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OS Question on Wrap-around. HELLLP!!!
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Mauwakee
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 OS Question on Wrap-around. HELLLP!!!
Hi. In Michael Myers 3rd edition, chapter 12, DOS Memory in a Windows World, page 836; he talks about wrap-around. I have read this several times and it stills seems fuzzy to me. Not a good fuzzy either. Can anyone explain it better for me?
Thanks
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Thanks
Mauwakee
It my name in Shawnee.
That is a American Indian Nation.
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 11-20-02 03:25 PM
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SomeGuy
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Wrap-around is when you try to address memory that a CPU cannot reach with its address bus. The 8088 can't "see" higher than FFFFF because it doesn't have enough wires to represent a 6th digit. So 10FFFF would be interpreted as 0FFFF. This makes the bus "wrap around" to a lower place on the address bus.
It's the same as Y2K. Non-Y2K compliant computers can't go higher than 1999 because they only use two digits. 1999 is 99, so 2000 is seen as 00 which is assumed to be 1900 by the system. It too is doing a kind of "wrap-around".
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A lazy idiot is the hardest worker. He tries to find the easiest path and always fails.
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11-20-02 07:20 PM
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cm2gj
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quote:
Originally posted by SomeGuy
Wrap-around is when you try to address memory that a CPU cannot reach with its address bus. The 8088 can't "see" higher than FFFFF because it doesn't have enough wires to represent a 6th digit. So 10FFFF would be interpreted as 0FFFF. This makes the bus "wrap around" to a lower place on the address bus.
It's the same as Y2K. Non-Y2K compliant computers can't go higher than 1999 because they only use two digits. 1999 is 99, so 2000 is seen as 00 which is assumed to be 1900 by the system. It too is doing a kind of "wrap-around".
nice. 
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11-20-02 09:23 PM
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Mauwakee
Oxygen Please
M
Registered: Apr 2002
Location: Columbus
Country: USA
State:
Certifications: A+,Network+, DSCE, EMT-R,Hazmat Operation, Firefighter2, CPR Inst, ACLS Inst, First Aid Inst, BTLS,
Working on: MCSE MCSDT
Total Posts: 537
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11-21-02 10:52 PM
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