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Create IBM PC (5150) product page with Infobox computer, full architecture and BIOS/motherboard revision details, sourced from IBM Technical Reference and minuszerodegrees.net.
 
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{{Infobox computer
{{Infobox computer
| name          = IBM Personal Computer
| name          = IBM Personal Computer
| logo          = [[File:IBM PC 5150 badge.svg|150px]]
| image        = [[File:IBM 5150 PC.jpg|260px]]
| image        = [[File:IBM 5150 PC.jpg|260px]]
| caption      = IBM 5150 Personal Computer with 5151 monochrome display and Model F keyboard
| caption      = IBM 5150 Personal Computer with 5151 monochrome display and Model F keyboard
| logo          = [[File:IBM logo.svg|110px]]
| developer    = IBM Entry Systems Division, Boca Raton
| developer    = IBM Entry Systems Division, Boca Raton (Don Estridge)
| manufacturer  = IBM
| manufacturer  = IBM
| type          = Desktop personal computer
| type          = Desktop personal computer
| release date  = August 12, 1981
| release date  = August 12, 1981
| discontinued  = April 2, 1987
| discontinued  = April 2, 1987
| price        = US$1,565 (base, 16 KB, no FDD); typical system ~US$3,000
| price        = US$1,565 (base, 16 KB, no FDD); typical home/school system around US$3,000
| units_sold    = ~3 million (1981-87 line)
| cpu          = Intel 8088 @ 4.77 MHz<br/>Optional Intel 8087 FPU
| cpu          = Intel 8088 @ 4.77 MHz<br/>Optional Intel 8087 FPU
| memory        = Early board: 16-64 KB on-board (4116 DRAM)<br/>Later board: 64-256 KB on-board (4164 DRAM)<br/>Expandable to 640 KB via ISA RAM cards
| memory        = Early board: 16-64 KB on-board<br/>Later board: 64-256 KB on-board<br/>Expandable to 640 KB via ISA RAM cards
| storage      = Cassette tape (built-in port); one or two 5.25" floppy drives (single-sided 160 KB, then double-sided 320/360 KB)
| storage      = Cassette port; one or two 5.25" floppy drives ([[Tandon TM100-1|TM100-1]] single-sided 160 KB; [[Tandon TM100-2|TM100-2]] double-sided 320/360 KB)
| display      = MDA + IBM 5151 monochrome display (80×25 text), or CGA + IBM 5153 colour display (640×200 mono, 320×200 4-colour)
| display      = [[IBM Monochrome Display Adapter|MDA]] + [[IBM 5151]] monochrome display, or [[IBM Color Graphics Adapter|CGA]] + [[IBM 5153]] colour display (separate adapter card)
| sound        = Internal PC speaker, driven by Intel 8253-5 PIT channel 2
| sound        = Internal PC speaker, driven by Intel 8253-5 timer channel 2
| dimensions    = 19.6" W × 16" D × 5.5" H (498 × 406 × 140 mm)
| dimensions    = 20" W × 16" D × 5.5" H
| weight        = ~21 lb (9.5 kg) base unit only
| weight        = 21 lb (no FDD); 25 lb (one FDD); 28 lb (two FDDs)
| os            = IBM PC DOS 1.0 (1981) through PC DOS 3.3 (1987); CP/M-86; UCSD p-System; Cassette BASIC in ROM
| os            = IBM PC DOS 1.0 through PC DOS 3.3; CP/M-86; UCSD p-System; [[IBM Cassette BASIC]] in ROM
| predecessor  = [[IBM 5100|IBM 5100]] (in spirit); [[IBM Datamaster (5322)|IBM Datamaster]] (immediate ancestor)
| successor    = [[IBM PC XT (5160)]]
| successor    = [[IBM PC XT (5160)]]
| codename      = Project Chess / Acorn
| codename      = Acorn (development project name)
| model        = 5150
| model        = 5150
}}
}}


The '''IBM Personal Computer''' (model '''5150''') is the original IBM PC, announced on August 12, 1981 and shipped from September 1981 through April 2, 1987. It was developed in roughly one year by a twelve-person team in Boca Raton, Florida under Don Estridge and William C. Lowe, using off-the-shelf parts to bring an IBM-branded microcomputer to market quickly. The architecture it established — Intel 8088 CPU, 8-bit ISA expansion bus, MS-DOS, an open BIOS interface, and Microsoft Disk BASIC in ROM — became the de-facto standard for personal computers for the following two decades.
The '''IBM Personal Computer''' (model '''5150''') is the original IBM PC, announced on August 12, 1981 and shipped from September 1981 through April 2, 1987. It was developed in roughly one year by a team in Boca Raton, Florida under Don Estridge and William C. Lowe, using off-the-shelf parts to bring an IBM-branded microcomputer to market quickly. The architecture it established — Intel 8088 CPU, 8-bit ISA expansion bus, MS-DOS, an open BIOS interface, and Microsoft Disk BASIC in ROM — became the standard for personal computers for the following two decades.


== Architecture and Processor ==
== Architecture and Processor ==
The 5150 uses an '''Intel 8088''' running at '''4.77 MHz''', a 16-bit CPU with an 8-bit external data bus chosen to reduce board cost. A second socket on the motherboard accepts an '''Intel 8087''' floating-point coprocessor, sold separately.
The 5150 uses an '''Intel 8088''' running at '''4.77 MHz''', a 16-bit CPU with an 8-bit external data bus. A second socket on the motherboard accepts an '''Intel 8087''' floating-point coprocessor, sold separately.


The CPU is supported by IBM's chosen 8088 'family' chipset:
The CPU is supported by the IBM 8088-family chipset:
* '''Intel 8259A''' — programmable interrupt controller (8 IRQ lines).
* '''Intel 8259A''' — programmable interrupt controller.
* '''Intel 8237A-5''' — DMA controller (4 channels).
* '''Intel 8237A-5''' — DMA controller, also responsible for DRAM refresh.
* '''Intel 8253-5''' — programmable interval timer (3 channels: system tick, DRAM refresh, speaker).
* '''Intel 8253-5''' — programmable interval timer (system tick, refresh trigger, speaker).
* '''Intel 8255A-5''' — programmable peripheral interface (keyboard input, DIP-switch readback, speaker enable).
* '''Intel 8255A-5''' — programmable peripheral interface (keyboard input, DIP-switch readback, speaker enable).
* '''Motorola MC6845''' — CRT controller (on the [[IBM MDA|MDA]] and [[IBM CGA|CGA]] display adapters, not on the motherboard).
* '''Motorola MC6845''' — CRT controller, on the [[IBM Monochrome Display Adapter|MDA]] and [[IBM Color Graphics Adapter|CGA]] display adapters, not on the motherboard.


== Memory and ROM ==
== Memory and ROM ==
Two motherboard revisions exist, distinguished by the amount of on-board RAM they accept.
Two motherboard revisions exist, distinguished by the amount of on-board RAM they accept and clearly marked in the silkscreen near the keyboard port.


<templatestyles src="Template:StyledTable/styles.css" />
<templatestyles src="Template:StyledTable/styles.css" />
{| class="wikitable styled-table" style="width:100%; text-align:center;"
{| class="wikitable styled-table" style="width:70%; text-align:center;"
|+'''IBM 5150 Motherboard Revisions'''
|+'''IBM 5150 motherboard revisions'''
! Revision !! On-board RAM !! RAM type !! Banks !! Years sold
! Silkscreen marking !! On-board RAM !! RAM chip type !! Banks
|-
|-
| 16KB-64KB (early) || 16 KB &ndash; 64 KB || 4116 (16 Kbit, 16-pin) || 4 × 16 KB || August 1981 &ndash; ~early 1983
| 16KB-64KB (early) || 16 KB &ndash; 64 KB || 4116 (16 Kbit, requires &minus;5 V) || 4 × 16 KB
|-
|-
| 64KB-256KB (later) || 64 KB &ndash; 256 KB || 4164 (64 Kbit, 16-pin) || 4 × 64 KB || ~early 1983 &ndash; April 1987
| 64KB-256KB (later) || 64 KB &ndash; 256 KB || 4164 (64 Kbit) || 4 × 64 KB
|}
|}


The motherboard carries 40 KB of ROM in five sockets:
The motherboard carries ROM in five sockets:
* '''U33''' &mdash; 8 KB BIOS ROM.
* '''U33''' &mdash; BIOS ROM.
* '''U29, U30, U31, U32''' &mdash; 32 KB of [[IBM Cassette BASIC|Cassette BASIC]] (Microsoft BASIC C1.0/C1.1).
* '''U29, U30, U31, U32''' &mdash; [[IBM Cassette BASIC]] (Microsoft BASIC).


There are four BIOS revisions, all dated rather than numbered (date format MM/DD/YY):
There are four documented BIOS revisions, all dated rather than numbered (date format MM/DD/YY):


{| class="wikitable styled-table" style="width:100%; text-align:center;"
{| class="wikitable styled-table" style="width:70%; text-align:center;"
|+'''IBM 5150 BIOS Revisions'''
|+'''IBM 5150 BIOS revisions'''
! Date !! IBM part number !! Compatible board !! Notes
! Date !! IBM part number !! Compatible board !! Notes
|-
|-
Line 64: Line 62:
| 10/19/81 || 5700671 || 16KB-64KB only || Same two limitations as 04/24/81
| 10/19/81 || 5700671 || 16KB-64KB only || Same two limitations as 04/24/81
|-
|-
| 08/16/82 || 5000024 || (rare/unreleased) || Has a bug where EGA / 5150-compatible VGA fail if SW1 video bits are ON-ON
| 08/16/82 || 5000024 || (rare/possibly unreleased) || Has a bug where EGA / 5150-compatible VGA fail if SW1 video bits are set ON-ON
|-
|-
| 10/27/82 || 1501476 || 16KB-64KB or 64KB-256KB || Removes the 1981 BIOS limits; requires all four motherboard banks populated; "C800 ROM" corruption beeps 1L+2S as if video failure
| 10/27/82 || 1501476 || 16KB-64KB or 64KB-256KB || Removes the 1981 BIOS limits; bug: a corrupted HDD expansion ROM at C8000 beeps "1 long + 2 short" instead of displaying "C800 ROM"
|}
|}


System configuration is set by '''two banks of DIP switches''' (SW1 and SW2) on the motherboard — there is no battery-backed CMOS on the 5150.
System configuration is set by '''two banks of DIP switches''' (SW1 and SW2) on the motherboard. The 5150 has no battery-backed CMOS &mdash; the DIP switches are read at every power-up.


== Storage and Expansion ==
== Storage and Expansion ==
* '''Cassette port''' (DIN-5, rear panel) &mdash; for tape data, paired with the Cassette BASIC ROM. Essentially unused once floppy drives became standard.
* '''Cassette port''' (5-pin DIN, rear panel) for tape data, paired with the [[IBM Cassette BASIC]] ROM.
* '''Floppy disk drive''' &mdash; one or two half-height 5.25" drives, originally [[Tandon TM100-1|Tandon TM100-1]] single-sided (160 KB), later [[Tandon TM100-2|Tandon TM100-2]] / TM100-2A or Micropolis 1015-5 double-sided (320 KB at PC DOS 1.1, 360 KB at PC DOS 2.0+). The drives connect to an [[IBM FDD Adapter|IBM FDD Adapter]] ISA card &mdash; the motherboard has no on-board floppy controller.
* '''Floppy disk drive''' — one or two half-height 5.25" drives: [[Tandon TM100-1]] single-sided (160 KB at PC DOS 1.0; 180 KB at PC DOS 2.0+) on the earliest 5150s, then [[Tandon TM100-2|Tandon TM100-2 / TM100-2A]] or Micropolis 1015-5 double-sided (320 KB at PC DOS 1.1; 360 KB at PC DOS 2.0+). Drives connect to an [[IBM FDD Adapter|IBM FDD Adapter]] ISA card; the motherboard has no on-board floppy controller.
* '''No internal hard drive support''' from the original PSU (63.5 W). The later '''Type 2''' (130 W) PSU made it possible to fit a 10 MB or 20 MB MFM hard drive on an [[IBM Fixed Disk Adapter|IBM Fixed Disk Adapter]].
* '''No internal hard drive support''' from the original 63.5 W Type 1 PSU. The later 130 W Type 2 PSU made it possible to fit an MFM hard drive on an [[IBM Fixed Disk Adapter|IBM Fixed Disk Adapter]].
* '''5 × 8-bit ISA slots''', spaced 1" apart (the 5150's slot spacing is wider than the later 5160 XT). Typical slot allocation: video card, FDD adapter, RAM expansion, serial card, modem or printer card.
* '''5 × 8-bit ISA slots.'''


== Display ==
== Display ==
The 5150 has no on-board video. All video is provided by an ISA adapter card driving a separate monitor:
The 5150 has no on-board video. All video is provided by an ISA adapter card driving a separate monitor:
* '''[[IBM Monochrome Display Adapter|IBM Monochrome Display Adapter (MDA)]]''' &mdash; 80×25 text only, monochrome (paired with the [[IBM 5151]] green-phosphor monitor).
* '''[[IBM Monochrome Display Adapter|IBM Monochrome Display Adapter (MDA)]]''' — 80×25 text only, monochrome; paired with the [[IBM 5151]] green-phosphor monitor.
* '''[[IBM Color Graphics Adapter|IBM Color Graphics Adapter (CGA)]]''' &mdash; 80×25 text, 640×200 monochrome graphics, 320×200 in 4 colours (paired with the [[IBM 5153]] RGB monitor or any composite TV).
* '''[[IBM Color Graphics Adapter|IBM Color Graphics Adapter (CGA)]]''' — text and graphics modes; paired with the [[IBM 5153]] colour monitor or any composite TV.
* Many 5150s shipped with both an MDA and CGA fitted, with the user toggling between monitors.


== Keyboard ==
== Keyboard ==
The 5150 ships with the '''[[IBM Model F (83-key)|IBM Model F (83-key)]]''' keyboard &mdash; the original capacitive buckling-spring keyboard. It connects to the rear of the case via a 5-pin DIN connector and a curly coiled cord. The Model F preceded the more familiar Model M and uses an 83-key XT-style layout: function keys F1-F10 on the left, no separate cursor cluster (the keypad doubles as cursor keys), and no Windows or context keys. Unlike later AT-class machines, the '''5150 has no keyboard controller IC on the motherboard''' &mdash; the keyboard interface is a simple shift-register feed read by the 8255 PPI.
The 5150 ships with the '''[[IBM Model F (83-key)]]''' XT-layout keyboard — the original capacitive buckling-spring keyboard. It connects to the rear of the case via a 5-pin DIN connector. Unlike later AT-class machines, the '''5150 has no keyboard controller IC on the motherboard''' — the keyboard interface is read by the 8255 PPI.


== Power Supply ==
== Power Supply ==
Two PSU revisions exist:
Two PSU revisions exist:
* '''Type 1''' &mdash; 63.5 W, sufficient for the base configuration of motherboard + floppy drive(s).
* '''Type 1''' — 63.5 W, sufficient for the base configuration of motherboard + floppy drive(s).
* '''Type 2''' &mdash; 130 W, introduced to support an internal hard drive. Externally identical.
* '''Type 2''' — 130 W, introduced to support an internal hard drive.


Both produce '''+5 V, +12 V, &minus;5 V, &minus;12 V''' on the motherboard's P8/P9 connectors. The &minus;5 V rail is required by both the [[#Memory and ROM|4116 DRAM]] (early board) and the [[#Storage and Expansion|cassette circuitry]] (chip U1 on the later board); a modern ATX adapter cannot drive this rail and causes specific failure modes (see [[IBM PC (5150) Troubleshooting Guide#No -5 V rail|Troubleshooting]]).
Both produce '''+5 V, +12 V, &minus;5 V, &minus;12 V''' on the motherboard's P8/P9 connectors. The &minus;5 V rail is required by the 4116 DRAM on the early 16KB-64KB board, and by the cassette circuitry on the later 64KB-256KB board.


== General Maintenance ==
== General Maintenance ==
Cleaning procedures, capacitor inspection, PSU voltage checks, and preventive care for the 5150 are documented in [[IBM PC (5150) Maintenance Guide]].
Cleaning procedures, PSU voltage checks, and preventive care are documented in [[IBM PC (5150) Maintenance Guide]].


== Capacitor Replacement Guide ==
== Capacitor Replacement Guide ==
The 5150 uses a mix of through-hole electrolytic capacitors on the PSU and tantalum capacitors on the motherboard and ISA cards. Short-circuit tantalum failure is one of the most common faults on this machine. Procedures and the per-board capacitor list are documented in [[IBM PC (5150) Capacitor Replacement Guide]].
The 5150 uses tantalum capacitors on the motherboard and ISA cards. Short-circuit tantalum failure is one of the most common faults on this machine. Procedures and the verified motherboard capacitor information are at [[IBM PC (5150) Capacitor Replacement Guide]].


== Troubleshooting ==
== Troubleshooting ==
POST beep codes, parity errors, RAM bank 0 failure, keyboard 301 errors, and PSU diagnostics are covered in [[IBM PC (5150) Troubleshooting Guide]].
POST beep codes, parity errors, RAM bank 0 failure, keyboard 301 errors, and PSU diagnostics are at [[IBM PC (5150) Troubleshooting Guide]].
 
== Technical Documentation ==
* The original ''IBM 5150 Technical Reference'' (part 6025005, August 1981) gives the full schematics, BIOS listing, and DIP-switch reference.
* See [[IBM Personal Computer Hardware Reference Library]] for the broader manual set.
* For all four BIOS dumps and per-revision differences, see [https://minuszerodegrees.net/5150/bios/5150_bios_revisions.htm minuszerodegrees.net &mdash; 5150 BIOS Revisions].


== Gallery ==
== Gallery ==
Line 117: Line 109:
* [[IBM PC (5150) Troubleshooting Guide]]
* [[IBM PC (5150) Troubleshooting Guide]]
* [[IBM PC (5150) Capacitor Replacement Guide]]
* [[IBM PC (5150) Capacitor Replacement Guide]]
* [[IBM PC XT (5160)]] &mdash; the immediate successor
* [[IBM PC XT (5160)]] — immediate successor
* [[IBM Personal Computer (5150) - DIP Switch Reference]]
* [[IBM Monochrome Display Adapter]] / [[IBM Color Graphics Adapter]]
* [[IBM Monochrome Display Adapter|MDA]] / [[IBM Color Graphics Adapter|CGA]] adapter pages
* [[IBM Model F (83-key)]]
* [[IBM Model F (83-key)|Model F (83-key) keyboard]]
 
== References ==


== See Also ==
* IBM, ''IBM 5150 Technical Reference'' (part 6025005, August 1981) [https://www.minuszerodegrees.net/manuals/IBM_5150_Technical_Reference_6025005_AUG81.pdf — bitsavers/minuszerodegrees mirror].
* [[List of IBM Personal Computer models]]
* "IBM Personal Computer" — Wikipedia.
* [[:Category:IBM|IBM hardware category]]
* [https://minuszerodegrees.net/5150/bios/5150_bios_revisions.htm 5150 BIOS Revisions], minuszerodegrees.net.
* [https://www.minuszerodegrees.net/5150/motherboard/5150_motherboard_revisions.htm 5150 Motherboard Revisions], minuszerodegrees.net.
* [https://oldcomputers.net/ibm5150.html IBM 5150 Personal Computer], OldComputers.net (dimensions and weight).


{{Navbox-IBMComputers|state=expanded}}
{{Navbox-IBMComputers|state=expanded}}


[[Category:IBM]]
[[Category:IBM]]

Latest revision as of 17:32, 23 May 2026

IBM Personal Computer
IBM 5150 Personal Computer with 5151 monochrome display and Model F keyboard
Specifications
DeveloperIBM Entry Systems Division, Boca Raton
ManufacturerIBM
TypeDesktop personal computer
ReleasedAugust 12, 1981
DiscontinuedApril 2, 1987
Intro priceUS$1,565 (base, 16 KB, no FDD); typical home/school system around US$3,000
CPUIntel 8088 @ 4.77 MHz
Optional Intel 8087 FPU
MemoryEarly board: 16-64 KB on-board
Later board: 64-256 KB on-board
Expandable to 640 KB via ISA RAM cards
StorageCassette port; one or two 5.25" floppy drives (TM100-1 single-sided 160 KB; TM100-2 double-sided 320/360 KB)
DisplayMDA + IBM 5151 monochrome display, or CGA + IBM 5153 colour display (separate adapter card)
SoundInternal PC speaker, driven by Intel 8253-5 timer channel 2
Dimensions20" W × 16" D × 5.5" H
Weight21 lb (no FDD); 25 lb (one FDD); 28 lb (two FDDs)
OS / FirmwareIBM PC DOS 1.0 through PC DOS 3.3; CP/M-86; UCSD p-System; IBM Cassette BASIC in ROM
SuccessorIBM PC XT (5160)
CodenameAcorn (development project name)
Model no.5150

The IBM Personal Computer (model 5150) is the original IBM PC, announced on August 12, 1981 and shipped from September 1981 through April 2, 1987. It was developed in roughly one year by a team in Boca Raton, Florida under Don Estridge and William C. Lowe, using off-the-shelf parts to bring an IBM-branded microcomputer to market quickly. The architecture it established — Intel 8088 CPU, 8-bit ISA expansion bus, MS-DOS, an open BIOS interface, and Microsoft Disk BASIC in ROM — became the standard for personal computers for the following two decades.

Architecture and Processor

[edit | edit source]

The 5150 uses an Intel 8088 running at 4.77 MHz, a 16-bit CPU with an 8-bit external data bus. A second socket on the motherboard accepts an Intel 8087 floating-point coprocessor, sold separately.

The CPU is supported by the IBM 8088-family chipset:

  • Intel 8259A — programmable interrupt controller.
  • Intel 8237A-5 — DMA controller, also responsible for DRAM refresh.
  • Intel 8253-5 — programmable interval timer (system tick, refresh trigger, speaker).
  • Intel 8255A-5 — programmable peripheral interface (keyboard input, DIP-switch readback, speaker enable).
  • Motorola MC6845 — CRT controller, on the MDA and CGA display adapters, not on the motherboard.

Memory and ROM

[edit | edit source]

Two motherboard revisions exist, distinguished by the amount of on-board RAM they accept and clearly marked in the silkscreen near the keyboard port.

IBM 5150 motherboard revisions
Silkscreen marking On-board RAM RAM chip type Banks
16KB-64KB (early) 16 KB – 64 KB 4116 (16 Kbit, requires −5 V) 4 × 16 KB
64KB-256KB (later) 64 KB – 256 KB 4164 (64 Kbit) 4 × 64 KB

The motherboard carries ROM in five sockets:

There are four documented BIOS revisions, all dated rather than numbered (date format MM/DD/YY):

IBM 5150 BIOS revisions
Date IBM part number Compatible board Notes
04/24/81 5700051 16KB-64KB only Recognises only 544 KB total RAM; ignores BIOS expansion ROMs (no EGA/VGA, no HDD)
10/19/81 5700671 16KB-64KB only Same two limitations as 04/24/81
08/16/82 5000024 (rare/possibly unreleased) Has a bug where EGA / 5150-compatible VGA fail if SW1 video bits are set ON-ON
10/27/82 1501476 16KB-64KB or 64KB-256KB Removes the 1981 BIOS limits; bug: a corrupted HDD expansion ROM at C8000 beeps "1 long + 2 short" instead of displaying "C800 ROM"

System configuration is set by two banks of DIP switches (SW1 and SW2) on the motherboard. The 5150 has no battery-backed CMOS — the DIP switches are read at every power-up.

Storage and Expansion

[edit | edit source]
  • Cassette port (5-pin DIN, rear panel) for tape data, paired with the IBM Cassette BASIC ROM.
  • Floppy disk drive — one or two half-height 5.25" drives: Tandon TM100-1 single-sided (160 KB at PC DOS 1.0; 180 KB at PC DOS 2.0+) on the earliest 5150s, then Tandon TM100-2 / TM100-2A or Micropolis 1015-5 double-sided (320 KB at PC DOS 1.1; 360 KB at PC DOS 2.0+). Drives connect to an IBM FDD Adapter ISA card; the motherboard has no on-board floppy controller.
  • No internal hard drive support from the original 63.5 W Type 1 PSU. The later 130 W Type 2 PSU made it possible to fit an MFM hard drive on an IBM Fixed Disk Adapter.
  • 5 × 8-bit ISA slots.

Display

[edit | edit source]

The 5150 has no on-board video. All video is provided by an ISA adapter card driving a separate monitor:

Keyboard

[edit | edit source]

The 5150 ships with the IBM Model F (83-key) XT-layout keyboard — the original capacitive buckling-spring keyboard. It connects to the rear of the case via a 5-pin DIN connector. Unlike later AT-class machines, the 5150 has no keyboard controller IC on the motherboard — the keyboard interface is read by the 8255 PPI.

Power Supply

[edit | edit source]

Two PSU revisions exist:

  • Type 1 — 63.5 W, sufficient for the base configuration of motherboard + floppy drive(s).
  • Type 2 — 130 W, introduced to support an internal hard drive.

Both produce +5 V, +12 V, −5 V, −12 V on the motherboard's P8/P9 connectors. The −5 V rail is required by the 4116 DRAM on the early 16KB-64KB board, and by the cassette circuitry on the later 64KB-256KB board.

General Maintenance

[edit | edit source]

Cleaning procedures, PSU voltage checks, and preventive care are documented in IBM PC (5150) Maintenance Guide.

Capacitor Replacement Guide

[edit | edit source]

The 5150 uses tantalum capacitors on the motherboard and ISA cards. Short-circuit tantalum failure is one of the most common faults on this machine. Procedures and the verified motherboard capacitor information are at IBM PC (5150) Capacitor Replacement Guide.

Troubleshooting

[edit | edit source]

POST beep codes, parity errors, RAM bank 0 failure, keyboard 301 errors, and PSU diagnostics are at IBM PC (5150) Troubleshooting Guide.

[edit | edit source]
  • IBM 5150 with 5151 monochrome display and Model F keyboard
    IBM 5150 with 5151 monochrome display and Model F keyboard
  • IBM 5150 front view, 5.25" twin-floppy configuration
    IBM 5150 front view, 5.25" twin-floppy configuration
[edit | edit source]

References

[edit | edit source]


Retrieved from "https://wiki.retrotechcollection.com/index.php?title=IBM_PC_(5150)&oldid=11037"