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Choosing the right Mac

By Dr. Jeff Seaman

About a year and a half ago, reasoning that a higher number of sales would make up for less profit on each individual sale, Apple Computer embarked on a price-cutting strategy to appeal to a much wider market. Clearly the strategy has paid off: Macintosh computers now have twice the market share they had when Apple first introduced its new marketing approach.

The result on campus is that a wider array of Macintosh computers are available at lower prices than ever before. But the question still remains: Which Macintosh is right for me? This article surveys the current Macintosh offerings, giving recommendations for both individual and departmental use.

A machine-by-machine tour

The Macintosh LC is the only computer in Apple's lineup that uses the 68020 processor chip; thus it lacks the performance of 68030-based Macs. Moreover, it is not possible to upgrade the processor or to add a numeric co-processor or memory management unit (and thus give it the functionality of a 68030). The trade press is full of rumors of a 68030-based LC coming out soon. The best advice is to wait for that new machine to ship rather than to buy the current version of the LC.

The Macintosh IIsi is an excellent machine that suffers from somewhat limited expansion potential. The IIsi is based on the 68030 processor, has very good memory expansion capability, and includes one expansion slot and a built-in video driver that supports almost all Mac displays. Performance is good for the price-noticeably better than the performance of a Classic II but still slower than that of a Mac IIci. Its single expansion slot and limited number of SIMM slots for memory expansion are its major weaknesses. The Mac IIsi is a very good choice for a high-end personal machine and an excellent choice for departmental use, assuming, however, that you don't need capabilities that require more than one expansion card, e.g. an add-in display driver and a network card.

The Macintosh IIci has the additional expansion potential that the Mac IIsi lacks. This, along with better performance from a faster 68030 processor and a built-in RAM cache, makes the IIci the best choice for departmental use. With excellent memory expansion, three open slots for your choice of expansion cards, a built-in video driver, and a design that does not take up a lot of desktop space, the Mac IIci will meet most computing needs today and can grow as your needs grow. Some individuals may require the added performance of a Mac IIci, but the main role of this machine will be to serve as a departmental workhorse.

The fastest desktop Macintosh is the Quadra 700. It features an excellent built-in display driver and very good memory expansion potential. The Quadra 700 falls down in only two areas: It costs so much more than other machines in the Macintosh line, and not all software is compatible with its 68040 processor (but almost everything soon will be).

The Quadra 900 is the floor-standing version of the 700. It does not offer significantly better performance than the 700, but it does have much more expansion potential. The case has room for multiple disk drives, CD-ROMs, etc., and the machine has more memory SIMM slots than any other Macintosh model. The 900 is the answer for those who need the highest performance that Macs offer, combined with significant expansion capability.

The Macintosh portable which is both smallest and lightest is the PowerBook 100. Its performance is better than that of the Mac Classic, but to gain its size and weight advantage significant trade offs have been made. The most important of these for most users is that the floppy drive is not built into the system-it's a plug-in extra. The PowerBook 100 is the ideal machine for the person who travels a lot, needs a computer for relatively simple tasks, and does not need to exchange files via floppy disk while traveling. For most people, however, the other members of the PowerBook family are better choices.

The PowerBook 140 has much better performance than the model 100 (the 140 uses a 68030 processor, the 100 uses a 68000). Its display screen is a little better, and it includes a built-in floppy drive. The price you pay for all this is a slight increase in weight, in size, and in cost. Unless the smallest possible size is of extreme importance, the 140 is preferable to the 100.

The PowerBook 170 takes some of the advantages introduced in the model 140 a few steps further: While size and weight stay the same, the processor is faster, the screen is a lot better, and a data/FAX modem is standard. Price is the only reason not to move up to a PowerBook 170. The model 170 is the equal in performance to many desktop computers-it's an excellent machine for those who need full computing capabilities while on the go.

Summary

Expansion needs for departmental computing are generally greater than they are for individuals; therefore the Mac IIsi is the lowest- level model that should be considered. The Classic II may have a departmental home, but only when it is very clear that there will be no need for further expansion. The workhorse for departmental computing is the Mac IIci-it has the power and expansion capability that departments need at a reasonable price.

Sidebar 1: Interpreting the table

Processor. The more powerful the processor, the better the performance compared to another processor running at the same speed. For most people this translates into buying a Macintosh based on the 68030 processor. Only those who need the highest possible performance (and can afford it) should select a model with a 68040 processor. Models based on older 68000 and 68020 processors are normally not a good choice.

Processor speed. The faster the clock speed of the processor, the better the performance (among machines with the same processor). For example, the Macintosh LC, IIsi, and IIci all use the 68030 but run it at three different speeds. The Mac IIci runs at the highest speed and has the best performance.

Numeric co-processor. For mathematically intensive applications like spreadsheet and statistical programs, the presence of a co- processor will greatly enhance performance; for word processing or occasional database access, a co-processor provides no real gains.

Display screen. Only the Classic II and the PowerBooks include a display built into the unit. All other Macintosh models support a wide range of external monitors.

Expansion slots. Most expansion for Macintosh systems can be handled without using a slot. There will, however, continue to be situations where an expansion slot is required. Most users should therefore look for at least one expansion slot, and more if they envision the need for multiple expansion options.

Preferred configuration. This refers to the amount of memory and hard disk capacity the Computing Resource Center recommends and includes pricing at the Computer Connection. You can never have too much memory- the minimum for adequate performance is 4 Mbytes, with more being better. A hard disk drive is essential-an 80 Mbyte drive is a good minimum for most desktop machines; however, you can get by with a smaller one in a portable, especially if it's your second computer.

Sidebar 2: What's memory got to do with it?

The total amount of memory that you can pack into a Macintosh depends on three factors: The amount of memory soldered onto the system board, the number of memory slots built into the computer, and the amount of memory on each memory module plugged into these slots.

Built-in memory

All but two of the current Macintosh models have some memory built into their system board. The Macintosh IIsi contains 1 Mbyte; the Classic II, the LC, and all the PowerBooks contain 2 Mbytes; and the Quadra 700 holds 4 Mbytes on its system board. Only the Mac IIci and the Quadra 900 do not have any memory permanently mounted on the system board.

Add-in memory

All Macintosh models except the PowerBooks use a plug-in memory expansion module called a SIMM (Single In-line Memory Module). SIMMs come in different densities (the amount of memory per SIMM). The most common types of SIMMs hold 1 Mbyte or 4 Mbytes. Other, less common densities are 256 Kbytes, 2 Mbytes, and a whopping 16 Mbytes. The 1 Mbyte and 4 Mbyte SIMMs cost about the same per Mbyte (approximately $40), while the larger 16 Mbyte SIMMs command a premium price, listing for more than four times the price of the 4 Mbyte variety. This differential will change over time as the 16 Mbyte SIMM comes into mass production.

SIMMs plug into 2 (Classic II and LC), 4 (Mac IIsi and Quadra 700), 8 (Mac IIci), or 16 (Quadra 900) SIMM sockets on the computer's system board. Memory SIMMs are added either in pairs (Classic II and LC) or in groups of four (all other models).

Sample memory math

A Macintosh IIsi has 1 Mbyte of memory on the system board and four SIMM slots. If each of the four slots contains a 1 Mbyte SIMM, then the total system memory is 5 Mbytes. Most Mac IIsi's ship with this memory configuration. If you replace the 1 Mbyte SIMMs with 4 Mbyte SIMMs, then the total memory jumps to 17 Mbytes (1 Mbyte on the system board plus four SIMMs each with 4 Mbytes). Using 16 Mbyte SIMMs increases the total to 65 Mbytes (1 Mbyte on the system board plus four times 16 Mbytes).

PowerBooks are different

Memory expansion is implemented differently in PowerBooks than in other Macintosh models. Each PowerBook has 2 Mbytes on the system board, with any additional memory on a special add-in memory "daughter board," which plugs into the machine's special expansion receptacle. PowerBook 170s ship with 4 Mbytes of memory: 2 Mbytes on the system board and 2 on an add-in board. To increase a 4 Mbyte PowerBook 170 to its maximum of 8 Mbytes, you must replace the existing 2 Mbyte board with one holding 6 Mbytes.