Re: (Network Connections)

[nathan@visi.com (Nathan Mates)]

In article <falcon-1510961130540001@cda0-15.iea.com>,
Ross Falconer <falcon@comtch.iea.com> wrote:
>May I add an idea to this discussion?

   Sure, but since it's not related to programming at all, and people
should be warned against trying to duplicate this setup if they value
their data at all, this is being moved to comp.sys.apple2. Basically,
unless they have a CMS SCSI board in their Apple II, this setup is
NOT recommended. 

>I have been following it for a few weeks, and I had an idea that I was
>waiting to try out myself to overcome the network connection problem
>between IIGSs and macs.

   Both have Appletalk. This is safe, and it works. Why are you
bothering to make this more complicated than it needs to be?

>I have a Quadra with on-board SCSI (ID 7), an internal 440Mb Seagate (ID
>0), and an external 45 Mb Syquest (ID 3). Nothing special there. But, I
>also added to the SCSI chain an Apple IIGS with the Apple high-speed SCSI
>card set with a SCSI ID of 2. It has access to both SCSI hard drives!!!

   Sharing the SCSI bus betweeen 2+ computers is a BAD idea,
especially if both sides are not set up for SCSI bus arbitration.
What happens when both computers try and access the bus at once?  What
happens when both computers try and write to the same drive or even
file at once?

   Even bus arbitration won't help for providing mutuallly exclusive
file access. The second two computers try and write to the same
partition at once, there's a damn good chance that the volume
bitmap'll be corrupted, leading to bad files, lost data, everything
else.

>The items required to make this connection are very cheap, just a SCSI
>card and a SCSI cable. According to the article in which I found out about
>this, the CMS SCSI card has all the utilities to make this a reliable and
>full-featured connection with security, passwords, etc. 

   However, the vastly more common Apple SCSI boards and RamFAST
boards don't do this reliably. If you're using one of those boards, do
NOT attempt to connect multiple computers to the SCSI chain. [That
is, unless you play flag football on the interstate and don't mind
losing your data.]

>If the mac server were a IIx, it could serve up to six GSs for every Nubus
>card it contained (up to six, I think). That would let a whole classroom

   SCSI tends to get flakey on long cable lengths, usually above about
10 feet. Trying to feed a classroom of computers off one mac would be
a nightmare. [Similar to thinnet ethernet: you _could_ connect 50+
computers to one strand of that. If it worked at all, it'd be really
slow and problematic.]

>This might be a perfect solution to overcome your AppleTalk connection
>limitation.

   It's //es that don't do Appletalk without the addon Apple II
workstation card. GSs work great on Appletalk.

Nathan Mates
--
<*> Nathan Mates http://www.visi.com/~nathan/      <*>
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