Given the vintage of this thing, you will be looking for 1488 and
1489 (TTL <-> RS232 level convertor chips) chips. Try putting a
scope on the TTL data lines that are coming from the PC. See if you
are getting anything on the other side of the RS232 receiver chip.
Did you ever find a manual on this thing? So you know how to set
the baud rate switches?
Jim
--- In Homebrew_PCBs@yahoogroups.com, Lez <lez.briddon@...> wrote:
>
> On 14/11/06, Scott Monsma <samonsma@...> wrote:
> >
> >
> >
> >
> >
> >
> > Maybe its time to pop it open- see if you can trace the serial
signal
> > from the connector into the innards of the plotter? I doubt it
has a
> > blown Max232 interface chip, but you might see something out of
whack...
>
> Yeah none of its pins seems to change state no matter what I put
into
> it, it does have another connector, a round one 8 pins, like old
hifi
> tapedecks used, I suppose that was for 'other' formats of PC, but
dont
> know what it is its not labled.
>
>
>
>
> Lez
>