IBM 51xx PC Family Computers

This website (minuszerodegrees.net) is intended to be a reference for computer-savvy people who are already familiar with the IBM 51xx PC family of vintage computers.
This website contains information that ranges from basic to very technical.

This website is not intended to be viewed via a mobile phone.

For queries or assistance, I suggest that you seek that at the Vintage Computer Forums.

Manuals   IBM 4860/5140/5150/5155/5160/5162/5170 IBM Options and Adapters IBM Hardware Maintenance Service IBM Hardware Maintenance Reference IBM DOS IBM - Some documentation errors   Third Party

4860 =  PCjr 5140 =  PC Convertible 5144 =  PC Convertible Monochrome Display 5145 =  PC Convertible Color Display 5150 =  PC 5151 =  Monochrome Display 5152 =  Graphics Printer 5153 =  Color Display                      ( display for CGA ) 5154 =  Enhanced Color Display      ( display for EGA or CGA ) 5155 =  Portable PC                        ( actually, a portable XT ) 5160 =  XT 5161 =  Expansion Unit 5162 =  XT Model 286         ( XT/286 ) ( an AT class system, not XT ) 5170 =  AT 5175 =  Professional Graphics Display      ( display for PGC ) 5181 =  PC Compact Printer                     ( intended for the IBM PCjr ) 5182 =  PC Color Printer

IBM 4860 Documentation

IBM 5126 Documentation

IBM 5140 Documentation

IBM 5144 / 5145 Documentation

IBM 5150  (IBM PC)
Basics	Power Supply
Documentation	Power Measurements
Motherboard Switch/Jumper Settings	Minimum Diagnostic Configuration
Known Problems/Issues	Test of SW1 and SW2 via BASIC
Motherboard Versions	Keyboard Support
BIOS Revisions	VGA Cards
Some IBM Expansion Cards and Options	Disk Cover Plate
Memory Map of the 640 KB to 1 MB Area	Substituting the U33 BIOS ROM
RAM Information	10/27/82 BIOS - Problem of less than 4 banks of RAM
Floppy Drive Support	Early Versions
Hard Drive Support	External 3.5" diskette drive
Motherboard Diagrams	Adding a Real-Time Clock (RTC)
Cassette BASIC	8087 Math Co-Processor (NPU)
Startup Sequence
POST - Some Errors	IBM 4450 - Tempest version of 5150
POST - Detailed Breakdown

IBM 5151 Documentation Known Problems/Issues Power Up Video Cable CRT's Cathode Heater Flyback Transformer IBM 4451 - Tempest

IBM 5152 Documentation Power Up Ribbon

IBM 5153 Documentation Known Problems/Issues Power Up IBM 4453 - Tempest

IBM 5154 Documentation Known Problems/Issues Power Up Flyback Transformer Colour Mapping

IBM 5155  (IBM Portable PC)
Basics	Power Supply
Documentation	Power Measurements
Motherboard Switch/Jumper Settings	Minimum Diagnostic Configuration
Known Problems/Issues	Test of SW1 via BASIC
Motherboard Versions	Expansion Slot 8
BIOS Revisions	Photo of Inside
Some IBM Expansion Cards and Options	CRT Display Unit
Memory Map of the 640 KB to 1 MB Area	External 3.5" diskette drive
RAM Information	Adding a Real-Time Clock (RTC)
Floppy Drive Support	8087 Math Co-Processor (NPU)
Hard Drive Support
Motherboard Diagrams
Cassette BASIC
Startup Sequence
POST - Some Errors
POST - Detailed Breakdown

IBM 5160  (IBM XT)
Basics	Power Supply
Documentation	Power Measurements
Motherboard Switch/Jumper Settings	Minimum Diagnostic Configuration
Known Problems/Issues	Test of SW1 via BASIC
Motherboard Versions	Keyboard Support
BIOS Revisions	VGA Cards
Some IBM Expansion Cards and Options	Expansion Slot 8
Memory Map of the 640 KB to 1 MB Area	Significant Differences to the IBM 5150
RAM Information	IBM/Xebec HDD Controllers Supplied
Floppy Drive Support	Hard Drive Cabling
Hard Drive Support	External 3.5" diskette drive
Motherboard Diagrams	Adding a Real-Time Clock (RTC)
Cassette BASIC	8087 Math Co-Processor (NPU)
Startup Sequence
POST - Some Errors	IBM 4455 - Tempest version of 5160
POST - Detailed Breakdown

IBM 5161
Basics	Cable
Documentation	Photos
Extender Card - Switch Settings	Reproductions
5160 models not supported	IBM 4458 - Tempest version of 5161

IBM 5162  (IBM XT Model 286)
Basics	Power Supply
Documentation	SETUP Procedure
Motherboard Switch/Jumper Settings	Hard Drive Type Number
Known Problems/Issues	Hard Drive Cabling
Motherboard Versions	80287 Math Co-Processor (NPU)
BIOS Revisions
Some IBM Expansion Cards and Options	POST - Codes
Memory Map of the 640 KB to 1 MB Area
RAM Information	Battery
Floppy Drive Support	Photos
Motherboard Diagrams
Cassette BASIC

IBM 5170  (IBM AT)
Basics	Power Supply
Documentation	SETUP Procedure
Motherboard Switch/Jumper Settings	Hard Drive Type Number
Known Problems/Issues	Hard Drive Cabling
Motherboard Versions	80287 Math Co-Processor (NPU)
BIOS Revisions	Keyboard Support
Some IBM Expansion Cards and Options	POST - Codes
Memory Map of the 640 KB to 1 MB Area	POST - Some On-Screen Errors
RAM Information	Battery
ROM Information	Failures of the CMI 6426 Hard Drive
Floppy Drive Support	Load Resistor
Motherboard Diagrams	Motherboard Sockets U17/U37
Cassette BASIC	IBM 4459 - Tempest version of 5170

IBM 5175 Documentation

IBM 5181 Documentation

IBM 5182 Documentation IBM 4454 - Tempest version of 5182

ROM's
Images of Various ROM's	EPROM Programmers
Images of BIOS ROM's for IBM 5150/5155/5160/5162/5170	EPROM Programming Services
Images of BIOS ROM's for Certain XT Clones
Images of BIOS ROM's for Certain AT Clones
Supersoft/Landmark Diagnostic ROM's for IBM 5150/5155/5160/5170

Miscellaneous
Programs	Commonly Failing Electronic Components (in vintage computers)
RTC Programs	Changes to the ST-506/ST-412 Interface
MDA / CGA / EGA	Micro Solutions Backpack CD-ROM Drive
BIOS Video Modes	Transferring Files From a Modern PC to an Old PC
POST Cards	History of 5150/5155/5160/5170 Motherboard Failure at the VCF
Resources at Other Internet Sites	Floppy Crossover Cable - Wiring
Serial ports	Timeline
DOS	Microsoft Mouse
Some Floppy Maths	Kodak Disk Drive Analyzer
Test Equipment	Laplink

Out of Scope
XT-IDE Card	Hard disk drive clocks
ESD	ICs mounted in frame
Laptops - External Power Supply - Unregulated versus Regulated
15 things about programming	Some electronics information
'CMOS' batteries	Trio CS-2110
BIOS passwords
eBay lingo
Criticality	Ray's playlist
-0°	Ray's thoughts