Re: Apple II Parallel Cards

["anoneds@netscape.net" <winston19842005@yahoo.com>]

Michael J. Mahon wrote:
> mdj wrote:
> > Michael J. Mahon wrote:
> >
> >>Greg Andrzejewski wrote:
> >>
> >>>Were there any parallel interface cards made for the Apple II that
> >>>completely adhere to the IEEE 1294 standard? Most of the ones I've seen seem
> >>>to missing/ignore some lines (nERROR, nSELECT, etc)
> >>
> >>Apple parallel cards were designed before there *was* a PC!
> >>
> >>IBM chose not to adhere to the Apple standard.  ;-)
> >
> >
> > :-) and the 1294 standard was introduced about the same time as the
> > first Pentium PC's in 1994.
> >
> > I don't recall any of the parallel ports implementing bidirectional
> > signalling, either. The exception would be the ProFile controller card,
> > but this was not strictly speaking a parallel comms card of course.
> >
> > Such a card could be very easily put together though - the PC style
> > parallel port is a very simple interface. I seriously doubt though that
> > the Apple II would have the processing power necessary to communicate
> > in ECP or EPP mode with any peripheral that required it
>
> There were one or two parallel port cards (intended for printers)
> that used a 6522 VIA.  That could in principle provide bidirectionality,
> though I doubt that any were actually wired and programmed to do so.
>
> The real determining factor for the Apple parallel printer interface
> was the _de facto_ Centronics interface, which most printers used.
>
> IBM followed suit with the PC, and it wasn't until printers got a lot
> smarter (LaserJet) that bidirectionality (other than handshaking and
> error signalling) became an issue.
>
>
I remember that my TI-99 had a bi-directional port. It was quite
capable of saving/loading programs through the parallel port, given a
proper cable. This wasn't true of all third-party cards, however.
Most people just made do with the serial port (that is saving/loading
over that).