DEC Opcodes

Dec Opcodes – DEC Architecture Reference

Before the microprocessor, there was DEC. The minicomputers built by Digital Equipment Corporation didn't just advance computing - they defined it. Unix was born on a PDP-7. Spacewar! ran on a PDP-1. The VAX powered universities and research labs worldwide for a generation.

DecOpcodes puts the complete instruction sets of these legendary machines in your pocket.

Five iconic architectures covered: PDP-1 (1960) · PDP-8 (1965) · PDP-10 (1966) · PDP-11 (1970) · VAX (1977)

For every instruction: 

• Full description of what the instruction does 
• Octal and hex encoding 
• Flags affected 
• Addressing modes, word count, and cycle counts 
• Assembly code examples and implementation notes

More than just opcodes: 

• Complete system specifications and register architecture 
• Historical context and cultural impact 
• Archival photographs - front panels, system cabinets, and more 
• Notable installations and the systems they powered 
• Architecture variants and successors

Built for exploration: 

• Search across all systems instantly 
• Filter by instruction category 
• Sort alphabetically or by category
• Favorite instructions for quick reference

Beautifully designed: 

• System-specific accent colours 

• Five themes including Terminal green and Blinkenlights orange 

• Full Dark Mode support

From the 18-bit simplicity of the PDP-1 to the 32-bit sophistication of the VAX, DecOpcodes is a fascinating journey through the machines that made modern computing possible.