RetroTechCollection

Macintosh LC 475

The Macintosh LC 475 is a personal computer released by Apple on October 21, 1993.[1] The LC 475 represented a major upgrade to the LC line, featuring a Motorola 68LC040 processor—the same architecture used in the Quadra line—making it the fastest LC model at launch.[2]

Macintosh LC 475
Macintosh LC 475 / Quadra 605
Specifications
ManufacturerApple Computer, Inc.
TypePersonal Computer
ReleasedOctober 21, 1993
DiscontinuedMay 1, 1994
Intro priceUS$1,085
CPUMotorola 68LC040 @ 25 MHz
Memory4–8 MB RAM (expandable to 36 MB official, 132 MB actual)
Storage80 MB, 160 MB, or 250 MB SCSI HDD, 1.44 MB SuperDrive
Display640×480 8-bit (512K VRAM) or 16-bit (1 MB VRAM)
Sound8-bit stereo input/stereo output
Dimensions2.9" H × 12.2" W × 15.3" D
Weight8.8 lbs (4.0 kg)
OS / FirmwareSystem 7.1 – Mac OS 8.1
PredecessorMacintosh LC III+
SuccessorMacintosh LC 580
CodenameAladdin
Model no.M1476

The LC 475 shares its logic board with the Quadra 605 and Performa 475/476, differing only in bundled software and marketing.

Model Variants

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The LC 475 was sold under several Performa brand names:

  • Performa 475 — Consumer variant
  • Performa 476 — Consumer variant with different bundle

The Quadra 605 uses the identical logic board and hardware.

Architecture and Processor

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The LC 475 uses a Motorola 68LC040 processor running at 25 MHz. The "LC" designation indicates this is a cost-reduced 68040 without a built-in FPU. However, the processor is socketed, allowing replacement with a full 68040 for FPU support.[3]

The 68LC040 includes:

  • 8 KB L1 cache (4 KB instruction + 4 KB data)
  • Integrated MMU
  • Full 32-bit data and address buses

The Gestalt ID for the Macintosh LC 475 is 89.

PowerPC Upgrade: The LC 475 can accept a PowerPC 601 upgrade card, enabling use of Mac OS 8.1 and PowerPC-native software.

Memory and Storage

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RAM Configuration

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The LC 475 shipped with 4–8 MB of RAM standard, officially expandable to 36 MB. In practice, the system can address up to 132 MB using a 128 MB 72-pin SIMM plus onboard RAM.

RAM Configurations
Configuration Method
4 MB 4 MB onboard
8 MB 4 MB onboard + 4 MB SIMM
12 MB 4 MB onboard + 8 MB SIMM
20 MB 4 MB onboard + 16 MB SIMM
36 MB 4 MB onboard + 32 MB SIMM (official max)
132 MB 4 MB onboard + 128 MB SIMM (actual max)

Video RAM

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The LC 475 includes 512 KB of VRAM (2×256 KB SIMMs), expandable to 1 MB (2×512 KB SIMMs):

  • 512 KB VRAM: 640×480 at 8-bit (256 colors)
  • 1 MB VRAM: 640×480 at 16-bit (thousands of colors)

This was the first LC to support stereo audio output.

Storage Systems

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Storage options included:

  • 80 MB, 160 MB, or 250 MB internal SCSI hard drive
  • 1.44 MB SuperDrive (manual-inject mechanism)

Input/Output and Expansion

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Port Configuration

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  • 1× Apple Desktop Bus (ADB) port
  • 1× External SCSI (DB-25)
  • 1× Audio input (3.5mm stereo minijack)
  • 1× Audio output (3.5mm stereo minijack) — Stereo output
  • 2× Serial ports (Mini DIN-8)
  • 1× Video output (DA-15)

Expansion

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The LC 475 features a single LC Processor Direct Slot (LC PDS). It does not have a separate FPU socket since the 68040 integrates FPU functionality (when using a full 68040 instead of the 68LC040).

Power Supply

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The LC 475 uses a 30W power supply.

General Maintenance

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For detailed maintenance practices including cleaning, PRAM battery management, and connector care, refer to the dedicated Macintosh LC 475 General Maintenance page.

Troubleshooting

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A comprehensive troubleshooting guide addressing common issues with the Macintosh LC 475 is available on the Macintosh LC 475 Troubleshooting page.

Capacitor Replacement

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The Macintosh LC 475 logic board contains fewer capacitors than earlier LC models and is generally easier to recap. Detailed replacement guidelines can be found on the Macintosh LC 475 Capacitor Replacement Guide page.

Technical Details

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Macintosh LC 475 Technical Specifications
Component Specification
CPU Motorola 68LC040 @ 25 MHz
FPU None (socketed, upgradeable to full 68040)
L1 Cache 8 KB (4 KB data + 4 KB instruction)
MMU Integrated in 68040
Data Bus 32-bit
System Bus 25 MHz
ROM 1 MB
RAM 4–8 MB (max 132 MB)
VRAM 512 KB (max 1 MB)
PSU 30W

References

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  1. ↑ Macintosh LC 475, Apple History—link(accessed 2026-02-09)
  2. ↑ Apple Macintosh LC 475 Specs, EveryMac.com—link(accessed 2026-02-09)
  3. ↑ Macintosh LC 475, Low End Mac—link(accessed 2026-02-09)
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