* VIC-20 SUPER CALCULATOR *

THE MACHINE, 1981

• The Commodore VIC-20 shipped in 1981 for about $299 — the first computer to sell one million units.
• It had 5 KB of RAM (about 3.5 KB free for BASIC after screen and system overhead) and a famously narrow 22-column screen driven by the VIC video chip.
• In COMPUTE! magazine (1981), Commodore legend Jim Butterfield wrote "VIC as Super Calculator" — pointing out that even with no program loaded, the machine on your desk out-computed any pocket calculator in the store.

WHY IMMEDIATE MODE = CALCULATOR

Commodore BASIC has two modes. Lines with numbers are stored as a program; lines without a number execute instantly — immediate mode. So the moment the READY. prompt appears you can type:

PRINT 355/113  (or the shortcut ?355/113)

and get an answer with full floating point, parentheses, exponentiation via ^, and built-in functions: SQR, INT, ABS, SIN, COS, TAN, LOG (natural), EXP, ATN and the π symbol (Shift+↑ on the real keyboard). No program, no storage used — Butterfield's "power hidden in plain sight."

NINE-DIGIT FLOATS

Commodore BASIC stores numbers in a 5-byte float format: 1 exponent byte + 4 mantissa bytes ≈ 32-bit mantissa, giving roughly 9 significant decimal digits — better than the 8 digits of most 1981 pocket calculators.

Try PRINT 1/3 above: you get .333333333 — nine threes, leading zero dropped, exactly as the real machine printed it. Angles are radians, LOG is base-e (use LOG(X)/LOG(10) for base-10), and results between 0.01 and 999,999,999 print without scientific notation.