Homebrew PCBs

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
>