Mitsubishi MP 286L

History and Diagnostics

Backstory

Mitsubishi, mainly based in Asia, is amongst the few conglomerate companies that offer services and products across many districts of business, which started from their renowned work for manufacturing vehicles and various industrial machinery.

When the late 80's came around, business was booming with the arrival of new innovations that changed computing history, including the creation the first ever laptops, and like The DAP/PMP wars of the early to mid 2000's, everyone had to have a go at it, even Mitsubishi. What they put out in the market was the MP 286L (models shown below in the specs), their first entry in the business computer wars, as part of a new innovation of computers called 'luggables'

This laptop computer has all the hallmarks of any relatively cheap desktop PC from the late 80's. Access to an array of old cable standards, very small hard drive storage, and a floppy drive to run any external software, all housed inside a sturdy clam shell with a sleek black finish. However, this PC has a few different features that make it relatively different from its competitors.

To start, it runs only on AC power through a power supply. By definition, it means this laptop is more 'transportable', because users can't take full advantage of it on-the-go due to its lack of a battery. This of course excludes the use of it on a train or a plane.

Another change is the inclusion of a Miniscribe stepper motor HDD for built-in storage, which was rather slow for the intel 80286 CPU inside the unit. At the time this was released, this choice of a hard drive was unfortunately from a company who began to perform fraudulent activities in their business that resulted in swift bankruptcy in the 90s. (refer to the link above)

One last thing that Mitsubishi did differently was the implementation of a full, built-in mechanical keyboard, which provides good-feeling, on-the-go typing. However, the layout of the keys are rather strange, having the last 4 function keys lined up above the first 4, and the arrow keys are half-sized, located in the top right corner (if facing towards the screen).

Due to both the Miniscribe drama and the competitive growth of technology, this luggable laptop only began to fall deeper into obscurity with time, having been knocked down by better computers, which include actual laptops. On that note, I had to go on a long and arduous web surf just to find all the information I can on this time capsule of a computer, and the rapid growth of technology isn't really helping with either that or the preservation of this thing.

Brand: Mitsubishi
Model form factor: MAXY (IBM compatible(see Software Things for details))

Model Numbers:

210 (with dual floppy 3.5" drives
220 (1 floppy drive, 1 hard drive)
240EVP (with an EGA screen)
MP-2120* (*I have this one, same 220)
MP-2130

Weight: ~10-16 lb (4.5-7.0 kg)

Original Price Range: 1750$ - 5000$

Size: (WxHxD) 12.3" x 3.5" x 14.2"

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Processor: Intel 80286

Clock rates: 5, 6, 8, 12 (standard), 16*, 20*, 25MHz* (*later models released by Fujitsu and AMD)
Processing power: 6-12MHz (1 wait state for anything above 8MHz)
- works with an optional Intel 80287 co-processor

Memory: 640 kb of RAM

expandable to 2.6 mb with proprietary memory card

Power:

Whole power supply unit:
- Model No.: PC21WA
- Voltage needed: 115V, 220V-*240V (*230V is the default factory setting)
- Power Cable: Standard IEC AC power cable within the above voltages
CMOS: Proprietary Varta Ni-Cd battery (just a fancy name for a time bomb)
- Volts & Amps: 3.6v, 170mAh

Built-in Storage: Miniscribe Hard Drive* (*Check links in the references for pictures)

No. of drive types: 0-47 (this is shown and requested in the setup disk software)
Model No. : M8425* (*often shortened to just 8425)
- interface: ST506
- Recording methods: MFM, SCSI* (*found in some old Macintosh systems)
- Capacity: 20-21 MB
- Phase: DTF
- Platter size: 3.5"
- No. of Heads: 4
- No. of Cylinders: 615

Floppy drive:

Compatible Diskettes: 3.5" floppy disks
Capacity Standards: 720 kb (standard), 1.44 mb (High Density)

Sound: 1x 15 mm x 2 mm Piezo speaker plate

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I/O: all of these are connected in the machine by 4 proprietary card slots

Serial ports: 2x male-end 9-pins
CRT Display out: 1x female-end 9-pin
- Can connect to an external 16-color CRT display
Network Inputs: 1x line, 1x telephone jacks (Both shaped like RJ45, not RJ11)
- works with optional 2400 bps internal modem which can be installed inside the machine (there's even an installation guide!)
External drive: 1x 26-pin floppy drive* (*female port end)
- connects with 5.25" 1.2mb or 3.5" 1.44mb floppy drive
- Cable Pinout
External input device: Female bus port end (for number pad mentioned in Included Software section)
Printer Cable: 1x 25-pin parallel* (*labeled as "PRT")
Back-Switches*: 2x arrays of 4 switches (for small, temporary changes after set up)
- DTS-4 to the left of FDD port (if looking from the back)
- DPS-4 to the right of CRT port (if looking from the back)
  - 6 levers present by CRT on MP-2130 Model

Keyboard:

No. of keys: 86
Key layout: Custom AT

Display:

Type: Cold CRT, back-lit passive-matrix LCD (with a neutral twist nematic)
- Knobs and switch on bottom right corner of front bezel control back light and blacks-on-whites contrast configuration
Dimensions: (WxH) 9" x 6.5", 11" diagonal
Pixel Resolution: 640 x 200-400, for graphics and text respectively
Character resolution: 80 characters/line
compatible aspect ratios: EGA and CGA

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Included In-Box Software:

Setup & diagnostics, utilities*, MS-DOS 3.30 driver (*for mouse and/or number pad, as well as system checkup and any business software)

BIOS: Phoenix 80286/80386 ROM BIOS version 3.10 (IBM BIOS clone)

Fun Fact: This is the same BIOS type used in the iconic Compaq Portable Laptop

Extra MS-DOS 3.30 info:

2nd Brand: IBM (*proprietary license)
Maximum Partition Limit: 32mb
Floppy storage capacities: 720 KB, 1.44 MB
Partition type: 05h
Filesystem: FAT12*, FAT16 (*FORMAT command is still integrated there)
- Wikipedia Article with more specs and info on FAT12 and FAT16

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below is a list of the names of the manuals that would come with these lap crushers: