IBM JX Information Page (original) (raw)

IBM JX Information Page

LAST UPDATED - 23rd June 2021 - See update log here

Introduction

The IBM JX was announced in Australia and New Zealand in Newsprint as early as September 1985 and in magazines in November 1985. See below for the original articles.

For images of a Japanese IBM JX variant, click here!

It was a completely integrated computer system that gave you the advantages of the PCjr Graphics and Sound, 100% software compatibility with the jr - including cartridges - while also giving you a good amount of compatibility with PC software with its maximum RAM capacity of 512k.

The JX Technical Reference details the differences between the JX and PCjr (p6-4) -
- PCjr shares RAM and Video RAM, JX has dedicated Video RAM
- The systems have different disk systems
- The JX has a different keyboard layout for Kanji Characters (however the AU/NZ models do not have this)
- They share the sound Sound Chips
- The JX does not come standard with a serial port

It was capable of using 2x 3.5" 720k Drives and 1x Hard Disk Drive with the relevant components. While you could technically connect a 5.25" drive at the same time as well as the hard disk (yes, that's drive A - C being floppy drives and D as the hard disk), you would have to find another way to power and extend the disk drive cable to the controller card. The Hard Disk unit had to be directly above the system unit as it relied on an interconnecting card linking the two units.

IBM claimed that this was the "First one megabit ROM used in a personal computer".

One magazine (Your Computer (Australia) December 1985) claims that IBM deployed this machine in Australia as a test market for this product - aiming it squarely at the education and home market.

According to the IBM JX users guide and this article, there were 3 models -

The JX could apparently be clustered together with a maximum of 64 computers built around a PC XT or AT as a host, however I have been unable to identify how this was done. An article referencing the Bendigo College of Advanced Eduction refers to using Janet / 2 - which apparently was a cluster networking solution made by the University of Waterloo in Canada.

According to the IBM Australia brochure (top) (bottom) better scan coming soon, there were to be 5 models -

1. "Basic" - 64k RAM, No Drives attached to a Cluster Network
2. "Starter" - 128k RAM, 1x 3.5" Drive
3. "Business" - 256k RAM, 2x 3.5" Drives
4. "Power" - 512k RAM, 2x 3.5" Drive and a Clock
5. "Extended" - 512k RAM, 2x 3.5" Drive, 1x 5.25" Drive, RS232 Port & Clock

Wikipedia advises - The JX was released in Japan in Quarter 4 1984 with the target being young business professionals. In 1984, IBM sold 6000 units. In 1985, IBM sold 2000 units. Production of the IBM JX halted in Quarter 2 1985. I cannot confirm this information as dates on ROMs, Disks and Manuals contradict the production halt date. Serial numbers on my units indicate at least 10,000 units sold - see serials below.

System Specifications

Documentation, Ads and Articles

Known IBM JX Software - Released or Planned (over 100 software packages are already available!)

Known IBM JX Hardware with Part Numbers (click here for parts list, 3rd Dec 1986)

External Links worthy of a visit for JX Information

Japanese Wikipedia for IBM JX - https://ja.wikipedia.org/wiki/IBM\_JX
Nerdy Pleasures Blog - IBM JX - http://nerdlypleasures.blogspot.com/2015/03/ibm-jx-pcjr-20.html?m=1
Mike Brutmans PCjr Page - https://www.brutman.com/PCjr/pcjr.html

Any comments or can provide more information? Please email abeckett@mac.com.
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