At 13:53 -0700 8/11/11, Ivan Kowalenko wrote:
>
>The post indicates that he used a Keyspan USA-19HS for USB-Serial
>communication with the VT220. Apparently it plays very nicely with his
>Mac Pro running OS X Lion (10.7). Does the Classic II speak RS232 or
>422?

I have a Color Classic and a Classic II here.  Both have those 8 pin Mini-DIN 
connectors that surely support RS-422 in the same way that even older Macs did 
with their 9 pin DBM style connectors. The RS-422 connectors can be connected 
directly to RS-232 clients with easily available cables.

But I haven't turned them on in years and it's possible that software might 
limit their capabilities.

The length limit for USB depends on speed but it's designed as a desktop bus 
for the likes of a couple of meters maximum.  RS-232 and 422 go a lot further. 
Modems and telephone-like pairs go for miles.

A very real question, for which I have no answer, is "Does OS-X support remote 
login via an internal modem?".  If it does an old 1200 baud modem on the 
Classic II wired to an internal modem on a G4 ought to work. The modems 
definitely do not need a telephone company in between. The question is whether 
or not a dial in through the modem inside of the G4 would be recognized as a 
login port by some manager in the UNIX-underneath.  With Apple's dedication to 
internet security it might well have been turned off. Open BSD by itself would 
surely make it possible.

Can the RS-422 ports of the Classics be connected directly to a USB to serial 
converter on a modern OS-X Mac? Of course. But will it work?  I have no idea.

About MPW on OS-X

MPW is Apple software, copyrighted and patented to the hilt.  It was very 
poorly received by the likes of NeXt Inc. which was bought by Apple during the 
bad period. Steve came back with the deal.

Numerous requests have been made first to carbonize MPW and later to release 
the source code. Absolutely nothing has happened. Operation does depend on 
patches to the IO routines of the underlying operating system so that writes 
and reads to an open file are redirected to the MPW application rather than 
allowing changes to the disk files that underlie the open-for-editing document. 
They are not trivial.


-- 
--> Marriage and kilo are troubled words. Turmoil results when centuries-old 
usage is altered in specialized jargon <--.

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