ZX81 Logic Signals Authors Publication Syntax Publication Details Volume: 3 Issue: 10 Date October 1982 Pages 13 Read the article See all articles from Syntax/Syntax ZX80 v3 n10 Reference signal levels for troubleshooting. Products Downloadable Media Related Articles Tags Syntax, 1982, Reference, TS 1000, ZX81 People No people associated with this content.