Macintosh Performa 640CD DOS Compatible
 | |
| Performa 630, which uses the same case (Hellis, Italian Wikipedia, CC BY-SA 3.0) | |
| Specifications | |
|---|---|
| Manufacturer | Apple Computer, Inc. |
| Type | Desktop personal computer |
| Released | 1 May 1995 (Apple); 14 May 1995 (EveryMac) |
| Discontinued | 1 February 1996 |
| Intro price | US$2,300 |
| CPU | Motorola 68LC040 at 33 MHz, no FPU; Intel 486DX2 at 66 MHz on the DOS-compatible board |
| Memory | Mac: 8 MB (4 MB on the logic board plus a 4 MB SIMM), 52 MB maximum; DOS board: 4 MB SIMM, 32 MB maximum |
| Storage | 500 MB internal IDE hard drive |
| Display | — |
| Sound | 8-bit mono input; 8-bit stereo output (16-bit in CD mode); Sound Blaster-compatible sound board for the PC side |
| Graphics | 1 MB DRAM frame buffer, not expandable; DB-15 port |
| ROM | 1 MB |
| Media | 1.4 MB Apple SuperDrive (manual insert); double-speed CD-ROM drive |
| Ports / interface | One ADB, two RS-232/RS-422 serial (mini DIN-8), SCSI (DB-25), DB-15 video, DB-15 PC game port, sound in and out |
| Expansion | LC processor-direct slot (occupied by the DOS adapter board), communications slot, video-in slot, TV tuner connector |
| Power | 100-240 V AC, 50-60 Hz, 45 W maximum |
| Dimensions | 4.3 × 16.5 × 12.6 in (10.95 × 41.95 × 32 cm) |
| Weight | 19 lb (8.6 kg) |
| OS / Firmware | System 7.5.1 to Mac OS 8.1; MS-DOS 6.22 and Windows 3.1 |
| Model no. | M3076 (Gestalt ID 98) |
The Macintosh Performa 640CD DOS Compatible is a low-profile desktop Macintosh with a 33 MHz 68LC040 and a second, PC-compatible processor: an Intel 486DX2 at 66 MHz on a DOS-compatible board. It runs the Mac OS and MS-DOS or Windows 3.1 programs side by side. Apple's specification sheet dates it 1 May 1995 and gives it 8 MB of Macintosh memory in two SIMM slots, a 500 MB IDE hard drive, a double-speed CD-ROM drive and a Sound Blaster 16-compatible expansion card, with MS-DOS 6.22 and Windows 3.1 included.[1] EveryMac gives 14 May 1995, a price of US$2,300 (order number M3939LL/A) and an external 14.4k modem.[2]
Apple services it with the LC 630/Quadra 630/Performa 640 Service Source, which describes it as based on the Macintosh LC 630 DOS Compatible, bundled with a 500 MB IDE hard drive and a double-speed CD-ROM drive, and says the LC 630 DOS-Compatible information applies to it unless stated otherwise.[3] The non-DOS models of the family are on the Macintosh Performa 630 page. Apple's sheet for the similar Performa 630CD DOS Compatible notes that that model was not sold in the US.[4]
Specifications
[edit | edit source]| Item | Specification |
|---|---|
| Macintosh processor | Motorola 68LC040 at 33 MHz, no FPU[1][3] |
| PC processor | Intel 80486DX2 at 66 MHz on the DOS-compatible board[3] |
| Macintosh memory | 8 MB as shipped: 4 MB built in and a 4 MB SIMM in one slot; 52 MB maximum (4 MB built in, 32 MB SIMM in the first slot, 16 MB in the second)[3] |
| PC memory | A 4 MB SIMM on the DOS-compatible board; 32 MB maximum. Both boards take 72-pin, 80 ns or faster SIMMs[3] |
| Video | 1 MB DRAM frame buffer, not expandable[3] |
| Drives | 1.4 MB SuperDrive, manual insert; 500 MB IDE hard drive; double-speed CD-ROM drive[3] |
| Slots | The LC processor-direct slot holds the DOS-compatible adapter board, which carries a DB-15 connector for a PC/AT game controller; 112-pin communications slot; 60-pin video-in slot; TV tuner connector[3] |
| Electrical | 100-240 V AC, 50-60 Hz; 45 W maximum, not including the monitor[3] |
The Service Source's processor table gives the DOS-compatible machine a full 68040, but its own take-apart procedure, Apple's specification sheet and EveryMac all give the 68LC040.[3][1][2]
DOS-compatible hardware
[edit | edit source]The DOS-compatible logic board assembly is four parts: the main logic board with its SIMM, the DOS-compatible board with its own SIMM, a DOS-compatible sound board and a DOS-compatible adapter board, plus their cables.[3] The DOS-compatible board plugs into the main logic board's '040 processor socket, and the 68LC040 moves up onto the DOS-compatible board; the adapter board sits in the processor-direct slot.[3]
Apple's take-apart for the assembly, with the logic board out of the machine:[3]
- Disconnect the 26-pin adapter board cable, lift the battery end of the adapter board to free it from the processor-direct slot, and pull it back and out.
- Remove the two Phillips screws from the sound board and lift it off.
- Disconnect the 16-pin external video-out cable from the logic board and remove the four Phillips screws from the DOS-compatible board.
- Loosen each side of the DOS-compatible board from the processor socket and lift it off, taking care not to bend the processor pins.
Apple returned a faulty DOS-compatible board with the 68LC040 still fitted. Before returning a main logic board, the technician moved the 68LC040 from the DOS-compatible board back into the logic board's own socket, supporting the socket area of the board on anti-static foam. A missing pin and socket hole mark the alignment corner.[3]
If the speaker gives static with the sound board fitted and the internal CD and play-through option selected, Apple's cure is to replace the sound card, part 661-0253.[3]
Using the PC side
[edit | edit source]Apple's user's guide for the LC 630 DOS Compatible describes the PC environment. The PC Setup control panel switches from the Mac OS to the PC; Command-Return always switches back, and a hot key can be set for both directions.[5] The two environments share the hard disk, the monitor, the keyboard and mouse, the serial ports and the CD-ROM drive, and the PC side can either share the Macintosh RAM or use its own SIMM on the DOS-compatible board.[5] A joystick plugs into the game port, the DB-15 connector on the adapter board.[5][3]
Battery
[edit | edit source]Apple's specification sheet gives the battery as 4.5 V alkaline.[1] The Service Source's symptom charts print "Unplug 4.5 battery" in one place and "Unplug 5.4 battery" in another for the same step; "5.4" is a misprint.[3] The battery sits beside the adapter board, which is lifted from that end to remove it.[3] Neutralise alkaline leakage with a weak acid such as vinegar; see Battery Explosion, Capacitor or Corrosion Damage.
Maintenance and repair
[edit | edit source]The LC 630 guides cover the shared logic board and case: Macintosh LC 630 General Maintenance, Macintosh LC 630 Troubleshooting and Macintosh LC 630 Capacitor Replacement Guide.
Documentation
[edit | edit source]- LC 630/Quadra 630/ Performa 640 Service Source: Apple's service manual for the LC 630, LC 630 DOS Compatible, Performa 640 DOS Compatible and Quadra 630.[3]
- Macintosh User's Guide for the Macintosh LC 630 DOS Compatible (Apple, 1995).[5]
Related pages
[edit | edit source]- Macintosh LC 630 DOS Compatible
- Macintosh Performa 631CD
- Macintosh Performa 630 and the rest of the Performa 630 series
References
[edit | edit source]- ↑ 1.0 1.1 1.2 1.3 Macintosh Performa 640CD DOS Compatible: Technical Specifications, Apple—link(accessed 2026-09-30) 68LC040 at 33 MHz, no FPU; second processor 486DX2 at 66 MHz; slots comm, TV, video in; one ADB; DB-15 video; "PC game port also available"; "Comes with Sound Blaster 16-compatible expansion card"; 45 W maximum, 100-240 V, 50-60 Hz; battery type 4.5 V alkaline; 4 MB on the logic board, two 72-pin SIMM slots, 8-52 MB, 80 ns; "Second SIMM slot can accept only 1, 4, or 16MB SIMMs. DOS card can accept one 72-pin SIMM, up to 32MB in size -- comes with 4MB SIMM installed"; introduced 5/1/1995; Gestalt ID 98; System 7.5.1; "Includes Microsoft MS-DOS 6.22 and Windows 3.1"; 500 MB IDE; 2x CD-ROM.
- ↑ 2.0 2.1 Apple Macintosh Performa 640CD (PC) Specs, EveryMac—link(accessed 2026-09-30) Introduced 14 May 1995, discontinued 1 February 1996; 33 MHz 68LC040; 8 MB, 52 MB maximum; 500 MB IDE; 2X CD-ROM; external 14.4k modem; the PC-compatible configuration has a 66 MHz 486DX2 card with up to 32 MB for DOS/Windows and did not ship with a monitor; order number M3939LL/A; model M3076; Gestalt ID 98; US$2,300.
- ↑ 3.00 3.01 3.02 3.03 3.04 3.05 3.06 3.07 3.08 3.09 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 Apple Computer, LC 630/Quadra 630/Performa 640 Service Source, File:Quadra.lc 630.performa 640.pdf; see LC 630/Quadra 630/ Performa 640 Service Source. PDF page numbers: title p. 1; LC 630 DOS-Compatible p. 4; Performa 640 DOS-Compatible p. 5; Internal Expansion Connections p. 7; DOS-Compatible logic board diagram p. 14; Processor p. 18; Memory pp. 19-20; Disk Storage p. 21; I/O Interfaces pp. 22-24; Sound and Video p. 26; Electrical p. 27; symptom charts pp. 33 (sound card 661-0253), 37 and 44 (battery step); DOS Compat. Logic Board take-apart pp. 78-91.
- ↑ Macintosh Performa 630CD DOS Compatible: Technical Specifications, Apple—link(accessed 2026-09-30) Same specification as the 640CD DOS Compatible (68LC040 and 486DX2/66; 8-52 MB; 500 MB IDE; introduced 5/1/1995); "This system is not sold in the U.S."
- ↑ 5.0 5.1 5.2 5.3 Apple Computer, Macintosh User's Guide for the Macintosh LC 630 DOS Compatible (1995), File:Macintosh LC 630 DOS Compatible User's Guide (1995).pdf. Features list, pp. ix-x; connecting a game controller, PDF p. 44; switching between the Mac OS and PC environments, pp. 39-40 (PDF p. 51).