IBM PCjr Model: 4860 Announced: November 1983 Available: March 1984 Canceled: March 1985 How Many: 270,000 Price: $669 for 64K (no floppy) $1,269 for 128K and floppy (monitor not included) CPU: Intel 8088 @ 4.77 MHz RAM: 64K, 512K max Display: Composite video, 80 X 25 text 640 X 200 (max) graphics 16 colors maximum Storage: internal floppy drive 5-1/4 inch, 360K storage Ports: 2 cartridge, 2 joystick, audio RGB and composite video serial, cassette OS: PC-DOS 2.10 in ROM

Following the success of the IBM PC business computer three years earlier, IBM attempted to capture the home market as well, with the IBM PCjr.

The PCjr was based on the same technology as the PC, and was compatible enough to run most of the software applications written for the PC.

Everyone had predicted it to be a huge success, until they actually used one. Hardware incompatibility issues and its relatively high price doomed it to failure.

The wireless keyboard was terrible, with its uncomfortable keys and troublesome cordless (infared) connection. The now infamous PCjr keyboard was quickly replaced by IBM - the original "chiclet" style had tall, hard plastic (not rubber) keys which made touch-typing virtually impossible.

Additionally, cost-saving techniques used in the design limited the expansion, memory and speed of the system. For instance, with no DMA (direct memory access) capability, the keyboard is disabled when accessing the floppy drive. Even worse, the serial port will drop data when the floppy drive is in use - don't try to download data straight to the floppy, or you will lose it.



The expansion and interface ports on the back of the PCjr are all non-standard - an attempt to either simplify, or control access - I don't know which, but no one liked it.


Certain options can be installed as a "sidecar" - an additional module that attaches to the right side of the PCjr. These include a parallel port ($99) and additional memory.

Related Links PCjr from IBM.COM PCjr Reborn! PCjr from CED timeline PCjr review from Classic Computer Magazine Archive IBM PCjr from BrainyEncyclopedia Mike's PCjr Page Ibm Pcjr from Wikiverse PCjr from explanationGuide 25 years of Junior

Partial History of the IBM Computers 1967: IBM builds the worlds first floppy disk. 1967: IBM introduces the worlds first 8" floppy disk. 1973: IBM introduces the IBM 3340 hard disk unit, known as the Winchester. 1975: September - IBM's Entry Level Systems unit unveils "Project Mercury", the IBM 5100 Portable Computer. 1981: September - IBM releases the IBM 5150 PC Personal Computer. 1982: April - Eight months after the introduction of the IBM PC, 50,000 units have been sold. 1982: May - Microsoft releases MS-DOS 1.1 to IBM, for the IBM PC. 1982: June - The first IBM PC clone, the MPC, is released by Columbia Data Products. 1982: August - After one year of production, IBM ships the 200,000th IBM PC. 1982: November - Compaq Computer introduces the Compaq Portable PC, the first 100% IBM compatible. It cost Compaq US$1 million to create an IBM-compatible ROM BIOS that did not violate IBM's copyright. 1982: At the West Coast Computer Faire, Davong Systems introduces its 5MB Winchester Disk Drive for the IBM PC, for US$2000. 1983: March - IBM announces the IBM PC XT, with a 10 MB hard drive, 128KB RAM and a 360KB floppy drive. It costs US$5000. 1983: November - IBM announces the IBM PCjr. It is US$700 for the bare configuration. 1984: February - IBM introduces the IBM Portable PC. 1984: March - IBM ships the IBM PCjr. It uses the 8088 CPU, 64KB RAM, and one 5.25-inch disk drive, but no monitor. It costs US$1300. 1984: August - IBM announces the PC AT, for US$4000-6700. 1985: April - IBM abandons production of the IBM PCjr. 1986: April - IBM announces the IBM PC Convertible, 80C88-based, 256K RAM, and two 720K floppy disks, for US$2000. 1986: April - IBM discontinues the IBM Portable PC. 1986: September - IBM announces the IBM PC-XT Model 286, with 640KB RAM, 1.2MB floppy drive, 20MB hard drive,serial/parallel ports, and keyboard for US$4000. 1987: IBM discontinues the IBM PC (model 5150) line. Source: Chronology of Events in the History of Microcomputers

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