Macintosh IIx
 | |
| Macintosh IIx | |
| Specifications | |
|---|---|
| Manufacturer | Apple Computer, Inc. |
| Type | Desktop personal computer |
| Released | 19 September 1988 |
| Discontinued | 15 October 1990 |
| Intro price | US$7,769; US$9,369 with 80 MB hard disk |
| CPU | Motorola 68030 at 15.67 MHz |
| Memory | 1 MB or 4 MB; eight 30-pin SIMM sockets (Apple: expandable to 8 MB; 128 MB with 16 MB SIMMs and 32-bit addressing) |
| Storage | Optional internal 40, 80 or 160 MB SCSI hard disk |
| Display | — |
| Sound | Apple sound chip, 8-bit stereo sampling at 44.1 kHz, four-voice wavetable synthesis |
| Graphics | None built in; NuBus video card required |
| ROM | 256 KB on a ROM SIMM |
| FPU / coprocessor | Motorola 68882 |
| Media | Internal 1.4 MB floppy drive; optional second internal 1.4 MB drive |
| Ports / interface | Two ADB, two RS-232/RS-422 serial (mini DIN-8), SCSI (DB-25), stereo sound jack; no external floppy port |
| Expansion | Six NuBus slots |
| Power | 220 W maximum excluding monitor; 100-240 V AC automatically configured, 48-62 Hz |
| Dimensions | 5.5 × 18.7 × 14.4 in (14.0 × 47.4 × 36.5 cm) |
| Weight | 24 lb (10.9 kg) without hard disk |
| OS / Firmware | System 6.0.1 to 7.5.5 |
| Predecessor | Macintosh II |
| Successor | Macintosh IIfx |
| Codename | Spock, Stratos[1] |
| Model no. | M5840 |
The Macintosh IIx is a desktop computer made by Apple Computer from September 1988 to October 1990. It uses the six-slot case and logic board layout of the Macintosh II, with a Motorola 68030 in place of the 68020, a 68882 floating-point unit in place of the 68881, and a 1.4 MB high-density floppy drive (the FDHD, also called the SuperDrive) driven by Apple's SWIM controller.[2] Apple's service manual covers it together with the Macintosh II and the Macintosh IIfx.[3]
History
[edit | edit source]Apple announced the Macintosh IIx on 19 September 1988. It cost US$7,769, or US$9,369 with an 80 MB hard disk.[4] The 68030 added a 256-byte data cache to the instruction cache the 68020 already had, and Macworld estimated the IIx at 10-15 per cent faster than the Macintosh II.[4][2] The IIx was the first Macintosh with a 68030 and a 68882, and the first with the 1.4 MB drive as standard.[4][5]
Apple sold a logic board upgrade that turned a Macintosh II into a IIx; the kit included a IIx identification decal for the bottom cover.[3] Larry Pina notes that the upgrade also needs at least one 1.4 MB floppy drive.[6] A later kit upgraded a II or IIx to a IIfx, with new 64-pin SIMMs and a new hard-disk power cable.[3][6] The IIx was discontinued on 15 October 1990.[5]
Specifications
[edit | edit source]| Item | Specification |
|---|---|
| Processor | Motorola 68030 with built-in paged memory management unit |
| Coprocessor | Motorola 68882 |
| Addressing | 32-bit registers, 32-bit address bus, 32-bit data bus |
| RAM | 1 MB, expandable to 8 MB (Apple's service figure) |
| ROM | 256K |
| Floppy drives | Internal 1.4 MB; optional second internal 1.4 MB |
| Hard disk | Optional internal 40, 80 or 160 MB |
| SCSI | 5 MB/s; eight devices maximum |
| Other I/O | Two ADB ports; two RS-232/RS-422 serial ports (mini DIN-8); six NuBus slots with full 32-bit address and data |
| Sound | Apple custom sound chip: 8-bit stereo sampling at 44.1 kHz, four-voice wavetable synthesis; stereo output through the sound jack |
| Power | 100-240 V AC, automatically configured; 48-62 Hz single phase; 220 W maximum, not including the monitor |
| Size and weight | 5.5 × 18.7 × 14.4 in (14.0 × 47.4 × 36.5 cm); 24 lb (10.9 kg), more with a hard disk |
The table is from the Service Source.[3] The Service Source prints the II and IIx clock as 15.6772 MHz; Apple's Guide to the Macintosh Family Hardware gives 15.6672 MHz for the Macintosh II and 15.67 MHz for the IIx.[3][2] There is no built-in video, and no external floppy disk connector.[2]
Hardware
[edit | edit source]
Logic board and memory
[edit | edit source]The logic board is Apple part 661-0529 (661-0528 for the II, 661-0522 for the IIfx); the bottom cover, 630-5494, is also specific to the IIx.[3] The board is printed "820-0229-A".[7]
The IIx has eight 30-pin SIMM sockets in two banks of four, filled four at a time, and needs RAM of 120 ns or faster.[2][5] Apple's Service Source gives the maximum as 8 MB; the Guide to the Macintosh Family Hardware gives up to 128 MB in four or eight SIMMs. The 256K ROM is "32-bit dirty", so the machine can only use more than 8 MB under 32-bit addressing with the MODE32 extension. EveryMac notes that SIMMs of 4 MB and larger must be PAL-equipped.[3][2][5]
Apple's symptom charts single out Apple-labelled SIMMs made by NEC with a date code of 9052 or earlier. They cause the error chord at start-up, failure to boot, ghosting or lost video, a hang when the first application launches, and ID errors; Apple's cure is to replace them.[3]
The ROM is on a 64-pin ROM SIMM; the Macintosh II has four socketed ROM chips instead.[2] The IIx has the PMMU built into its 68030, so it has no separate MMU socket.[2]
Power supply
[edit | edit source]The power supply is Apple part 661-0375, the same as the Macintosh II (the IIfx uses 661-0542).[3] Apple's hardware guide gives its input ranges as 90-140 V and 170-270 V at 47-63 Hz, 230 W (rms) maximum input under peak load, and its outputs as follows:[2]
| Rail | Output limits | Maximum load | Peak load | Ripple / switching noise (p-p) |
|---|---|---|---|---|
| +5 V | 4.90-5.20 V | 18 A | 18 A | 20 mV / 40 mV |
| +12 V | 11.50-12.80 V | 2.5 A | 4.5 A | 30 mV / 50 mV |
| −12 V | −13.40 to −10.80 V | 1.0 A | 1.0 A | 30 mV / 50 mV |
Total output is 132 W at maximum load and 156 W at peak load; the peak lasts no more than 15 seconds at a 10 per cent duty cycle, and +12 V may drop to 11 V during it. A regulator on the logic board makes −5 V.[2] The supply connects to the logic board through a 15-pin connector: pin 1 +12 V, pins 2-6 +5 V, pins 7-12 ground, pin 13 not connected, pin 14 −12 V and pin 15 /PFW (power fail warning).[2]
The supply shuts down within 25 ms if any output is shorted to ground, and shuts down if the heat sink of its primary switching devices goes above 125 °C, pulling /PFW low for at least 2.2 ms first.[2] Apple's symptom chart for a machine that shuts down intermittently starts with clearing the vents on the sides and top of the case, and says the machine should work again after 30-40 minutes.[3]
The supply contains mains-voltage circuitry and capacitors that stay charged after the plug is removed. See Capacitor Failure Symptoms before working on it.
Batteries
[edit | edit source]The logic board carries two lithium cells. Apple's hardware guide says they keep charged the capacitor that switches the supply on when the power key on the keyboard is pressed; Pina calls this cell B2 and gives it as the usual cause when the machine will not start from either the keyboard or the rear power switch.[2][6] Apple's symptom chart for a machine that will not power on has "Check batteries" before replacing the power supply or logic board.[3]
Apple's test: remove the cover and the drive mount, set the meter to the 10 V DC range, and replace any cell that reads below 3.2 V.[3] Pina reads good cells at 3.2-3.85 V, weak at 2.3-3.1 V and dead below 2.3 V.[6]
Early IIx boards have 3 V Varta cells with pigtail leads soldered to the board; later boards have 3.6 V Tadiran TL-5112 ½AA cells in a snap-in battery box in the same place.[6] Before changing the batteries on a II or IIx without a holder, Apple fits a battery holder board: cut the old leads, desolder the four connections from the underside with an iron of 50 W or less without forcing them (forcing lifts the copper), and solder in the holder with its positive side in the two holes marked positive. Wrong orientation can damage the logic board.[3]
A leaking cell corrodes the logic board. Recap-a-Mac expects trace damage near the batteries on unrestored IIx boards.[7] These are lithium cells: neutralise residue with bicarbonate of soda, not vinegar. See Battery Explosion, Capacitor or Corrosion Damage and Battery Refurbishment.
Capacitors
[edit | edit source]The 820-0229-A logic board has 20 electrolytic capacitors, all rated 16 V. Console5's list, MacDat's list and Recap-a-Mac's annotated photograph agree on the values:[8][7][9]
| Value | Voltage | Qty | Designators (Console5) | Type |
|---|---|---|---|---|
| 47 µF | 16 V | 15 | C1, C2, C4, C5, C6, C7, C9, C10, C11, C12, C13, C16, C19, C20, C21 | Surface-mount |
| 470 µF | 16 V | 3 | C15, C17, C18 | Axial |
| 220 µF | 16 V | 1 | C3 | Axial |
| 10 µF | 16 V | 1 | C8 | Axial, with surface-mount pads under it |
Recap-a-Mac lists 15 surface-mount and 5 axial electrolytics and expects corrosion above the NuBus slots, near the power switch and around the sound chips as well as near the batteries.[7] See Capacitor Failure Symptoms.
Opening the case
[edit | edit source]Remove the cover mounting screw at the rear, push in the tabs at the rear and lift the cover off back first. Apple warns not to tilt it more than 45 degrees, which can damage the floppy drives, and to check that none of the sheet-metal tabs inside the cover is bent inwards before refitting it.[3] The drive mount comes out before the batteries can be reached or the logic board removed; the board is held by two screws and nine plastic tabs.[3]
Floppy and hard disks
[edit | edit source]The 1.4 MB drive is controlled by the SWIM and reads, writes and formats 400K, 800K and 1.4 MB disks.[2] To eject a stuck disk, Apple's chart says to hold the mouse button down while switching the machine on; if a disk will not eject fully, reseat the top cover so that the drive slots line up. Disks for use in both an MS-DOS drive and the 1.4 MB drive should be formatted on the MS-DOS drive.[3] See Macintosh Floppy Drive Maintenance.
The internal hard disk is SCSI ID 0 and the computer is ID 7; an external device must not use either. Apple's cure for a drive icon that does not appear, or for lost or corrupted data, is to check SCSI termination. If an internal disk does not spin and its LED does not light, Apple checks the +5 V and +12 V lines to the drive before replacing it.[3] See Macintosh HDD Maintenance.
Troubleshooting
[edit | edit source]Apple's symptom charts for the II, IIx and IIfx cover the error chord, power, video, floppy drives, hard disks and peripherals.[3] Selected entries:
| Symptom | Apple's cures, in order |
|---|---|
| Error chord at start-up | SIMM verification; replace NEC SIMMs dated 9052 or earlier; logic board |
| No power: black screen, fan off, LED off | Cables; monitor on its own wall socket; power cord; check batteries; power supply; logic board |
| Clicking, chirping or thumping | Remove extra NuBus cards; power supply; logic board |
| Shuts down intermittently | Clear the vents and wait 30-40 minutes; power cord; batteries; power supply; logic board |
| Black screen, fan and LED on, drives working | Monitor brightness; try the monitor on another Mac; video cable; move the video card to another slot; video card; SIMMs; logic board; power supply |
| Ghosting, or video lost after booting | Replace NEC SIMMs dated 9052 or earlier |
| Internal hard disk dead, LED off, no spin | Remove the data cable; power cable; check +5 V and +12 V at the drive; drive; logic board |
| Works with internal or external SCSI device, not both | External device must not be ID 0 or 7; check termination; terminator; the external device |
| No sound from speaker | Volume set to 1 or above; reset PRAM; speaker; logic board |
Two things that look like faults are not. A IIx that shows only 8 MB with more fitted is running with 24-bit addressing.[5] A machine that switches itself off after long use with blocked vents has been shut down by its thermal protection.[3] The start-up tones and Sad Mac codes are on Sad Mac Error Codes.
Documentation
[edit | edit source]- Macintosh II/IIx/IIfx Service Source: Apple's service manual for the family, with specifications, symptom charts, take-apart, upgrades, battery procedures and exploded view.[3]
- Guide to the Macintosh Family Hardware, second edition (File:Apple Guide to the Macintosh Family Hardware 2nd Edition 1990.pdf): Apple's hardware reference, with the II-family power supply specifications and connector pinouts.[2]
- Macintosh II Repair and Upgrade Secrets: Larry Pina's 1991 repair and upgrade book for the II family.[6]
Related pages
[edit | edit source]- Macintosh II
- Macintosh IIfx
- Macintosh IIcx
- Macintosh IIci
- Macintosh Floppy Drive Maintenance
- Macintosh HDD Maintenance
- Battery Refurbishment
- Recommended Tools
References
[edit | edit source]- ↑ List of Apple codenames, Wikipedia—link(accessed 2026-09-30)
- ↑ 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 2.10 2.11 2.12 2.13 2.14 Apple Computer, Guide to the Macintosh Family Hardware, second edition (Addison-Wesley, 1990), hosted as File:Apple Guide to the Macintosh Family Hardware 2nd Edition 1990.pdf. Printed page numbers: pp. 26-28 (Macintosh II and IIx components; the IIx differences list, ROM on a ROM SIMM; up to 128 MB of RAM); p. 81 (no external floppy connector on the II and IIx); p. 194, Table 5-3 (IIx CPU clock 15.67 MHz); p. 216 (120 ns RAM); p. 232 (IIx ROM is a 64-pin ROM SIMM); p. 244 (power-on capacitor kept charged by two 3 V lithium batteries); p. 251, Table 6-6 (power supply connector); pp. 256-257 and Table 6-11 (AC input); pp. 263-264, Tables 6-23 to 6-25 (DC output limits, loads, ripple); p. 265 (short-circuit and over-temperature shutdown).
- ↑ 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 3.19 Apple Computer, Macintosh II/IIx/IIfx Service Source (1995), File:Macintosh ii.iix.iifx.pdf; see Macintosh II/IIx/IIfx Service Source. PDF page numbers: Specifications pp. 5-12; Symptom Charts pp. 15-31; Cover p. 33-35; Power Supply pp. 36-37; Mac IIx Logic Board Upgrade pp. 54-55; Mac IIfx Logic Board Upgrade pp. 56-57; Battery Verification pp. 69-70; Battery Replacement pp. 71-73; Battery Holder Board pp. 74-79; Exploded View p. 87.
- ↑ 4.0 4.1 4.2 Macintosh IIx, Wikipedia—link(accessed 2026-09-30) Prices from Apple's press release of 19 September 1988 (Business Wire), as cited there; the 68030's 256-byte instruction and data caches and the 10-15 per cent performance estimate from Ann Garrison, "68030 at Last", Macworld, December 1988, p. 83.
- ↑ 5.0 5.1 5.2 5.3 5.4 Apple Macintosh IIx Specs, EveryMac—link(accessed 2026-09-30) Introduced 19 September 1988, discontinued 15 October 1990; model M5840, Gestalt ID 7; order numbers M5280 (1 MB, one floppy drive), M5830 (4 MB, 80 MB hard disk) and M5850 (the same with A/UX); ROM "32-bit dirty"; 120 ns 30-pin SIMMs in groups of four, PAL SIMMs needed for 4 MB and larger; 128 MB with MODE32 and 16 MB SIMMs; System 6.0.1 to 7.5.5; two 3.6 V lithium batteries.
- ↑ 6.0 6.1 6.2 6.3 6.4 6.5 Larry Pina, Macintosh II Repair and Upgrade Secrets (Brady Publishing, 1991, ISBN 0-13-929530-5), hosted as Macintosh II Repair and Upgrade Secrets. Pp. 101-102 (II-to-IIx and II/IIx-to-IIfx upgrades); pp. 102-103 (B2 and the power-on fault; soldered Varta 3 V cells on the original Macintosh II and early IIx, Tadiran TL-5112 3.6 V snap-in cells on later IIx boards; cell test bands). A secondary source.
- ↑ 7.0 7.1 7.2 7.3 Macintosh IIx, Recap-a-Mac—link(accessed 2026-09-30) Annotated photograph of logic board 820-0229-A, hosted here as File:Mac IIx Recap Guide.jpg: 15 × 47 µF, 3 × 470 µF, 1 × 220 µF and 1 × 10 µF, all 16 V; 15 surface-mount and 5 axial electrolytics; the 10 µF axial has surface-mount pads under it; corrosion expected near the batteries, the power switch, above the NuBus slots and around the sound chips.
- ↑ Macintosh IIx, Console5 TechWiki—link(accessed 2026-09-30) Cap list for 820-0229-A by designator. A secondary source. It prints C19 twice (once as 470 µF, once as 47 µF); the board photograph shows C17 and C18 beside the two 470 µF parts at the lower left.
- ↑ Macintosh IIx Capacitor Reference, MacDat—link(accessed 2026-09-30) Logic board: 3 × 470 µF 16 V axial, 1 × 220 µF 16 V axial, 15 × 47 µF 16 V surface-mount, 1 × 10 µF 16 V axial with surface-mount pads. A secondary source.