After having invented the first IBM-compatible transportable computer, and having recorded half a billion dollars turnover, Compaq decided to launch its second portable AT clone. The system featured an 8 MHz processor and a 10 MB hard disk in a package 30% smaller and 20% lighter than previous PC model.
The general engineering idea behind this machine was to provide a cut-down IBM PC/AT clone with fewer expansion slots (5), a small hard disk and a floppy disc. This allowed Compaq to make the Portable II smaller and lighter without sacrificing too much specification.
Like many portable systems of the time, the keyboard attached to the front of the case and when the machine was ready for carrying, it was like a sewing machine.
The machine was supplied with 640 KB of RAM which was the maximum that could be fitted to the main board. However, RAM could be taken up to 2.1 MB by using a custom-designed expansion card.
Technically the Portable II gave its user more power than an IBM PC/AT for almost half the price.
At the same time, Compaq delivered two desktop computers, the Deskpro PC/XT and Deskpro PC/AT, and two portable systems, the Portable/Plus PC/XT and the Portable 286 which was a full function PC/AT clone.
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Lucio Libertini says:
The Portable 2 comes with a single 360kb 5.25" floppy drive, but it is compatible with 3.5" ones. Indeed, replacing the drive is the first thing that should be done, as 5.25" floppies in decent conditions are getting almost impossible to find, while 3.5" ones are still being manufactured. 360kb is also uselessly small for most applications.
A suitable floppy cable is required for the modification, not to mention a caddy to put the smaller drive in the tray. One can always affix it in there with other means, but the result is most inelegant.
The Portable 2 doesn't boot any MS-DOS bootdisk above version 3.2; 3.21, 3.3 and 6.22 didn't work. There is a likely exception: I didn't test MS-DOS 6.00 floppies, but the hard drive mine came with has that inside, so it must have been installed from floppies.
The Portable 2 does boot DR-DOS floppies of versions 3.41 and 6.00 (5.00 untested), but 6.00 is awfully slow, so I suggest sticking with the older version.
The compaq diagnostic floppy that's required for BIOS setup is incredibly hard to find; after extensive Googling I managed to find a floppy image that contained the required programs, but wasn't bootable. I made a bootable floppy with DR-DOS 3.41 and the diagnostics; you can find it here. It's a raw image, writable with rawwrite (and many other apps) under Windows and dd under Linux. The BIOS access program is setup.exe.
Mark Dodd's memories:
One arm is longer than the other after having to lug these things around for a year or so.
We had several within Telecom Australia equipped with network sniffer cards and other addon cards for looking after the myriad of different network technologies that existed within the 84,000 employee behemoth.
My biggest nightmare was getting caught between buildings at the end of the day so I had to lug the thing home on public transport. I remember one old fellow looking at it with amazement on the train and telling me how the same power used to take up two floors of a building. I told him it still weighs the same....
Rob Brown also remembers:
This was the field service engineers nightmare. You were supposed to be Compaq trained to service this machine but very few engineers were. The main challenge was just getting it open. It was the first pc to use the torx type screws. You could not get hold of a torx screwdriver for love nor money in those days and I had a specially filed down flat head screwdriver which could just about turn a screw if wasn't too tight.
Once you got the plastic case off, there was another steel case to contend with. There were a few access panels, but trying to get to the right components was really difficult. Then you had to put it back together, which was even harder.
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I was having trouble booting MS-DOS 6.20 from a 360k floppy, as it would just reset on bootup right after displaying the "Staring MS-DOS" message. I think the problem is caused by the dual-mode CGA graphics card on the system. As soon as I disabled that feature in Compaq Diagnostics, and booted in pure CGA mode, it would boot MS-DOS just fine and all apps worked as expected.
I just bought a Compaq Portable II with 286 CPU, which has a fixed hard drive (20MB), which is temperamental because it''s not being recognized at bootup. In about 1990, I had borrowed a Compaq Portable (from work) with two 5.25" floppy drives but no fixed hard drive. I used this to write assembly programs. Now (5/17/2015), I can used this Compaq Portable II to read and run files from my old diskettes, which contains some of my work. I need a new hard disk for the Compaq Portable II.
It will run on MS-DOS versions 6.20, IBM-DOS 3.30, Compaq-DOS 3.31, but not MS-DOS 5.0, 3.2, or 3.30. It''s a little strange that certain flavors of MS-DOS will not work, yet IBM and Compaq flavors do.
I have the IBM Diagnostics for IBM Personal Computer AT diskette (version 2.03). And it''s readable on the Compaq Portable II.
I also need the MS-DOS 6.2 disks to install on my new hard disk.
Sunday 17th May 2015
MDOC7 (Virginia, U.S.A.)
I''ve been trying to use the "send more information" form to correct the info I supplied ages ago (and that I forgot about entirely until I came across this page again and read my name), but it doesn''t seem to work, so I''m adding this post instead.
Ignore what I wrote about the versions of MS-DOS supported by the computer. I think I messed up while making the disk images, or possibly used bad disks$ the computer does indeed boot and run MS-DOS 6.22. Mine has it currently installed on the hard drive. Takes up quite some HD space, but it runs speedily. It''s possible to use drivespace compression, but when doing so everything involving disk access slows down to a crawl (the 286-8 is not a fast CPU), so I just dealt with it.
I managed to find a compatible 40MB Quantum hard disk (a ProDrive, I think - I don''t have it around now so I can''t check), but it''s a voice coil unit, and I like the stock stepper-motor drive''s delicious retro nature and sounds, so I kept that in.
Thursday 18th December 2014
Lucio Libertini
NAME
Portable II
MANUFACTURER
Compaq
TYPE
Professional Computer
ORIGIN
U.S.A.
YEAR
1986
BUILT IN LANGUAGE
None
KEYBOARD
Full stroke 84-key with numeric keypad and 10 function keys
CPU
80286
SPEED
6 ou 8 MHz
CO-PROCESSOR
Socket for 80287 math coprocessor
RAM
640 KB on board, up to 2.1 MB
VRAM
Unknown
ROM
16 KB (BIOS)
TEXT MODES
40 or 80 chars. x 25 lines (IBM CGA or monochrome modes)
GRAPHIC MODES
640 x 200 dots
COLORS
16 (Grey shades on built-in monitor)
SOUND
Built-in loudspeaker
SIZE / WEIGHT
17.7 (W) x 13.9 (D) x 7.5 (H) in. / 26 lbs
I/O PORTS
Serial, Parallel, external CGA monitor, Composite video
BUILT IN MEDIA
1/2 5.25'' 360 KB floppy disc drives, or 1 x FDD + 10 MB Hard disk
