Figure 1: ZX Spectrum. Dimensions (mm) are 230x144x30 (WxHxD)
Figure 2: Jet Set Willy copy protection screen. Used under fair dealing and fair use for research and commentary
Figure 3: Jet Set Willy physical artefacts for the ZX Spectrum, including copy protection card (left). The card's dimensions (mm) are 61x98 (WxH), allowing it to easily fit inside a standard cassette tape case (centre)
Figure 4: No Copi paper used for copy protection in Jack Nicklaus' Unlimited Golf & Course Design (1990) for DOS. The blank rectangle is a modern photocopy attempt
Figure 5: Jet Set Willy physical artefacts for the MSX platform. The copy protection card (bottom) folds out to 315x99 (WxH, in mm) and is printed on both sides, but again folds up to fit inside a cassette tape case
Figure 6: Partial instruction execution trace from Jet Set Willy. As a record of the actual instructions executed, some are repeated (
ldir at $86f1) and others are skipped (one instruction is omitted after the
Figure 7: Partial annotated execution trace from Jet Set Willy, showing analysis
Figure 8: Textual reconstruction excerpt of Jet Set Willy copy protection
Figure 9: Graphical reconstruction of Jet Set Willy copy protection
Figure 10: Interpretation of bits in a byte from Jet Set Willy copy protection table
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