[rescue] rescue Digest, Vol 59, Issue 26

[Robert Darlington]

MAX232 will translate between RS232 and TTL.  I prefer the MAX233
because it doesn't require external caps but it also doesn't meet the
RS232 recommended spec of +/- 12 volt swings (it does +/- 10 volt).
You can get free samples from Maxim Semiconductor.

-Bob

On 10/25/07, Earl D. Baugh Jr. <earl at baugh.org> wrote:
> >> I am wondering if you can build an inverse adapter for Sun 4 and 5
> >> keyboards to allow them to work on a Sun 3 kbd machine.
> >
> > Yes.  The keyboards are identical in terms of signal levels and
> > first-level protocol (1200-baud RS232 bit trains, except using TTL
> > signal levels instead of RS232 signal levels).  There are differences,
> > but they are relatively subtle - for example, the response to a
> > keyboard reset command can differ.
> >
> > Sun even sold an adapter for using "new" (miniDIN-8) keyboards on
> > "old"
> > (DA15) machines, though if you're not afraid of soldering and have a
> > miniDIN-8-to-miniDIN-8 cable that carries all 8 wires to cut in
> > two, it
> > borders on trivial to build your own.  (I've seen the Sun adapter, but
> > have little use for it, since I want to use type-3 keyboards on
> > miniDIN-8 machines, and Sun's adapter goes the other way.)  See
> > ftp.rodents.montreal.qc.ca:/mouse/misc/sun-kbd-cable.txt and .ps for
> > more.
> >
> > /~\ The ASCII                         der Mouse
> > \ / Ribbon Campaign
> >  X  Against HTML             mouse at rodents.montreal.qc.ca
> > / \ Email!         7D C8 61 52 5D E7 2D 39  4E F1 31 3E E8 B3 27 4B
>
> Do you happen to have a part number, or a pointer to where I might
> get a couple of these?  I don't have any spare miniDIN-8 and DA15
> connectors, so I'd have to buy both... and it probably would be less
> hassle to pick up 2 if they're not ridiculously expensive.
>
> T = $ as they showed in that old Far Side... (Einstein proving Time =
> $ 8-) )
>
> Earl
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