22 Sep
2004
22 Sep
'04
8:36 p.m.
>> I
don't like the fact that you're supposed to pay for an ID
>> (and have thr device 'certified') if you want to make your
>> own stuff. Never had this problem with RS232 :-)
You need to pay for and get certified if you are going to make a legitimate
network appliance also [MAC ID]. Of course most products purchase a pre-sertified module. Same if you are going to create
a cellular product [I
happen to use WaveCom modules in mine].
Ah, sop now if I buy a product the first thing I have to do is write
special drivers for it..... And hope that I can get enough of a spec on
the product to allow me to do this.
>> And the fact that you seem to need
special drivers for many
>> devices which you can bet are not available for any of my machines.
Although I can not find the link at presend, there is source code for low
level drivers. Since your environment (by choice) is the use of equipment that is not currently supported, rooling your own
drivers seems reasonable
to me.
OK, Asynchronous bit-serial data, sent LSB first, using the RS232 voltage
and connector specifications :-)
>> And the fact that it's very
assymmetric (there are 'masters' and
>> 'slaves') is something I don't like either. RS232 was much
>> more symmetrical.
RS-232 is an ELECTRICAL Specification. The protocols that are run on
This are independand. Lets keep it apple and apples..... >> More
modern palmtops have USB ports. They're slaves,
>> designed to hang off a PC. You can't link them directly to
>> a printer. It's interesting that some of my older handhelds
>> have HPIL ports, but by default the handheld is the loop
>> controller ('master'), so you can link them straight to a
>> printer. But they can be 'slaves' if you want to link them
>> to a larger machine. We've gone backwards (as usual)
>>
To be honest, I have not looked into the electricals on this. I am NOT sure
that they are *REQUIRED* to be slaves. >> All my
PCs have ISA slots only. Other machines have Unibus,
>> Qbus, BBC 1MHz bus/Torch X-bus, various custom I/O slots
>> (like on th HP9830), HPIL, PERQlink, etc. Just about all of
>> those have RS232 (or compatible) ports, I've nver seen USB
>> for any of them
>>
Again, development boards ARE out their that give you everything you need to
interface to nearly any host... >> > I also don't understand your
statement that it is not a bus.....
>>
>> Electrically it's not a bus. If it was, I could just parallel up
>> connectors and plug in several devices, there'd be no need
>> to _always_
>> have a hub (which, from what I've seen, contains a fair
>> amount of logic).
By that argument (which has valid aspects), then ArcNet was not a bus
either, and RS-232 is DEFINITELY not a bus architecture (it is purely point
to point).