Josh: New page: PowerBook 100 from Apple's Service Source, developer note and spec page; boards, display, power, known faults

2026-10-02T08:45:18Z

New page: PowerBook 100 from Apple's Service Source, developer note and spec page; boards, display, power, known faults

New page

{{Infobox computer
| name = PowerBook 100
| image = [[File:PowerBook 100 (Klaus with K).jpg|260px|frameless]]
| caption = PowerBook 100, US version (Klaus with K, Wikimedia Commons, CC BY-SA 3.0)
| manufacturer = Sony for Apple Computer, Inc.
| type = Notebook computer
| release_date = 21 October 1991
| discontinued = 3 August 1992
| price = US$2,500 (1991)
| cpu = Motorola 68HC000 at 15.6672 MHz
| memory = 2 MB pseudostatic RAM soldered; one expansion slot; 8 MB maximum
| rom = 256 KB
| storage = 20 or 40 MB 2.5-inch SCSI hard disk; external 1.4 MB floppy drive (HDI-20)
| display = 9-inch backlit FSTN LCD, 640 × 400, monochrome
| sound = Apple Sound Chip; mono speaker and sound out
| power = Sealed lead-acid main battery; three CR2430 lithium backup cells; 7.5 V adapter
| dimensions = 1.8 × 11 × 8.5 in
| weight = 5.1 lb (2.3 kg)
| os = System 7.0.1 to 7.5.5
| predecessor = [[Macintosh Portable]]
| successor = [[PowerBook 145]]
| codename = Derringer, Rosebud
}}
The '''PowerBook 100''' is the smallest of the three original PowerBooks, introduced on 21 October 1991 with the [[PowerBook 140]] and PowerBook 170. Sony designed and built it for Apple. Its internal architecture is based on the backlit [[Macintosh Portable]], with the same 16 MHz 68HC000, Power Manager and custom chips, in a case 11 inches wide; the floppy drive is an external unit.<ref name="wp">Wikipedia, [https://en.wikipedia.org/wiki/PowerBook_100 "PowerBook 100"] (retrieved 2026-10-02). Designed and manufactured by Sony; introduced 21 October 1991 at COMDEX; US$2,500; external floppy drive; discontinued 3 September 1992; sold off below US$1,000. History only.</ref><ref name="dn">Apple Computer, ''Macintosh PowerBook 100 Developer Note'' (1991), hosted here as [[:File:PowerBook 100 Developer Note (1991).pdf]] (see [[PowerBook 100 Documentation]]). Chapter 1, pp. 1-4: based on the backlit Macintosh Portable; features list (68HC000 at 15.667 MHz; 256 KB ROM and 2 MB PSRAM soldered to the secondary logic board; 70-pin RAM connector for 2, 4 or 6 MB cards; FSTN LCD 640 × 400; 2.5 Ah sealed lead-acid battery; three 3.5 V lithium backup batteries; 11 × 8.5 × 1.75 in; about 5.3 lb); Portable expansion cards do not fit; sound by the Apple Sound Chip and a Sony sound chip.</ref> Apple's specification page gives the discontinuation date as 3 August 1992; Wikipedia gives 3 September 1992.<ref name="sp">Apple, [https://support.apple.com/en-us/112153 "Macintosh PowerBook 100: Technical Specifications"] (retrieved 2026-10-02). 68000 at 16 MHz; 16-bit data path; logic board 2 MB, 2-8 MB, cards of 2, 4 and 6 MB, 100 ns; external floppy HDI-20; SCSI HDI-30; battery type PB100, lead acid; 17 W, 100-240 V; introduced 10/21/1991, discontinued 8/3/1992; Gestalt ID 24; 5.1 lb; 1.8 × 11 × 8.5 in; 24-bit addressing only; ROM 256K, ROM ID $037A; System 7.0.1 to 7.5.5.</ref><ref name="wp" /> Low End Mac gives the code names Derringer and Rosebud and a launch price of US$2,500.<ref name="lem">Low End Mac, [https://lowendmac.com/1991/powerbook-100/ "PowerBook 100"] (retrieved 2026-10-02). Introduced 1991.10.21 at $2,500, discontinued 1992.08.03; code names Derringer and Rosebud; 24-bit only; first PowerBook with SCSI Disk Mode; 7 V lead-acid battery unique to the PB 100; three CR-2430 PRAM batteries; AC adapter 7.5 V, 1.5 A nominal; power switch on the back for long-term storage, which clears the RAM disk and PRAM. Secondary source.</ref>

The PowerBook 100 runs in 24-bit mode only and is the first PowerBook with SCSI Disk Mode, which lets a desktop Mac mount its internal disk through an adapter cable on the HDI-30 port.<ref name="lem" /><ref name="dn" />

== Specifications ==
<templatestyles src="Template:StyledTable/styles.css" />
{| class="wikitable styled-table" style="width:70%;"
|+ '''Apple's specifications'''<ref name="ss">Apple Computer, ''PowerBook 100'' Service Source, hosted here as [[:File:PowerBook 100 Service Source.pdf]] (see [[PowerBook 100 Service Source]]). PDF page numbers: Specifications pp. 3-11; Troubleshooting pp. 13-36; Take Apart pp. 38-85; Upgrades pp. 87-95; Additional Procedures pp. 97-114; Exploded View p. 116.</ref>
! Item !! Specification
|-
| Processor || Motorola 68HC000, 16-bit CMOS, 15.6672 MHz; 24-bit address bus, 16-bit data bus
|-
| RAM || 2 MB of 100 ns pseudostatic RAM, expandable to 8 MB
|-
| ROM || 256K in two 128K × 8 chips, 150 ns
|-
| PRAM || 128 bytes
|-
| Video RAM || 32K pseudostatic
|-
| Hard disk || 20 MB or 40 MB, 2.5-inch, Apple SCSI interface
|-
| Floppy drive || Optional external HDI-20 1.4 MB drive
|-
| Ports || HDI-20 floppy; HDI-30 SCSI (1.5 MB/s, up to five devices); ADB (50 mA total); one external RS-422 serial port, plus an internal serial connection for the modem; sound out
|-
| Keyboard and trackball || Built-in keyboard on ADB; 25 mm two-button trackball
|-
| Display || 9 in (229 mm) diagonal backlit FSTN, 640 × 400, 75 dpi
|-
| Sound || Apple Sound Chip
|-
| Main battery || Sealed lead-acid, 7 V; 2.5 hours maximum
|-
| Backup batteries || Three lithium cells, industry-standard CR2430
|-
| Power adapter || Input 85-270 V AC, 48-62 Hz; output 7.0-7.6 V (7.5 V nominal), 5 mA-2 A (1.5 A nominal)
|}

The developer note's block diagram labels the main battery 6.5 V SLA where the Service Source says 7 V, and both Apple documents give the backup cells as 3.5 V.<ref name="dn" /><ref name="ss" /> The developer note gives the size as 11 × 8.5 × 1.75 in and the weight as about 5.3 lb; the specification page gives 1.8 in and 5.1 lb.<ref name="dn" /><ref name="sp" />

== Hardware ==

=== Boards ===
The main logic board is Sony's PU-58 (Sony 1-640-290, Apple service part 661-0673), and the processor, ROM and soldered RAM sit on a daughterboard, Sony IF-54 (1-640-491, Apple 661-0674), that plugs onto it at connectors J318 and J319.<ref name="ss" /><ref name="md">MacDat, [https://macdat.net/repair/cap_reference/apple/powerbook/100.php "Capacitor Reference - PowerBook 100"] (retrieved 2026-10-02). Board photographs showing PU-58 1-640-290-13 / 661-0673 and IF-54 1-640-491-11 / 661-0674; every PowerBook 100 must be fully recapped; the logic board's varnish turns sticky with isopropyl alcohol; logic board, CPU board, Sharp LM64P791 LCD, inverter and trackball capacitor lists. Secondary source.</ref> A small interconnect board, an inverter and a brightness and contrast board sit in the display; the interconnect cable also carries the speaker.<ref name="ss" /> The SCSI and serial ports run from a single Combo chip, the AM85C80.<ref name="scsi">68kMLA forum thread [https://68kmla.org/bb/threads/powerbook-100-scsi-chip.51999/ "Powerbook 100 scsi chip"], April 2026. Fizzbinn: SCSI and serial are handled by the Combo chip, AM85C80; imactheknife: a PB100 that could not see its disk was cured by reflowing the chip after cleaning corrosion from its legs. Community repair report.</ref>

=== Display ===
The display is a Sharp LM64P791 FSTN panel with a CCFL backlight.<ref name="md" /> Apple's service charts treat a slight white line across the middle, rainbow colours at extreme angles, an uneven image and a display that stops working in extreme heat, cold or light as normal for this screen.<ref name="ss" /> The panel's drive voltage, LCD_VEE, of about −22 V is generated on the logic board.<ref name="vee">68kMLA forum thread [https://68kmla.org/bb/threads/powerbook-100-display-lcd_vee-issue-but-inductors-ok.49563/ "PowerBook 100 display, LCD_VEE issue but inductors ok?"], March-May 2025. asentientbot: LCD_VEE measured at test point TP055; inductors L2, L3, L4; finkmac: the LCD needs about −22 V and will not show a picture without it; clean under the inductors and U25, the FA7611 controller; alexGS: start by replacing C22, which is involved in producing the LCD drive voltage, and recap the eight 3.3 µF capacitors on the LCD. Community repair reports.</ref>

=== Power ===
The PowerBook 100 runs from a sealed lead-acid battery unique to this model.<ref name="lem" /> Three CR2430 lithium coin cells behind a door at the rear back up the PRAM and clock, and a storage switch on the back disconnects all power for long-term storage, which clears the RAM disk and PRAM.<ref name="ss" /><ref name="lem" /> Some motherboards have their fuse soldered in, and replacing it means replacing the board; boards Apple supplied as spares have a removable fuse.<ref name="ss" /> See [[PowerBook 100 Battery Replacement]].

== Known faults ==
* Leaking electrolytic capacitors on the logic board, the CPU board and the LCD. MacDat's advice is that every PowerBook 100 must be fully recapped. See [[PowerBook 100 Capacitor Replacement Guide]].<ref name="md" />
* A blank screen with the backlight on, from a missing LCD_VEE supply. See [[PowerBook 100 Troubleshooting#Video]].<ref name="vee" />
* Corrosion inside the LCD's ribbon cables, which takes out a band of rows at the bottom of the screen and is not repairable.<ref name="blue">68kMLA forum thread [https://68kmla.org/bb/threads/powerbook-100-1-8-of-screen-is-still-blue-after-recapping.49834/ "Powerbook 100 1/8 of screen is still blue after recapping"], May 2025. 3lectr1cPPC: loss of the bottom rows is now very common, caused by a failed row driver or by corrosion from the leaking capacitors inside the ribbon cable, and there is no practical fix; replacement LM64P791 panels are hard to find. Community experience.</ref>
* Dead lead-acid batteries and flat backup cells.<ref name="lem" />
* Leaking capacitors in the original power adapters; see [[PowerBook 140 Troubleshooting#Power adapter]], which covers the shared 100-series adapter.
* A pink bloom on the LCD where the trackball presses against the closed lid, with small cracks in the panel over time.<ref name="bloom">68kMLA forum thread [https://68kmla.org/bb/threads/powerbook-100-recapped-lcd-and-logic-board-but-screen-is-blobby.50914/ "Powerbook 100 - Recapped LCD and Logic board but screen is 'blobby'"], October 2025. Byrd: many PB100 displays have a pink bloom where the trackball rests under the LCD, causing small fractures over time; finkmac: blotches after a recap were liquid between the diffuser film and the acrylic light guide, which are sensitive to oils and solvents; swap the backlight parts from a panel with a broken LCD. Community repair report.</ref>

== Maintenance and repair ==
* [[PowerBook 100 General Maintenance]]
* [[PowerBook 100 Troubleshooting]]
* [[PowerBook 100 Capacitor Replacement Guide]]
* [[PowerBook 100 Battery Replacement]]

== Documentation ==
* [[PowerBook 100 Service Source]]: Apple's module-level service manual.
* [[PowerBook 100 Documentation]]: the developer note and the PU-58 EVT2 logic board schematic.

[[File:PowerBook 100 exploded view (Service Source).png|thumb|center|450px|Apple's exploded view of the PowerBook 100 with service part numbers (Service Source, PDF p. 116)]]

== Related pages ==
* [[PowerBook 140]]
* [[PowerBook 145]]
* [[Macintosh Portable]]
* [[Battery Explosion, Capacitor or Corrosion Damage]]

== References ==
<references />

{{Navbox-AppleVintage|state=collapsed}}

[[Category:Apple Vintage Computers]]

PowerBook 100 - Revision history

Josh: New page: PowerBook 100 from Apple's Service Source, developer note and spec page; boards, display, power, known faults