[comp.sys.mac] Mac Serial ports

David_Greg_Herlihy@cup.portal.com (07/16/88)

It seems that multiple serial port cards will become popular soon.  Res
Nova is also working on a Mac II and SE card that will allow 4 additional
serial ports.  The primary purpose will be to give the mac multiple node
Bulletin Board capability under Nova Link BBS software.

Any one interested can call one of the few multiple node Mac BBS's in the
world at: (401) 351-1465.  Currently this board only has two nodes, but
with the introduction of the card, will have six.

David Herlihy

David_Alan_Newman@cup.portal.com (07/17/88)

David Herlihy in article 1090.3.6372.1 writes:
 
> It seems that multiple serial port cards will become popular soon.  Res
> Nova is also working on a Mac II and SE card that will allow 4
> additional serial ports.  The primary purpose will be to give the mac
> multiple node Bulletin Board capability under Nova Link BBS software.
> 
> Any one interested can call one of the few multiple node Mac BBS's in
> the world at: (401) 351-1465.  Currently this board only has two nodes,
> but with the introduction of the card, will have six.
 
There are several multiple serial port boards available now for the Mac II.
What I did not see you mention is the fact that Mac OS does not support
them, and non of the board manufacturers have agreed upon a standard
way of using them. In short the will be very little support from
software houses for these boards until Apple introduces it long promised
Serial Manager. Nova faces rewritting their software down the road to be
compatible with the Mac OS, and the boards that get reworked to support
the Serial Manager.

Dave Newman

paul@unisoft.UUCP (n) (07/20/88)

In article <7384@cup.portal.com> David_Greg_Herlihy@cup.portal.com writes:
>It seems that multiple serial port cards will become popular soon.  Res
>
>world at: (401) 351-1465.  Currently this board only has two nodes, but
>with the introduction of the card, will have six.
>

actually I know of someone with 5 SuperMac CommCards who has 22 ports ....


		Paul


-- 
Paul Campbell, UniSoft Corp. 6121 Hollis, Emeryville, Ca
	E-mail:		..!{ucbvax,hoptoad}!unisoft!paul  
Nothing here represents the opinions of UniSoft or its employees (except me)
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palmer@tybalt.caltech.edu (David Palmer) (11/21/89)

I am wiring up a micro-controller (an (oh the shame of it) Intel 8052
with a built-in (double shame) BASIC interpreter)

This controller has a TTL (0 - 5V) input-output serial port.  What do
I need to do to get my Mac to speak to it?  I am wiring my own cable.
Do I have to wire the RxD- line on the Mac to set it to +2.5 V so that
the differential goes positive and negative? or does it drift to that
value automatically?

Also, the controller serial port is set up to use an inverting buffer.
Is it reasonable to just use the RxD- and TxD- lines from the Mac, and
wire the RxD+ line to +2.5V?  This would eliminate another chip from
what is now a 4-chip design, which is aesthetically pleasing even if
it is bad engineering practice.

Thanks in advance.

		David Palmer
		palmer@tybalt.caltech.edu
		...rutgers!cit-vax!tybalt.caltech.edu!palmer
	Meanwhile, on eng.string.floss, the waxed vs. unwaxed flamewar
	continues unabated.