Editing Zilog Z80 (section)

==== New syntax ====
Because Intel claimed a copyright on their assembly mnemonics,<ref>{{Cite book |title=Intel Component Data Catalog 1978 |date=1978 |publisher=Intel Corporation |location=Santa Clara, CA |pages=11–17 |chapter=8080A/ 8-Bit N-Channel Microprocessor |quote=All mnemonics copyright Intel Corporation 1977}}</ref> a new assembly syntax had to be developed for the Z80. This time a more systematic approach was used:
* All registers and register pairs are explicitly denoted by their full names
* Parentheses are consistently used to indicate "memory contents at" (constant address or variable pointer dereferencing) with the exception the jump instructions <code>JP (HL)</code>, <code>JP (IX)</code>, and <code>JP (IY)</code>. These load the new PC address from the respective register directly, without indirecting through memory.{{efn|Jump (<code>JP</code>) instructions, which load the program counter with a new instruction address, do not themselves access memory. Absolute and relative forms of the jump reflect this by omitting the round brackets from their operands. Register based jump instructions such as "<code>JP (HL)</code>" include round brackets in an apparent deviation from this convention.<ref>{{Cite web |title=Z80 Relocating Macro Assembler User's Guide |url=http://z80cpu.eu/mirrors/oldcomputers.dyndns.org/manuals/z80asm.pdf |url-status=dead |archive-url=https://web.archive.org/web/20110720173724/http://z80cpu.eu/mirrors/oldcomputers.dyndns.org/manuals/z80asm.pdf |archive-date=July 20, 2011 |access-date=June 4, 2009 |page=B–2}}</ref>}}
* All load and store instructions use the same mnemonic name, LD, for LOAD (a return to the simplistic Datapoint 2200 vocabulary); other common instructions, such as ADD and INC, use the same mnemonic regardless of addressing mode or operand size. This is possible because the operands themselves carry enough information.

These principles made it straightforward to find names and forms for all new Z80 instructions, as well as [[Orthogonality (programming)|orthogonalizations]] of old ones, such as <code>LD BC,1234</code>.

Apart from naming differences, and despite a certain discrepancy in basic register structure, the Z80 and [[Intel 8086|8086]] syntax are virtually [[isomorphic]] for a large portion of instructions. Only quite superficial similarities (such as the word MOV, or the letter X, for extended register) exist between the 8080 and 8086 assembly languages, although 8080 programs can be translated to 8086 assembly language by [[Assembly language translator|translator programs]].<ref name="Scanlon 1988" /><ref name="Nelson 1989" />