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I'm new to assembly and I'm currently reading a guide that would frequently express things like ax:bx, ds:dx, ss:sp.

I'll use one of the above in an example from the book "Mastering Turbo Assembly" Page 85.

Notice that the logical address in ss:sp points to the byte below the last byte in the stack.

What is the meaning of the : notation?

Kind regards.

Seki
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Wobit Nyen
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1 Answers1

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Those are memory addresses expressed in the segment:offset scheme. See e.g. http://thestarman.pcministry.com/asm/debug/Segments.html

Ulrich Schmidt-Goertz
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    At least for `segreg:reg` pairings. In some contexts you'd use `:` simply to denote a pair of registers, e.g. when you use `DIV`/`IDIV` with a 16-bit operand you're dividing the 32-bit register pair `DX:AX` by the value of the operand. – Michael Jul 19 '13 at 15:05