int 0x13 ah = 0x08
- bloodhound23
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int 0x13 ah = 0x08
int the interrupt list, what does it mean when it says "CL = maximum sector number(5-0)" specifically the 5-0 part.
I thought I wasn't thinking, I thought wrong.
CL = maximum sector number (bits 5-0)
high two bits of maximum cylinder number (bits 7-6)
CH = low eight bits of maximum cylinder number
low 6 bits of CL contain maximum sector number
high 2 bits of CL contain higher 2 bits of maximum cylinder number
that is; max cylinder number is actually 10 bit..
8 bits in CH, 2 bits in CL
max sector number is only a 6bit field.
let's say CHS = 257:2:63
CL[0..5] = 63
CL[6,7] = 01b
CH[0..7] = 00000001b
Cylinder is 01 combined with 00000001b -> 0100000001b = 257
high two bits of maximum cylinder number (bits 7-6)
CH = low eight bits of maximum cylinder number
low 6 bits of CL contain maximum sector number
high 2 bits of CL contain higher 2 bits of maximum cylinder number
that is; max cylinder number is actually 10 bit..
8 bits in CH, 2 bits in CL
max sector number is only a 6bit field.
let's say CHS = 257:2:63
CL[0..5] = 63
CL[6,7] = 01b
CH[0..7] = 00000001b
Cylinder is 01 combined with 00000001b -> 0100000001b = 257
- bloodhound23
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- Joined: Wed Jan 23, 2008 7:13 pm
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- bloodhound23
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- Posts: 115
- Joined: Wed Jan 23, 2008 7:13 pm
- Contact: