Six pages built by MAKE_TABLES at every new game: every byte value shifted right two, four and six places across two bytes. Page $FA holds the part that stays in a byte for a shift of two and $FB the bits that fall out into the next; $FC and $FD the same for four, $FE and $FF for six. The sprite drawing (SPRITE_SHIFTED_FOUR) and the tile drawing (PUT_TILE) read a pair, page $F8 plus bits 1 and 2 of x and the page above it.

Until the game builds them, these pages hold what the machine left there before the tape loaded, all overwritten before the game reads any of it (measured by stage 1): zeros; below RAMTOP, what the ROM's stack held as the BASIC loader ran -- among it ERR_SP's return into the ROM's main loop, and the end marker of the GOSUB stack at RAMTOP itself; and in the last 168 bytes the ROM's user-defined graphics, the letters A to U as the ROM sets them up.