Mac LC III

“With double its predecessor’s speed and more than triple the RAM capacity, the LC III is a significant entry into the low end of Apple’s line.” MacUser, April 1993

Macintosh LC IIIThe LC III (a.k.a. Performa 450 and code named Elsie III and Vail) is a significantly faster computer than the LC II. Running at 25 MHz on a newly designed motherboard with a 32-bit data bus, the LC III offers nearly the same performance as the Mac IIci and twice the performance of the LC and LC II.

One big difference is that the LC III uses an extended version of the 16 MHz LC PDS slot – most cards were designed for 16-bit access, so adding a video card or ethernet port makes the computer run about 1/6 less efficiently than the IIci.

Significantly faster than the LC II, the LC III also broke the 10 MB RAM barrier, allowing expansion to 36 MB. This was the first Mac to use 72-pin SIMMs.

The LC III supports 16-bit video on a 640 x 480 monitor without a VRAM upgrade if you select the 640 x 400 pixel mode under Options in the Monitors control panel and then restart the computer.

This was Apple’s first computer to use the Roman numeral III since the ill-fated Apple III.

Details

  • LC III introduced 1993.02.10 at $1,350; discontinued 1994.02.14
  • Performa 450 introduced 1993.04.12 at $1,350; discontinued
  • Gestalt ID: 27
  • model no.: M1254
  • upgrade path: Quadra 605

Mac OS

  • requires System 7.1 (with Enabler 003 ) to 7.6.1
  • addressing: 24-bit or 32-bit

Core System

  • CPU: 25 MHz 68030
  • FPU: 68882 (optional)
  • ROM: 1 MB
  • RAM: 4 MB on motherboard, expandable to 36 MB using a single 100ns 72-pin SIMM; can use 1 MB, 2 MB, 4 MB, 8 MB, 16 MB, or 32 MB SIMM
  • L2 cache: none

Performance

  • 3.6, relative to SE (compare to 3.5 for Mac IIci)
  • 6.3 MIPS
  • 2.31, MacBench 2.0 CPU
  • 6.9, Speedometer 3
  • 0.43, Speedometer 4
  • see Benchmarks: LC III for more details

Graphics

  • video: 512 KB VRAM onboard, expandable to 768 KB; supports 512 x 384, 640 x 480, 640 x 870, and 832 x 624 resolutions
    • 512 x 384: 16-bit @ 512 KB
    • 640 x 400: 16-bit @ 512 KB
    • 640 x 480: 8-bit @ 512 KB, 16-bit @ 768 KB
    • 640 x 870 (portrait): 4-bit @ 512 KB, 8-bit @ 768 KB
    • 832 x 624: 8-bit @ 512 KB, 16-bit @ 768 KB
  • VRAM: accepts one 256 KB 100ns VRAM SIMM to upgrade VRAM to 768 KB total, other specs unknown, VRAM SIMM appears to be specific to early Macs.

Drives

  • Hard drive: 40, 80, or 160 MB
  • floppy drive: 1.4 MB double-sided

Expansion

  • ADB ports: 1
  • serial ports: 2 DIN-8 RS-422 ports
  • SCSI ports: DB-25 connector on back of computer
  • enhanced LC PDS slot

Physical

  • size (HxWxD): 2.9″ x 12.2″ x 15.3″
  • Weight: 8.8 lb.
  • PRAM battery: 3.6V half-AA
  • power supply: 50W

Accelerators & Upgrades

  • Chipping the LC Series, bring the LC III to 33 MHz
  • Quadra 605 motherboard (25 MHz 68LC040), although it’s probably cheaper to just buy a Quadra 605/LC 475
  • MicroMac Diimo/030 (50 MHz 68030), 64 KB cache, optional 50 MHz 68882 FPU
  • Sonnet Presto Plus (33 MHz 68LC040 or 68040, Ethernet, and 32 MB additional RAM)

Online Resources

Cautions

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