Internet Software

Last month, Martin Russ got caught up in Apple takeover fever. This month, he explains how the situation has completely changed...

Last month, Apple looked like a prime takeover target, with most of the financial press tipping Sun Microsystems as the likeliest partner for the troubled computer giant. This month, however, all bets are off, with Apple battling on alone as the only major alternative to Microsoft and Intel.

Hanging on to their 10% of the computing marketplace has been very costly for Apple in the last year or two, and the continued lowering of prices in pursuit of a larger market share has changed the direction of the company, perhaps forever. After reporting a loss of $69 million for the last quarter of 1995, accompanied by 1,300 job losses and the promise of more to come, it was obvious that ex‑suitors like IBM, Sony, Fujitsu, Hewlett Packard and Sun might have another go at trying to buy Apple. The first sign of some concrete developments was when the Apple board met at the beginning of February, and Chief Executive Officer Michael Spindler was ousted.

New CEO (and chairman) Gilbert F Amelio has a reputation as a mover and shaker, having turned around the ailing fortunes of the National Semiconductor Corporation in the space of only four years. NatSemi were one of the longest‑established semiconductor companies, with a history of innovation and a wide range of products. Despite inventing many of the standard analogue op‑amps and other chips, NatSemi's performance had been in the doldrums until Amelio's arrival, when vigorous change and a new logo restored them to profit. Indeed, Amelio has described himself before now as a 'transformation manager'.

Apple may need some transforming. The licensing of clones using the Mac Operating System has been woefully late and small‑scale, while some interesting but not‑overly successful projects like the Newton seem to have distracted the company from their core business. Despite lots of talk about Windows 95 being where the Mac was five years ago, the gap does seem to be closing, while Apple's full multi‑tasking, totally reworked System 8.0 (Copland) seems to be receding into the distance rather than getting closer.

But Amelio should change this. Apple has huge strengths: a loyal customer base; easy‑to‑use products (even in these days of blanket Windows 95 coverage in the technology media); innovative software (PowerTalk e‑mail, Open Transport networking and OpenDoc mini‑programs) and the potential for huge sales of Mac OS clones. There are also all the people in the music business who use Macs to produce music, audio, and multimedia — not the largest of markets, perhaps, but leading‑edge, high‑profile stuff nevertheless.

Apple are not about to vanish — they never were, even if Sun had bought them! There may be changes in the next year or two, but I, for one, am not looking to change to a PC. In fact, after borrowing an 8100/110 for a month or so in order to review Opcode's Studio Vision Pro v3.0 for SOS (thanks again to MCMXCIX), I'm now thinking about a new Power Mac!

How It Works: Internet Software

Last month, I talked about the modem part of an internet connection, which is the only hardware link in the chain. Everything else is software, so let's look at how the Mac gets you connected.

The internet uses a protocol to enable the movement of bits of information from one computer to another. MIDI is another protocol that you might be more familiar with — it's just a set of instructions about how messages are put together, and what they do. The internet protocol is called IP, surprisingly enough, and it supports functions like addressing (roughly analagous to MIDI channels) to make sure that the information heads towards its intended destination. It also specifies the structure of a message packet: header, data, footer.

Some types of computer network can work directly with IP, but unfortunately, telephone networks aren't one of these. Although a modem can move computer data through telephone cables, IP and modems don't work together very well. What is needed is another protocol to enable the telephone line to be used to carry the IP messages or packets.

There are two common ways of doing this on the Macintosh: SLIP and PPP. SLIP stands for Subscriber Line Internet Protocol, whilst PPP stands for Point‑to‑Point Protocol. Both of these do nothing more than enable you to move IP packets between your computer and the internet, using a telephone cable and a modem.

The internet is not like a telephone network. You don't make a call to the far end and then send data over that connection. Instead, it's more like posting a letter: you address the letter and post it, and then the post people take care of delivering it to the address. It travels to a sorting office, where it is routed to a sorting office nearer to the destination, and from there, delivered. On the internet, you post a message, and it gets passed around from computer to computer until it arrives at one which can deliver it. Rather like the mail, the internet is not 100% reliable — you can't assume that because you posted a letter, it arrived. In order to make sure that something is delivered, you need to keep track of the letter as it is moved around, and get confirmation that it has finally been delivered.

In the postal system, this is where additional services like Registered, Special Delivery and Recorded Delivery are used. On the internet, you just need to add another protocol! TCP, the Transport Control Protocol, handles these functions. TCP and IP are often bundled together into one, but they have very different purposes. On the Mac, they are both handled by a system extension called MacTCP. Applications like WWW Browsers and Terminal Emulators talk to MacTCP.

By now, you should now have a clearer picture of the organisation of this 'low‑level' part of the internet interface to your computer. At the bottom is SLIP or PPP, which allow IP packets to be conveyed over a telephone line. Above this is TCP, which organises the transport of the IP packets, and above TCP are the actual applications that you use. Next month we'll look at SLIP and PPP in more detail.