Compaq Portable 386

CGA, serial, parallel, ISA Erweitungsslot

The Compaq Portable 386/20 was introduced in 1987 by Compaq Computer Corporation. He was one of the last "suitcase computer " with remarkable 11 kg weight in the standard version, but has a very powerful, socketed Intel 80386 processor running at 20 MHz. He had, in contrast to today's devices no battery and is powered by a normal computer power supply with IEC connector with power, but uses internally apart from the molex connections to proprietary back.

The Portable 386 could be extended with the Compaq Expansion Unit to two ISA slots, which could accommodate two full-length cards - thus he was, apart from an optional modem expansion card, network-capable.

By default, it came with a 5.25 " floppy drive with 1.2 MB and a 40 or optional 100 MB hard drive. The integrated graphics card can display a maximum of CGA with a non-standard resolution of 640 × 400 pixels with 2 colors ( monochrome ), but is otherwise the standard at that time (80 × 25 characters, 640 x 200 pixels, 320 × 240 pixels) compatible. EGA and VGA only work with ISA expansion card on an external monitor - the internal, as the " Compaq Portable Plasma" designated, the display offers at a resolution of 640 × 400 pixels with 16 gray levels.


The BIOS Configuration Utility is in contrast to other devices not directly stored in a chip, but must be loaded from disk. If you no longer have this, so you can override it nowadays still easily found on the Internet:

  • 3.5 " 720 KB Version: SP0308.EXE or SP0308.ZIP
  • 5.25 " 360 KB Version: SP0316.EXE or SP0316.ZIP



The CPU, a 386DX -20 could, Although easily replace by its base, but only against an equally fast model since the 386 processors still had no multiplier, the entire system had to run with the clock frequency. The unit also provides a socket for a 80387 floating point unit ready, as this is not included in the standard.

Main memory

The memory can be expanded up to 10 MB. The main board can accommodate 4 512K SIMMs the proprietary format. The expandable to 10 MB total builds on the following:

This also only optional Compaq 32-bit memory / modem interface board is required to provide the connections for the following cards:

  • On this an expansion card with 4 MB (8 x 512KB 80ns, Compaq memory expansion board ) is inserted, and it is needed again
  • To put on this another 4 MB ( 8 × 512 KB 80 ns, Compaq memory expansion kit) card. That's a total of 10 MB.

Graphics Card

The graphics card can ( briefly MDA) are jumpered only between CGA and Monochrome Display Adapter - the lesser evil, the CGA output is mandatory for the Compaq plasma display driver from Windows 2.x and 3.x. Although it may a better graphics card be upgraded via Expansion Unit, but are not used with the internal display.

Hard disk

The device provides a slot for a hard drive full height ready can even record two 3.5 "hard drives without a floppy drive, since a normal IDE cable. The BIOS is limited to the entry of hard disk types, Type 42 with 528 MB ( 504 MB under DOS ) is the greatest option. The BIOS reveals no details of how many sectors, heads, and clusters these are set up. But as long as you use a modern hard drive in the gigabyte range, makes no problems also the greatest option. The important thing is that you're exceeding the CHS Setting the system BIOS to the hard drive.

Alternatively can be via adapter also normal 2.5 " notebook hard drives or CompactFlash cards operate. For applications that require more than 504 MB, a disk manager as Ez -Drive recommended that overrides the BIOS values ​​.


In conjunction with a 2.5 "hard disk or CompactFlash card, you can then free the 5.25" use - bay for CD -ROM drive, if you switch to an IDE cable with two plugs.

Floppy disk drive

Original the device was always " delivered 1.2 MB drive, but there was the possibility for an additional charge a 3.5 " with a 5.25 to order -1.44 MB drive. Used a normal ribbon cable as in desktop computers.

ISA expansion cards

As mentioned above, the device can be expanded to include the " Compaq Expansion Unit ", a housing top with two 16-bit ISA slots full-length. This can invariably use all ever published ISA bus cards - at least upgrade a network card so that the brightest case.

  • Portable computer
  • Computer