[Coco] Telepak RS232 Pak

[Roger Taylor]

At 03:53 AM 1/17/2009, you wrote:
>On Saturday 17 January 2009, Roger Taylor wrote:
> >At 10:31 PM 1/16/2009, you wrote:
> >>Hi Mark,
> >>
> >>Thanks for the explanation. So if I understand correctly, the TelPak uses a
> >>newer hardware technology and can be used without the services of an MPI.
> >>Other than that they both do about the same thing... correct?
> >>
> >> > I should expand.
> >> >
> >> > There is a MAX chip in the TelePak that has acharge pump in it that
> >> > creates the RSR232 rail voltages.
> >> >
> >> > What this means is that you DO NOT need a multi-pak for this device to
> >> > work in a CoCo3 as the Tandy pack does.
> >
> >I've never known the Deluxe RS-232 Pak to not work in a CoCo 3
> >without an MPI.  There's a ROM in the pak which means you probably
> >can't use it at the same time a floppy controller is plugged into Any
> >CoCo unless you're using an MPI.
>
>It works if that teeny little Aztec 5 volt to +-12 volt switcher in it works,
>but the draw on the 5 volt line is more than the cc3 supply can do well.  I
>have seen several cc3s with blown fuses because that supply hiccuped.  The
>one in mine let out all the smoke and died a decade ago, so it works in an
>MPI only now.



Why would the RS-232 pak need 12 volts?  The chips need 5v and are 
few, plus the DC Modem Pak has more circuitry with the phone modem 
portion so does it work on a CoCo 3?   The reason I'm asking this is 
because we're working on a simple RS-232 pak the size of a game pak 
and I see nothing in it that should draw too much current from the 
CoCo.  My hacked DC Modem pak works well on my CoCo 3 and someone 
added the signal level converter ICs.


-- 
Roger Taylor

http://www.wordofthedayonline.com