NEC UltraLite SL/2C
The UltraLite SL/25C is a 386SL-based laptop that was released in January 1992. It was the first notebook-sized computer with an Active Matrix (TFT) Color display. At the time, Sharp had a bulky TFT screen available that had been used in some luggables, including the Toshiba T3200SXC, but this LCD was too thick to fit in a true laptop computer. Instead, NEC used a custom panel that they designed. According to reviews, the quality was good, although it required warm-up time before the colors looked optimal.
Specifications
| Spec | Details |
|---|---|
| CPU | CPU Type: Soldered QFP Intel 386SL @25MHz - Optional 387 Coprocessor |
| Chipset | Intel KU82360SLB1 |
| RAM | Type: Proprietary Standard: 2MB Maximum: 12MB |
| Storage | 2.5" IDE Requires Adapter: Yes Standard: 80 or 120MB |
| Display Options | 9.5" Active Matrix Color LCD @640x480 (NEC) |
| Graphics Chipset | Cirrus Logic GD6410 VRAM: Unknown |
| Audio | PC Speaker |
| Main Battery | NiCad (12V) |
| CMOS Battery | CMOS and Reserve batteries, unknown chemistry |
| Power Supply | 8-pin Mini-DIN - NEC PAD-128 |
| Media Drives | 3.5" 1.44MB Floppy Drive (Citizen V1DA) |
| PC Cards | None |
| Networking | Modem (Optional) |
| Other I/O | - 1x Parallel - 1x Serial - 1x VGA Out - 2x PS/2 - 1x Dock Connector - 1x Numpad Port - 1x External FDD Port |
| BIOS | Unknown |
| Pointing Device | None |
Resources
 Hard Disk Image |
|---|
Common Faults & Maintenance
Leaking Capacitors
Electrolytic capacitors on the SL/25C's DC/DC board will always fail and begin to leak corrosive fluid. They must be replaced for reliable operation, and it is likely that a non-recapped unit will simply not power on.
The troublesome thing about this laptop is that the DC/DC board is soldered to the motherboard, whihc is going to make it a real pain to remove and recap.
There are also around 5 electrolytic caps (through hole type) on the LCD panel's circuit boards that I'd recommend replacing.
Missing Power Supplies
The biggest obstacle many will have getting an SL/25C running is the proprietary power supply that seems to always be missing from SL/25C for sale listings. The supply (NEC PAD-128) is unobtanium. For a quick test, you can hook up a 12V supply to the battery terminals. More permanently, you may wish to build a custom supply. The power supply has multiple voltage rails, however, it may boot with just the main power rail connected. This I'm unsure of, as my SL/25C is dead (needs recapping still). Here's a photo of the supply, which shows its pinout:
Brittle Plastic
While not nearly as bad as the later Versa laptops, the SL/25C does appear to be somewhat brittle. The hinge mounts at the display-side are extremely overbuilt and unlikely to ever break, but the ones at the base split in my unit. The good news is that there is plenty of room to repair and reinforce these with JB Weld.
Other Issues
My SL/25C shipped with a Quantum GoDrive hard disk. These drives are now nearly always dead, as they have multiple rubber bumpers that melt with time, which causes the heads to stick. One of these bumpers is under the platters, so repairing the drive is not practical. Somehow, my unit's GoDrive still worked, so I was able to back it up and upload the contents to archive.org.
Likewise, the SL/25C's floppy drive won't usually work without maintenance either. It used the Citizen V1DA series drive, which like other Citizen drives uses a belt to drive the spindle motor. This belt falls apart with age nearly 100% of the time and will need to be replaced. There are probably also a couple leaky caps to replace in the drive.
Gallery
Coming soon.
Page last updated (MM/DD/YYYY): 03/09/2025
Update Reason: page created
Have additional information on this laptop? Want to send me photos to use on the site? Send me an email: macdatnet@gmail.com
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