Networks are used to link computer workstations to provide electronic mail, file
sharing and program linking. The Mac includes all the system software and
interfaces necessary to create a simple network.
Network Hardware
qqqqqqqqqqqqq
A Local Area Network (LAN) operates over a small area, usually in a single building, connecting together a number of computers used as workstations. A point in the network where two or more circuits converge (usually the site of a workstation) is a node. The network’s topography, the arrangement of cables between nodes, is one of the following:-
z Linear
In a daisy-chain or series network each device is connected by a single cable — just
one lost connection can cause total failure. In a bus network the disconnection of
a single branch doesn’t harm the network.
z Star
Individual circuits originate from a central hub or concentrator. Although
expensive on cable such systems are highly reliable.
z Ring
A single cable in a circular path around which data passes to all devices.
AppleTalk Network Types
wwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwww
All Macs come with software to support the following types of network:-
LocalTalk (230.4 kbit/s)
  A linear network accommodating up to 32 nodes at a real rate of 10 KB/s. It uses
78 ohm twisted-pair cable with an overall screen and can be used over distances
of up to 300 metres.
To set up a LocalTalk network you simply connect a serial port of each Mac (or a network printer) to a LocalTalk box (containing an isolating transformer). Then you must link together each of these boxes using network cable fitted with suitable 3 way mini DIN plugs.
Although you can make up your own network cables, its usually easier to buy them ready-made. For long distances you can join together one or more cables with a LocalTalk coupler, consisting of two back-to-back 3 way sockets in the form of a gender reverser.
Each box automatically terminates the network when a network plug falls out — which they often do! You can get round this problem by using PhoneNet (see below) or by fixing each box to its associated device — and by tying network cables to the furniture!
The Mac’s printer port must be used for LocalTalk with Classic AppleTalk, and this is often convenient for printer access. Either port can be used if Open Transport AppleTalk is active. For Open Transport AppleTalk on a PowerBook 190 the modem port must be used.
à You must select LocalTalk in the AppleTalk or Network control panel.
à MIDI software may have to be disabled to use LocalTalk.
à To create a network between two Macs (or between a Mac and printer) just plug
them together with a standard printer cable.
PhoneNet (230.4 kbit/s)
  This is Farallon’s alternative to LocalTalk for linear or star networks over distances
of up to 900 metres — but longer cables can be used if repeater boxes are fitted.
PhoneNet employs telephone cable and RJ11 4 way modular plugs, as used on US
telephones. You must fit terminator plugs in unused sockets.
A linear PhoneNet distribution can be easily constructed by attaching an adaptor to each device. This incorporates an 8 way mini-DIN plug that connects into the serial port of a Mac (or printer) and two RJ11 sockets for the network cables. These adaptors are linked together using 2-pair (4-wire) cable wired to RJ11 plugs.
In a star distribution only a single circuit from an adaptor is connected to the hub. This connection can be made via a wallplate fitted with an RJ11 socket.
You can connect PhoneNet into a LocalTalk network by using a cable with a 3 way mini-DIN plug at one end and an RJ11 plug at the other. The mini-DIN plug connects into any LocalTalk box or into a LocalTalk cable via a LocalTalk coupler.
à You must select LocalTalk in the AppleTalk or Network control panel.
à MIDI software may have to be disabled to use PhoneNet.
EtherTalk (10 Mbit/s)
  For a Ethernet linear network with a real speed of over 100 KB/s — or less if
disk drives slow it down. It needs terminators at unused points, but some devices
have auto-termination to save you the worry! It comes in three forms:-
Code Generic Name Cable Connector Max Distance (m)
10Base-5 Thick Ethernet 0.5 inch coaxial UHF 500
10Base-2 Thin Ethernet 0.2 inch coaxial BNC 300
10Base-T Twisted Pair Telephone cable RJ45 100 to hub
10Base-5 and 10Base-2 are used in linear networks. 10Base-T is a star network that uses a centrally-located hub — it has the advantage of using low-cost Category 3 to 5 telephone cable (containing four twisted pairs) and reliable RJ45 modular plugs. Short cables can be used as patch cables to quickly reconfigure a network’s hub connections.
Ethernet devices can be connected to a Mac by one of the following:-
z Built-in Ethernet connector
z Built-in AAUI-15 connector and an external Ethernet Media Adaptor
z PCI or NuBus slot fitted with an Ethernet card
z Communications slot fitted with an Ethernet card
z SCSI port and an external SCSI-Ethernet adaptor
Some PowerMacs and printers have a 10Base-T and/or AAUI-15 connector.
For Fast Ethernet (100Base-TX), running at 100 Mbit/s, you must provide every device with a suitable interface and install a 100Base-TX hub. Some Mac clones support a built-in 100Base-TX interface but others require a Fast Ethernet card or external adaptor. 100Base-TX will happily operate over any existing 10Base-T wiring.
à You must select EtherTalk in the AppleTalk or Network control panel.
à To use a NuBus Ethernet card in a Mac without NuBus slots you must fit a
Processor Direct Slot (PDS) to NuBus adaptor card
à You can use a bridge to connect LocalTalk devices to an Ethernet network.
TokenTalk
  For a Token Ring network in which tokens are sent to permit any terminal to
transmit. This network type is popular with educational establishments.
A TokenTalk card must be fitted to use it.
à You must select TokenTalk in the AppleTalk or Network control panel.
√π See the Network Protocols chapter for further details about networks
AppleTalk
qqqqqqq
  AppleTalk comes with the Mac’s system. It permits Macs to operate over LocalTalk,
EtherTalk or TokenTalk, together with all kinds of servers, bridges and routers. It can
be used on its own or with other networking software.
The Chooser can be used to enable or disable AppleTalk. It can also be used to select any printer driver, including those that use AppleTalk. The modern form of AppleTalk is known as Open Transport. With file sharing enabled AppleTalk uses over 300 K of memory.
Open Transport
wwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwww
  Open Transport works with PowerMacs and models with a 68030 processor or
better. It operates via built-in LocalTalk or EtherTalk ports or with any AppleTalk
network card or adaptor (NuBus, PCI, PC card or SCSI), including Fast Ethernet,
ATM or FDDI. It works with Apple Remote Access (ARA) for dialling-up a network.
It needs at least 8 M of memory which may necessitate the use of Virtual Memory. To use Open Transport you must install the necessary files and enable it in the Chooser.
The AppleTalk Control Panel
  The AppleTalk control panel lets you select the Modem Port or Printer Port, or any
EtherTalk or TokenTalk network card, as the network connection. It also includes a
Setup area for other settings. All of your choices can be saved as a Configuration
for recall at a later date — this can be useful for restoring a connection in a hurry!
The Edit menu can switch between Basic, Advanced or Administration modes — the latter, optionally protected by a password, lets the network administrator lock any settings that shouldn’t be modified by the user in other modes. The panel appears as shown below:-
 
To specify an AppleTalk address you must click in the checkbox and enter the values:-
 
If you select Get Info or press the Info button a window appears, as shown below. It gives the address of This Macintosh (consisting of Network and Node address) the Hardware Address (as stored in your Ethernet card or Token Ring card or in the Mac’s hardware for a built-in EtherTalk port) and Router Address (for a router joining you to a larger network):-
 
The AppleTalk address is decided by the Mac at startup and can vary, unless predefined by the user (see above). The Router Address may change during network operation.
The Options button in Advanced or Administration mode allows you to turn AppleTalk on or off — turning it off can save memory.
The Communications Toolbox (in the system) allows over 8000 AppleTalk zones on a single network. You can monitor the network using the File Sharing Monitor control panel.
à AppleTalk must also be turned on in the Chooser!
à The TCP/IP control panel should be used for Internet or Intranet operation.
à To get the Infrared Port to work on a PowerBook 190 you may have to put the Mac to
sleep and wake it up again — or you can select Modem/Printer Port in the AppleTalk
control panel and then reselect Infrared Port.
Classic AppleTalk
wwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwww
  Classic AppleTalk works on any Mac except a PCI-based PowerMac and is only
preferable to Open Transport with older networking applications — it’s unlikely to
be supported by future versions of the system! To use it you must install the
necessary files and enable it in the Chooser.
The Network control panel is used instead of the AppleTalk panel to set up the network. It allows you to use AppleTalk via the printer port or a port on an expansion card, as used for EtherTalk or TokenTalk. The modem port isn’t available for Classic AppleTalk.
à The MacTCP control panel should be used for Internet or Intranet operation.
The Network Software Selector
  The NSS application lets you switch between Open Transport and Classic AppleTalk
— useful if you need to use network applications that only work with one of the
two forms of AppleTalk. Once you’ve made your choice you must restart the Mac.
After restart the network may revert to LocalTalk operation — just use the Network or the AppleTalk panel (as appropriate) to restore the required connection.
The NSS disables the MacTCP or TCP/IP control panels by a devious method — it makes either file invisible and changes its type. If you install a new copy in the Control Panels folder it disappears from view if the NSS is in the wrong mode! To restore normality just use the NSS to select the required version of AppleTalk.
AppleTalk File Sharing
wwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwww
To share files over AppleTalk you must follow these steps:-
ON THE COMPUTER THAT HAS FILES TO SHARE WITH OTHERS: qqqqqqqqqq
Start File Sharing in the Sharing Setup Control Panel
  Open the panel, enter the required information and then click on Start to enable
File Sharing — it’s best to begin with Program Linking turned off. After a while File
Sharing will become active. This process effectively creates a file server.
  A removable disk or CD-ROM must be on the desktop before File Sharing is started.
You can eject any disk or CD-ROM as long as a user isn’t working with it.
Audio CDs can’t be shared.
Set Up the Users and Groups Control Panel
  This panel creates users and groups that appear in the Sharing window (see below).
If you want guests to read your files just double-click on the <Guest> icon and
select Allow guests to connect. You can create other users and groups as required.
Give Other Users Permission to use a Volume
  AppleTalk lets other users open volumes on the server Mac, but only if they have
your permission. A volume can an entire hard disk or just a folder. Click on the
volume you want to share and then select Sharing in the File menu.
In the window that appears you must ensure that Share this item and its contents (at the top of the window) is selected, You now have the option to pick the users or groups who can use the volume:-
 
In this example it appears that only the Administrator can make changes — but there may be others in the User/Group menu! Once you’ve made your choice you’ll be given the chance to save these settings.
ON THE COMPUTER THAT NEEDS TO USE SHARED FILES: qqqqqqqqqqqq
Get Access to the Shared Volume
  To open a shared volume you must have the AppleShare file in the Extensions
folder inside the System Folder. The Chooser should be opened and the
appropriate file server should be selected, as shown below:-
 
You’ll now be presented with two dialogs in succession. The first allows you to set a Name and Password for a Registered User — a Guest can bypass this! The next dialog shows the volume (or volumes) to be shared. Having clicked OK you’ll see the shared items on the Desktop. For instant access the next time you should create an alias of each volume!
Use the Shared Volume
  You can now use the volume in the same way as your own drive — but the
owner may have prevented you saving some files by not selecting Make Changes!
à The Trash and Desktop Folder items may be visible in a shared disk or disk partition.
PowerTalk
wwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwww
  PowerTalk, a form of the Apple Open Collaboration Environment (AOCE) provides
extra features such as Catalogs and the AppleMail application for use over a
network. It also adds a Mailbox to the desktop for incoming and outgoing mail.
Dedicated File Servers
wwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwww
  Large AppleTalk networks often use a dedicated computer as a file server to
provide information to the client workstations. The server can’t be used as a
workstation itself and doesn’t have to use the Mac’s operating system.
Many servers in a Mac-based network use AppleShare software. The Transcendental
Operating System (TOPS) server allows shared files be stored on both Macs and PCs.
Working with PCs
wwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwww
Communication between a PC and Mac is only possible if both have suitable hardware and software. Although PC AppleTalk cards are available it can be simpler to use Ethernet since many Macs come already equipped with it.
Suitable software must be provided to allow PCs and Macs to reach each others drives over Ethernet. PC MacLAN (Miramar Systems) includes Mac software and Windows 95 software for a PC. If you only want the PC to work with Mac drives you can used COPSTalk (CoOperative Printing Solutions). To open PC documents on a Mac you’ll need MacLinkPlus (DataViz); to open Mac files on a PC you’ll need Conversions Plus (DataViz).
√πSee the Archives & Foreign Files chapter for more about transferring documents
