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Which is not zero in the Z80 assembler?
If the result of mathematical operation is zero the bit is set (= 1 = “Z”) other ways the bit is reset (= 0 = “NZ”) “Not zero” Bit 5, YF, copy of the results 5th bit. Bit 4, HF, “Half-carry” from bit 3 to 4. Z80 uses this internally for BCD correction. Bit 3, XF, copy of the results 3rd bit. Bit 2, PF/VF, Parity flag.
Which is the least significant bit in Z80?
Z80 uses this internally for BCD correction. Bit 3, XF, copy of the results 3rd bit. Bit 2, PF/VF, Parity flag. This is copy of the results least significant bit. If the bit is set (= 1 = “PO”) the parity is odd otherways the result is even. (= 0 = “PE”) On some cases this bit might be used to indicate 2-compliment signed overflow.
What is the carry flag in Z80 assembler?
Bit 1, NF, this bit is used by Z80 internally to indicate if last operation was addition or subtraction (needed for BCD correction) Bit 0, CF, Carry flag = Overflow bit. This bit is the most high bit that did not fit to the result.
Which is the most important Register on the Z80?
On the Z80 you havethe following important Registers: AF BC DE HL IX IY (there are others, but we won’t use them in my examples,I don’t even unstand them all) These registerscan be broken up into TWO 8bit (1 byte) registers each. (ie A,F,B,C,D,E,L,..) Of these 8 bit registers, A is the most important.
How to learn multiplatform Z80 assembly programming?
Beginners Series – lets learn the basic Z80 commands by example! Lesson 2 – Memory copy, Symbol definitions, Loops and Conditional Jumps! Platform Specific Series – Lets learn how the hardware of the systems work, so we can get it to do what we want… Covers Amsrad CPC,MSX,ZX Spectrum, TI-83,Enterprise 128/64 and Sam Coupe!
Can a Z80 be thought as a general memory?
The registers can not be thought as a general memory since not all of the Z80 commands can accept all registers as parameters and this may feel a bit hard at start. Each register pair have anyway their own characteristics of what they are good for.