Editing Macintosh Quadra 950

{{Infobox computer
| name         = Macintosh Quadra 950
| image        = [[File:Macintosh_Quadra_950.jpg|250px]]
| caption      = Macintosh Quadra 950
| manufacturer = Apple Computer, Inc.
| type         = Workstation / Personal Computer
| release date = May 18, 1992
| discontinued = October 14, 1995
| price        = US$8,500–$9,600
| cpu          = Motorola 68040 @ 33 MHz
| memory       = 8 MB or 16 MB RAM (expandable to 256 MB)
| storage      = 230 MB, 400 MB, or 1 GB SCSI hard drive; 1.44 MB floppy
| display      = 512×384 to 1152×870 (via onboard video)
| sound        = 8-bit stereo audio
| dimensions   = 18.6" × 8.9" × 20.6" (47.2 × 22.6 × 52.3 cm)
| weight       = 36.8 lbs (11.5 kg)
| os           = System 7.0.1 – Mac OS 8.1
| predecessor  = [[Macintosh Quadra 900|Quadra 900]]
| successor    = [[Power Macintosh 9500]]
| codename     = N/A
| model        = M4300
}}
The '''Macintosh Quadra 950''' is a high-end workstation computer introduced by Apple Computer on May 18, 1992.<ref>{{cite web |url=https://everymac.com/systems/apple/mac_quadra/specs/mac_quadra_950.html |title=Macintosh Quadra 950 Specs |publisher=EveryMac.com |access-date=2026-02-10}}</ref> It replaced the [[Macintosh Quadra 900|Quadra 900]] and utilized the same large tower enclosure. The Quadra 950 featured a faster 33 MHz Motorola 68040 processor (up from 25 MHz in the 900), making it one of the most powerful 68k Macintoshes produced.<ref>{{cite web |url=https://lowendmac.com/1992/macintosh-quadra-950/ |title=Macintosh Quadra 950 |publisher=Low End Mac |access-date=2026-02-10}}</ref>

The Quadra 950 was marketed toward professionals requiring maximum expandability and processing power. It remained in production for over three years until being replaced by the [[Power Macintosh 9500]] in 1995. Apple also sold a server variant, the Workgroup Server 95, based on the same hardware.

== Architecture and Processor ==

The Quadra 950 is built around the Motorola 68040 processor running at 33 MHz with an integrated floating-point unit (FPU).<ref>{{cite web |url=https://www.apple-history.com/q950 |title=Quadra 950 |publisher=Apple History |access-date=2026-02-10}}</ref> The 68040 features an 8 KB instruction cache and 8 KB data cache. The system bus also runs at 33 MHz.

{| class="wikitable" style="width:70%"
|-
! Component !! Specification
|-
| Processor || Motorola 68040 @ 33 MHz
|-
| FPU || Integrated (68040)
|-
| L1 Cache || 8 KB (4 KB instruction + 4 KB data)
|-
| System Bus || 33 MHz
|-
| ROM || 1 MB
|-
| Gestalt ID || 26
|}

== Memory and Storage ==

=== RAM Configuration ===

The Quadra 950 shipped with either 8 MB or 16 MB of RAM. It has 16 30-pin SIMM slots supporting up to 256 MB of RAM using third-party 16 MB SIMMs, though Apple officially supported a maximum of 64 MB.<ref>{{cite web |url=https://everymac.com/systems/apple/mac_quadra/specs/mac_quadra_950.html |title=Macintosh Quadra 950 Specs |publisher=EveryMac.com |access-date=2026-02-10}}</ref> RAM must be installed in matched groups of four identical SIMMs.

{| class="wikitable" style="width:70%"
|-
! Specification !! Value
|-
| RAM Type || 30-pin SIMM
|-
| Minimum Speed || 80 ns
|-
| Standard RAM || 8 MB or 16 MB
|-
| Maximum RAM || 256 MB (with 16× 16 MB SIMMs)
|-
| SIMM Slots || 16 (install in groups of 4)
|}

=== Storage Systems ===

Storage options included SCSI hard drives of 230 MB, 400 MB, or 1 GB capacity. The system includes a 1.44 MB SuperDrive floppy and an optional internal 2× CD-ROM drive. The tower case provides three internal 5.25" drive bays (two front-accessible if no CD-ROM is installed).

== Display and Graphics ==

The Quadra 950 includes onboard video with 1 MB of VRAM, expandable to 2 MB via four 80 ns VRAM SIMM slots. Video capabilities depend on VRAM configuration:

{| class="wikitable" style="width:70%"
|-
! VRAM !! Resolution !! Color Depth
|-
| 1 MB || 512×384 || 24-bit (millions)
|-
| 1 MB || 640×480, 832×624, 1152×870 || 8-bit (256 colors)
|-
| 2 MB || 832×624 || 24-bit (millions)
|-
| 2 MB || 1152×870 || 8-bit (256 colors)
|}

Additional displays can be supported via NuBus video cards.

== Input/Output and Expansion ==

=== Port Configuration ===

{| class="wikitable" style="width:70%"
|-
! Port !! Type !! Quantity
|-
| Serial || Mini DIN-8 || 2 (Modem, Printer)
|-
| SCSI || DB-25 || 1
|-
| ADB || Mini DIN-4 || 2
|-
| Floppy || DB-19 || 1
|-
| Audio In || 3.5mm stereo || 1
|-
| Audio Out || 3.5mm stereo || 1
|-
| Ethernet || AAUI-15 || 1
|}

=== Expansion Slots ===

The Quadra 950 offers extensive expansion capability:

* '''5 NuBus slots''' — Three provide 15W of power; two provide 25W
* '''1 Processor Direct Slot (PDS)''' — 68040 PDS for accelerator cards

The tower case accommodates up to three internal drive bays.

== General Maintenance ==

For detailed maintenance practices including cleaning, PRAM battery management, and connector corrosion prevention, refer to the dedicated [[Macintosh Quadra 900 General Maintenance]] page. The Quadra 950 shares the same case and many components with the Quadra 900.

== PCB Schematics & Service Manual ==

The Macintosh Quadra 950 shares its service documentation with the [[Macintosh Quadra 900|Quadra 900]] and Workgroup Server 95.

=== Apple Service Manual ===

<pdf width="800" height="500">File:Quadra_900.950.ws_95.pdf</pdf>

All Apple Service Manuals can be found on the [[:Category:Apple Service Source|Apple Service Source]] page.

== Capacitor Replacement Guide ==

Detailed capacitor replacement guidelines can be found on the [[Macintosh Quadra 900 Capacitor Replacement Guide]] page. The Quadra 950 uses the same logic board design as the Quadra 900.

== Retrobrite ==

To address plastic yellowing, detailed instructions can be found on the [[Retrobrite]] page.

== Troubleshooting ==

A comprehensive troubleshooting guide addressing power issues, video problems, and common failures is available on the [[Macintosh Quadra 900 Troubleshooting]] page.

== Technical Details ==

<templatestyles src="Template:StyledTable/styles.css" />

=== System Architecture at a Glance ===

{| class="wikitable styled-table" style="width:90%; text-align:center;"
! Sub-system !! Specification (Macintosh Quadra 950, 1992)
|-
| '''CPU''' || Motorola 68040 @ 33 MHz
|-
| '''FPU''' || Integrated
|-
| '''Bus width''' || 32-bit data • 32-bit address
|-
| '''ROM''' || 1 MB
|-
| '''RAM''' || 8–256 MB (16 SIMM slots)
|-
| '''VRAM''' || 1–2 MB
|-
| '''Video''' || 512×384 to 1152×870
|-
| '''Sound''' || 8-bit stereo
|-
| '''Storage''' || SCSI (230 MB–1 GB), 1.44 MB floppy
|-
| '''Expansion''' || 5 NuBus, 1 PDS
|-
| '''Networking''' || AAUI-15 Ethernet
|-
| '''Power''' || 100–240V AC, 303W max
|}

== Service Documentation ==

The official Apple Service Source documentation for this model:

<pdf width="800" height="500">File:Quadra_900.950.ws_95.pdf</pdf>

== See Also ==

* [[Macintosh Quadra 900|Macintosh Quadra 900]]
* [[Power Macintosh 9500]]
* [[Macintosh Quadra]]

== References ==

<references />

[[Category:Apple Vintage Computers]]
[[Category:Macintosh Quadra]]