How the Apple ][ Works!

The 8-Bit Guy2 minutes read

The Apple II, released in 1977, offered unique features like bit-mapped graphics, color, sound, and expansion slots, setting it apart from competitors despite initial overheating issues. Schools heavily invested in Apple II compatible educational software, ensuring the longevity of these systems well into the late 1990s, even using them alongside Macintoshes and IBM PCs in classrooms.

Insights

  • The Apple II, released in 1977, competed with the Commodore PET and RadioShack's TRS-80, forming the 1977 trinity of home computers. Despite personal biases, the Apple II stood out due to unique features like bit-mapped graphics, color, sound, and expansion slots, setting it apart from its competitors.
  • The Apple II's evolution included addressing overheating issues, offering DIY board-only options for customization, and expanding graphics capabilities through user-friendly RAM upgrades. With innovations like the Disk II controller and language card, Apple II maintained relevance in education and business sectors, outshining competitors like the Commodore 64 by emphasizing functionality over advanced graphics and sound capabilities.

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  • What were the unique features of the Apple II?

    Bit-mapped graphics, color, sound, expansion slots.

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Summary

00:00

1977 Trinity: Apple II, Commodore, TRS-80

  • The Apple II, released in 1977, faced competition from the Commodore PET and RadioShack's TRS-80, forming the 1977 trinity of home computers.
  • Byte magazine is often credited with coining the term "1977 Trinity," but the actual reference was found in a 1995 retrospective issue, not in the 1977 editions.
  • Personal anecdote shared about the narrator's experience with Apple II computers in 1988 during junior high, preferring Commodore computers due to perceived superiority.
  • Despite the narrator's bias, the Apple II offered unique features like bit-mapped graphics, color, sound, and expansion slots, setting it apart from competitors.
  • The original Apple II model lacked side vents, leading to overheating issues, which were later rectified in subsequent models like the II Plus.
  • The Apple II was available in a board-only form for DIY enthusiasts, allowing customization and upgrades.
  • The Apple II's keyboard layout, though unconventional by modern standards, was comparable to its competitors like the TRS-80 and Commodore PET.
  • Graphics capabilities of the Apple II included low-res mode with 40x48 pixels and 16 colors, and hi-res mode requiring additional RAM for operation.
  • Upgrading the Apple II's RAM to 16K or more was necessary for utilizing hi-res graphics, with the system designed for easy user upgrades.
  • Apple II graphics were unique and challenging due to a quirky system and memory layout, requiring specific RAM configurations for optimal performance.

12:00

Apple II Graphics, Sound, and Expansion Options

  • Apple II graphics required complex math for pixel placement in memory, making it challenging for coders and slower for computers to display graphics.
  • Monochrome mode on Apple II provided a 280x192 monochrome bitmap with no shades of gray, where 8 bits in memory corresponded to 7 pixels on the screen.
  • Apple II color graphics lacked a dedicated graphics chip, using off-the-shelf parts to create color. Color was generated by pixel placement on a color monitor, with two pixels lighting up for each bit.
  • In hi-res mode, Apple II could create 4 colors initially, later expanding to 6 colors with an additional bit controlling the palette.
  • Displaying graphics designed for color screens on monochrome screens resulted in vertical line patterns instead of shades of gray.
  • Apple II sound generation involved a programmable speaker producing clicks when accessing specific memory addresses, with limitations in creating tones due to CPU involvement and lack of internal timers.
  • Expansion options for Apple II included 8 expansion slots, with the Disk II controller being a significant addition for loading and saving programs.
  • Disk II controller had two ROM chips onboard, with each slot having a dedicated area in the memory map for peripheral cards like the disk controller.
  • Booting up the Apple II without a bootable disk led to the computer staying at the Apple II logo, requiring a bootable disk for software to run.
  • Various expansion cards were available for Apple II, including a serial card, printer card, Microsoft softcard for running CP/M software, sound card, and an 80-column card, along with the language card for switching between Integer BASIC and Applesoft BASIC.

23:41

Evolution of Apple II: RAM, Sound, Graphics

  • The language card adds 12K of RAM that can be switched between ROM or RAM, with an additional 4K that can also be banked, totaling 16K of RAM.
  • It was initially intended to load different languages like BASIC, PASCAL, or Fortran, and could be write-protected to behave like ROM.
  • Over time, it became popular for adding more RAM to boost the computer up to 64K, as games and software required this capacity.
  • In 1980, Apple II standardized on 64K and a floppy disk drive, moving away from cassette tapes for software distribution.
  • The Apple II faced competition in the 1980s, leading to the introduction of the Apple III, which failed in the market, prompting Apple to refocus on the Apple II line.
  • Legal issues with Apple Corps, owned by the Beatles, hindered Apple from improving the sound system of the Apple II.
  • A third-party company created the Mockingboard sound card in 1983, enhancing sound capabilities with 1 or 2 AY-3 sound chips and 6522 control chips.
  • The Mockingboard offered better sound than the internal speaker but had limited software support, mainly for games and some music applications.
  • An 80 column card improved text and graphics resolution on the Apple II, doubling the horizontal text resolution to 80 columns and offering monochrome bitmap resolution.
  • Apple released the Apple IIe in 1983, integrating the language card internally, adding 80 columns and 64K of RAM, with visual and keyboard improvements, and a more elegant disk drive design.

35:30

Apple II: A Long-Lasting Educational Legacy

  • Fast disk access and 128K of RAM were crucial for businesses interested in running word processors, spreadsheets, or databases, with graphics and sound being less important. The Apple II was preferred over the Commodore 64 for such tasks, and Apple excelled in the education market by providing free computers to school systems through programs like "Kids Can't Wait" and initiatives like the "Apple Bill."
  • Schools could purchase a complete Apple IIe system with disk drive and monitor for as little as $736 in 1987, making it competitive with other offerings. Schools heavily invested in Apple II compatible educational software, ensuring the longevity of these systems well into the late 1990s, with some even using Apple IIs alongside Macintoshes and IBM PCs in classrooms.
  • The last Apple IIe was produced in 1993, with the Apple IIe card allowing its integration into certain Macintosh computers until 1995. The Apple II remained in production in some form for close to 19 years, featuring prominently in numerous movies like The Explorers, 2010 The Year we Make Contact, Young Sheldon, and Spies like Us.
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