IBM PS/2 Model L40 SX
| Company type | Product model |
|---|---|
| Industry | Computer hardware |
| Predecessor | IBM PC Convertible |
| Founded | 1991 |
| Headquarters | Armonk , United States |
| Products | Laptop computer |
The IBM Personal System/2 Model L40 SX (also referred to as PS/2 Model L40 SX) represents a laptop introduced by IBM within the IBM Personal System/2 lineup. It followed the IBM PC Convertible and incorporated the Intel 80386SX processor.
Development
By 1989, IBM faced challenges in the portable computer market; its initial offering, the PC Convertible, was criticized for its steep cost and outdated technology. Following the relatively better reception of the PS/2 P70 luggable, IBM set out to develop a laptop powered by the Intel 80386 processor that would also provide enhanced battery longevity.
The design and production of the L40 SX spanned thirteen months from 1990 to 1991. To prevent launching a product already outdated due to its delayed entry in the 386SX laptop segment, IBM expedited the development process.
Manufacturing of the case and keyboard took approximately five months, utilizing innovative techniques involving former subsidiary Lexmark and Leap Technologies. These companies employed IBM's CATIA CAD–CAM software to design and fabricate injection molds. Their use of electronic data interchange eliminated the need for physical prototypes, accelerating production but introducing greater risk of expensive design flaws.
For the casing material, Leap and Lexmark chose a robust polycarbonate–ABS composite supplied by Dow Chemical, which could be colored and plated to comply with FCC electromagnetic interference regulations. Unlike competitors who relied on metallic paint for shielding, IBM opted for electroless plating—a more expensive yet effective solution given the power demands of the 386SX processor.
The L40 SX featured a 10-inch passive-matrix LCD panel provided by Toshiba; active-matrix displays were dismissed due to their higher energy consumption. Western Digital partnered in designing the motherboard and supplied video and disk controller chipsets, facilitating IBM's eventual assembly of the units internally.
Production faced delays caused by component shortages, particularly hard drives; nonetheless, around 4,000 pre-production units were manufactured and selectively distributed, including sales to Harvard Business School’s Class of 1992.
When released in March 1991 at a price point of $5,995, the L40 SX's cost was met with criticism despite IBM marketing it as a desktop replacement rather than a typical notebook. Its larger chassis allowed for a full-sized keyboard and advanced technical specifications but did not fully persuade some customers regarding its cost-effectiveness.
Notable features comprised suspend mode functionality, dynamic CPU clock throttling to conserve power, and LCD-based status indicators instead of traditional LEDs. Connectivity options included serial, parallel, external AT expansion, VGA, and PS/2 mouse ports. An optional modem with fax capabilities was also offered.
Specifications
- CPU: 20 MHz Intel 386SX
- Display: Toshiba LRS1751-R1AE / LS035OLG 10" monochrome VGA (640x480)
- Operating System: DOS versions 3.3 or 4.0, Windows 3.0, OS/2 1.31
- Storage: 2.5" IDE hard disk drive
- Expansion Bus: ISA
Optional Accessories
- Trackpoint device (convertible between trackball and mouse)
- Rapid Charging Unit
- Adapter for Car Battery Use
- Built-in Data Fax Modem
- Premium Carrying Case
Product Recall
According to a report from The Wall Street Journal, IBM encountered 15 cases involving a short circuit caused by contact between internal circuitry and a conductive coating inside the casing, which led to partial melting. This defect was observed during battery operation. IBM addressed the problem by incorporating a fuse to prevent overheating and proceeded to recall approximately 150,000 units.
Follow-up Models
On March 24, 1992, exactly one year following the debut of the L40 SX, IBM launched three notebook models along with a laptop: the N51SX, N51SCL, N45SL (all part of the IBM PS/2 Note lineup), and the CL57SX. The CL57SX represented IBM’s inaugural laptop featuring a color TFT screen, signaling a deliberate expansion into the U.S. notebook computer market.