Re: Help identifying hardware

[Masterkit <masterkit@mediaone.net>]

> Doubtful that any engineer would use a 6522 for a serial card.  It's highest and
> best use is in ports, both for control and data, particularly well suited to
> parallel transfers of info in byte-wide sizes.  It's basically a souped-up
> version of the 6821 PIA from motorola.  With better support for handshaking,
> including serial to parallel shift registers and timers.  And though you could
> use it in a serial data transfer, it would be iffy as to whether you could fully
> implement the RS-232 standard without significant amounts of processing and
> overburdening the cpu.    =)  not to say there weren't poor designs out there...

    The chips to use for a serial adapter would have been the 6850 or the 6551
ACIA's.

If you're unable to find the datasheets on the 6522 VIA and you require them, I'll
scan 'em for you.

~M

>
> > >> The other didn't have many chips on it (2-3) but it did have a 6522
> > >> chip on it with a (15 pin?) adapter for a ribbon cable.
> > Turns out it had 20 pins (sorry, my bad memory)
> > >
> > >ftp://tarnover.dyndns.org/cabi/Apple.CLASSIC.GRAPHICS/
> > >and
> > >ftp://tarnover.dyndns.org/cabi/FAQs.and.INFO/ .
> >
> > tried there, didn't see anything that looked like it.
> > But on a little more inspection on the web, it seems that the 6522 is
> > a good trip for controlling serial or parallel information.  In this
> > case, I believe it is an el-cheapo serial card.