Expired doesn't mean useless...

This is a collection of old PS/2 and Micro Channel related patents issued to IBM and other subjects.

Disclaimer: Most, if not all, listed patents are long expired but remain useful for their content of technical information. We (the Ardent Tool team) don't hold any of the listed patents. If you find any other relevant items missing from this list, please Let Us Know.

   Design Patents
Chips and Technologies
Future Domain
Wells, III

Gathered by Tomáš Slavotínek and Louis Ohland. Last update: 03 Mar 2023


Patent No.,
Local PDF
Patent TitleGoogle PatentsSubject, Notes
EP0281999B1Data processing system with pluggable option cardMCA/POS
EP0282637B1Computer system accepting feature cardsMCA adapters
EP0283580B1Computer system with direct memory access channel arbitration
EP0288607B1Computer system having a multi-channel direct memory access arbitration
EP0343768B1Microcomputer system incorporating a cache subsystem using posted writes
EP0343770B1Multi-bus microcomputer system with bus arbitration.
EP0402054B1Command delivery for a computing systemSCB
EP0419004B1Computer system with program loading apparatus and loading methodIBL/IML
EP0426330B1Enclosure for a computerModel 85/95
EP0434267A2Shared hardware interrupt circuit for personal computers.MCA
EP0468625B1Personal computer system with protected storage for interface and system utility programs
EP0472274A1Data processing apparatus having connectors to receive system components386SX/DX socket
EP0478119B1Personal computer system with interrupt controller
EP0508685A2Power-on control system for a computer.
EP0511769A1Method and apparatus for processing interrupts in a computer system
EP0517406A2Computer system for enabling a choice of error detection technologies
EP0518504B1Personal computer with local bus arbitration
EP0567237A1Method and apparatus for increasing usable memory spaceL40SX?
EP0576241A1Computer system and system expansion unit
EP0654742A2Multiple bus interfaceISA/MCA/PCMCIA
EP0656586A1Method and system for switching between a processor upgrade card and a planar processor
EP0661632A1Booting of operating systems in computers
EP0661638A1Method and apparatus for transferring data in a computer
EP0661640A1System and method for accessing data in a computer system including a cache controller and a memory controller connected in parallel
US4118611Buckling spring torsional snap actuatorModel M K/B
US4692691Test system for keyboard interface circuit
US4890219Mode conversion of computer commands
US4901234Computer system having programmable DMA control
US4928237Computer system having mode independent addressing
US5004866Self-contained grounding stripModel 85/95 chassis
US5008829Personal computer power supplyModel 90/95 (and other)
US5021922Portable personal computerModel P70
US5022077Apparatus and method for preventing unauthorized access to BIOS in a personal computer system
US5032952Pivoting power supplyModel 85/95 PSU
US5034917Computer system including a page mode memory with decreased access time and method of operation thereof
US5038142Touch sensing display screen apparatusTouchselect
US5038239Integrated electronic card-frame assembly for a rigid disk drive
US5038320Computer system with automatic initialization of pluggable option cardsPOS
US5040993Interchangeable adapter module for electronic devices
US5043877Architecture converter for slave elementsMCA to EISA adapter bridge
US5043931Wrap test system and methodACPA?
US5045998Method and apparatus for selectively posting write cycles using the 82385 cache controller80386/82385
US5047898Deflectable contact for providing positive surface contact for shielding electromagnetic interference
US5051096Planar board support structureModel 85/95 planar
US5054360Method and apparatus for simultaneous output of digital audio and MIDI synthesized musicACPA?
US5063496Signaling attempted transfer to protected entry point BIOS routine
US5067041Apparatus for reducing electromagnetic radiation from a computer deviceModel 85/95 chassis
US5083931Device grounding spring
US5098175Removable guide apparatus for a rail-mounted device employed in a computerModel 85/95 chassis/DASD
US5100215Enclosure apparatus for retaining devices within a computerModel 85/95 chassis/DASD
US5109490Data transfer using bus address linesMCA: 64-bit streaming
US5109506Microcomputer system including a microprocessor reset circuit
US5112119Support structure for devices in a computer apparatusModel 85/95 chassis/DASD
US5119498Feature board with automatic adjustment to one of two bus widths based on sensing power level at one connection contactMCA adapters
US5125080Logic support chip for at-type computer with improved bus architecture
US5125084Control of pipelined operation in a microcomputer system employing dynamic bus sizing with 80386 processor and 82385 cache controller80386/82385
US5128995Apparatus and method for loading a system reference diskette image from a system partition in a personal computer systemconv. partition, IBL/IML
US5129090System bus preempt for 80386 when running in an 80386/82385 microcomputer system with arbitration80386/82385
US5131082Command delivery for a computing system for transfers between a host and subsystem including providing direct commands or indirect commands indicating the address of the subsystem control blockSCB
US5136465Personal computer with tandem air flow dual fans and baffle directed air coolingModel 90
US5136713Apparatus and method for decreasing the memory requirements for BIOS in a personal computer system2-stage IBL/IML
US5138706Password protected enhancement configuration register for addressing an increased number of adapter circuit boards with target machine emulation capabilitiesPOS extension
US5142447Grounding apparatus for rail-mounted devices employed in a computerModel 85/95 DASD cage
US5146582Data processing system with means to convert burst operations into memory pipelined operations
US5161218Memory controller for using reserved DRAM addresses for EMS
US5162979Personal computer processor card interconnect systemProcessor Complex
US5170471Command delivery for a computing system for transferring data between a host and subsystems with busy and reset indicationSCB
US5170481Microprocessor hold and lock circuitry
US5175822Apparatus and method for assigning addresses to SCSI supported peripheral devicesSpock card edge?
US5175826Delayed cache write enable circuit for a dual bus microcomputer system with an 80386 and 8238580386/82385
US5185864Interrupt handling for a computing system with logical devices and interrupt resetSCB
US5187781Shared hardware interrupt circuit for personal computers
US5187792Method and apparatus for selectively reclaiming a portion of RAM in a personal computer system
US5191544Personal computer enclosure with shieldingModel 90
US5193161Computer system having mode independent addressing
US5193170Methods and apparatus for maintaining cache integrity whenever a CPU write to ROM operation is performed with ROM mapped to RAM
US5193174System for automatically redirecting information to alternate system console in response to the comparison of present and default system configuration in personal computer systemModel 85/95 serial console
US5210875Initial BIOS load for a personal computer systemIBL/IML
US5214695Apparatus and method for loading a system reference diskette image from a system partition in a personal computer systemIBL/IML
US5226134Data processing system including a memory controller for direct or interleave memory accessingcomplex
US5230052Apparatus and method for loading BIOS into a computer system from a remote storage location
US5235602Synchronous/asynchronous i/o channel check and parity check detector
US5237676High speed data transfer system which adjusts data transfer speed in response to indicated transfer speed capability of connected deviceMCA: Streaming
US5237690System for testing adaptor card upon power up and having disablement, enablement, and reconfiguration optionsMCA: SLOTFLAG
US5239631CPU bus allocation control
US5241661DMA access arbitration device in which CPU can arbitrate on behalf of attachment having no arbiter
US5245615Diagnostic system and interface for a personal computer
US5255374Bus interface logic for computer system having dual bus architectureT3+ complex
US5265255Personal computer system with interrupt controller
US5276864Personal computer with alternate system controller error detection
US5280588Multiple input/output devices having shared address space
US5287460Bus interface circuit for dual personal computer architecture peripheral adapter board
US5287519LAN station personal computer system with controlled data access for normal and unauthorized users and methodC2 security
US5289477Personal computer wherein ECC and parity error checking can be selectively chosen for memory elements installed in the system, memory elements enabling selective choice of error checking, and methodECC
US5293493Preemption control for central processor with cache
US5299315Personal computer with programmable threshold FIFO registers for data transfer
US5301282Controlling bus allocation using arbitration holdT3+ complex
US5307482Computer, non-maskable interrupt trace routine override
US5307491Layered SCSI device driver with error handling circuit providing sense data from device directly to the driver on the occurrence of an errorSCSI ABIOS
US5313475ECC function with self-contained high performance partial write or read/modify/write and parity look-ahead interface schemeECC
US5313592Method and system for supporting multiple adapters in a personal computer data processing system
US5313593Personal computer system with bus noise rejection
US5313627Parity error detection and recoveryT3+ complex
US5319770Data processing method and apparatus for verifying adapter description file choices
US5325264Device for removing a direct access storage device from a personal computer
US5325492System for asynchronously delivering self-describing control elements with a pipe interface having distributed, shared memory
US5327531Data processing system including corrupt flash ROM recovery
US5327545Data processing apparatus for selectively posting write cycles using the 82385 cache controller80386/82385
US5329634Computer system with automatic adapter card setupPOS for ISA
US5333274Error detection and recovery in a DMA controllerT3+ DMA
US5341422Trusted personal computer system with identificationC2 security
US5341487Personal computer having memory system with write-through cache and pipelined snoop cycles
US5353202Personal computer with shielding of input/output signalsModel 90 (and other)
US5353417Personal computer with bus interface controller coupled directly with local processor and input/output data buses and for anticipating memory control changes on arbitration for bus access
US5355489BIOS load for a personal computer system having a removable processor cardModel 90/95
US5375084Selectable interface between memory controller and memory SIMMs
US5379304Method and structure for providing error correction code and parity for each byte on SIMM'sECC, EOS
US5379342Method and apparatus for providing enhanced data verification in a computer system
US5379386Micro channel interface controllerMCA
US5379400Method and system for determining memory refresh rate
US5381538DMA controller including a FIFO register and a residual register for data buffering and having different operating modesT3+ DMA
US5381541Computer system having planar board with single interrupt controller and processor card with plural processors and interrupt directorProcessor Complex
US5388156Personal computer system with security features and methodC2 security
Computer system having dynamically programmable linear/fairness priority arbitration scheme
US5396597System for transferring data between processors via dual buffers within system memory with first and second processors accessing system memory directly and indirectly
US5396619System and method for testing and remapping base memory for memory diagnosticsPOST
US5404452Personal computer bus and video adapter for high performance parallel interface
US5410699Apparatus and method for loading BIOS from a diskette in a personal computer systemfloppy IBL/IML
US5420760Microcomputer enclosure with interrupted wedge locking arrangement and shielding linerModel 90 (and other)
US5423045System for distributed power management in portable computersL40SX?
US5430847Method and system for extending system buses to external devices
US5432939Trusted personal computer system with management control over initial program loadingC2 security
US5432946LAN server personal computer with unattended activation capabilityremote pwr-on
US5442629Token ring speed detector
US5446869Configuration and RAM/ROM control of PCI extension card residing on MCA adapter cardMCA/PCI
US5446898Method and apparatus for configuring and installing a loadable ABIOS device support layer in a computer system
US5450559Microcomputer system employing address offset mechanism to increase the supported cache memory capacity80386/82385
US5452429Error correction code on add-on cards for writing portions of data words
US5459839System and method for managing queue read and write pointers
US5459842System for combining data from multiple CPU write requests via buffers and using read-modify-write operation to write the combined data to the memoryECC
US5465357Method and apparatus for an automated dynamic load of an ABIOS device support layer in a computer system
US5469577Providing alternate bus master other publications with multiple cycles of bursting access to local bus in a dual bus system including a processor local bus and a device communications busGearbox
US5471585Personal computer system with input/output controller having serial/parallel ports and a feedback line indicating readiness of the portsI/O controller
US5477242Display adapter for virtual VGA support in XGA native modeXGA
US5481552Method and structure for providing error correction code for 8-byte data words on SIMM cardsECC-P
US5481709Method and apparatus for providing a modular ABIOS device support layer in a computer system
US5481724Peer to peer computer-interrupt handling
US5481754Apparatus and method for bios interface to features in multiple adapter cards in one operation using registers with bits distributed across the adapter cards
US5495611Method and apparatus for dynamic load of an ABIOS device support layer in a computer system
US5499378Small computer system emulator for non-local SCSI devices
US5500934Display and control system for configuring and monitoring a complex systemLANACS
US5504904Personal computer having operating system definition file for configuring computer system
US5504905Apparatus for communicating a change in system configuration in an information handling network
US5509120Method and system for detecting computer viruses during power on self test
US5515474Audio I/O instruction interpretation for audio cardACPA?
US5522064Data processing apparatus for dynamically setting timings in a dynamic memory systemT1+ Mem. Ctrl.
US5524267Digital I/O bus controller circuit with auto-incrementing, auto-decrementing and non-incrementing/decrementing access data ports
US5530887Methods and apparatus for providing automatic hardware device identification in computer systems that include multi-card adapters and/or multi-card planar complexesPOS
US5537607Field programmable general purpose interface adapter for connecting peripheral devices within a computer system
US5539912Computer system having a selectable memory module presence detect information option
US5541941Method and structure for providing automatic parity sensingECC, EOS
US5544346System having a bus interface unit for overriding a normal arbitration scheme after a system resource device has already gained control of a busT3+ complex
US5544334Micro channel bus computer system with IDE hard drive interfaceLacuna
US5548786Dynamic bus sizing of DMA transfersT3+ DMA
US5551009Expandable high performance FIFO design which includes memory cells having respective cell multiplexorsT3+ complex
US5553306Method and apparatus for controlling parallel port drivers in a data processing system
US5555373Inactivity monitor for trusted personal computer systemC2 security
US5557784Power on timer for a personal computer system
US5568611Unauthorized access monitorServer 95
US5574786Securing trusted personal computer system against unauthorized movementModel 56/57, Model 76/77
US5586327Extended initialization for personal data processing systemsIPL
US5598542Method and apparatus for bus arbitration in a multiple bus information handling system using time slot assignment valuesPCI/MCA
US5600793Method and system of bi-directional parallel port data transfer between data processing systems
US5630078Personal computer with processor reset control
US5634137Method and apparatus for updating system configuration based on open/closed state of computer housing cover
US5644729Bidirectional data buffer for a bus-to-bus interface unit in a computer systemT3+ complex
US5651139Protected system partition read/write access on a SCSI controlled DASDIBL/IML partition
US5655106Personal computer with riser connector for expansion bus and alternate master
US5659696Method and apparatus for determining address location and taking one of two actions depending on the type of read/write data transfer requiredT3+ complex
US5671372Data processing system with microprocessor/cache chip set directly coupled to memory bus of narrower data widthC5/C8, T4 consideration?
Real-time clock with extendable memory
US5680288Hot plugging of an adapter cardMCA
US5684960Real-time ring bandwidth utilization calculator by sampling over a selected interval latch's states set by predetermined bit pattern on the transmission mediumTR TAP
US5692190Bios emulation of a hard file image as a diskette
US5726922Assembly for removably connecting data storage devicesModel 95A RAID bay
US5732280Method and apparatus for dynamically assigning programmable option select identifiersPOS
US5742758Password protecting ROM based utilities in an adapter ROM
US5754821Method and system for providing access to a protected partition of a memory device utilizing a passthru commandIBL/IML partition
US5761533Computer system with varied data transfer speeds between system components and memoryT3+ complex
US5765008Personal computer with riser card PCI and micro channel interfacePC 700 riser
US5802363Bios dynamic emulation of multiple diskettes from a single media
US5826075Automated programmable firmware store for a personal computer systemflash update
US5850562Personal computer apparatus and method for monitoring memory locations states for facilitating debugging of post and BIOS code
US5873129Method and apparatus for extending physical system addressable memory
US5878256Method and apparatus for providing updated firmware in a data processing systemflash update
US5898857Method and system for interfacing an upgrade processor to a data processing systemCPU upgrade
US5918007Trusted personal computer system with limited accessibilityC2 security
US5966728Computer system and method for snooping date writes to cacheable memory locations in an expansion memory deviceT3+ complex
US5980275Electronic circuit board interface mounting bracketMCA bracket

Design Patents

Patent No.,
Local PDF
Patent TitleGoogle PatentsSubject, Notes
USD293444Personal computer housingModel 30
USD293909Floor standing computerModel 60/65/80
USD293910Personal computer housingModel 50/70
USD297893Face panel for a computer hard file or similar articleModel 30?
USD298252Diskette drive front panel
USD300428Voice communication module for use with computersSpeech Adapter
USD302152Computer displayIBM 851x
USD304178Disk drive shroud enclosure for an industrial computerGearbox
USD304179Computer displayIBM 3151
USD304323Modular computerGearbox
USD306438Face panel for a computer hard file or similar article
USD307137Cursor control for a computer system"Finger" Mouse
USD307746Control unit for a personal computerIBM 6900
USD308360Information entry keyboard or the likeTerminal Space Saver
USD308855Program function keyboardCADAM
USD308966Diskette drive casingIBM 4869
USD310067Computer display workstationModel 25
USD314195Front panel for a computerModel 95
USD314559Computer display stationPS/1 2011
USD315550Data processorSystem/36 5363
USD315553Portable computerModel P70
USD318657Display for computerIBM 8515
USD318861Data display for computerInfoWindow
USD319219Personal computer or similar article
USD320978Word processor system unit
USD321344Computer displayInfoWindow II
USD321345Computer crt monitorPS/1 2011/2121
USD321684Front panel for optical drive
USD322430Computer coverRS/6000 Deskside
USD322601Disk drive unit for computerPS/1
USD322778Computer housingRS/6000 Desktop
USD322965Computer lower expansion unitPS/1
USD324212Reduced height floppy disc drive bezelModel 90 Bay B?
USD324862Front panel for optical disk driveModel 90 Bay D
USD325378Personal computer enclosureModel 90
USD328067Optical disk drive front panel
USD328596Cursor control for computerThinkPad Mouse
USD330199Computer keyboardPS/1 Keyboard
USD331396Shield for electromagnetic radiation for personal computerModel 90 Bay B
USD332036Tool for removing computer hard drivesModel 90
USD332448Front panel for optical disk driveModel 90 Bay B?
USD332784Display for computers
USD334741Display for computer
USD337106Auxiliary keypad? Keypad
USD339111Computer housingModel 85/95
USD339112Portable computer housingModel L40 SX
USD341280Floor pedestal for a computer
USD341359Back panel for a computerModel 57/77
USD341360KeyboardL40 SX Keypad
USD342722Computer housingRS/6000 Slim
USD343612Computer system unitPS/1 2121
USD345345Enclosure for a computerModel 57/77
USD347420Personal computerPS/55 Z 5510
USD347625Personal computerModel 56/76
USD347834Control panel for a computer77 Ultimedia
USD348049Personal computerPS/55 Z 5530
USD352932Combined computer display and base therefor
USD354740Computer system unitPS/1 2133
USD357468Flat panel computer monitorPS/2 E Display
USD357908Computer monitor
USD360409Computer housing
USD362238Computer housingPC Server 500
USD363469Controller unit with display
USD363475Visual display unit
USD364851Desktop personal computerPC730


Patent No.,
Local PDF
Patent TitleGoogle PatentsSubject, Notes
US5321827Computer system with modular upgrade capability


Patent No.,
Local PDF
Patent TitleGoogle PatentsSubject, Notes
US5111423Programmable interface for computer system peripheral circuit cardMCA interface chip

Chips and Technologies

Patent No.,
Local PDF
Patent TitleGoogle PatentsSubject, Notes
US4991085Personal computer bus interface chip with multi-function address relocation pins


Patent No.,
Local PDF
Patent TitleGoogle PatentsSubject, Notes
US5291585Computer system having system feature extension software containing a self-describing feature table for accessing I/O devices according to machine-independent formatDell's XBIOS vs. ABIOS

Future Domain

Patent No.,
Local PDF
Patent TitleGoogle PatentsSubject, Notes
US5434516Automatic SCSI termination circuit
US5544326Interface and control circuit for regulating data flow in a SCSI initiator with multiple host bus interface selection18C50 (FD MCS-700 / IBM Patriot)
US5732223ASCSI host adapter with shared command and data buffer


Patent No.,
Local PDF
Patent TitleGoogle PatentsSubject, Notes
US5379403Method and interface adapter for interfacing an ISA board to an MCA system by the issuance of an ILLINI-CDCHRDY signal from the interface adapter


Patent No.,
Local PDF
Patent TitleGoogle PatentsSubject, Notes
US5919259Method and apparatus for supplying power to a CPU using an adaptor card
US5938769CPU escalating adapter with multivoltage and multiple frequency selectionPL-MMX v2.0


Patent No.,
Local PDF
Patent TitleGoogle PatentsSubject, Notes
US5077683Expansion slot adapter with embedded data device interfaceProcom PIRA

Wells, III

Patent No.,
Local PDF
Patent TitleGoogle PatentsSubject, Notes
US4971563Modular Backplane Assemblies for ComputersCompuStar 100

Content created and/or collected by:
Louis F. Ohland, Peter H. Wendt, David L. Beem, William R. Walsh, Tatsuo Sunagawa, Tomáš Slavotínek, Jim Shorney, Tim N. Clarke, Kevin Bowling, and many others.

Ardent Tool of Capitalism is maintained by Tomáš Slavotínek.
Last update: 08 May 2024 - Changelog | About | Legal & Contact