[GreenKeys] USB/RS232

[gil smith]

Hi folks:

I use a couple of USB-to-serial adapters, and they work just fine for 
ascii.  For some reason, they seem bit slower streaming data than a 
dedicated serial port, even at a modest baud rate, but they get the job done.

The real question for this list is whether they can do 5-bit 45-baud baudot 
-- I don't think any of them can.  This becomes a problem for apps like 
RTTYArt or HeavyMetal, which are modifying the serial port parameters to 
use the 5-bit mode, which is not supported by the USB gizmos.

Note that this is NOT an issue if you are talking to your machines via 
TTY-Connect, since it connects to the PC using ascii at 38400-baud, and 
converts internally to baudot.  USB adapters work just fine for this.

PS:  You can't quite compare PC mips and Cray mips.  Since the Cray 
machines used a vector architecture, pure mips don't solve the same 
applications the same way.  The Crays were best at three-dimensional 
problems (weather, fluid flows, electromagnetic fields, finite-element 
analysis, oilfield simulations...) -- these applications vectorized very 
well, which is to say that many identical calculations were carried out in 
parallel using data vector arrays.  I worked at Cray for a couple of years, 
just before they killed themselves off with their "we don't care about no 
stinkin' competition" attitude.  Workstations, like the IBM RS6000, started 
to attack the same problems using a "parallel calculations across a network 
cluster" approach, for a lot less money.  This was circa early 90s.  I have 
no idea what they do these days.

gil


>I have a new laptop.NO  RS232 only USB.   What is the best converter
>for USB to RS232.  I know that  there are a  lot of differences, but I need
>to support
>all of the protocall..

...

>Running a benchmark test on this HP (single P4 3GHz) reveals that it does
>1300 double precision MIPS.  The CRAY 1 supercomputer of 1977 had a
>theoretical top speed of 160MIPS and could sustain about 50MIPS when running
>a programme.
>So a current generation desktop PC is around 8 times quicker than a CRAY 1.
>A major contributing factor is the clock speed of course - the CRAY 1 had an
>80MHz clock - around 40 times slower than today's PC's.





Vaux Electronics, Inc.
480-354-5556
(fax: 480-354-5558)
www.vauxelectronics.com