A computer usually displays its answers on a screen. If you want the computer to copy the answers onto paper, attach the computer to a printer, which is a device that prints on paper.

Midwest Micro offers the greatest variety of printers, a free catalog, and toll-free technical help but charges more than the other three companies. To get special attention, ask Tri State for David Rohinsky at extension 223 and tell him you’re reading The Secret Guide to Computers.

To get low prices locally, walk into chains of discount superstores, such as Comp USA (which sells all kinds of computer equipment) and Staples (which sells all kinds of office supplies and some computer equipment).

Reconditioned printers Another way to get a printer cheap is to phone a printer manufacturer, Epson, at its Accessories Division (800-873-7766) and ask for a catalog of Epson printers that are factory-reconditioned (which means "used but fixed up by the manufacturer to be like new"). They’re usually older models, at reduced prices. You get a 30-day money-back guarantee and 2-year warranty. Customers who got those printers were thrilled by the fine quality at ridiculously low prices! But alas, Epson recently raised its prices for factory-reconditioned printers; now they cost just slightly less than new ones.

A dot-matrix printer looks like a typewriter but has no keyboard. Like a typewriter, it smashes an inked ribbon against the paper. Like a typewriter, it’s cheap: it typically costs about $150.

An ink-jet printer looks like a dot-matrix printer; but instead of containing a ribbon, it contains tiny hoses that squirt ink at the paper. It prints more beautifully than a dot-matrix printer and costs more. It typically costs about $250.

A laser printer looks like a photocopier. Like a photocopier, it contains a rotating drum and inky toner. It prints even more beautifully than the other two kinds of printers. Like a photocopier, it’s expensive: it typically costs about $400.

Color If you need to print in color (instead of just black-and-white), get an ink-jet printer. (Dot-matrix printers produce colors too crudely and slowly. Color laser printers cost too much — about $8,000.) Ink-jet printers that can print in color cost about $300.

Mailing labels Although you can print mailing labels on all three kinds of printers, the easiest way to print mailing labels is on a dot-matrix printer.

Multi-part forms If you want to print on a multipart form (using carbon paper or carbonless NCR paper), you must buy a dot-matrix printer.

Old accounting software Some old accounting software requires that you buy a dot-matrix printer. It also requires that the printer be an expensive kind that can handle extra-wide paper.

Although the most popular kinds of printers are dot-matrix, ink-jet, and laser, some folks still use an older kind of printer, called a daisy-wheel printer. It’s cute! Here’s how it works.…

Like a typewriter and a dot-matrix printer, a daisy-wheel printer smashes an inked ribbon against paper. To do that, the daisy-wheel printer contains a device called a daisy wheel, which is an artificial daisy flower made of plastic or metal. On each of the daisy’s petals is embossed a character: a letter, a digit, or a symbol. For example, one petal has the letter A embossed on it; another petal has B; another petal has C; etc.

Notice that each character is embossed. (The word "embossed" is like "engraved", but an "embossed" character is raised up from the surface instead of etched into the surface.)

Boldface The printer can print each character extra-dark or regular. To print a character extra-dark, the printer prints the character, moves to the right just 120^th of an inch, and then reprints the character. Since the second printing is almost in the same place as the original character, the character looks darkened and slightly fatter. Those darkened, fattened characters are called boldfaced.

Different wheels You can remove the daisy wheel from the printer and insert a different daisy wheel instead. Each daisy wheel contains a different font. For example, one daisy wheel contains italics; a different daisy wheel contains Greek symbols used by scientists.

Manufacturers The most famous daisy-wheel printer manufacturer was Diablo, founded by Mr. Lee in California. He sold the company to Xerox, then founded a second daisy-wheel printer company, Qume (pronounced "kyoom"), which he sold to ITT. In 1988 he bought Qume back. Other companies (such as Brother and Juki) invented imitations that claimed to be Diablo & Qume compatible.

Variants of the daisy wheel Over the years, many variants of the daisy wheel have been invented.

For example, Nippon Electric Company (NEC) invented a "wilted" daisy wheel, whose petals are bent. The wilted daisy wheel is called a thimble. Computerists like it because it spins faster than a traditional daisy and also produces a sharper image. It’s used just in NEC’s Spinwriter and Elf printers.

Another variation of the daisy wheel is the plastic golf ball, which has characters embossed all over it. IBM calls it a Selectric typing element. IBM uses it in typewriters, typesetting machines, and printers. It produces better-looking characters than daisy wheels or thimbles. Since it spins too slowly and needs too many repairs, IBM is discontinuing it.

Gigantic printers used by maxicomputers and minicomputers have characters embossed on bands, chains, and drums instead of daisies. Those printers are fast and cost many thousands of dollars.

A dot-matrix printer resembles a daisy-wheel printer; but instead of containing a daisy wheel, it contains a few guns, as if it were a super-cowboy whose belt contains several holsters.

If the printer is of average quality, it has 9 guns — and therefore 9 pins. It’s called a 9-pin printer. The 9 guns are stacked on top of each other, in a column that’s called the print head. If all the guns fire simultaneously, the pins smash against the ribbon simultaneously, so the paper shows 9 dots in a vertical column. The dots are very close to each other, so that the column of dots looks like a single vertical line. If just some of the 9 pins press against the ribbon, you get fewer than 9 dots, so you see just part of a vertical line.

The pattern of dots that makes up a character is called the dot matrix. That’s why such a printer’s called a 9-pin dot-matrix printer.

When microcomputers first became popular, most dot-matrix printers for them were built by a New Hampshire company, Centronics. In 1980, Japanese companies took over the marketplace. Centronics went bankrupt. The two Japanese companies that dominate the industry now are Epson and Panasonic.

Epson Epson became popular because it was the first company to develop a disposable print head — so that when the print head wears out, you can throw it away and pop in a new one yourself, without needing a repairman. Also, Epson was the first company to develop a low-cost dot-matrix impact printer whose dots look "clean and crisp" instead of looking like "fuzzy blobs". Epson was the main reason why Centronics went bankrupt.

Epson is part of a Japanese conglomerate called the Seiko Group, which became famous by timing the athletes in the 1964 Tokyo Olympics. To time them accurately, the Seiko Group invented a quartz clock attached to an electronic printer. Later, the quartz clock was miniaturized and marketed to consumers as the "Seiko watch", which became the best-selling watch in the whole world. The electronic printer, or "E.P.", led to a better printer, called the "son of E.P.", or "EP’s son". That’s how the Epson division was founded and got its name!

Epson’s first 9-pin printer was the MX-80. Then came an improvement, called the FX-80. Those printers are obsolete; they’ve been replaced by Epson’s newest 9-pin wonders, the FX-870 ($280) and the FX-1170 (which can handle extra-wide paper and costs $370). Epson’s cheapest and slowest 9-pin printers are the LX-300 ($169) and the Action Printer 2250 ($100). You can get those prices from discount dealers (such as Tri State and USA Flex).

Panasonic For a 9-pin printer, I recommend buying the Panasonic 1150 instead, because it prints more beautifully and costs just $125 from discount dealers such as Tri State. Too bad it can’t handle extra-wide paper!

Other Japanese Besides Epson and Panasonic, four other Japanese companies are also popular: NEC, Oki, Citizen, and Star.

Compatibility Printers from all six of those Japanese companies are intended mainly for the IBM PC, though they work with Apple 2 and Commodore computers also.

Apple The most popular printers for the Mac were the Imagewriter and the Imagewriter 2. They were designed by Apple to print exact copies of the Mac’s screen. They even print copies of the screen’s wild fonts and graphics. Apple stopped marketing them, but you can still buy a refurbished Imagewriter for $127 and a refurbished Imagewriter 2 for $199 from Computer Town in New Hampshire at 603-898-3200. (Refurbished means "used but fixed up to be as-good-as-new".)

Manufacturers The first company to popularize 24-pin printers was Toshiba. Its printers printed Japanese — and English — beautifully. 24-pin Toshiba printers became popular in America, because they print English characters more beautifully than 9-pin printers.

The Epson Action Printer 3250 has a black ribbon and costs $150.

The Panasonic 2130 has a black ribbon and costs $169 ($199 minus $30 rebate).

The Panasonic 2135 has a multicolor ribbon and costs $239.

The Epson LQ-570+ is sturdier, easier to operate, has a black ribbon, and costs $240.

The cheapest 24-pin printer that handles wide paper is the Epson LQ-1070+ ($380).

Pin arrangement In a typical, cheap 24-pin printer (such as the Epson Action Printer 3250), the even-numbered pins are slightly to the right of the odd-numbered pins, so you see two columns of pins. After firing the even-numbered pins, the print head moves to the right and fires the odd-numbered pins, whose dots on paper overlap the dots from the even-numbered pins. The overlap insures that the vertical column of up to 24 dots has no unwanted gaps.

Although the first dot-matrix printers had just 7 pins and printed ugly characters, the newest 9-pin and 24-pin printers from Epson and Panasonic print prettier characters than the average daisy wheel. Moreover, you can make the typical 9-pin printer imitate an 18-pin printer by doing 2-pass printing, in which the printer prints a line of text, jerks the paper up very slightly, and then prints the line again so the new dots fill the gaps between the old dots.

An ink-jet printer resembles a dot-matrix printer but contains hoses instead of guns. The hoses (called nozzles) squirt ink at the paper. There are no pins or ribbons.

The most popular ink-jet printers are made by Hewlett-Packard (HP). Recently, Epson and Canon have started making ink-jet printers also.

HP’s ink-jet printers are called Desk Jets. Canon’s ink-jet printers are called Bubble Jets. Epson’s ink-jet printers are called Styluses.

Most printers are designed for the IBM PC. Most printers can be attached to a Mac also. Special Mac-only models are also available: HP’s Mac-only models are called Desk Writers; Canon’s Mac-only models, called Stylewriters, are marketed by Apple.

Some brands of paper absorb ink better. If you choose the wrong brand, the ink will wick (spread out erratically through the strands of the paper’s fiber). Start by trying cheap copier paper, then explore alternatives. The paper brand you buy makes a much bigger difference with ink-jet printers than with dot-matrix or laser printers. Canon’s printers are the best at tolerating paper differences, but Canon’s ink is water-based and smears slightly if the paper or envelope gets wet (from rain or a sweaty thumb).

Tri State tends to have the lowest prices on HP printers.

Harmony has the lowest prices on Canon & Epson printers.

USA Flex has the most informative ads.

The most popular category is dual-cartridge color. If you buy an ink-jet printer in this category, you can insert two ink cartridges simultaneously, side by side.

One cartridge contains black ink. The other cartridge contains the color trio (red, blue, and yellow). The computer mixes together all 4 (black, red, blue, and yellow) to form all possible colors. That method is called the 4-color process.

Epson’s main such printer is the Stylus Color 600, which costs $249 (from Harmony). It’s the most appropriate Epson printer for most folks to buy.

Epson also sells the Stylus Color 800.

Epson also sells the Stylus Color 400.

To compete against Epson, Canon offers the Bubble Jet Color 4300 (BJC-4300).

Canon’s price for this nice printer is ridiculously low: just $185. That low price makes it the best bargain of all printers from all companies. For $34 extra, Canon will include Photo ink to make photographs print better, but still not as nice as Epson’s, since Canon’s resolution is just 720´ 360. To save money, get an older model (the BJC-4100), refurbished, for just $139. Those Canon prices are from discounters such as Harmony.

A cheaper category is single-cartridge color. This category lets you insert either a black cartridge or a color cartridge, but you cannot insert both cartridges simultaneously.

But the price is deliciously low! The best such printer is Canon’s BJC-250.

Canon’s main competitor is HP’s Desk Jet 400L.

Portable You can buy these portable ink-jet printers, which are tiny and weigh little: Canon’s BJ-10SX ($149, prints just in black), BJ-30 ($249, prints just in black), Canon’s BJC-80 ($249, colors), and HP’s Deskjet 340 ($269, just black, upgradable to color for $39 extra). They work slowly, print less beautifully than desktop printers, and can’t handle big stacks of paper.

Wide-carriage Most ink-jet printers handle just normal-width paper, which is 8½ inches wide. To print colors on wider paper, get Canon’s BJC-4550 ($269, 11"-by-17" paper) or Epson’s Stylus 1500 ($469, 17"-by-22").

4-cartridge color Suppose you’re printing a picture that contains lots of red but not much blue or yellow. When you use up all the red ink in a tri-color cartridge, you must throw the whole cartridge away, even though blue and yellow ink remain in the cartridge. What a waste! Canon’s BJC-620 prevents such waste.

A laser printer, like an office photocopier, contains a drum and uses toner made of ink. The printer shines a laser beam at the drum, which picks up the toner and deposits it on the paper.

HP’s best affordable printer is the Laserjet 5, invented in 1996. It improves on earlier models (the Laserjet 1, Laserjet 2, Laserjet 3, and Laserjet 4), which are no longer sold. I printed this book on a Laserjet 5. It’s terrific!

It can print 12 pages per minute (12 ppm). It can print 600 dots per inch (600 dpi); and it uses a trick called Resolution Enhancement Technology (RET), which can shift each dot slightly left or right and make each dot slightly larger or smaller.

Its ROM contains the definitions of 45 fonts. Each of those fonts is scalable: you can make the characters as big or tiny as you wish. You also get a disk containing the definitions of 65 additional scalable fonts: put that disk into your computer, copy those font definitions to your computer’s hard disk, then tell your computer to copy those font definitions to the printer’s RAM. So altogether, the printer can handle two kinds of fonts: the 45 internal fonts that were inside the printer originally, and soft fonts that are copied into the printer’s RAM from the computer’s disks.

The printer contains 4 megabytes of RAM, so it can handle lots of soft fonts and graphics on the same page. Moreover, the printer uses a trick called data compression, which compresses the data so that twice as much data can fit in the RAM (as if the RAM were 8 megabytes).

For folks who can’t afford $988, HP has developed a cheap Personal version (called the Laserjet 5P) and an even cheaper Lower-cost version (called the Laserjet 5L).

HP is always inventing improvements. When this book went to press, HP was selling a slightly improved Laserjet 5P, called the Laserjet 6P; and it was selling a slightly improved Laserjet 5L, called the Laserjet 6L.

In the cheapest laser printer (by Panasonic), the ROM’s fonts are bitmap, which means "non-scalable", which means you cannot make those fonts bigger or smaller: to get bigger or smaller fonts, you must use Windows and wait for Windows to copy scalable fonts from your computer’s hard disk to your printer’s RAM.

Back in 1994, HP invented the Laserjet 4V. It resembles the Laserjet 5 but prints 16 pages per minute (instead of 12) and can accept Very-large paper (11 inches by 17 inches, instead of just 8½ inches by 14 inches). That very-large paper, called tabloid size, is big enough to be the entire page of a tabloid newspaper! Moreover, the Laserjet 4V can print even at the paper’s edge (without requiring a margin).

When IBM decided to stop manufacturing printers, IBM sold its printer factory (in Lexington, Kentucky) to the factory’s employees, who called their new company Lexmark. IBM let them still use the "IBM" name in their advertising, even though they’d become an independent company.

They became the first company to manufacture a 600 dpi laser printer. When HP copied their idea and invented the HP Laserjet 4, they upped the ante and invented a 1200 dpi laser printer! Moreover, it comes with 86 fonts! It’s called the Lexmark IBM Optra R+.

You can buy color laser printers, but they’re very expensive. The cheapest is the QMS Magicolor WX, which lists for $3999. It prints 600 dpi. Black printing is 12 ppm; color printing is 6 ppm.

The Laserjet 2 contains just a few bitmap fonts — and they’re all ugly! If you have a Laserjet 2, you can add extra fonts to it by inserting a font cartridge, which contains ROM chips holding the definitions of extra fonts. The most popular font cartridges for the Laserjet 2 are the Microsoft Z cartridge (manufactured by HP) and the 25-in-1 cartridge (manufactured by Pacific Data). If you have a Laserjet 3, 3P, 4, 4P, 4L, 4 Plus, 4V, 5, 5P, 5L, 6P, or 6L, don’t bother buying font cartridges, since those Laserjets include many good scalable fonts already.

HP laser printers understand a code called Printer Control Language (PCL). It was invented by HP. The newest version of PCL is called PCL 5e. It’s understood by the Laserjet 4 (and by the Laserjet 4 Plus, 4V, 4P, 4L, 5P, and 5L). Older HP printers understand just older versions of PCL and can’t perform as many tricks.

Most IBM-compatible laser printers (such as the ones by Epson, Panasonic, and Sharp) understand PCL, so that they imitate HP’s laser printers, run the same software as HP’s laser printers, and are HP-compatible. But most of them understand just old versions of PCL and can’t perform as many tricks as the Laserjet 4 series.

Some laser printers understand a different code, called Postscript, which was invented by a company called Adobe.

For the Mac, the most popular laser printer is Apple’s Laserwriter, which comes in many versions:

the 9-pin Epson Action Printer 2250 ($100)

the 24-pin Epson Action Printer 3250 ($150)

the 24-pin Epson LQ-570+ ($240)

Canon BJC-4300 (720´ 360 dpi, $185)

Epson Stylus Color 600 (1440´ 720 dpi, $249)

PanasonicKX-P6100 (300 dpi+RET, 6 ppm, $259)

Brother HL-720 (600 dpi, 6 ppm, $319)

HP Laserjet 6L (600 dpi+RET, 6 ppm, $379)

HP Laserjet 6P (600 dpi+RET, 8 ppm, $709)

HP Laserjet 5 (600 dpi+RET, 12 ppm, $988)

A printer that smashes an inked ribbon against the paper is called an impact printer. The most popular kind of impact printer is the dot-matrix printer. Other impact printers use daisy wheels, thimbles, golf balls, bands, chains, and drums. They all make lots of noise, though manufacturers have tried to make the noise acceptable by putting the printers in noise-reducing enclosures and by modifying the timing of the smashes.

A printer that does not smash an inked ribbon is called a non-impact printer. Non-impact printers are all quiet! The most popular non-impact printers are ink-jet printers and laser printers. Other non-impact printers are thermal printers (whose hot pins scorch the paper), and thermal-transfer printers (which melt hot colored wax onto the paper).

If a printer creates characters out of dots, the quality of the printing depends on how fine the dots are — the "number of dots per inch", which is called the print resolution.

9-pin printers usually print 72 dots per inch vertically. That’s called draft quality, because it’s good enough for rough drafts but not for final copy. It’s also called business quality, because it’s good enough for sending memos to your coworkers and accountant.

If you make a 9-pin printer do 2 passes, it prints 144 dots per inch. That’s called correspondence quality, because it’s good enough for sending pleasant letters to your friends. It’s also called near-letter-quality (NLQ), because it looks nearly as good as the letters produced on a typewriter. The typical 9-pin printer has a switch you can flip, to choose either 1-pass draft quality (which is fast) or 2-pass correspondence quality (which is slower but prettier).

A 24-pin printer prints 180 dots per inch. That’s called letter quality (LQ), because it looks as good as the letters printed by a typical typewriter or daisy-wheel printer. It’s good enough for writing letters to people you’re trying to impress.

A standard laser printer prints 300 dots per inch. That’s called desktop-publishing quality, because it’s good enough for printing newsletters. It’s also called near-typeset-quality, because it looks nearly as good as a typesetting machine.

Width Like an old-fashioned typewriter, a traditional printer makes each character a tenth of an inch wide. That’s called "10 characters per inch" or 10 cpi or 10-pitch or pica (pronounced "pike uh").

Some printers make all the characters narrower so you get 12 characters per inch. That’s called 12 cpi or 12-pitch or elite.

The typical dot-matrix impact printer lets you choose practically any width you wish. For example, the Epson LQ-850 can print 5, 6, 7½, 8 1/3, 10, 12, 15, 16²/₃, and 20 cpi. The widest sizes (5, 6, 7½, and 8¹/₃ cpi) are called double-width, because they’re twice as wide as 10, 12, 15, and 16²/₃ cpi. The narrowest sizes (16²/₃ and 20 cpi) are called condensed or compressed; they’re 60% as wide as 10 and 12 cpi.

Some printers make each character a different width, so that a "W" is very wide and an "i" is narrow; that’s called proportional spacing. It looks much nicer than uniform spacing (such as 10 cpi or 12 cpi). The typical modern printer lets you choose either proportional spacing or uniform spacing. Uniform spacing is usually called monospacing.

Height The typical sheet of paper is 11 inches tall. If you put one-inch margins at the top and bottom, you’re left with 9 inches to print on.

The fanciest printers, such as laser printers, can make characters extra-tall or extra-short. The character’s height is measured in points. Each point is ¹/₇₂ of an inch. A character that’s an inch tall is therefore called "72 points tall". A character that’s half an inch tall is 36 points tall.

Like a typewriter, a printer normally makes characters 10 points tall. (More precisely, it makes the top of a capital "Y" 10 points higher than the bottom of a small "y".) It also leaves a 2-point gap above the top of the "Y", to separate it from the characters on the previous line. That 2-point gap is called the leading (pronounced "ledding"). That technique is called "10-point type with 2-point leading". Since the type plus the leading totals 12 points, it’s also called "10-point type on 12" (or "10 on 12" or "10/12").

You can make a capital T in two ways. The simple way is draw a horizontal bar and a vertical bar, like this: T. The fancy way is to add serifs at the ends of the bars, like this: T. A character such as T, which is without serifs, is called sans serif, because "sans" is the French word for "without".

Monospaced fonts The most popular monospaced fonts are Courier (which has serifs) and Letter Gothic (which is sans serif). Letter Gothic was invented by IBM in 1956 for typewriters. Courier was invented for typewriters also.

Proportionally-spaced fonts The most popular proportionally spaced fonts are Times Roman (which has serifs) and Helvetica (which is sans serif). Times Roman was invented by The Times newspaper of London in 1931. Helvetica was invented by Max Miedinger of Switzerland in 1954. (The name "Helvetica" comes from "Helvetia", the Latin name for Switzerland.)

Samples Here are samples from the laser printer that printed this book (an HP Laserjet 5 printer):

This is 9-point Times Roman, 10-point Times Roman, 11-point Times Roman,

12-point Times Roman, 13-point Times Roman,

This is 9-point Helvetica, 10-point Helvetica, 11-point Helvetica,

12-point Helvetica, 13-point Helvetica,

This is 10-point Albertus, and this is 10-point Albertus Extra Bold.

Laser printers and most ink-jet printers accept a stack of ordinary copier paper. You put that paper into the printer’s paper tray, which is also called the paper bin and also called the cut-sheet paper feeder.

Dot-matrix printers Though some dot-matrix printers handle stacks of ordinary copier paper, most dot-matrix printers handle paper differently. Here’s how.…

The simplest method is to imitate a typewriter: use a rubber roller that grabs the paper by friction. That method’s called friction feed. Unfortunately, friction is unreliable: the paper will slip slightly, especially when you get near the bottom of the sheet.

A more reliable method is to use paper that has holes in the margins. The printer has feeder pins that fit in the holes and pull the paper up through the printer very accurately. That method, which is called pin feed, has just one disadvantage: you must buy paper having holes in the margins.

If your printer uses pin feed and is fancy, it has a clamp that helps the pins stay in the holes. The clamp (with its pins) is called a tractor. You get a tractor at each margin. A printer that has tractors is said to have tractor feed. Usually the tractors are movable, so that you can move the right-hand tractor closer to the left-hand tractor, to handle narrower paper or mailing labels.

A dual-feed printer can feed the paper both ways — by friction and by pins — because it has a rubber roller and also has sets of pins. The printer has a lever to the left of the roller and pins: if you pull the lever one way, the paper will pass by the roller, for friction feed; if you pull the lever the other way, the paper will pass by the pins, for pin feed.

Paper that has holes in it is called pin-feed paper (or tractor-feed paper).

Like a long tablecloth folded up and stored in your closet, pin-feed paper comes in a long, continuous sheet that’s folded. Since it comes folded but can later be unfolded ("fanned out"), it’s also called fanfold paper. It’s perforated so you can rip it into individual sheets after the printer finishes printing on it. If the paper’s fancy, its margin is perforated too, so that after the printing is done you can rip off the margin, including its ugly holes, and you’re left with what looks like ordinary typing paper.

The fanciest perforated paper is called micro-perf. Its perforation is so fine that when you rip along the perforation, the edge is almost smooth.

Paper width Most printers can use ordinary typing paper or copier paper. Such paper is 8½ inches wide. On each line of that paper, you can squeeze 85 characters at 10 cpi, or 170 characters at 20 cpi, if you have no margins.

Some printers can handle pin-feed paper that’s extra-wide (15 inches). Those wide-carriage printers typically cost about $130 more than standard-width printers.

The typical printer’s advertisement brags about the printer’s speed by measuring it in characters per second (cps) or lines per minute (lpm) or pages per minute (ppm). But those measurements are misleading.

Dot-matrix and ink-jet printers For example, Epson advertised its LQ-850 dot-matrix printer as "264 cps", but it achieved that speed only when making the characters small (12 cpi) and ugly (draft quality). To print characters that were large (10 cpi) and pretty (letter quality), the speed dropped to 73 cps.

Daisy-wheel printers To get an amazingly high cps rating, one daisy-wheel manufacturer fed its printer a document consisting of just one character repeated many times, so the daisy never had to rotate!

Laser printers To justify a claim of "8 pages per minute", Apple salesmen noticed that their Laserwriter 2 NT printer takes a minute to produce 8 extra copies of a page. They ignored the wait of several minutes for the first copy!

Keep your eyes open Don’t trust any ads about speed! To discover a printer’s true speed, hold a stopwatch while the printer prints many kinds of documents (involving small characters, big characters, short lines, long lines, draft quality, letter quality, and graphics).

One end of the cable plugs into a socket at the back of the printer. The other end of the cable plugs into a socket at the back of the computer. The socket at the back of the computer is called the computer’s printer port.

If you open your computer, you’ll discover which part of the computer’s circuitry the printer port is attached to. In a typical computer, the printer port is attached to the motherboard; but in some computers (such as the original IBM PC), the printer port is attached to a small PC card instead, called a printer interface card, which might not be included in the computer’s advertised price.

Serial versus parallel The cable contains many wires. Some of them are never used: they’re in the cable just in case a computer expert someday figures out a reason to use them. Some of the wires in the cable transmit information about scheduling: they let the computer and printer argue about when to send the data. If the computer’s port is serial, just one of the wires transmits the data itself; if the computer’s port is parallel, eight wires transmit the data simultaneously.

Standard cables The typical parallel printer expects you to use a cable containing 36 wires. Just 8 of the wires transmit the data; the remaining wires can be used for other purposes. That 36-wire scheme is called the industry-standard Centronics-compatible parallel interface.

The typical serial printer expects you to use a cable containing just 25 wires. Of the 25 wires, just 1 transmits data from the computer to the printer; the remaining wires can be used for other purposes. That 25-wire scheme is called the recommended standard 232C serial interface (RS-232C serial interface).

Weird cables If your computer is an IBM PC or clone, you’ll get a surprise when you try attaching it to a parallel printer (which expects 36 wires): your computer’s parallel port contains just 25 wires instead of 36! To attach the computer’s 25-wire parallel port to a 36-wire parallel printer, computer stores sell a weird cable that has 25 wires on one end and 36 wires on the other.