Headland HT12

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Headland HT12
Headland HT12.jpg
Bus type ISA
Bus width 16-bit
Bus speed 32 MHz
8-bit ISA compatible? Yes
Manufacturer Headland Technologies
Chipset Headland Technologies HT12
Compatible with AT
Connectors AT Keyboard
Requires -5VDC? Unknown
"Unknown" is not recognized as a Boolean (true/false) value.
Requires -12VDC? Unknown
"Unknown" is not recognized as a Boolean (true/false) value.
Config method Jumpers, Software
Form factor Baby AT
Power connector
CPU socket Unknown
"Unknown" is not in the list (Socket 5, Socket 7, Socket 8, Slot 1, Socket 370, PLCC68, Socket 3, PGA132, Slot 2, Slot A, ...) of allowed values for the "Has CPU socket" property.
ISA slots 1 @ 8-bit
6 @ 16-bit
RAM slots 4 @ 30-pin
Maximum RAM 4MB
4,194,304 B
Boot ROM Socket, 28-pin JEDEC, read-only
Manual Vogonsdrivers
Driver Vogonsdrivers

The Headland HT12 was a chipset commonly found in many late 286 motherboards from the early 90s. These boards have either socketed or soldered CPUs, mainly Harris or AMD, which can reach up to 16MHz operation.

The maximum amount of RAM is 4MB, with hardware EMS support. These boards usually came with AMIBIOS and onboard diagnostics written into the ROM.

The manufacturer of some of these board is unknown, so it has been documented here as the Headland HT12.

Additional photos


Hardware EMS

This motherboard works with the HT12 chipset drivers, which provide an EMS interface allowing a chosen amount of memory above 1MB to be accessed as EMS. Thus it is possible for this board to be configured to have conventional, EMS, XMS and Int15 extended memory available, all at the same time.


The chipset does not natively support backfilling unused parts of upper memory with UMBs. However if EMS support is not required, third party drivers can use the hardware EMS facility to make a small amount of memory available in as UMBs.

External links