Thanks to John Gruber for mentioning my recent analysis of the new MacBooks (and MB Pros).

From there, several other sites picked it up. The emphasis and comments on some were… interesting. Let’s go into that a little.

The article at Wired has a somewhat sensationalistic headline (which was copied by others): “Killing FireWire on MacBooks Was Necessary”. Well, a careful reading will reveal I didn’t say so outright. I said that under the design conditions that were chosen there was no good way to include a FireWire port on the MacBook. Also, most of my arguments didn’t touch on the FireWire port at all, and there were almost no comments about those; so I’ll mostly confine myself to FireWire in my answers here.

By the way, the lack of the FireWire port on the MacBook doesn’t necessarily mean that Apple is “killing” FireWire at all. Yes, Apple killed the floppy drive, ADB, serial ports and so forth; because no shipping Macs include these. Contrast to FireWire: two shipping laptops don’t have the ports, all others have them.

The Wired article also features some feedback from iFixIt, whose pictures of the laptop’s disassembly I’d linked to:

IFixit’s Luke Soules, who performed the disassembly of the MacBook cited by Brockerhoff, agreed with the engineer’s assessment that there isn’t room for a FireWire port given the new unibody design and motherboard layout. Soules added that it’s also important to keep in mind that the new MacBooks are substantially thinner than their predecessors (.95″ vs 1.08″).

I spent some time reading all comments posted to the various sites. Some people, as expected, hadn’t read my post at all, or not carefullly. After filtering out the noise, here’s a list of points of view expressed in decreasing order: (percentages sum to more than 100% since some people scored in more than one category)

35% say Apple/Steve Jobs are idiots and/or just want your money and/or don’t care as long as idiot Mac users pay. I don’t know how to respond rationally to that, so I’ll leave it to the specialists.

31% agree with my arguments, at least for the most part. Thanks.

25% say that Apple can do anything they want to, so they obviously didn’t want to in this case. These were about equally divided between people disagreeing with the particular trade-off chosen (which is reasonable) and people of the “bah just jam an extra port in there, make it so” variety (who overlap a lot with the first crowd, above).

(Most of the following arguments suggest inserting a FireWire port. To make things shorter, I’d like to recall my previous comments about any such port needing extra board space in form of a PHY (transceiver) chip and filters, several watts extra power supply requirements, extra battery capacity, all implying in either much shorter battery life or increasing the size of the machine. Yes, Apple could use Sony’s 4-pin connector, or leave the 6-pin connector unpowered, getting around part of the problem… but imagine the complaints!)

18% say Apple should have put an extra FireWire port elsewhere; on the other side, in front or on the back. Of course it’s not possible to put anything on the back – the hinge precludes that – or on the front, as that would have meant cutting down a little on the battery (refer to these photos). Putting one or more ports on the side, near the optical drive, means moving or shrinking the speaker (see also my comment below on the security lock). Some people objected to my describing this as an expensive solution, no doubt thinking of the cheap ribbon cables used inside desktop PCs. Well, inside a laptop such cables have to be thin and shielded against interference, especially at FireWire speeds. Think of your normal FireWire cable… with the thinner body, there’s little or no space to route that behind other components. In older laptops, Apple got partially around that problem by using very thin (and therefore, flimsy and expensive) flat cables.

15% say that Apple should have left off one USB port and put a FireWire port in its place. At first glance this sounds reasonable; port sizes are about the same, the functions are supposed to be about the same, and the existence of adapters like the USB->Ethernet adapter for the MacBook Air reinforce this opinion. (Many people also asked why Apple doesn’t bundle or make USB->FireWire or Ethernet->FireWire adapters; see more on that below.) Then again, some were complaining about having only two USB ports…

12% say that Pro users should buy the Pro models. However, much of the controversy is either about Apple’s definition of what “Pro” means, or about people wanting “Pro” features at “Con” price. It’s easy to forget that these are just temporary marketing names for price points.

11% complain that Apple is putting form over function, and letting the designers run free. Of course that’s Apple’s shtick, so to speak (ahem), and a big part of their appeal. (And yes, it doesn’t always work out fine.) But in my humble opinion that’s not the case with the MacBooks.

8% want even more things: more(!) USB ports, two FireWire ports for chaining devices (perhaps the “consumer pros”?), an ExpressCard slot, or one or more “media card” slots. Unsurprisingly, most of these also belong into the “make it so” group; they want it all, but in a small cheap package.

7% say that Apple should have moved the security lock to the other side (where it indeed is, in the MacBook Pros), and put a FireWire port where the notch in the motherboard is. But moving the lock would also mean flipping the battery latch mechanism to the other side, which would mean having the lock just above the hard drive, moving the optical drive upwards, and leaving no space for the speaker.

5% would opt for leaving out the Ethernet port and inserting a FireWire port there (nearly all of these were immediately contradicted by people who do need Ethernet). The Air’s USB->Ethernet adapter is a makeshift, since it can’t attain gigabit speeds. All Macs (except the Air) do have gigabit Ethernet, so… (Yikes! Apple would be killing Ethernet!!!)

5% say that Apple should have made the MacBook thicker or longer, or made the battery smaller. Can you imagine Steve Jobs signing off on that?

The rest are miscellaneous ideas: using stacked ports, leaving out the optical drive, crowding the connectors closer together, combining two ports, and so forth; and fall under similar arguments.

A common thread in many suggestions is a misunderstanding, or perhaps just ignorance, of the technical details of USB and FireWire. While their areas of application overlap, the solutions they offer are different, and so are the protocols they use. USB is master/slave, FireWire is peer-to-peer. Converting one to the other isn’t simply a matter of rearranging pins, or reencoding signals, as happens inside most video adapters; you’d need a fast processor and RAM to do that, and even so you can’t replicate special functions like target mode or streaming on the USB side. You’ll find very few such converters on the market, and they’ll all have some limitations.

Finally, a frequent question is “why doesn’t Apple just implement target mode on USB”? It’s not that simple. On FireWire, target mode is just a software matter – since the interface is peer-to-peer, no chip change is necessary. On the USB side, target mode would imply switching the originating Mac from master to slave and using a hard-to-find A-to-A plug. Current USB chips don’t support that, and connecting such a cable without the port being pre-switched would probably fry one end or both. The upcoming USB On-The-Go supplementary standard supports this over two new protocols and a new connector type; neither work over hubs, and it needs different PHY chips too.