Peter,
The logic probe measures whether logic states in TTL or CMOS
circuitry are a binary 1 or 0. Remember we talked about how the
binary pattern on lines A, B, C, INH set which outputs on IC31 are
selected? This tool would tell us how they are set and whether they
were switching on a the right time.
However, from the description how the six LEDs are lighting up (yes,
one after the other in POLY mode - I am an idiot!) it sounds like
IC31 is working correctly and keyboard assigner is sending the right
binary pattern to the switch.
I expect the input on pin 3 is the problem. What I will do is take
some reading from my working Polysix and let you know how the
circuitry should function. I'll post this after the weekend, if you
can wait.
Also, I'll take you are playing with the settings in manual mode and
not from the patch banks? When the SRAM (memory) failed on my P6 the
patch banks just contained random bit patterns which produced sound
which could be very much be described as 'out of tune'! Just a
thought...
Cheers,
Andy
--- In PolySix@yahoogroups.com, "hjulskov" <hjulskov@...> wrote:
>
> Thanks Andy,
>
> The LEDS (D10) does light in order in polymode (which I think was
what
> you meant?) -in unison they all light simultaniously.
> In Polymode all voices sounds equally (bad).
>
>
> I'm not sure about your last question (Can you lay your hands on a
> logic probe at all?)?
>
>
> Cheers,
> Peter
>
>
> --- In PolySix@yahoogroups.com, "Andrew Jury" <andy@> wrote:
> >
> > Hi Peter,
> >
> > I am afraid we can't make that assumption until the logic that
controls
> > IC31 has been tested. This device is basically a switch. You
apply a
> > binary pattern to lines A, B, C and INH and this determines which
one
> > of the outputs is connected to the input. The input is marked X
the
> > outputs marked X0, X1, X2, etc. It is the outputs which we just
tested
> > and which don't seem to move. Tell me, do the voice LEDs (D10)
come on
> > in order in Unison mode? Everytime you press a key an alternate
voice
> > LED should light up. I suspect not?
> >
> > Can you lay your hands on a logic probe at all?
> >
> > Cheers,
> > Andy
> >
>