View source for IBM Portable Personal Computer

{{Short description|1984 computer developed by IBM}}
{{Infobox information appliance
| name = IBM Portable PC 5155 model 68
| logo = IBM Portable Personal Computer badge recreation.svg
| logo_upright = 0.5
| image = File:IBM 5155 (1).jpg
| caption = An IBM Portable PC  with two 5.25-inch floppy diskette drives installed
| developer = [[IBM]]
| manufacturer = 
| carrier = 
| family = 
| type = [[Portable computer]]
| generation = 
| releasedate = {{Start date and age|1984|02}}
| lifespan = 
| price = {{USD|4225|1984|round=-1}}
| discontinued = {{End date|1986|04}}<ref name=MUELLER2ND/>
| unitssold = 
| unitsshipped = 
| media = 
| os = [[IBM PC&nbsp;DOS]] Version 2.10 (disk)<!-- operating system -->
| power = 
| cpu = [[Intel 8088]] @ 4.77&nbsp;MHz
| storage = One or two half-height {{frac|5|1|4}}-inch 360&nbsp;KB [[floppy disk]] drives
| memory = 256&nbsp;KB (expandable to 640&nbsp;KB)
| display = [[Color Graphics Adapter|CGA]] card connected to an internal 9-inch monochrome (amber) [[composite monitor]]
| graphics = 
| sound = 
| input = 
| location = <!-- GPS or Wi-Fi based -->
| controllers = 
| output = 
| connectivity = 
| service = <!-- online service/s offered -->
| dimensions = 
| weight = 30 pounds (13.6 kg)
| compatibility = 
| predecessor = [[IBM Personal Computer]]
| successor = [[IBM PC Convertible]]
| related = 
| website = 
| image_size = 250px
}}

The '''IBM Portable Personal Computer 5155 model 68''' is an early [[portable computer]] developed by [[IBM]] after the success of the suitcase-size [[Compaq Portable]]. It was released in February 1984 and was quickly replaced by the [[IBM Convertible]], only roughly two years after its debut.

==Design==
The Portable was basically a [[IBM Personal Computer XT|PC/XT]] motherboard, transplanted into a Compaq-style luggable case. The system featured 256 [[kilobyte]]s of memory (expandable to 640&nbsp;KB), an added [[Color Graphics Adapter|CGA]] card connected to an internal monochrome amber [[composite monitor]], and one or two half-height {{frac|5|1|4}}-inch 360&nbsp;KB [[floppy disk]] drives, manufactured by Qume. Unlike the Compaq Portable, which used a dual-mode monitor and special display card, IBM used a stock CGA card and a 9-inch amber monochrome composite monitor, which had lower resolution. It could, however, display color if connected to an external monitor or television. A separate 83-key keyboard and cable was provided, which uses a front panel mounted phone jack styled connector [[RJ11]]. The cable from the connector then went to the back of the machine, where the original XT keyboard jack was.

Experts {{Who|date=April 2024}} stated that IBM developed the Portable in part because its sales force needed a computer that would compete against the Compaq Portable.<ref name="rosenberg19840228">{{Cite news |title=Doubts Raised About PCjr |last=Rosenberg |first=Ronald |date=1984-02-28 |work=The Boston Globe}}</ref> Because it was based on the [[IBM PC XT]], the IBM product is slightly less [[IBM compatible]] with the original [[IBM PC]] than the Compaq Portable.<ref name="edwards20250616">{{Cite web |last=Edwards |first=Gareth |date=2025-06-16 |title=The Man Who Beat IBM |url=https://every.to/the-crazy-ones/the-man-who-beat-ibm |access-date=2025-08-07 |website=Every}}</ref> If less sophisticated than the Compaq, the IBM had the advantage of a lower price tag. The motherboard had eight expansion slots. The power supply was rated 114 watts and was suitable for operation on either 115 or 230 VAC.<ref name=MUELLER2ND> Scott Mueller, ''Upgrading and Repairing PCs, Second Edition'', Que, 1992 {{ISBN|0-88022-856-3}} pp. 76–81</ref> Hard disks were a very common third-party add-on as IBM did not offer them from the factory.<ref name=MUELLER2ND/>  Typically in a two-drive context, floppy drive A: ran the operating system, and drive B: would be used for application and data diskettes.  

Its selling point as a "portable" was that it combined the monitor into a base unit approximating a medium-sized suitcase that could be simply set on its flat side, the back panel slid away to reveal the power connector, plugged in, the keyboard folded down or detached, and booted up for use, though printers at the time, if needed, still tended to be less "portable". At thirty pounds, it may have been difficult to carry for some, and was often referred to as "luggable".

==Timeline==
{{Timeline of the IBM Personal Computer}}

==References==
{{Reflist}}
;Notes
{{refbegin}}
* IBM (1984). ''Personal Computer Hardware Reference Library: Guide to Operations, Portable Personal Computer''. IBM Part Numbers 6936571 and 1502332.
{{refend}}

== External links ==
* [http://oldcomputers.net/ibm5155.html Obsolete Technology Website: IBM Portable PC 5155 model 68]
* [http://www.minuszerodegrees.net IBM 5155 information at www.minuszerodegrees.net]

{{IBM personal computers}}

[[Category:X86 IBM personal computers|Portable Personal Computer]]
[[Category:Portable computers]]
[[Category:Computer-related introductions in 1984]]