Editing IBM PCjr Technical Reference

The '''IBM PCjr Technical Reference''' (Hardware Reference Library), '''Revised Edition, November 1983''', is the 572-page technical reference for the [[IBM PCjr|IBM PCjr]] (4860).

== What it contains ==

* '''Section 1, Introduction'''.
* '''Section 2, Base System (2-1)''' &mdash; the 8088 and its support devices; the '''8259A interrupt controller''' and the PCjr interrupt assignments (2-13 to 2-17); the ROM subsystem; the '''input/output channel''' (2-21) and the input/output interfaces (2-29) including the 8255 bit map (2-30); the '''video and graphics subsystem''' (2-39 onwards) with its major component definitions, the '''palette''' (2-50), alphanumeric modes (2-54), graphics modes (2-55), the '''video gate array''' (2-63) and the CRT/processor page register (2-79); the keyboard; and the remaining on-board interfaces.

The PCjr's architecture is unlike the 5150's in several ways that matter to a repairer &mdash; the video gate array, the page register and the interrupt assignments in particular &mdash; and this is the only manufacturer document that describes them.

== What it does not contain ==

Not a service manual: no FRU part numbers, no removal procedures, no symptom-to-FRU index and no fault codes. '''No text layer''' in the scanned sections, so searching is unreliable; work from the section and page numbers.

There is no component-level parts list. The power brick, the internal power board and the sidecar power arrangements are described functionally and by connector, not by component.

== What it settles ==

It is the primary source for the PCjr's '''video gate array and palette registers''', its '''cartridge and sidecar interfaces''', and its '''infrared keyboard protocol''' &mdash; the three parts of the machine most often described wrongly from memory.

<pdf> File:IBM PCjr Technical Reference.pdf </pdf>

Download it here: [[:File:IBM PCjr Technical Reference.pdf|IBM PCjr Technical Reference.pdf]]

== Related pages ==

* [[IBM PCjr]] &middot; [[IBM PCjr Maintenance Guide]] &middot; [[IBM PCjr Troubleshooting Guide]] &middot; [[IBM PCjr Capacitor Replacement Guide]]
* [[IBM PCjr BASIC Reference (June 1983)]] &middot; [[IBM Cassette BASIC]]
* [[IBM PC 5150 Technical Reference]]

[[Category:IBM Service Manuals]]
[[Category:Service Manuals]]