See all articles from TS Bulletin S-7-90
Continuation of the Amateur Programmers’ Line column exploring a technique for packing 7-digit telephone numbers into 3 bytes of ZX-81/TS1000 RAM. Discusses the encoding strategy, edge cases (leading zeros, digit groups exceeding 255, null/empty numbers requiring reserved codes), and variable-length field design for memory-constrained database applications on orphan computers. Includes a short BASIC type-in program demonstrating POKE-based storage and PEEK-based retrieval of a sample phone number using fixed RAM addresses from 16523 upward.