6502 SpASM (6502 Spreadsheet Assembler and Linker) v1.2.0

This is a ~~proof-of-concept~~ full-featyres 6502 assembler with linker in a spreadsheet (works with Excel, Libre Office, etc.). If you're using Libre Office, you need Libre Office v7.1.x or later if you want to use the linker.

The XLSX file is the latest release. Instructions included in the spreadsheet.

Features

all the 6502 instructions plus a couple of pseudo-instructions
all addressing modes
global and local labels
EQUs to declare constants
use of +/- offsets with constants/labels
use of "#" to reference values
decimal notation by default (0-65535)
use of "$" for hexadecimal notation (2 bytes max)
use of "%" for binary notation (16 bits max)
use of ">" and "<" to point to MSB and LSB (2 bytes only)
display cycle count
ORG within code to define different starting addresses for modules
HEX pseudo-instruction to define HEX data
ASC/STR pseudo-instructions to define text constants (with ASC, hi-bit is unset, while with STR, it is)
syntax highlighting
linking of object modules (sheets) in the same workbook
global labels across the workbook
negative values are supported for decimal notation
error checking (highlighted in brown)

Revisions

v1.0 (Jan 31, 2021)

initial release

v1.0.1 (Jan 31, 2021)

fixed zp jmp/jsr
fixed ld_ #> and ld_ #<

v1.1 (Feb 6, 2021)

fixed bytes needed for some opcodes
added cycles display
added support of ORG in the middle of the code
added support for #label and #<label and #>label for HEX opcode

v1.1.1 (Feb 8, 2021)

fixed more bytes count for some opcodes
rewrote the byte count detection in order to avoid possible circular references
column D is now colored as comments, it's meant to be used as full-line comments
new official name "SpASM" !

v1.1.2 (Feb 8, 2021)

fixed instructions because columns were shifted with latest release
added syntax highlighting for SUBs
deleted Excel external link

v1.2.0 (Feb 15, 2021)

added linker
linker requires Libre Office v7.1.x or above (or MS Excel)
added globals labels page
removed more external links
little fixes here and there
removed Wagner's code samples
can reference ASCII values with ' or "
errors highlighting
added numerous examples in instructions_code sheet (used as a test sheet)

Licence

You may freely use, copy (etc) this spreadsheet for your own creations and you may also redistribute it on any kind of media as long as the "instructions" sheet is included and not modified. If you mention this file or distribute it elsewhere, please send me a message. I'm on Facebook's "Apple II Software Enthusiasts" and "Apple II Enthusiasts" groups, among others.

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