Editing Macintosh LC 475

{{Infobox computer
| name         = Macintosh LC 475
| image        = [[File:Macintosh LC 475.jpg|250px]]
| caption      = Macintosh LC 475 / Quadra 605
| manufacturer = Apple Computer, Inc.
| type         = Personal Computer
| release_date = October 21, 1993
| discontinued = May 1, 1994
| price        = US$1,085
| cpu          = Motorola 68LC040 @ 25 MHz
| memory       = 4–8 MB RAM (expandable to 36 MB official, 132 MB actual)
| storage      = 80 MB, 160 MB, or 250 MB SCSI HDD, 1.44 MB SuperDrive
| display      = 640×480 8-bit (512K VRAM) or 16-bit (1 MB VRAM)
| sound        = 8-bit stereo input/stereo output
| dimensions   = 2.9" H × 12.2" W × 15.3" D
| weight       = 8.8 lbs (4.0 kg)
| os           = System 7.1 – Mac OS 8.1
| predecessor  = [[Macintosh LC III+]]
| successor    = [[Macintosh LC 580]]
| codename     = Aladdin
| model        = M1476
}}
The '''Macintosh LC 475''' is a personal computer released by Apple on October 21, 1993.<ref>{{cite web |url=https://www.apple-history.com/lc_475 |title=Macintosh LC 475 |publisher=Apple History |access-date=2026-02-09}}</ref> 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.<ref>{{cite web |url=https://everymac.com/systems/apple/mac_lc/specs/mac_lc_475.html |title=Apple Macintosh LC 475 Specs |publisher=EveryMac.com |access-date=2026-02-09}}</ref>

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

== Model Variants ==

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 ==

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.<ref>{{cite web |url=https://lowendmac.com/1993/macintosh-lc-475/ |title=Macintosh LC 475 |publisher=Low End Mac |access-date=2026-02-09}}</ref>

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 ==

=== RAM Configuration ===

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.

{| class="wikitable"
|+ '''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 ===

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 ===

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 ==

=== Port Configuration ===

* 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 ===

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 ===

The LC 475 uses a 30W power supply.

== General Maintenance ==

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

== Troubleshooting ==

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

== Capacitor Replacement ==

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 ==

{| class="wikitable" style="width:70%; text-align:center;"
|+ '''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 ==
<references />

[[Category:Apple Vintage Computers]]