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Macintosh Performa 476

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Macintosh Performa 476
Macintosh Performa 475, the same machine and case as the Performa 476. Photo: All About Apple museum, Wikimedia Commons, CC BY-SA 3.0
Specifications
ManufacturerApple Computer, Inc.
TypeDesktop personal computer
ReleasedOctober 18, 1993
DiscontinuedApril 1, 1996 (EveryMac)
Intro priceUS$1,800 (EveryMac)
CPUMotorola 68LC040 at 25 MHz (socketed; no FPU)
Memory4 or 8 MB, one 72-pin SIMM socket, 36 MB maximum
Storage160 or 230 MB SCSI hard drive; 1.4 MB SuperDrive
DisplayExternal; two VRAM SIMMs, 512 KB or 1 MB
Sound8-bit stereo output; mono input
ROM1 MB
Dimensions7.7 × 31.0 × 38.2 cm (3.0 × 12.2 × 15.0 in)
Weight4.0 kg (8.8 lb)
OS / FirmwareSystem 7.1P3 – Mac OS 8.1
CodenameAladdin
Model no.M1476

The Macintosh Performa 476 is a desktop Macintosh sold by Apple through consumer retail shops. It is the same machine as the Macintosh LC 475, sold to schools, and the Macintosh Quadra 605, sold to businesses: a 25 MHz Motorola 68LC040 in the low LC case.[1][2] Low End Mac describes it as the first 68040-based Performa.[3] EveryMac describes it as the Performa 475 with a 230 MB hard drive; Apple's manual lists a 160 or 230 MB drive.[1][4]

Apple gives the introduction date as October 18, 1993, with System 7.1P3 and System Enabler 364 as the original system software; Apple lists Mac OS 8.1 as the last supported version.[5] EveryMac gives a US price of US$1,800, discontinuation on April 1, 1996, order number M2154LL/A and model number M1476.[1] Wikipedia gives Aladdin as the codename for this hardware.[6]

Specifications

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Apple's figures
Item Figure
Processor Motorola 68LC040 at 25 MHz; 32-bit data bus; 8 KB on-chip cache; no FPU
RAM 4 or 8 MB standard; one 72-pin SIMM socket for 1, 2, 4, 8, 16 or 32 MB SIMMs of 80 ns or faster; 36 MB maximum
ROM 1 MB
VRAM Two VRAM SIMMs: 2 × 256K (512 KB) or 2 × 512K (1 MB)
Floppy drive Apple SuperDrive 1.4 MB, auto-inject or manual-insert
Hard drive at introduction 160 or 230 MB SCSI
Bundled monitor Performa Display Plus
Ports One ADB, two serial (printer and modem, mini DIN-8), SCSI DB-25, DB-15 video, mono sound input and stereo sound output
Expansion One 114-pin slot for 030/040 cards; takes LC-compatible I/O, display, network and video-capture cards, but not 030 accelerator or cache cards
Electrical 100–240 VAC, 47–63 Hz, automatically configured; 26 W maximum (Service Source); 50 W (technical specifications)
Size and weight 3.0 × 12.2 × 15.0 in (7.7 × 31.0 × 38.2 cm); 8.8 lb (4.0 kg)

Sources: Apple's technical specifications and the Performa 400 Series Service Source, pp. 3–15.[5][4]

Hardware notes

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The 68LC040 is a 68040 without the floating-point unit. It sits in a socket, so a full 68040 can replace it; an expansion card cannot add an FPU.[2] Apple's Macintosh Processor Upgrade puts a PowerPC 601 card with a 256K cache card into the processor socket; the customer's 68LC040 moves to a socket on the upgrade card. Apple warns that the EMI clips under the logic board flex easily, and has the installer support the board on antistatic foam and use a processor removal tool (pp. 53–70).[4]

Video memory is on two 68-pin VRAM SIMMs, which must be the same size. With 512 KB the machine shows 256 colours at 640 × 480 and 832 × 624; with 1 MB, thousands.[2][5]

Apple states that the slot is not a processor-direct slot: it is not connected to the 68LC040, so accelerators, FPU cards and cache cards do not work. A card must not dissipate more than 4 W.[2] Among the Performa 400 series only the 475 and 476 have stereo sound output. Recording is mono, and the input jack mixes a stereo source to mono. The line-level input takes the Apple PlainTalk microphone.[4][2]

The PRAM battery is a 3.6 V lithium cell, Apple part 742-0011; Apple says to replace it below 3.0 V.[5][4]

Known faults

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  • Leaking surface-mount electrolytic capacitors on the logic board and in the power supply. Recap-a-Mac's photograph of the 820-0364-A board shows nine 47 µF 16 V and two 100 µF 6.3 V parts; the list is on Macintosh LC 475 Capacitor Replacement Guide.[7]
  • A flat PRAM battery: Apple's charts for this family put "Check batteries" first for "No video" and in the no-power entries.[4]

Fault-finding follows the Performa 400 series symptom charts; see Macintosh LC 475 Troubleshooting and Macintosh Quadra 605 Troubleshooting.

Service documentation

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Apple covers the Performa 476 in the Macintosh Performa 400 Series Service Source, including the PowerPC upgrade. The same board is covered as the LC 475 and Quadra 605 in the Macintosh LC Series/Quadra 605 Service Source, and described in the Macintosh LC 475 and Quadra 605 Developer Note.[4][2]

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References

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  1. ↑ 1.0 1.1 1.2 EveryMac, "Macintosh Performa 476 Specs".
  2. ↑ 2.0 2.1 2.2 2.3 2.4 2.5 Apple Computer, Macintosh LC 475 and Macintosh Quadra 605 Developer Note (1993), File:Macintosh LC 475 and Quadra 605 Developer Note.pdf; see Macintosh LC 475 and Quadra 605 Developer Note. Printed pages: pp. 7-13 (RAM and VRAM); pp. 17-18 (sound input); p. 19 (the expansion slot is not a PDS); pp. 22-25 (68LC040 in a socket); pp. 39-40 (power for the expansion card).
  3. ↑ Low End Mac, "Apple's Performa Line, 1992 to 1997".
  4. ↑ 4.0 4.1 4.2 4.3 4.4 4.5 4.6 Apple Computer, Service Source: Macintosh Performa 400 Series (1995), File:Performa 400 series.pdf; see Macintosh Performa 400 Series Service Source. Page numbers are PDF pages.
  5. ↑ 5.0 5.1 5.2 5.3 Apple, "Macintosh Performa 476: Technical Specifications".
  6. ↑ Macintosh Quadra 605, Wikipedia—link(accessed 2026-09-30) Codename Aladdin, citing Pogue and Schorr, Macworld Mac Secrets, 5th ed., pp. 475-476.
  7. ↑ Macintosh LC475 & Quadra 605, Recap-a-Mac—link(accessed 2026-09-30)
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