Tuesday, September 26, 2006

The Cutting-Edge of Yesteryear

Today I'd like to talk a little about the Apple II computer.

"Huh...what? Am I on the wrong blog?"

No, I'm just taking a moment to put aside all my modern high-tech technologies to take a walk down memory-lane, to where all this stuff began. My first computer was an Apple II+ in 1979, near the beginning of the personal computer revolution.

I still collect, repair, and program old computers (mostly Apple II's), and I find it fascinating at times to look back and remember this stuff, and see how far we've come. Often times I am amazed at the progress of modern technology, but other times I am amazed of just how capable these old machines were and what they were able to accomplish with such limited resources!

This is an Apple II computer. And not just any Apple II computer, but one of the very first of the first. A true “II“ (2) computer, not a II+ or IIe or IIc or any of the later models.

(Note: All pictures in this article can be enlarged by clicking on them.)

The Apple II was not the very first personal computer, but it was the first good mainstream computer that a middle-class family could buy and use in their home. It was sold fully functional with no assembly required. (Unlike the Apple 1 and Altair).

As with Ford’s Model-T car, it wasn’t the first of its kind, but it was the first that attained mass-market popularity and longevity. The Apple II computer line ran from June 5, 1977 through October 15, 1993. For all 16 years of these years, the fundamental architecture, firmware, CPU, and style of the Apple II computer remained virtually unchanged. As recent as 1993, Apple was still selling 1 MHz CPU Apple IIe computers. They had become such a fixture of the computing landscape that these machines still had their uses and loyal fans, even as 33mhz “Wintel” computers were becoming common.

In a world governed by Moore’s Law, where computing power doubles every 18 months, one architecture lasting 16 years is truly phenomenal.

By the early 1980’s, the Apple II had competition from many brands of newer and cheaper computers, most notably the popular Commodore-64. But the Apple II (in my humble opinion) was the overall best of its day. And Apple is the only computer maker of that era that is still in business today and is still making their own unique brand of computers. Even IBM doesn’t make personal computers anymore.

I'm not telling you anything about the history of computers that you can't find on Wikipedia or any number of historical computer references. But I do notice these resources are missing some of the finer details of the construction of the early Apple II computers...the kinds of details that collectors of old computers would find important.

Most Apple fans will remember the height of the Apple II line, when the Apple IIe and Apple IIgs computers had become common-place in schools and homes. But few Apple fans have seen the beginning of the Apple II line.

So here is my nickel tour of how it started, complete with pictures!

This is the original Apple II computer as it was sold. The name-plate on the computer just says "Apple ][". Most people now use the spelling "Apple II" instead of "Apple ][" because bracket characters are notorious for causing problems in search engines and eBay.

Over 99% (I'm not exaggerating) of the Apple II computers you’ll find for sale on eBay have the word “plus” in green letters on this name plate. That indicates it’s a newer Apple II+ computer made in or after 1979. An original non-plus Apple II is especially rare, as relatively few were made.

I have many old Apple computers, but this the only one I have that is an original Apple II "Revision-0" (zero) model. It is serial #369, made in late June of 1977, one of the very first Apple II's ever sold. I bought this computer from its original owner. (But that’s another story.) This is a picture of the serial-number sticker on the bottom of the computer. Note the words "MADE IN U.S.A.".

Apple II+ computers generally have a green sticker on the bottom, and the model number is "A2S2" instead of "A2S1".

Here is the inside of the Apple II computer. One of the things that made the Apple II such a cool computer was that you had easy access to the insides for upgrades or other modifications. The case just popped open without having to unscrew anything. It was a natural hacker’s box. There are 8 slots for add-on cards, and every chip is socketed. One of the reasons I like collecting and working on these old Apples is the ease with which I can repair them.

These are rows of 16K RAM chips for the Apple II. Each row is 16K (kilobytes) worth of 18K (carat) gold. This is back in the day when RAM was so expensive it could afford to be flashy, and gold really does make the best conductor for electronic circuits. But you sure don’t see much gold circuitry in computers these days. Modern computers are too cheap for that!

Late-model Apple II computers (1979-1982) generally have black ceramic or (ugh) plastic memory chips with aluminum or steel pins.

The Apple II came with 8 slots for add-on cards. These connected your peripheral cards right into the system bus, and made the Apple II the most expandable and flexible computer on the market. Note the use of gold contacts.

But what’s even rarer than gold contacts are the light-green slots (connectors) that house them. Apple II computers generally had DARK-green slots. Later Apple II+ computers had black slots. But when Steve Wozniak started making the first Apple II computers, he got a special deal from Hewlett Packard on a batch of light-green connectors. These connectors were only used for the first production run and were soon replaced with the dark green connectors.

Here is the heart of the computer: The famous 6502 CPU. (The long black chip in the middle that is laying sideways.)

Right below the CPU are ROM chips. The early Apple II computers only came with 4 ROM chips, even though the Motherboard had sockets for 6 ROM chips. The remaining 2 sockets were left empty for user upgrades. And this particular Apple II has a ROM upgrade (far right ROM with a white stamp on it) that allows it to display extra video modes.

Each ROM had 2K of data, and mapped into the upper 16K address space of the Apple II. This left the lower 48K of the address space available for user programs. The 6502 processor only had a 16-bit address bus, so it could only access a maximum of 64K of memory. But memory was so expensive that most Apple’s were sold with only 16K. This particular early Apple II of mine was sold with 16K, and was later upgraded to 32K, and then later upgraded to 48K and finally a full 64K. (I can tell this by the types of RAM chips in this computer.)

This old Apple II has a very primitive set of ROMs, containing a small version of BASIC (written by Bill Gates and Marc McDonald), and a mini-Assembler (written by Steve Wozniak).

Later Apple II computers came with a full set of 6 ROMs, stuffed with a better version of BASIC, and also the Auto-Start ROM. The Auto-Start was a ROM that would actually boot your disk drive and load the operating system when you turned the computer on. What a concept!

Before the Auto-Start ROM, the Apple II just gave you a cursor (at best) when you turned it on. You had to manually enter commands to engage the disk-drive (or more likely read the tape-drive) to load something.

If you see an Apple II computer for sale on eBay that has all 6 AppleSoft ROMs, beware that this is most likely an upgraded Apple II and not an original. Most Apple II users had their ROMs upgraded to the new AppleSoft ROMs when they became available. This made them effectively an Apple II+ computer in an Apple II case, and unfortunately that decreases its value to collectors. Any Apple II computer that still has the original 4 Integer BASIC ROMs is especially rare.

This is the motherboard serial number (#623). There were hundreds of early prototype and test motherboards before production began. Apple would write the serial number in this little white box because they really didn’t think they’d ever make more than a few thousand of these things, and so room for 3 or 4 digits seemed plenty for a serial number. (The serial number on the bottom of the case was also only set for 4 digits.)

Later, Apple started writing the Julian “year/week” date in this white box. In most Apple II computers, you will see a 4-digit number like “7904” which means the 79th year and 4th week. (Late January of 1979) This is a pretty standard way of labeling dates on chips. You can see this Julian date in the close-ups of all the chips on this computer.

If you see a computer on eBay claiming to be an original Apple II, but it has a motherboard date of 8124 (the 24th week of 1981) then you are not getting a complete original. That motherboard was replaced at some point in that machine's history.

The early Apple II computers had “Memory Select” jumpers. This allowed you to select either 4k or 16k RAM chips in your computer. 16K chips were considered prohibitively expensive in those days. And with 3 rows of 4K chips, you could still have a computer with a full 12K of RAM, which was enough memory for the time.

When collecting old Apple II computers, the Memory Select chips are something to look for, because they indicate an early-model computer. I snagged a really nice Apple II off eBay for a good price because I happened to magnify the picture that the seller provided, and I was able to see the edge of the Memory Select chips. The seller didn't know what a rarity he had!

This is a regular keyboard encoder which is very common in the Apple II and II+ computers made from 1979 onward.

This is the keyboard encoder that is on this old Apple II computer. It's not at all like the one above, and I wish I knew more about it. For now, it's just a thing of fascination for me. Every time I see it, I just say "huh!" and I want to take it apart to see how it works, but it's the only one I have. It appears to be roughly the same circuit design, only with a different layout and more primitive parts. And it's built right into the keyboard instead of being a separate board attached by that goofy extra-long pin connector that I'm used to seeing.

This is a close-up of the Apple II keyboard. Note the old-school location of the quote, apostrophe, and parenthesis keys. The parenthesis keys are on 8 and 9 instead of 9 and 0.

Also note there are two shift keys, but those are only for the special symbols. This computer had no concept of lower-case letters whatsoever. (And hence no caps-lock either).

This computer also had no concept of “up” or “down” arrow keys. These were the days before full-screen word processors. Everything was done by line-editing, and so only left and right were needed. Also there is no Alt key, no Delete key, no Function keys, no Tab key, no underline...and oh ya...no mouse! But there is a “Repeat” (REPT) key that you would press if you wanted a key to repeat multiple times.

There is a “Control” key and an “Escape” key...and that was pretty cutting-edge for the day. Also notice there is a “BELL” key that is activated by typing “Control-G”. That’s another hold-over from old typewriters and teletype machines that actually did have a little metal bell in them! :)

On this computer, the RESET key is in the top-right corner, and pressing this key triggers a hard reset of the whole computer, which stops the CPU and dumps all memory. I’ve already accidentally erased a few of my sample programs on this machine by reaching for the “=” key and hitting RESET by accident.

Later Apple II computers made the RESET key harder to reach, harder to press, and required that you hit the CONTROL and RESET keys together...sort of a forerunner to the famous “Control-Alt-Delete”.

Of course, on modern computers, they’ve taken the Control-Alt-Delete away from us, because even THAT is now considered "too dangerous". Control-Alt-Delete is now just a fancy way of launching the Windows Task Manager. The day will come when they take the power button away too, so that only the OS can shut the computer down. Mark my words! :)

Another rarity you’ll see on this computer is the raised “POWER” light in the bottom left corner. That's another indicator of an early model Apple. It looks just like another key on the keyboard, except it's white. Naturally, users would hit this button thinking that it was the power button, but it’s just a light. It doesn’t move. If you try to press it hard you’ll probably break it. So Wozniak made a change in future Apple computers to make the power light level (flush) with the case so that it didn’t look like a button.

This is the underside of an Apple II keyboard. Understanding the mechanics and circuit of the keyboard is important to any Apple II collector. The keys on the keyboard are moving parts, and thus they can wear out with time and have to be repaired or replaced. The older Apple II keyboards (like the one in the picture above) are the best, because they are made of key switches that are individually soldered. So if a key goes bad or breaks, it's a simple matter to desolder the faulty key switch and replace it with another. (I keep tons of spare key switches from junked Apple II's I've bought off eBay.)

This is the underside of the keyboard from a late-model Apple II+. The blue area is the keyboard, and the little green board on top is the encoder. As you can see, there are no solder points for the keys. The whole keyboard was manufactured as a single unit (to save money). And these kinds of keyboards are FAR more difficult and impractical to repair. If any key breaks you pretty much have to replace the whole keyboard. And since replacement keyboards can't be purchased these days, you usually have no choice but to throw the whole computer away, or salvage the motherboard chips and power supply for parts.

Whenever I examine an old Apple II computer, I always open the lid and feel under the keyboard to see if I feel solder points. If there are solder points, I know I can repair the keyboard if any keys are bad. If I'm buying a computer off eBay, it's hard to tell what kind of keyboard it has. Sellers never think to try and take a picture of the underside of the keyboard. However, if the seller has given a good clear picture of they keys on the keyboard, I can often tell if it's an old keyboard. The older Apple II keyboards have shinier (glossy) keys. Newer keyboards tend to be made of a slightly more textured plastic with slightly less concave key-tops. It's a very subtle difference, but you can sometimes see it in the way the shiny concave key-tops capture the camera flash. The older keyboards reflect a nice sharp white sphere of light. (I had to dim my flash and come in at an angle to take that non-reflective picture of my keyboard shown earlier.)

Here is a keyboard that I salvaged from an old and very broken Apple II+. I've removed all the key caps and I keep those for spares. This is the good kind of keyboard that has soldered key switches. And as you can see from this picture, I've already removed several of them to use to repair keys on other computers. I'm holding one of the key switches in my hand. Each key switch has two solder points that you can desolder with a soldering gun and a desolder tool. (See your local Radio Shack.) And once you've removed a broken key switch, you can just plug in another one, and re-solder the two connections.

Generally, I wouldn't recommend getting near a computer with a soldering gun unless you've had a lot of practice, because soldering delicate circuits takes a lot of skill. However, key switches are a little less sensitive to heat and static than IC chips, and you have more room to work because the pins are far apart. So even with only moderate soldering skills, you should be able to safely replace a key switch. Just make sure you don't buy a soldering gun with more than 40 watts of power, and try not to keep the tip on the soldering joint for more than 4 seconds. Even though the key switch could withstand longer durations of heat, the etching board can't. So you still have to be a little careful. Try to get a soldering gun with a grounded tip as well. Static discharge might not hurt the key switch, but it could still travel into the keyboard encoder and zap something there.

Also make sure you get a good multi-meter, so you can check the circuit when you press and release the key, to make sure the problem really is in the key, and to make sure your replacement key switch will work.

For all you Apple computer collectors out there, it's important to know what kind of Apple II motherboard computer you have. Above are three pictures side-by-side. Each picture is a close-up of the upper right-hand corner of a different variety of Apple II motherboard.

The picture on the left is the original Apple II Revision-0 motherboard. The very first.

The picture in the middle is a later Revision-1 motherboard for the Apple II. Note the small white box with a single video-signal pin, just right of center in the picture. Also note the dark-green slots that still have gold contacts.

The picture on the right is represents a late-model Apple II motherboard, Revision 2 or later. (1979 or later). The single video pin has been replaced with a two-pin connector. Also note the slots are black and the connectors are made of steel (and are rusting if you click on the close-up). If you have this kind of motherboard, you probably have a common Apple II+. But there was a transition period in 1979 when Apple produced the Apple II and Apple II+ at the same time, and used the same motherboards for both. The only difference was in the ROM set. So there are a few Apple II's floating around out there that have relatively late-model motherboards.

Also, if the Game Connector socket (bottom right of each picture) is white, then you definitely have a late-model Apple II+.

After 1982, Apple stopped production of all of the Apple II and II+ Motherboards, and started producing the Apple IIe motherboards. The Apple IIe motherboard used the same general architecture as the Apple II motherboards, but advances in chip technology allowed Apple to achieve the same design with far fewer chips and fewer parts, thus allowing them to be manufactured more cheaply, which was crucial for competing with the rock-bottom priced Commodore-64.

Apple IIe motherboards also have more chips that are soldered down instead of socketed...which makes them far more difficult to repair. :(

The very earliest Apple II computers (like this one) used tape-drives instead of disk drives. Disk Drive technology for the Apple II was pretty expensive and awkward until Apple made the "Disk II" system in 1978. Early software for the Apple II (like this copy of Microsoft BASIC) was most often distributed on cassette tapes.

By 1980, Disk Drives were so inexpensive that using a cassette player to load and save programs on an Apple II became rare. And yet the Apple IIe continued to support cassette input-output ports to the end of it's days in 1993.

This badly-faded tape is a copy of "16K STARTREK". You can't underestimate the effect of Star Trek on the computer industry. :)

This is the Apple II Disk Drive, a 140K, single-sided, 5.25" floppy drive. It used a drive controller that Steve Wozniak designed himself, and it was genius for the day. Unlike other Disk Drive systems on the market, Wozniak strived for simplicity, and created a Disk system that was largely controlled through software (and some firmware) instead of hardware.

This design lead to a drive that as inexpensive, rugged, easy to repair, and didn't require a separate power supply. The fact that the low-level I/O routines were implemented in software rather than hardware also allowed for the creation of some very clever customizations to the OS, including writing data between tracks (half-tracks), and custom encoding schemes for security.

This is the inside of the Apple II Disk Drive. It's just a drive motor, a stepper motor, minimal circuitry, and a read/write head. The read/write head is the tiny black square in the white circle in the middle. With a metal case and metal frame with metal parts, this disk drive is way overkill in its ruggedness. We used to refer to them as "Tonka Drives" or "Fisher-Price Drives" back in the day, because they were so tough that even a kid couldn't damage them.

Any long-time Apple II fans will recognize the little gold screw in the bottom right-hand corner. That's the potentiometer that controls the speed of the drive motor, and once every few years you have to adjust it if you drive starts running too slow or too fast.

If you keep the drive speed adjusted, and keep the drive heads clean (with cleaning solution), and maybe replace the rubber drive belt (with a rubber band if necessary) once a decade, you can keep these drives running forever.

This is the ever-popular 16K expansion card for the Apple II. A regular Apple ][ has a maximum of 48k of RAM, because the upper 16K is reserved for the ROM. However, Apple invented a 16K expansion card that could "shadow" the upper 16K of memory. By using bank-switching, you could have the computer either access the ROM, or this 16K bank of RAM. This 16K card was commonly called a "Language" card, because a common practice was to use it to hold other programming languages (besides the BASIC built into the ROMs). This was back when most programming languages could easily fit in 16K. Can you imagine?

There were several models and flavors of the original Apple II computers, but this flavor is truly striking. This is the Bell & Howell version of the Apple II computer, also known as the "Darth Vader" Computer. It's absolutely beautiful! Apple should have made more black computers.

Apple made these black computers for the Bell & Howell so that they could be used in schools. Bell & Howell supplied audio/visual equipment (which was all black) to many major school systems. But shortly after Bell & Howell sold some of these Apple computers, Apple managed to win a few school contracts on their own, and pretty soon Apple no longer needed Bell & Howell. So the "Darth Vader" is a pretty rare and short-lived computer. Only a few thousand were ever made. Too bad!

Operating the APPLE II

When you turn on this early Apple II computer, this is what you get; a screen full of question marks and an asterisk for a cursor. Yes, that IS how it's supposed to work.

When the compter is turned on, the text buffers default to 11111111. (All 1's) And this is displayed as a question mark on the Apple ][.

[Thanks to user "mmphosis" for the following information which I'm quoting:]

11111111 is 255 in decimal, FF in hex. This character is "ASCII 8" where the hi-bit is set. Converted to ASCII 7, this equates to 01111111, 127 or 7F in hex. This particular character is a control character: rubout (DEL, or Delete).

In another way of looking at it, this character is also the lower case version of the upper case underscore character "_". On the text screen of an Apple II, this character is the rubout character displayed in NORMAL mode. The Apple II, and Apple II+ displayed these "lower case" characters using ASCII punctuation characters.

So, the rubout character, or lower case underscore character appears as a question mark "?"

Your picture shows a screen full of NORMAL mode question marks with the monitor prompt on the bottom line. There are three "modes" for characters displayed on the text screen: NORMAL, INVERSE, and FLASHing. There are also control characters which appear in NORMAL mode as upper case alpha's on the Apple II and Apple II+. By flipping a soft switch, these can appear as "Mouse Text" characters on Apple IIe's and later models. Lower case characters appear in NORMAL mode as punctuation characters.

There are 255 characters that can be displayed on the Apple II 40 column text screen. Here they are:

00-3F: 64 INVERSE upper case and punctuation characters.

40-7F: 64 FLASH upper case and punctuation characters.

80-9F: 32 NORMAL upper case (control) characters. "Mouse Text" characters on Apple IIe and later when enabled.

A0-DF: 64 NORMAL punctuation and upper case characters. (Regular ASCII with the hi-bit set.)

E0-FF: 32 NORMAL punctuation (lower case) characters.

The upper case characters are "@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_" with ASCII values 40 to 5F in hex.The punctuation characters are " !"#$%&'()*+,-./0123456789:;<=>?" with ASCII values 20 to 3F in hex.


If you turn on your Apple and it tries to boot a disk, or it says "Apple ][" at the top of the screen, then you have an Apple II+, or an Apple II with upgraded ROMs.

At the monitor prompt (the “*” prompt), you now have direct access to memory and instructions, and you can enter and execute any program you want...assuming you are fluent in machine code!

If you want to use the version of BASIC built into the computer, you have to press "CTRL-B" and then press "RETURN".

And here I am walking through memory, and then switching to BASIC. The monitor isn't as fuzzy as it looks in these pictures. These very old green-phosphor monitors have a harsh glow and reflective echo to them that gives my camera fits. (These old monitors were really awful!)

This monitor, by the way, is an Apple /// monitor made about 1980. Most early Apple II owners simply hooked their Apple to a television set.

This Apple II came with a primitive version of the "Integer BASIC" language built into the ROM chips. This BASIC was written by Bill Gates and Marc McDonald at the brand new start-up company called "Microsoft". (Or rather, Microsoft implemented BASIC after stealing the idea and design from earlier innovators. Do you see the start of a pattern here?)

This original flavor of BASIC could only do simple operations and commands, and did not even support floating point numbers. As you can see in the picture above, I get errors when I try to manipulate floating-point numbers. This BASIC became known as “Integer BASIC”, and was quickly replaced with an improved version called “AppleSoft Basic” (also known as “Floating Point BASIC”) in later Apple II computers.

Here's something you don't see often. All Apple II+ computers came with AppleSoft BASIC built into the ROMS. But the System Master disk for the Apple would automatically load Integer BASIC into your 16K "language" card. This way you would have both versions of BASIC handy so you could run programs in either one.

However, if you put the System Master disk in an old Apple II that still has the original Integer BASIC ROMs, it would detect that fact and then it would load AppleSoft BASIC into the 16K card.

So, on a normal Apple II+ or upgraded Apple II, you would see the message "(LOADING INTEGER INTO LANGUAGE CARD)", but on this early Apple II, you see the message "(LOADING APPLESOFT INTO LANGUAGE CARD)". Only the hard-core Apple geeks out there can appreciate the humor of that.

This System Master Disk contained either Apple DOS 3.2 or Apple DOS 3.3. (Not to be confused with MS-DOS or any other flavor of DOS). Apple DOS 3.3 was released in 1980, and continued to be a dominant operating system for the Apple computer for the next 13 years of its life. There was never a DOS 3.4. (There was a ProDOS....but that's a different beastie.)

Here's is the famous "Brian's Theme" program that made pretty patterns on the Apple screen. The dirty secret of this program was that it was not doing anything other than drawing straight lines on the screen with various step values, and taking advantage of the lack of anti-aliasing algorithms in the Apple line-drawing routine. Lines drawn in this manner would look choppy and jagged, and if you drew a lot of lines close together they made interesting patterns just by chance.

Just marvel at these ancient Apple II graphics!

Why aren't you marveling?!? If this was 1977 you would be marveling!

One thing that was not so marvelous about Apple graphics was the limitation of 8K of memory for the High-Resolution graphics page. At a time when Apple II computers commonly had 16K of memory, using more than 8K for graphics video would be asking too much. So Wozniak designed an ingenious system (a hack) to coax a High-Resolution screen with 4 (or 6) colors out of just 8K of memory!

The Apple II High-Resolution graphics mode that consisted of 280 by 192 pixels. At that resolution, you can't use 2 bits for each pixel and still have it fit in 8K bytes. So you only get to have 1 bit per pixel. But how on earth do you get 4 or 6 color values in 1 bit of information? Well buckle-up:

Here are the rules that get you the first 4 colors of white, black, violet, and green:

  • If the bit is 0, the pixel black.
  • If the bit is 1, and the pixel is in an even-numbered column, then it is violet.
  • If the bit is 1, and the pixel is in an odd-numbered column, then it is green.
  • Any two pixels placed side-by-side anywhere on the screen, turns both pixels white.

Okay, so far, that ugly kluge gets us to 4 colors. And that’s all the colors my early Revision-0 motherboard supports. But Apple soon released a Revision-1 motherboard for the Apple ][ that supported 2 more colors (red and blue) for a total of 6 colors, by using another hack.

The Apple only used the lower 7 bits of each 8-bit byte for most character and video operations. The Revision-1 motherboards incorporated a hack that said “if you set the high bit of the byte (the unused bit) to 1, then the “violet/green” color palette for that whole byte will replaced with a “red/blue” color palette.

So here are the complete rules that derive the 6 colors of white, black, violet, green, red and blue:

  • If the bit is 0, the pixel is black.
  • If the bit is 1, and the high bit of the byte is 0, and the pixel is in an even-numbered column, then the pixel is violet.
  • If the bit is 1, and the high bit of that byte is 1, and the pixel is in an even-numbered column, then the pixel is blue.
  • If the bit is 1, and the high bit of that byte is 0, and the pixel is in an odd-numbered column, then the pixel is green.
  • If the bit is 1, and the high bit of that byte is 1, and the pixel is in an odd-numbered column, then the pixel is red.
  • If the bit is 1, and there is another pixel next to it, then both pixels become white, even if the other pixel is in a different byte.


The later Apple ][e computer supported yet another clever hack called “Double Hi-Res”, which could give you 560 pixels across and double the number of colors by using a memory-expansion card to hold a parallel grid of bits. (This made for a whopping 16K of kluge-graphics).

Not klugey enough for you? Well the consider this:

The rows on the screen were interlaced in groups of 8! So, from top to bottom, you started off with row 0, and the next row was row 8, then row 16, row 24, row 32, row 40, row 48, row 56, then row 1, row 9, row 16 and so on. This made programming quite a challenge because drawing a simple vertical line involved calculating the interlaced row offsets!

As awkward as the Apple graphics system is, it was revolutionary for its time. Seriously!

Of course the price of being first is that you are stuck with using that scheme in order to keep your software backward compatible. And newer computers (like the Commodore 64) were able to support better sound and graphics chips built into the motherboard.

But Apple took advantage of the fact it had 8 expansion slots (whereas the Commodore 64 had none), so plenty of add-on boards were soon made to boost the graphics and sound capabilities of the Apple.

Here are some pages from reference manual that came with the computer. Note that this manual was written on a type-writer and then copied for publication. Very quaint. All pictures had to be hand-drawn in the blank spaces (as seen above) by Steve Wozniak himself. The reference manual is quirky in that it contains both basic operating instructions, as well as highly technical detailed schematics that cover every part in the entire system. The manual reflects a time when most computer users were still the hardcore geeks, but personal computers were gaining popularity with the non-technical crowd.

Future Apple computers came with much more "dumbed down" manuals that skipped all the technical details and focused on clear explanations of the operation of the computer.

This is end screen shot of the end of the "AppleVision" demo program that came with the System Master disk. It featured an animated stick-man dancing on the little T.V. screen while the computer beeped and booped out the tune "Turkey in the Straw". When I got my first Apple computer, I thought this was the coolest thing in the world!

Okay, and this is also the end of my tour of the original Apple II computers. Hopefully it is of some use to antique computer collectors out there! And maybe it will help you dodge the rip-off artists (or just unknowledgeable sellers) who try to pass off upgraded Apple II's, repaired Apple II's, or old Apple II+'s as original Apple II's!

These old computers are quite fun to study, and I hope other people keep this knowledge alive on the internet, because it really helps complete the picture of where we've been and what computers are really useful for. I think most people would be surprised to see what these old machines can really do. They could do e-mail, communications, word processing, spread-sheets, drawing, game playing, audio processing, run Web Services (seriously!) and basically do all the things we use computers for today...only on a more limited scale with less graphics.

In fact, a cynic could argue that the hundreds of billions of dollars spent on advances in computing technology haven't really made the darn things any more reliable or safe or easy to learn. It's mostly been about "better graphics".

What does every new gaming console offer that the last 10 gaming consoles didn't have? Better graphics. What does DVD offer over VHS? What does HD-TV offer over regular TV? Why is that LCD monitor better than a CRT? Better graphics! What does broadband get you that you can't get with dial-up? Better graphics. If the web was text-only, then dial-up would be fast enough!

We buy upgraded video cards for computers, and flashy new OS versions that take advantage of the better graphics. Why do we like IMAX screens for certain types of movies? Better graphics. All cell phones can make calls, so what have been the greatest advances in cell phone technology? Bigger screens, more memory, and higher speeds...all so we can have better graphics. What do the new iPods proudly offer as a selling point? Better graphics.

We buy new digital cameras with ever-more "megapixels", and color printers with ever-more "dots per inch", all for better graphics. And on and on. We are a visual culture for sure, so there's no use in downplaying the importance of better graphics.

But aside from graphics, the fundamental nature of what a computer can "do" and how it can be used hasn't changed much since 1977. And I find that very surprising, and yet fascinating. It makes the 1970's revolution in personal computing all the more awe-inspiring!

The big collapse in technological innovations will not come when Moore's law starts to fail...rather it will come when all these devices have graphics to match the abilities of the human eye, and thus there will be no need to improve them further! :)