Appendix C 3270 Bit Assignment and Character Translation Tables

Table of Contents

Character Sets

This Appendix contains the following tables related to 3270 data stream communication:

See Table C-1 “3270 Write Control Character Bis Assignment” for 3270 Write Control Character (WCC) bit assignment.
See Table C-2 “Attention ID Codes Generated by SNA IMF” for Attention ID (AID) codes generated by SNA IMF.
See Table C-3 “Command Codes for IBM Control Units” for 3270 command codes for IBM control units.
See Table C-4 “3270 Field Attribute Character Bit Assignment” for bit assignments for the 3270 Field Attribute Character.
See Table C-5 “3270 Buffer Control Orders” 3270 buffer control orders.

Information about ASCII and EBCDIC character translation tables and HP 3000 Native Language Support (NLS) is also provided at the end of this Appendix.

Table C-1 3270 Write Control Character Bis Assignment

Bits	Meaning
0	Value is determined by the contents of bits 2-7.
1 RESERVED	Always a 1.
2-3 Line length	Defines line length in printout as follows:
	00 = 132-character line when orders are not present. The NL, EM, and CR orders in the data stream determine printed line length. 01 = Printed line is 40 characters. 10 = Printed line is 64 characters. 11 = Printed line is 80 characters.
4 Start printer	When set to 1, bit 4 starts printing at the completion of the write operation.
5 Alarm	When set to 1, bit 5 sounds an alarm at a selected output device as soon as an operation ends.
6 Keyboard enable	When set to 1, bit 6 reenables the keyboard of a selected device so that it will accept input.
7 MDT reset	When set to 1, bit 7 resets all modified data tag (MDT) bits in the data in the existing buffer of the selected device before writing any data or executing any orders.

See Table C-2 “Attention ID Codes Generated by SNA IMF” for Attention ID (AID) codes that are generated by SNA IMF.

Table C-2 Attention ID Codes Generated by SNA IMF

AID	Decimal Code	ASCII Code (Octal/Hex)	EVCDIC Code (Hexadecimal)	Graphic Character
ENTER	39	047/27	7D	' (Apostrophe)
PF 1	49	061/31	F1	1
PF 2	50	062/32	F2	2
PF 3	51	063/33	F3	3
PF 4	52	064/34	F4	4
PF 5	53	065/35	F5	5
PF 6	54	066/36	F6	6
PF 7	55	067/37	F7	7
PF 8	56	070/38	F8	8
PF 9	57	071/39	F9	9
PF 10	58	072/3A	7A	:
PF 11	35	043/23	7B	#
PF 12	64	100/40	7C	@
PF 13	65	101/41	C1	A
PF 14	66	102/42	C2	B
PF 15	67	103/43	C3	C
PF 16	68	104/44	C4	D
PF 17	69	105/45	C5	E
PF 18	70	106/46	C6	F
PF 19	71	107/47	C7	G
PF 20	72	110/48	C8	H
PF 21	73	111/49	C9	I
PF 22	91	133/5B	4A	[ (ASCII) (cent sign) (EBCDIC)
PF 23	46	056/2E	4B	. (period)
PF 24	60	074/3C	4C	<
PA 1	37	045/25	6C	%
PA 2	62	076/3E	6E	>
PA 3	44	054/2C	6B	, (comma)
CLEAR	95	137/5F	6D	_ (underscore)
SYSTEM REQUEST	48	060/30	F0	0

See Table C-3 “Command Codes for IBM Control Units” for the Command Codes for IBM Control Units.

Table C-3 Command Codes for IBM Control Units

Command	ASCII Code (Octal/Hex)	EBCDIC Code (Hexadecimal)	Graphic Character
Erase All Unprotected	77/3F	6F	?
Erase/Write	65/35	F5	5
Erase/Write Alternate	75/3D	7E	=
Read Buffer	62/32	F2	2
Read Modified	66/36	F6	6
Write	61/31	F1	1
Read Modified All	76/3E	6E	>




	NOTE: SNA IMF does not support the Write Structured Field command.

See Table C-4 “3270 Field Attribute Character Bit Assignment” for bit assignments for the 3270 Field Attribute Character.

Table C-4 3270 Field Attribute Character Bit Assignment

Bits	Field Description
0	Value is determined by the contents of bits 2-7.
1 RESERVED	Always a 1.
2 U/P	0 = Unprotected 1 = Protected
3 A/N	0 = Alphanumeric 1 = Numeric
4-5	Display indicator 00 = Normal display 01 = Normal display and light pen detectable 10 = Intensified display and light pen detectable 11 = Non-display and non-print
6 RESERVED	Set 0 0 by the host.
7 MDT	Modified data tag (MDT) indicates whether the field associated with this attribute character has been modified. 0 = Field has not been modified. 1 = Field has been modified either by the terminal operator or by the host program when it sent this attribute character to the terminal




	NOTE: When bits 2 and 3 are both on, an automatic skip occurs.

See Table C-5 “3270 Buffer Control Orders” for 3270 buffer control orders.

Table C-5 3270 Buffer Control Orders

Byte 1		Byte 2	Byte 3	Byte 4
Order	Order Code (EBCDIC Hex/ ASCII Hex)
Start Field (SF)	1D/1D	Field attribute character
Set Buffer Address (SBA)	11/11	Address (1st byte)	Address (2nd byte)
Insert Cursor (IC)	13/13
Program Tab (PT)	05/09
Repeat to Address (RA)	3C/14	Address (1st byte)	Address (2nd byte)	Character to be repeated
Erase Unprotected to Address (EAU)	12/12	Address (1st byte)	Address (2nd byte)




	NOTE: SNA IMF does not support the following 3270 buffer control orders: Start Field Extended Set Attribute Modify Field Graphic Escape

Appendix C 3270 Bit Assignment and Character Translation Tables

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