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NETWORKING

A1200 networking from the next room to the next world

Network to Anywhere

If you own two computers you could benefit by networking them with PD or commercial software, through any convenient pair of ports. Whether you want to share files, reduce copies or ease backups, networks are useful. You need no longer ferry floppies back and forth, in the old "sneakernet" approach.

The Internet makes people keen to link all their machines to the world outside. There are ample good combinations and many pitfalls. This feature explains the options that make Amigas a peer with any wired computer in the world.

Options range from a one pound serial cable, adequate for remote input and file transfer at modem rates, up to £100 per station for Envoy, CNet and the A1200 Reset fix. That makes Amigas almost interchangeable in continuous use, an ideal setup for collaborations.

You can link any combination of Amiga, Unix, PC, Mac, Archimedes or other system into a single shared environment. Samba, NetFS or Envoy talk Internet Protocol to a remote file system. Samba emulates a Windoze 'standard'; NetFS is a Unix favourite, freely available on other platforms, which maps more closely to the Amiga way of doing things.

Proprietary Amiga protocols are discussed later. The best use Envoy, the Commodore-endorsed network package which supports automatic disk change recognition, Amiga file types and permissions.

To share screens as well as files and printers, run Mac emulation or close-couple your Amiga to a PC with commercial Amiga Forever or Siamese packages. These support serial links, but they're much more useful with Ethernet. Siamese is harder to set up, but does more, once you've got it working.

Both allow file sharing; Siamese can retarget Amiga graphics onto the PC display, while Amiga Forever runs UAE emulation, using the Amiga as an adapter for 880K floppies which the PC cannot otherwise read. Cloanto's Amiga Explorer software extends Windows9x to "explore" any Amiga drive.

This means your CNet card is loose or didn't reset

PrepCard confirms that the PCMCIA card is working

Bargain Networks

This section explains the new Ethernet options for PCMCIA Amigas, network protocols, connections, and alternatives. If you can live without Ethernet's speed and long cable runs, there are cheap ways to connect Amigas and PCs.

Two terminal packages can be linked by a null modem cable. If both machines could access the same Bulletin Board, they could just as well talk directly. Most terminals support ZModem protocol, including Amiga NComm and Term, which allows data compression, error detection and correction.

More specialised utilities come with matched 'servers' to run at each end of the link, and are easier to set up as they do not bother you about the non-existent modems in a serial network. Aminet has EasyTransfer, PC2Amiga, TwinExpress and many more.

ParNet, SerNet and ProNet are Amiga-specific network systems, devised by The Software Distillery a decade ago. SerNet works with any serial port and a null-modem cable, a standard seven wire serial connection, known as 'Serial Laplink' in PC shops - but check their plugs match your ports. One wire is earth; two more let both ends talk at once; the other four say "please" and "thank you" both ways, for reliability.

Serial cables use from three to seven wires, and parallel from nine to 25, both through 25 way D plugs or sockets. You can switch these with cheap mechanical switch boxes, but intelligent printer switches won't like the direction changes and software will probably be confused when another program adjusts the hardware after they thought they'd set it up. Networks need a dedicated port at each end.

ParNet

ParNet is dedicated to the Amiga bidirectional parallel port, and a custom 16-wire cable, available from Epic. It's connected straight through but for two extra links bridging pins 10 and 13 both ends, and pins 1, 14-17, 23-25 disconnected.

ParNet status prefers you to use the old Topaz font

Such networks mount a drive called NET:, with the volume name Network:. Drives on the remote machine appear there as you refer to them, rather like deferred assignments. At first you only see RAM: and SYS:, two paths guaranteed to exist. ParNet initialisation can copy "node.rinfo" files to other drives that you want to appear immediately on the Workbench.

ParNet is less robust than TCP/IP networks. If you reset one end of the link you block access to partitions with outstanding 'locks' where the other machine was using them. You may dodge this by ASSIGNing new names, but eventually you'll need to reset to bring both back into sync.

ParBench is a modern installer for the venerable ParNet

Three Way Action

ParNet is most common between two Amigas, but the protocol allows custom cables that link three or more Amigas in parallel. The maximum recommended cable length is ten metres, though five is a safer bet - you're using a printer port, after all.

Data transfers are eight bits wide, using four control lines and five earths. All stations share the available bandwidth, ranging from 20K per second on old Amigas to 40K or more between modern machines.

ParNet and SerNet support Amiga file attributes and message-passing, but not disk changes or notification. ParNetKeys allows keyboard and mouse control redirection over the network. Source is freely available, so minor variants abound. ParBench is a friendly installer for ParNet.

ProNet uses the same cables, but is newer, more flexible shareware. It's modular, recognises disk changes, and supports GVP and Multiface parallel ports as well as the motherboard one. It requires Kickstart 2 or 3. ProNet allows messages, real-time chat, and remote commands, even over the phone. If you're not afraid of shell commands to set it up, it's far nicer than ParNet between modern Amigas.

Network PC

PC2Amiga is a serial and parallel file server from Aminet, bundled as Network PC with a custom cable, Amiga and MSDOS disks, by Weird Science. The PC runs as a slave, giving the Amiga access to all its drives. The PC needs at least MSDOS 6.

With PC2Amiga you can make an IBM your slave

Parallel port transfers use four wires each way, boosting speed past 20K per second, while temporarily throttling the Amiga side. Trimming the transfer priority leaves more time for other tasks, but then Network PC times out on a heavily loaded system. You can configure the maximum packet size, from 312 to 8192 bytes, and the number of retries before an error is reported.

PC2Amiga has friendly installer scripts, clear AmigaGuides, commodity and Win95 file name support. It comes with good utilities. I use NetPCspeed for Envoy, Samba, ParNet and NetFS tests, as well as timing PC2Amiga transfers. It has some rough edges, but these are well explained.

Serial options

NCP is the networking scheme designed for Psion 3 notebook computers, but Aminet's AmigaNCP works well over a serial link between two Amigas. NCP implementations for other computers include the shell MCLINK.EXE for MSDOS PCs and versions for Apple Mac and Acorn Archimedes, so it's a contender to link any pair of those machines, whether or not you have a Psion.

Amiga NCP is concise and complete, with a print and file server and informative debug monitor. It supports long file names but requires odd punctuation, so you access SYS:S/Startup-Sequence on the remote machine by chanting: REM::\\SYS:\\startup-sequence - ugh!

TwinExpress offers fast serial transfers between Amigas or an Amiga and a PC connected with a null modem cable. It bangs the serial port hardware at both ends, allowing speeds up to 11K per second even on fairly basic machines. TwinExpress supports PC and Amiga wildcards, and translates between ANSI and MSDOS character sets. Its main limitation is that it runs as a shell, rather than a file server, so you have to use its own commands rather than your usual application file requesters.

Internet Protocol

TCP/IP stands for Transfer Control Protocol/Internet Protocol. It's the standard for global networks, devised by the cold war Advanced Research Projects Agency. AmiTCP was the first Amiga implementation, based on Unix code, followed by Termite and Miami.

TCP is configured by text files, but Genesis and Miami have front ends to simplify setting these up. Lacking these, try to modify an existing setup, be systematic, and prepare for a lot of reading. TCP/IP is powerful, but not simple.

TCP/IP is the scaffolding of the Internet, a reliable way of transmitting 'packets' of data over any connection. Ethernet is ideal, but TCP/IP can run over serial ports (SLIP) or parallel (PLIP), though the parallel cable is wired unlike Amiga-specific ParNet ones. Many other protocols - from UTP timing to HTTP web access, and innumerable network file systems - run on top of a TCP/IP stack.

Amiga PLIP cables almost match ParNet, but are nothing like Laplink

Magic numbers

Every machine on a TCP/IP network has an unique 32 bit identifying number, split into four bytes, 0 to 255, separated by dots. A 'domain name server' translates names like www.amiga.com into the corresponding numbers, but you can use the numbers directly for web and FTP access if you know what to type.

The limit of 4.3 billion stations upset megalomaniacs so the IP engineers are expanding it to 128 bits, for 341, billion, billion, billion, billion addresses! Most local networks get by with 254 from a group of about 65,000 reserved for local systems not visible to the wider Internet. An Amiga with TCP/IP is a full global peer if online, or a 'closed net' with all the Internet capabilities.

Out of the four billion possible Internet numbers, about 65,000 are reserved for small local networks. Other reserved groups allow subnets up to a few million. These numbers can be reused in any local network, because they are not visible outside. They start 192.168 followed by two byte values - I use 192.168.0.1, 192.168.0.2, and so on.

There's no need to change earlier numbers unless you have more than 254 stations. IFCONFIG sets your machine's address and network adapter, once TCP/IP is running. My example script is enough to use SynClock, Telnet, FTP and NetFS over AmiTCP 3 or later.

The simplest TCP/IP command is PING, which sends empty packets to a remote address and checks that they return intact. PING is the basic test of a connection between machines. If you can't PING it, it's not connected!

0 (Zero) is conventionally assigned to "the network", rather than any specific machine; the last number 255 is reserved for 'broadcasts' to all machines in a subnet, associated by a netmask which has zero for 'don't care' bits. The normal local net mask is 255.255.255.0, so if you PING 192.168.0.255 you'll get replies from yourself as well as all other machines with numbers starting 192.168.0.

It's vital that every station has an unique number, just as on a SCSI chain, but that's just the start. You need matching file system software at both ends of the link to manage necessary abstractions like named files, dates and times, print spools, commands or key-presses. The "file system" sections below summarise your options.

IP Routing

Any machine can reach any other on a TCP/IP network, but local IP numbering mean messages from the outside world must be forwarded by the machine with a direction connection. If you want to use Amiga Internet programs via another computer that's already connected to an ISP, you need a program to mediate between all three.

Windows users can run the Wingate or Sygate to forward messages. Unix needs no separate program to do IP routing. NetBSD and Linux have gateway and proxy serving built in, known as NAT or IP masquerading. AmiTCP and the full version of Miami can do routing on Amigas.

Ping for Telnet

You can run basic services like PING over TCP/IP, and some more esoteric ones like SynClock, which uses the TCP: device to open an NTP port in Network Time Protocol, and a mixture of ARexx and shell script to read the time on a remote machine and update the local clock accordingly. SynClock 192.168.0.3 reads the time from local station 3 - append SAVE to update your machine's clock.

Success! Amiga greets Wintel by the magic of PING

Telnet lets you type commands on one machine to run on another. To open a shell on the second local machine, type TELNET 192.168.0.2, then the user name telnet and password Telnet, to log on.

The remote Shell is effectively restricted to command-line applications because you lose control as soon as a command starts up a task on the remote Workbench or a custom screen. Thus Bustest smoothly reports the speed of remote memory in your Shell window, but ED is useless because you can't type anything into the editor once it's started up.

You quit Telnet with the usual ENDCLI. It's not unusual to have discarded shells lying around if you experiment with commands and lose control by accident, but once you learn which programs run entirely in the shell Telnet is useful way to monitor or off-load rendering or compiling effort to a remote system.

All TCP/IP stacks support File Transfer Protocol (FTP), whether from a Shell with NCFTP, a dedicated GUI application like AmFTP, FTPmount or Opus 5 extensions, but it's limited to copying whole files around, less versatile than real file systems. File Transfer Protocol struggles with random-access and Amiga-specific file attributes. It's fine for wafting archives back and forth, but if you want access to remote drives as if they were on your local machine - from Workbench and applications as well as the shell - you need a file system like Samba, NFS or Envoy.

File Systems

File System 1 - Samba

In Unix and IBM-land SaMBa stands for Session Message Block, not to be confused with the recent Amiga football game. For that matter, PCMCIA CNet cards are unrelated to the old Amiga CNet bulletin boards. Samba is a Unix package that speaks IBM's LAN-Manager protocol, like Windows 3.11 and subsequent nineties versions. "Dave" is a commercial version of Samba for Macs.

Power's Amiga PD version of Samba works, but it's torpid. A dozen or more messages must be exchanged for every file transfer, however small, so Directory Opus file transfers are painfully slow. Disappointed that it was taking about a second to copy each small file between a hot 68040 and 75 MHz 68060, I called the estimable Salvatore at Power Computing, whose company-wide Samba network includes A1200 and A4000 Amigas. He confirmed my findings, reporting that it took one and a quarter minutes to copy 51 files, totalling just 116K, between RAM drives on 68030 machines.

If you copy lumps of 50K or more, Samba comes closer to the speed of the network - my relatively fast Amiga 1200s got about 100K per second at best, for large file transfers. Samba works OK for this sort of thing, and Power are to be commended for configuring a package which gets Amigas and PCs networking together without extra expense, but it's PC-sluggish if you want to browse remote directories over Workbench - you'd be far better off with ParNet or even SerNet for the small transfers of icons and directory data which Workbench expects.

The only reason to tolerate Samba's sloth on small files is its compatibility with the LAN Manager protocol. If you need to link Amigas and PCs, Samba is the safest option because the PC end should be set up right from the start; that's the most painful place to have to fiddle around, otherwise.

Power Computing ship a mid-nineties port of Samba with Helsinki Tech's AmiTCP 3. This is close to the Unix code, reliant on IXEmul for emulation in the Amiga environment. If you own AmiTCP 4 or better - Genesis is paradoxically the latest incarnation - you should seek out Olaf Barthel's more Amigafied version. It's smaller, faster and more stable, because it runs without IXEmul and has been partly recoded by someone who understands Amigas. AFCD48 saves you a 2.3 megabyte download.

Samba shows Amiga drives on a Wintel laptop

File System 2 - NetFS

NetFS is another package to run on top of TCP/IP, and the file system of choice for networking Amigas on a tight budget. It lacks some Amiga niceties - when you change disks, the old name and icon remains on remote systems, though you can access the new contents by clicking therein. File links are supported; these short cuts across (soft links) or between drives (hard links) were a late arrival in AmigaOS, and are a useful Unix-style alternative to ASSIGN.

User names and file protection are supported, but NetFS is not a secure system. As with Samba, a competent TCP/IP hacker could get and use anyone else's password without much difficulty. Do not confuse NetFS with the Unix-compatible NFS, which could netmount the whole 400 Gigabyte Sunsite, including all of Aminet from 193.63.255.4:/public - you need Linux or NetBSD to do this, although a true Amiga NFS has been long-awaited. For now, you'll have to do this with FTP.

The big advantage of NetFS is that it has lower overhead than Samba. Opus copies small files ten or more times faster over the same network hardware, and large transfers are completed in 60 per cent of the time. This is still short of the potential of Ethernet, rated at 10 megabits per second, but at least we're in the right order of magnitude - well tuned Zorro and PC Ethernet systems manage a few hundred K per second over this type of Ethernet, and the old TCP/IP stack, PCMCIA cards and CNet driver take their toll alongside NetFS.

Workbench windows open and fill with icons at acceptable speed - faster than from most CD ROMs but slower than a decent hard drive. NetFS is a bit quicker than ParNet, but small file speed is not much greater - each TCP/IP transfer is complicated, with overhead to allow for packets being re-ordered or machines coming and going while the network as a whole stays up.

Power Computing's installation supports NetFS if you remove a semicolon from the amitcp:db/services file, before the line "amiganetfs 2500/tcp", and add lines like "netmount 192.168.0.1 sys: NetBoot:" for each remote drive you wish to use. Salvatore recommends this to people who want to link Amigas, rather than PCs. You can run NetFS at the same time as Samba, for the best of both worlds.

Example Startup script for TCP/IP 3 and NetFS

Assign AmiTCP: sys:AmiTCP-3.0b2 ;Shorthand for TCP/IP location
Path AmiTCP:bin add ;Add TCP/IP files to default command path
Run >nil: AmiTCP:AmiTCP
WaitForPort AMITCP ;Wait till TCP/IP is up and running
Run >nil: ifconfig cnet0 192.168.0.1 netmask 255.255.255.0
Mount tcp: from AmiTCP:devs/Inet-Mountlist
Run >nil: inetd ; Start daemon so others can access this machine
;Mount partitions or drives on other machines via NetFS
netmount 192.168.0.2 sys: boot2:
netmount 192.168.0.2 ram: Ram2: ;etc, etc!

Note: An extended version of this script appears on AFCD48

File System 3 - Envoy

Envoy offers four types of network printer redirection

Envoy is the ultimate in Amiga networking. It supports 'notification' so file views are updated automatically as applications create or move data, disk insertions and removals are promptly recognised, and Amiga file types and filenote comments are faithfully preserved.

Configure remote drives by "importing" them with Envoy

Envoy 3 (AF120) offers spooling, mouse and keyboard redirection, and even distributed ARexx commands! Envoy supports any SANA II compatible connection, independent of TCP/IP, file permissions through Aminet's MultiUserFS, custom directory paths, and write-protected paths which are handy when sharing removable media.

Export options tell Envoy which drives to share

Envoy uses Internet Protocol packets with different contents from the Unix TCP/IP protocol stack, while sharing a common addressing scheme. Since release 2, SANA II drivers can run both at once through a given interface, Envoy sharing the link alongside NetFS or Samba.

Envoy works with SLIP and PLIP as well as Ethernet

If you want a fast, seamless Amiga network, Envoy is matchless. It's distributed by Aminet benefactors Schatztruhe and costs £40 from Weird Science in the UK. It richly deserved its Format Gold award, being easy to install, well documented and supported. It does the basics as well or better than other file systems, and much more besides.

Friendly icons make Envoy configuration a cinch


 

Envoy Ethernet Speeds

System Speed
68020 to 68060 254 K/s
68020 from 68060 334 K/s
68040 to 68060 337 K/s
68060 from 68040 384 K/s
68060 to 68040 374 K/s
68060 from 68040 346 K/s
68060 to 68020 307 K/s
68060 from 68020 228 K/s

Notes: 

1. Testing cnet.device between PCMCIA A1200s
2. CPUs: 14 MHz 68020, 40 MHz 68040, 75 MHz 68060

Ethernet Standards

Standard Plug Cable Requirements
10-Base-T RJ45 Cat-5 Hub if more than two boxes
10-Base-2 BNC Coax Termination, may bottleneck
10-Base-5 D15 Thicknet Repeater per box, obsolete

"Standard" Ethernet cables might resemble US phone wire, UHF TV flex or yellow water pipes!
 
 
 
 
 
 
 



Product reviews

Power PCMCIA Ethernet 
Power Computing's Ethernet adapter plugs into the PCMCIA port on the A600 or A1200. It is keenly priced under £50, including four floppy disks of software - three of them Amiga-specific, and adapters as well as the type 2 PCMCIA network card itself, but cables are extra. 

A 15 way connector on the outer card edge accommodates a latching plug for the standard Ethernet sockets. These are fitted in a small plastic box with two lights on it, as well as an RJ-45 telephone-style socket, and the older BNC bayonet-fitting UHF connector. The Ethernet connections are standard so Power's pack will fit happily into existing Amiga, PC, Mac or Unix networks. 

It's up to you whether to use the new telephone-style socket or the coaxial cable. Either way you need to provide your own network cable. A three way T-shaped adapter lets you daisy-chain coaxial cables. Both ends of such a network must be terminated, so the T-piece is essential. The Power Computing bundle does not include the terminators required at each end of the chain, but these are readily available 50 ohm resistors in a BNC plug. 

Power also supply a small hand-assembled circuit-board with three wires. This fixes a fault of the A1200 PCMCIA port, which does not implement the card reset signal. Once you've soldered the three wires to your A1200 Gayle chip, PCMCIA automatically resets when you switch on or reset the Amiga. 

Otherwise, you need to slide the card out of its socket and plug it back in to reset that end of the network. This is a safe operation because PCMCIA cards have short power pins designed for 'hot plugging', but if you are not afraid of a bit of soldering, the reset adapter board is more elegant. There's no need for this bodge on A600s as they implements credit card slot resets correctly. 

If you encounter a wide list of arcane complaint messages from TCP/IP, or sullen inaction - the network interface light unblinking - the card must be reset. Hardware interrupts monitor card changes and data transfers, so you can't confuse things by hot plugging. 

The Amiga is slowed, but still continuously usable, even during flat-out transfers. The top throughput is less than CPU-hogs like IDE manage, but other work can continue at the same time. The overhead is much more noticeable on a 14 MHz 68020 than an expanded A1200. 

Software

The printed documentation is brief and dispensible, all related to the PC components of the package. You get drivers on one high density floppy disk, and a few desultory pages of American instructions, repeated in German, French, Spanish, Italian, Portuguese and Russian. 

The vital extras are on the Amiga disks. Power Computing's network expert Alessio has spent weeks extending and configuring cnet.device to supports Samba and NetFS as well as raw TCP/IP. Power's bargain bundle makes your Amiga a peer of PCs, which is useful though unadventurous. Amiga, Mac and Linux links are also possible. If you run several Amigas, the hardware could really hum, and at this price, you can afford to experiment. 

Pros and Cons + Three disks of Amiga net software 
+ Amiga Samba setup instructions 
+ Includes solderable reset fix gadget 
- Slower than upmarket Zorro cards 
Price £49.95 (check current advert) 
Score 81% 
Requires A1200 or A600 
Supplier Power Computing
82a Singer Way
Woburn Road Industrial Estate
Kempston
MK43 2JK

Tel: 01234 851500. 

Overall Works out of the box - but a lot better if carefully tuned! 


Eyetech CNet PCMCIA 
Eyetech's CNet package comprises a largely empty 880K floppy with two versions of the device driver, the unavoidable PC disk, card and manual, a silver T-piece for terminated coaxial cable, and an interface box with BNC and RJ45 sockets. Two lights on this box indicate UTP linkage and dataflow through one or other socket, just like Power's variant. 

The wiring options are listed in the table. All allow long cables, at varying cost. Coax is being displaced by twisted pair UTP, but that requires a 'hub' to connect more than two stations. 

Aminet's cnet.device is free, and fine as far as it goes. It gives a consistent hardware-independent interface to one or many AmigaOS tasks, complying to the Amiga standard SANA II (Standard Amiga Network Architecture). It neatly brings virtually all resources available in a PCMCIA "cod-ISA" network card to the Amiga. It offers optional diagnostics and comes with clearly annotated assembler source code; you won't need either but they're well done anyway. 

CNet software deals in "packets": short numbered blocks of data, internally cryptic. Everything else can be interpreted by software already written for modems, ISDN, Zorro, serial or parallel links, because the Amiga is a device-independent system - all devices share code so application programs can use them identically regardless of speed or location, and the minimum, best-tested code does the maximum work. 

CNet is just the start. Eyetech expect you to roll your own file system, or buy a ready-made Ethernet application. They originally sourced CNet cards for Siamese Amiga/PC systems, which use Ethernet for files and graphics. 

The RESET bodge

The cnet.device cannot solve one A1200 hardware problem. Hot plugging works fine on the A600, but the A1200 omits a pulse the PCMCIA card expects, to ensure it starts correctly. One way to provide the card with the expected pulse is to solder a small electrolytic capacitor between the Gayle input and the power supply, so that a signal builds up in a fraction of a second after the Amiga resets. If the card starts up relatively fast, this works, but the winner depends on the card and the Amiga expansion. In other words, it might not work. 

A sliver of circuit board and three components permit a more certain cure, straddling the Gayle interface with three soldered wires. When comparing Eyetech, Power and DIY Ethernet prices, remember that Power make this adapter for you, and Eyetech even fit it for you. 

Eyetech's authentic CNet card works impeccably, but so does the clone model from Power Computing, and that includes a complete, if basic, PC and multi-Amiga network package. Eyetech charge substantially more, but fix the A1200 PCMCIA reset as a matter of professional pride. You'd not get a Zorro Ethernet card for any less, but might get better software. With the right bundle either could yet be worth a Format Gold. 

If you're lucky this Aminet fix might cure PCMCIA reset problems

Pros and Cons + Genuine CNet hardware 
+ Price includes A1200 reset fix 
- Only basic hardware drivers 
- No network setup instructions 
Price £79.95 
Score 71% 
Requires
Supplier Eyetech
The Old Bank
12 West Green
Stokesley
North Yorkshire
TS9 5BB

Tel: 01642 713 185. 

Overall Suits Siamese systems and people more confident in software than hardware hacking 

Web links

Envoy and NetworkPC software: www.weirdscience.co.uk
Windows Amiga Explorer: www.cloanto.com/amiga/forever
Power PCMCIA Networking: www.powerc.co.uk
PCMCIA Ethernet, Siamese, Miami: www.eyetech.co.uk
Help: home.intekom.com/jacog/howtonet/dullmodem.html

There's vast amounts of network-related material on AFCD48 and Aminet

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