipsia.de/~enigma/mos6581r4/full_q30.jpg
>>      <http://mail.lipsia.de/~enigma/mos6581r4/full_q30.jpg>
>>
>>      the paddle inputs should be the 2nd and 3rd pad from the bottom on
>>      the left side of the die. Between them is a mirrored structure which
>>      should be the measuring circuit.
>>
>>      Close to each pad, I can see something that looks like a transistor
>>      that connects the pad to the GND line. But it's a lot smaller than
>>      the drivers for the data pins.
>>
>>      The paddle resistors are 500K max, but I don't know what their
>>      minimum value is. The schematics suggest that it's zero, but that
>>      would be more than any NMOS driver can handle...
>>
>>        Gerrit
>>
>>
>>
>>
>>
>>
>>
>>            Message was sent through the cbm-hackers mailing list
>>
>
>        Message was sent through the cbm-hackers mailing list
>
>
>     


       Message was sent through the cbm-hackers mailing list