DP / DF pointers in assembly
I'm reviewing some books and notes about assembly language and found two types of pointers, DP (define pointer) and DF (define far pointer), but there is no more information available, just a brief 1 line example on how to declare one but not how to use it. For example:
myByte DB 0
myPointer DP 0
myFarPointer DF 0
and that's all that show my books and google takes me to places that show the same declaration but not how to use them.
Anybody has a small sample code or a resource (url, txt, pdf, anything) that would help me to understand how they work? I already use segments/offsets and a variety of addressing forms, but want something about DP and DF.
Thanks for any help
pointers assembly x86-16 tasm
edited Nov 14 '18 at 21:59
Peter Cordes
128k18190326
asked Nov 14 '18 at 21:41
kanito73kanito73
321
add a comment |
I'm reviewing some books and notes about assembly language and found two types of pointers, DP (define pointer) and DF (define far pointer), but there is no more information available, just a brief 1 line example on how to declare one but not how to use it. For example:
myByte DB 0
myPointer DP 0
myFarPointer DF 0
and that's all that show my books and google takes me to places that show the same declaration but not how to use them.
Anybody has a small sample code or a resource (url, txt, pdf, anything) that would help me to understand how they work? I already use segments/offsets and a variety of addressing forms, but want something about DP and DF.
Thanks for any help
pointers assembly x86-16 tasm
edited Nov 14 '18 at 21:59
Peter Cordes
128k18190326
asked Nov 14 '18 at 21:41
kanito73kanito73
321
Is that a MASM or TASM directive? It doesn't exist in NASM; you just use DW or DD for a word or dword sized block of data.
– Peter Cordes
Nov 14 '18 at 21:47
It is a TASM directive... just I'm curious, don't really need it but never like to keep doubts :)
– kanito73
Nov 14 '18 at 21:55
I'd assume you'd use it to statically initialize a pointer, likemyptr DP symbol_name. Just guessing at the syntax, DF might usemyFP DF segname:symbol_name, or just a bare symbol_name and pick the right segment. Isn't there a TASM manual you could check, since you're using that assembler?
– Peter Cordes
Nov 14 '18 at 22:01
add a comment |
I'm reviewing some books and notes about assembly language and found two types of pointers, DP (define pointer) and DF (define far pointer), but there is no more information available, just a brief 1 line example on how to declare one but not how to use it. For example:
myByte DB 0
myPointer DP 0
myFarPointer DF 0
and that's all that show my books and google takes me to places that show the same declaration but not how to use them.
Anybody has a small sample code or a resource (url, txt, pdf, anything) that would help me to understand how they work? I already use segments/offsets and a variety of addressing forms, but want something about DP and DF.
Thanks for any help
pointers assembly x86-16 tasm
edited Nov 14 '18 at 21:59
Peter Cordes
128k18190326
asked Nov 14 '18 at 21:41
kanito73kanito73
321
I'm reviewing some books and notes about assembly language and found two types of pointers, DP (define pointer) and DF (define far pointer), but there is no more information available, just a brief 1 line example on how to declare one but not how to use it. For example:
myByte DB 0
myPointer DP 0
myFarPointer DF 0
and that's all that show my books and google takes me to places that show the same declaration but not how to use them.
Anybody has a small sample code or a resource (url, txt, pdf, anything) that would help me to understand how they work? I already use segments/offsets and a variety of addressing forms, but want something about DP and DF.
Thanks for any help
pointers assembly x86-16 tasm
pointers assembly x86-16 tasm
edited Nov 14 '18 at 21:59
Peter Cordes
128k18190326
asked Nov 14 '18 at 21:41
kanito73kanito73
321
edited Nov 14 '18 at 21:59
Peter Cordes
128k18190326
asked Nov 14 '18 at 21:41
kanito73kanito73
321
edited Nov 14 '18 at 21:59
Peter Cordes
128k18190326
edited Nov 14 '18 at 21:59
Peter Cordes
128k18190326
edited Nov 14 '18 at 21:59
Peter Cordes
128k18190326
128k18190326
asked Nov 14 '18 at 21:41
kanito73kanito73
321
asked Nov 14 '18 at 21:41
kanito73kanito73
321
asked Nov 14 '18 at 21:41
kanito73kanito73
321
321
Is that a MASM or TASM directive? It doesn't exist in NASM; you just use DW or DD for a word or dword sized block of data.
– Peter Cordes
Nov 14 '18 at 21:47
It is a TASM directive... just I'm curious, don't really need it but never like to keep doubts :)
– kanito73
Nov 14 '18 at 21:55
I'd assume you'd use it to statically initialize a pointer, likemyptr DP symbol_name. Just guessing at the syntax, DF might usemyFP DF segname:symbol_name, or just a bare symbol_name and pick the right segment. Isn't there a TASM manual you could check, since you're using that assembler?
– Peter Cordes
Nov 14 '18 at 22:01
add a comment |
Is that a MASM or TASM directive? It doesn't exist in NASM; you just use DW or DD for a word or dword sized block of data.
– Peter Cordes
Nov 14 '18 at 21:47
It is a TASM directive... just I'm curious, don't really need it but never like to keep doubts :)
– kanito73
Nov 14 '18 at 21:55
I'd assume you'd use it to statically initialize a pointer, likemyptr DP symbol_name. Just guessing at the syntax, DF might usemyFP DF segname:symbol_name, or just a bare symbol_name and pick the right segment. Isn't there a TASM manual you could check, since you're using that assembler?
– Peter Cordes
Nov 14 '18 at 22:01
Is that a MASM or TASM directive? It doesn't exist in NASM; you just use DW or DD for a word or dword sized block of data.
– Peter Cordes
Nov 14 '18 at 21:47
Is that a MASM or TASM directive? It doesn't exist in NASM; you just use DW or DD for a word or dword sized block of data.
– Peter Cordes
Nov 14 '18 at 21:47
It is a TASM directive... just I'm curious, don't really need it but never like to keep doubts :)
– kanito73
Nov 14 '18 at 21:55
It is a TASM directive... just I'm curious, don't really need it but never like to keep doubts :)
– kanito73
Nov 14 '18 at 21:55
I'd assume you'd use it to statically initialize a pointer, like
myptr DP symbol_name. Just guessing at the syntax, DF might use myFP DF segname:symbol_name, or just a bare symbol_name and pick the right segment. Isn't there a TASM manual you could check, since you're using that assembler?– Peter Cordes
Nov 14 '18 at 22:01
I'd assume you'd use it to statically initialize a pointer, like
myptr DP symbol_name. Just guessing at the syntax, DF might use myFP DF segname:symbol_name, or just a bare symbol_name and pick the right segment. Isn't there a TASM manual you could check, since you're using that assembler?– Peter Cordes
Nov 14 '18 at 22:01
add a comment |
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Is that a MASM or TASM directive? It doesn't exist in NASM; you just use DW or DD for a word or dword sized block of data.
– Peter Cordes
Nov 14 '18 at 21:47
It is a TASM directive... just I'm curious, don't really need it but never like to keep doubts :)
– kanito73
Nov 14 '18 at 21:55
I'd assume you'd use it to statically initialize a pointer, like
myptr DP symbol_name. Just guessing at the syntax, DF might usemyFP DF segname:symbol_name, or just a bare symbol_name and pick the right segment. Isn't there a TASM manual you could check, since you're using that assembler?– Peter Cordes
Nov 14 '18 at 22:01