OEL TTX2000 Issue 2.3: Routine at 1277

1277: clear_page_number: Copy page number display to number_display_buffer and clear to spaces.

Used by the routines at enter_page, select_channel and hold_page.
clear_page_number	1277	PUSH HL	Preserve registers.
	1278	PUSH AF
	1279	PUSH BC
	127A	LD HL,(page_display_buffer_pointer)	Copy first 8 bytes from page display buffer to number_display_buffer.
	127D	LD DE,number_display_buffer
	1280	LD BC,$0008
	1283	LDIR
	1285	LD B,$08	Clear row 0 in page display buffer to $20 (space).
	1287	LD HL,(page_display_buffer_pointer)
clear_page_number_0	128A	LD (HL),$20
	128C	INC HL
	128D	DJNZ clear_page_number_0
	128F	POP BC	Restore registers and return.
	1290	POP AF
	1291	POP HL
	1292	RET