LCC+ Instruction Set Addendum

This document summarizes the additions and differences between the original LCC instruction set and the LCC+ extension (see src/plus/ and plusdemos/ in repository at https://github.com/avidrucker/lccjs).

New Machine Instructions

Mnemonic	Binary Format	Flags Set	Description
rand	1010 dr sr1 0 01110	none	Generate pseudo-random number in range [dr, sr1] and store in dr

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New TRAP Instructions

The following TRAP instructions use trap vectors from 0x000F and up:

Mnemonic	Trap Vector	Flags Set	Description
clear	0x000F	none	Clears the terminal screen
sleep	0x0010	none	Pauses execution for r[dr] milliseconds
nbain	0x0011	none	Non-blocking ASCII input (returns ASCII code in dr, or 0 if no input available)
cursor	0x0012	none	Shows or hides cursor based on value in dr (0 = hide, else = show)
srand	0x0013	none	Seeds RNG using value in sr
millis	0x0014	none	Puts current system time milliseconds (0–999) into dr
resetc	0x0015	none	Resets cursor position to top-left of screen

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New Assembler Directives

Directive	Description
.lccplus	Marks the file as an LCC+ file. Required for LCC+ assembly. Triggers special output header format ('p').

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Additional Notes

• File extensions: LCC+ source files must end in .ap; compiled output will be .ep.

• Header Signature: LCC+ .ep files must begin with 'op' header (not 'o').

• Breakpoint (bp): Trap vector 0x000E is supported as in LCC, but enhanced in LCC+ to allow "press any key to resume" functionality.

• rand instruction:

  • Generates a number in an inclusive range between the values in dr and sr1.
  • Uses a pseudo-random number generator based on a seeded Linear Congruential Generator (LCG) + XOR shift.