Macintosh 128/512K.. Hello Mac!

Submitted by binaryvalue on Wed, 06/01/2022 - 11:31

Released in January 1984, the 128K is the original Apple Macintosh personal computer. The Macintosh features the 68000 CPU from Motorola, a GUI, and bundled with MacPaint and MacWrite.

  • The Macintosh 128K was sold for $2,495 ($6,950 in today’s money)
  • The 128K Sold over 70,000 units, and the 512K sold much more


  • Mac OS 1.0 with GUI (Graphical User Interface)
  • 9-inch integrated CRT monitor (monochrome)
  • Motorola 68000 CPU running at 7.8336 MHz (effective clock rate of 6.0 MHz)
  • 128 KB of RAM (upgradable to 4 MB via third parties)
  • 64 KB ROM chip
  • 400 KB, single-sided 3.5-inch floppy disk drive from Sony
  • Came with a keyboard and mouse

OS Operating System & Software

 The Macintosh 128K came with MACOS 1.0, known as "System 1.0". There were three OS upgrades before it was discontinued.

  • GUI Operating System
  • Not software-compatible with the Mac XL (Lisa)
  • MacPaint and MacWrite were included with the Mac
  • Other available software included the Microsoft Word, MacProject, and MacTerminal
  • Programming languages included MacBASIC and MacPascal
  • The Microsoft Multiplan was only running on the 512 KB model

graphics Graphics & Modes

  • 512 × 342 pixels resolution
  • only 2 colors

sound Sound Capabilities

 The MAC offered an internal speaker generating 8-bit monaural sound.

  • 8-bit Pulse-width sound driver (2 TTL chips)
  • Sampled at 22.25 kHz
  • Sound amplification (2 analog chips)
  • Internal speaker

ports I/O Ports

Mac128 Advert
Macintosh 128K advertisement (1984)

 Basically, the MAC offers 2 RS-422 serials ports (for devices such as printers and modems), plus the ability to add an external drive.

  • 2 x RS-422 (non-standard) DE-9 serial ports
  • Proprietary connector (19-pin D-sub) for an external floppy drive

 upgradesExpansions & Upgrades

There were several upgrades from third parties:

  • Up to 4 MB of RAM (even for MAC 128K)
  • Internal SCSI hard drive (20 MB)
  • External SCSI port
  • 68881 FPU at 16 MHz
  • 68020 CPU at 16 MHz accelerator
  • Cooling fan

 variants Related Models -The Macintosh 512K

 The Macintosh 512K was released in September 1984, and it was sold for $3,195 ($8,900 in today’s money). The 512K is practically the same computer with the 128K, offering more memory. The 512K can be upgraded to Mac OS 4.1.

  • 512 KB of RAM
  • Mac OS 1.0 and up to 4.1


Macintosh 128/512K (c)