Jump to content

IBM PC AT 5170 Technical Reference (March 1984)

From RetroTechCollection
Revision as of 20:47, 30 September 2026 by Josh (talk | contribs) (Contents checked against the manual; note comment-form number 1502494 and bundled Update 4; drop unsupported "frequently mis-stated" claims; sense levels; citing pages)
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)

The Technical Reference for the IBM Personal Computer AT (5170), First Edition (March 1984), is IBM's design reference for the AT as first shipped, with the type 1 system board. Minuszerodegrees.net lists its part number as 1502243; the reader's comment form at the back of this scan is numbered 1502494. The hosted PDF has 462 pages. Its BIOS listing is headed "TEST1 11/28/83", the source for the first AT BIOS, released as 01/10/84. The scan includes Technical Reference Update Number 4 (6138321, August 24, 1984), which replaces pages 1-27, 1-28, 1-28.1 and 1-28.2.

Contents

[edit | edit source]

From the manual's contents list (pp. vii to ix):

  • Section 1, System Board (1-1): description (1-3), memory and microprocessor (1-4), system performance (1-7), system timers (1-8), system interrupts (1-10), ROM and RAM subsystems (1-11, 1-12), DMA (1-12), the I/O channel (1-15), other circuits (1-30) including the speaker, the jumper, the display adapter switch and the variable capacitor (1-31) and the keyboard controller, real-time clock and CMOS RAM information (1-45), specifications (1-55), connectors (1-57) and logic diagrams (1-61)
  • Section 2, Coprocessor (2-1): the 80287
  • Section 3, Power Supply (3-1): inputs and outputs (3-3), output protection and the dummy load (3-4), output voltage sequencing (3-4), no-load operation and the power-good signal (3-5), fan-out and connectors (3-6)
  • Section 4, Keyboard (4-1): interface, key code scanning, buffer, power-on reset and basic assurance test (4-4), commands from the system (4-5), scan codes (4-10), clock and data signals (4-14), layout (4-16), connector (4-23)
  • Section 5, System BIOS (5-1): BIOS usage, keyboard encoding and extended codes, and the listing
  • Section 6, Instruction Set (6-1): the 80286 and 80287 instructions
  • Section 7, Characters, Keystrokes and Color (7-1)
  • Section 8, Communications (8-1)
  • Section 9, IBM Personal Computer Compatibility (9-1): hardware considerations, including what the AT does not support (9-5), and application guidelines
  • Glossary, bibliography and index

What this manual does not contain

[edit | edit source]

What it settles

[edit | edit source]
  • The AT power supply's dc load requirements, the 1-second minimum off time, the 100 to 500 ms Power Good delay and the minimum sense levels of +4.5, −3.75, +10.8 and −10.4 V (pp. 3-3 to 3-6). IBM's 1989 service manual gives −4.3 V and −10.2 V for the negative rails.
  • The dummy load and no-load behaviour: with no load the supply may switch off and need a power-on cycle, without damage (pp. 3-4, 3-5).

Pages that cite this document

[edit | edit source]

Download: IBM PC AT 5170 Technical Reference Mar84.pdf

[edit | edit source]