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Largest Hard Drive that can be used on a 80286 motherboard

barney

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Does anybody out there know the largest size hard drive that will be recognized on a typical early 90's 286 motherboard. I am thinking about buying a 2.5GB drive but not sure if it would work. Would a motherboard BIOS from back then recognize it?

Barney
 

Chuck(G)

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You can install a drive overlay and get around any motherboard settings. In reality, the hardware for 16-bit IDE hasn't changed much; it's all in the software (BIOS).
 

per

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To read about the limitations of the BIOS Int 13h interface, consult this webpage: http://web.inter.nl.net/hcc/J.Steunebrink/bioslim.htm

An overlay is a terminate-and-stay-resident program that replaces the original Int 13h interface. This is possible as the vector to the software routine is located in RAM and can thus be changed.

In addition, the OS has limitations as well. DOS 3.x is capable of supporting partitions of up to 32MB. With DOS 4.x and more recent, 2GB partitions are supported. As DOS don't support eINT 13h, DOS can only see and use about 8GB of space on any disk greater than this limit.
 

barney

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I will be using the latest version of DOS (6.22). Question is, where do I obtain a copy of a Drive Overlay program. Also, If I didn't use this drive overlay software, what size hard drive can be recognized by a typical 286 motherboard from the early 90's?
 

Chuck(G)

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That's not an easy question to answer without more information 386 and above had largely replaced 286 boards by 1990, so it mostly depends on your BIOS. Is the IDE adapter part of the motherboard or are you using an ISA adapter for IDE support? Does it have a BIOS on it?
 

barney

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You raise a good point. I will be using an ISA IDE/Floppy controller by Acculogic. I guess my hard drive limitations will be determined by the controller and not the motherboard?

That's not an easy question to answer without more information 386 and above had largely replaced 286 boards by 1990, so it mostly depends on your BIOS. Is the IDE adapter part of the motherboard or are you using an ISA adapter for IDE support? Does it have a BIOS on it?
 

Agent Orange

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I will be using the latest version of DOS (6.22). Question is, where do I obtain a copy of a Drive Overlay program. Also, If I didn't use this drive overlay software, what size hard drive can be recognized by a typical 286 motherboard from the early 90's?

Ontrack Disk Manager DOS Version 9.57 will work on a 286.
 
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