OEL TTX2000 Issue 2.3: Routine at 10F0

10F0: enter_subcode_and_clear: Get valid page subcode then clear the page buffer.


enter_subcode_and_clear	10F0	LD HL,(page_display_buffer_pointer)	Load page_display_buffer_pointer into HL and add 3.
	10F3	LD BC,$0003
	10F6	ADD HL,BC
enter_subcode_and_clear_0	10F7	CALL get_dec_digit	Get a keypress in the range 0-9.
	10FA	PUSH AF	Set subpage_search_flag.
	10FB	LD A,$01
	10FD	LD (subpage_search_flag),A
	1100	POP AF
	1101	CP $30	If number is 0 or greater than 3 loop back and get another keypress.
	1103	JR C,enter_subcode_and_clear_0
	1105	CP $34
	1107	JR NC,enter_subcode_and_clear_0
	1109	INC HL	Else write key code to next byte in page display buffer.
	110A	LD (HL),A	Else write key code to next byte in page display buffer.
	110B	AND $0F	Convert to an integer.
	110D	LD (subcode_S4),A	Store in subcode_S4.
	1110	CALL display_header_row	Decode and display header row data.
	1113	CALL get_hex_digit	Get a keypress in the range 0-9 or A-F.
	1116	INC HL	Write key code to next byte in page display buffer.
	1117	LD (HL),A	Write key code to next byte in page display buffer.
	1118	CP $41	Convert to integer.
	111A	JR C,enter_subcode_and_clear_1
	111C	ADD A,$09
enter_subcode_and_clear_1	111E	AND $0F
	1120	LD (subcode_S3),A	Store in subcode_S3.
	1123	CALL display_header_row	Decode and display header row data.
enter_subcode_and_clear_2	1126	CALL get_dec_digit	Get a keypress in the range 0-9.
	1129	CP $38	If number greater than 7 loop back and get another keypress.
	112B	JR NC,enter_subcode_and_clear_2
	112D	INC HL	Else write key code to next byte in page display buffer.
	112E	LD (HL),A	Else write key code to next byte in page display buffer.
	112F	AND $0F	Convert to integer.
	1131	LD (subcode_S2),A	Store in subcode_S2.
	1134	CALL display_header_row	Decode and display header row data.
	1137	CALL get_hex_digit	Get a keypress in the range 0-9 or A-F.
	113A	INC HL	Write key code to next byte in page display buffer.
	113B	LD (HL),A	Write key code to next byte in page display buffer.
	113C	CP $41	Convert to integer.
	113E	JR C,enter_subcode_and_clear_3
	1140	ADD A,$09
enter_subcode_and_clear_3	1142	AND $0F
	1144	LD (subcode_S1),A	Store in subcode_S1.
	1147	CALL display_header_row	Decode and display header row data.
This entry point is used by the routine at enter_page_and_clear.
enter_subcode_and_clear_4	114A	CALL clear_page_buffer	Clear page display buffer.
	114D	CALL clear_receive_rows	Clear all rows except header in page receive buffer.
	1150	XOR A	Clear ignore_packets_flag and return.
	1151	LD (ignore_packets_flag),A
	1154	RET