Overview
An emulator core for the Radio Shack / Science Fair Electronic Project Lab kits — starting with the 200-in-One (28-262), with the 300-in-One (Maxitronix, breadboard-style) next. It’s the companion piece to the Minivac 601 and Microcomputer Trainer emulators.
How It Works
Unlike the Minivac’s relay-resistor network, these kits are full analog electronics — transistors, diodes, transformers, oscillators, radios — so the core is a genuine circuit simulator: modified nodal analysis with Newton-Raphson, trapezoidal / backward-Euler integration, junction limiting, breakdown clamps, and a “rescue ladder” tuned until the manuals’ own projects actually run. Multivibrators blink, blocking oscillators sing through the output transformer (and die out as the 100µF drains, exactly like page 26 says), the relay latches, and the Wheel of Fortune spins its display.
epl> power on epl> select b epl> run 1500 # meter pegs: 33K across 9V is 267 µA epl> select a epl> run 1500 # 47K+33K in series: 112 µA, needle at ~45%
Current Status
The engine and an interactive text playground are working, with 43 tests that use the engine physics and the manuals’ own projects as ground truth. A deployable static site build (Claude Design’s approved mock plus fresh project bundles) is in progress.