Alien (BUGFIX 1.7): Routine at 31369

Draws one 8-pixel-tall column of a sprite tile onto the screen. Reads a tile index byte from (DE), multiplies by 8 to get an offset into the 8-byte-per-row character bitmap table at $68F5 (26869 + index×8), then writes all 8 bytes vertically downward from the current draw pointer at 31257 (INC H steps through ZX Spectrum display rows within the same character cell column).

Input: (DE) = tile/character index; (31257) = screen destination address Output: screen updated; DE advanced; H incremented 8 times

Used by the routines at 31634, 31690, 32143, 32385, 32536, 37221, 39572, 42581 and 44509.

Draws one 8-pixel-tall column of a sprite tile onto the screen. Reads a tile index byte from (DE), multiplies by 8 to get an offset into the 8-byte-per-row character bitmap table at $68F5 (26869 + index×8), then writes all 8 bytes vertically downward from the current draw pointer at 31257 (INC H steps through ZX Spectrum display rows within the same character cell column). Input: (DE) = tile/character index; (31257) = screen destination address Output: screen updated; DE advanced; H incremented 8 times Used by the routines at 31634, 31690, 32143, 32385, 32536, 37221, 39572, 42581 and 44509.
31369	LD A,(DE)	read tile index from source pointer
This entry point is used by the routines at 32143, 32536, 32670, 33479, 37322 and 40149.
31370	LD L,A	L = tile index
31371	LD H,0
31373	ADD HL,HL	HL = index × 2
31374	ADD HL,HL	HL = index × 4
31375	ADD HL,HL	HL = index × 8
31376	LD BC,26869	BC = $68F5 (character bitmap base)
31379	ADD HL,BC	HL = address of first row of tile bitmap
31380	EX DE,HL	DE = bitmap source; HL = old DE (tile index ptr)
31381	LD HL,(31257)	HL = screen destination (DrawScreenPtr)
31384	LD B,8	8 pixel rows per character
31386	LD A,(DE)	read bitmap byte for this pixel row
31387	LD (HL),A	write to display file
31388	INC H	next display row (INC H steps within 8-row band)
31389	INC DE	next bitmap byte
31390	DJNZ 31386	repeat for all 8 rows
31392	RET