 | |
| Also known as | Type 8543 |
|---|---|
| Manufacturer | IBM |
| Product family | IBM PS/2 |
| Type | Laptop |
| Release date | March 26, 1991; 34 years ago (1991-03-26)[1] |
| Introductory price | US$5,995 (equivalent to $13,430 in 2024)[1] |
| Discontinued | February 1993 (1993-02)[2] |
| Units sold | 150,000+[2] |
| Operating system | DOS, Windows 3.0, OS/2 |
| CPU | Intel 80386SX @ 20 MHz (optionalIntel 80387SX math co-processor) |
| Memory | 2 to 18 MB (two expansion slots) |
| Storage | 60 MB hard drive 3.5" 1.44 MB floppy drive |
| Display | 10" monochromeSTN LCD |
| Graphics | VGA (640x480) |
| Connectivity | parallel port, serial port |
| Power | Battery: Ni-Cd |
| Weight | 3.49 kg (7.7 lb) |
| Predecessor | IBM PC Convertible |
| Successor | |
TheIBM Personal System/2 Model L40 SX (stylized asPS/2 Model L40 SX)[3][4] is alaptop made byIBM as part of theIBM PS/2 series.[1] It was the successor to theIBM PC Convertible.[5] The "SX" in the name refers to its CPU, theIntel 80386SX.
By 1989IBM had been unsuccessful in thelaptop computer market.[6]InfoWorld wrote that the company's first laptop, thePC Convertible, was "a dismal failure" because of high price and inferior technology. After the more successfulPS/2 P70luggable, IBM stated that year its intention to release anIntel 80386-based laptop with "a battery that doesn't have to be recharged every half hour".[7]
The L40 SX was designed and manufactured over the course of thirteen months between 1990 and 1991.[8][9] By 1990, IBM were already late to the market of 386SX-powered laptops. Faced with releasing an obsolete product, should they have followed their normal two-yearlead time, IBM hastened development of the L40 SX.[8]
The L40 SX's case and keyboard assemblies took roughly five months to produce and involved novel methods to achieve this time frame.[10]: 27 IBM hired their former subsidiaryLexmark ofLexington, Kentucky, and Leap Technologies ofOtsego, Michigan, to achieve this production.[8] Both companies used IBM's ownCatia CAD–CAM systemto design the models of the parts for the aforementioned assemblies.[11]: 48 [12] Lexmark were responsible for drafting these models, sending themelectronically to Leap for revisions. Once revised, Leap used these models to machine theinjection molds for each part.[12] The two companies' electronic exchange of models was novel for the time and accelerated production by eliminating the need formocking up andprototyping.[12][8] It also posed a risk, however, as any design flaws realized after manufacturing would set production back up to a year and compel IBM to cancel the laptop.[11]: 48 Because of this, both Leap and Lexmark used specialized software to predict how the parts would result from Leap's molds.[10]: 27
Before designing began, however, Leap and Lexmark had to source suitable plastic. They settled on apolycarbonate–ABSpolyblend byDow Chemical that was durable,colorable, andplateable. The latter quality was necessary for compliance with theFCC's regulations onelectromagnetic interference.[10]: 27 Integrated circuits, such asmicroprocessors, cause such interference; most companies at the time compensated by spraying a thick layer of metallic paint on their cases' interiors. Because the 386SX's power overrode such shielding, however, IBM turned toelectroless plating—a method that was novel for laptops. This provided the case with stronger shielding and not much more weight but also considerable expense for IBM.[11]: 48 Research on the method was also costly: as electroless plating had seldom been used on their polyblends, Dow had to perform rigorous laboratory tests.[10]: 28 After designing ended and the molds were machined, Leap performed injection only on the molds for the case assembly parts,[12] shipping the molds for the keyboard assembly parts to Lexmark.[13] Leap performedultrasonic welding on their parts where necessary and handed the responsibility of plating to a company in Michigan. Leap then sent the completed case assemblies to Lexmark.[10]: 28
Toshiba of Japan provided IBM with the L40 SX'sliquid-crystal display, which was a 10-inch,sidelit,passive-matrix panel. Final assembly of these panels were performed inRaleigh, North Carolina. IBM considered using Toshiba'sactive-matrix LCD which provided a better response times, widerviewing angles, and no blotching, but these displays drew too much power. IBM also teamed withWestern Digital of Irvine to design the L40 SX's motherboard. Western Digital provided assembly of the L40 SX's entire motherboard as well as their 7600LP series of video andhard disk drive controllerchipsets, as well as the means for IBM to assemble the motherboard themselves further down the line.[13]
Manufacture of the L40 SX was plagued with parts shortages, but IBM were able to produce roughly 4,000 pre-release units which were sold to select members of the public (including 880 members ofHarvard Business School's Class of 1992). Hard disk drives were the latest shortage in April 1991, with IBM having to look at producing its own 2.5-inch 60 MB drives instead of waiting forConner Peripherals.[13]
The substantial price raise of the L40 SX in March 1991 drew criticism from potential buyers who had enthusiastically praised it at IBM's last press briefing. IBM justified this price raise by classifying the L40 SX as adesktop replacement. The L40 SX's larger-than-notebook dimensions was advantageous for IBM in both raising its technical capability, fitting its coveted full-sized keyboard, and meeting the expectations of buyers specifically looking for a desktop replacement machine. Potential buyers felt the L40 SX's exceptionally comfortable keyboard and low power consumption failed to justify its launch price, however. At the time of the company's announcement of their price raise for the L40 SX, IBM were evaluating demand for a low-priced notebook computer in the United States after releasing thePS/55 Note in Japan.[13]: 11
At the time, the L40 SX differed from most other laptops in operation by offering asuspend mode, a dynamic CPU clock cycle that slows down when the processor is idle, and the use of LCDs for status indicators, as opposed to LEDs. The latter two features lower the L40 SX's power draw. The back of the L40 SX sports oneserial port, oneparallel port, an external AT expansion port, aVGA port, and aPS/2 mouse port. IBM provided an optional modem that can receivefax transmissions.[13]: 11
 IBM PS/2 L40SX "Convertible" Pointing Device, YouTube video |
The Wall Street Journal reported that IBM had received 15 complaints of ashort circuit occurring between the circuitry and a conductive coating inside the case which, in some instances, has melted a small hole in the case. The short occurs when the laptop is run on batteries, and IBM reported it will install afuse to stop overheating. They had to issue arecall for 150,000 machines.[2]
One year after the announcement of the L40 SX, on 24 March 1992, three notebooks and a laptop were announced by IBM: N51SX, N51SCL, N45SL as part of theIBM PS/2 Note series and theCL57SX.[14] The CL57SX was the first laptop from IBM that featured a colorTFT display.[15]
| Preceded by | IBM PS/2 L40SX | Succeeded by |