QL System Variables

Reference guide to selected Sinclair QL system variables with addresses, sizes, and usage notes. Covers RAMTOP+1 (memory expansion detection at 163950), SCREEN_CTD (TV mode status at 163990), SCREEN_STATUS (screen activity at 163991), NET# (network number at 163995), REPEAT_DELAY (163986 word), REPEAT_FREQ (163952 word), and CAPS_LOCK (163976 word, noting a correction to a previous TimeLinez article). Also explains POKE_L/PEEK_L, POKE_W/PEEK_W, and POKE/PEEK usage, and provides the formula for calculating free memory: PEEK_L(163985) – PEEK_L(163965) – 5168.