[Ham-Mac] USB Serial adapters

[David Kelly]

On Jun 23, 2005, at 6:14 PM, Bill Coleman wrote:

>
> On Jun 23, 2005, at 11:05 AM, Chris Smolinski wrote:
>
>
>> The problem is that some PC devices (like the early RigBlasters,  
>> maybe even the current ones?) were not happy wiith the +/- 5 volt  
>> output from a Mac serial port, they expected the +/- 12 volt  
>> outputs common on PCs.
>>
>
> Technically, though, they should be satisfied with +/- 5 volts. The  
> RS-232 spec says anything in a range of + / 3-25 volts is valid.

Correct. But the *real* problem with incompatibility with some PC- 
oriented devices was that only 0 to +5 was being used and many PC  
serial ports accepted this so many newbie hardware designers wrongly  
believed this was universal and acceptable because it was compatible  
with their particular PC.

--
David Kelly N4HHE, dkelly at HiWAAY.net
========================================================================
Whom computers would destroy, they must first drive mad.