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Re: a USB for the Apple II smoke test



The Wizard of Oz wrote:
On Thu, 28 Jul 2005 11:09:11 -0700, Michael J. Mahon wrote:


The Wizard of Oz wrote:

On Wed, 27 Jul 2005 09:47:49 -0700, pilgrimer wrote:

<snip>

I wonder,
could it be the baud rate on the SSC?  could it be something else? could
it be God never  intended this sort of thing?  Do I really wanna take
this one any further?  Not really, but it was interesting.


	I think you may be on to something. I seem to recall the early days of
the mouse on the PC there used to be problems with baud rates. As I recall
anything above 9600 was fine. It might be cool to see the GS with two
mice. Since the PC mice are serial devices (the "S" in USB) I see no
reason why it wouldn't work in theory. Perhaps the problem with the SSC
could be related to it allowing one connection instead of the three
available on the backplate. Since there were mice available which didn't
use the ADB connector, it seems logical there would be drivers for them in
GSOS.

Actually, USB has about as much in common with RS-232 as a
giraffe has with a grapefruit.


	Bad analogy. A better one would be like what a bison has to do with a
cow. The hardware protocols can't be a lot different. After all there is a
direct path from RS-232 to USB. I bought a couple of RS-232 to RS-232-C
(25 pin to 9 pin) adaptors. Friends have bought RS-232-C to USB adaptors.
None of these adaptors required circuitry. It was all a matter of wiring.

The analogy is not so bad as you think.

Those are not "adapters"--they only permit connections to the adaptive
capability already in certain specific devices.  There is no such thing
as a passive USB-to-RS-232 adapter.

USB is a multipoint network, using complex protocols just to set up a
data transfer.  Its lowest data rate is 1.5Mbits/second, way out of
RS-232's league.

RS-232 and USB have almost nothing in common that would allow
interoperation.

Read the USB spec--it is easily 20x more complex than RS-232
to do _anything_.

-michael

8-voice music synthesizer using NadaNet 2.0 networking!
Home page:  http://members.aol.com/MJMahon/

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