Intel SIM4-02 Name Address X Function KEY, Txx, T6R, Pun, Ipr, Retn, Msg, Space, Digit, Pdn, Bcd

the typing of some specializ~d sequences of characters, partial decimal to binary conversion on input, and 6-bit teletype char- acter input with control character checking. A test program may use these subroutines to facilitate checkout of complex programs, or the ROM may be included in the final program if teletype interface and the same ancillary routines are needed.

The following is a summary of the subroutines and their calling parameters:

NAME ADDRESS (X) FUNCTION

KEY	120	(11-15)	This routine inputs one 7-bit character from the teletype keyboard, and returns it, left-justified,
		in index registers 14 and 15. Index registers 12 and 13 are cleared to zero. The least significant bit of
		register 11 determines whether the character is echoed back (0 = yes, 1 = no). The carry is set if the
		character typed in is printable.
TTl	117	(11-15)	This routine inputs one 7-bit character from the teletype paper tape reader or keyboard (the
		reader control is enabled), and is otherwise exactly the same as KEY.
TXX	234	(10, 11, 14, 15) This routine examines the carry bit set by KEY or TTl as well as the accumulator value
		and the character in registers 14 and 15 to determine if one of the following conditions obtains:

1.The character is some printable graphic between "0" and '+".If so, the character is biased to a six- bit value, centered in the byte. The carry is turned on if it is a letter. A normal return is taken, acc=O.

2.The character is a control character between null and ETB (control-Y) or a printable graphic between space and slash. An indirect jump to the address in ROM page 1 contained in index registers 10 and 11 is taken.

3.The character is a control between CAN (Control-X) and US (Shift-Control-O). An unconditional jump to location 256 is taken.

4.The character is one of those not generated by a KSR33 teletype, or a rubout. A normal return is taken, with the accumulator non-zero.

T6R	205	(10-15) This routine combines TTl and TXX such that normal return occurs only on characters "0"
		through ' ...". Characters in group (4) above are ignored, and the alternate exits are taken for control
		characters and delimiters. Note that if the address to which the delimiter return is to be made is odd,
		no echo occurs. On normal return, the character is right-justified in registers 14 and 15, and the carry
		is set if the character is a letter or higher.
T6l	220	(10-15) This routine is the same as T6R, except that on normal return the carry is always zero, and the
		character is left-justified in registers 14 and 15, leaving the lower two bits zero. Both T6R and T6l
		contain subroutine calls nested three deep, and may only be called from the main program, except
		during simulation.

010183 (4-7, 10-15) This subroutine multiplies the 12-bit binary number in registers 5-7 times ten, and adds the number in register 15 to the product, then goes to T6R to input another digit. This routine may be called repeatedly to input and convert to binary a decimal number. A terminal delimiter takes the alternate exit in registers 10 and 11. Register 4 is used for scratch.

Z47	6	(4-7) This routine clears registers 4 through 7 to binary zero in preparation for 010.
PUN	80	(11-15)	This routine prints or punches the character in registers 14 and 15 out on the teletype. Registers
		11 through 15 are cleared to zero on return.
IPR	70	(11-15)	This routine does the same as PUN, except that if register 11 is initially even (echo mode on input),
		a 15 ms delay occurs to allow the teletype printer to settle.
RETN	107	(11-15)	This routine types out a carriage return, a null, and a linefeed. It may only be called from the
		main routine.
MSG	66	(11-15)	This routine types out the character in registers 14 and 15, then follows it with a bell.
SPACE	63	(11-15)	This routine types one space.
DIGIT	53	(10-15)	This routine types an ASCII digit corresponding to the BCD number in the accumulator. If it is
		zero, and the register 10 contains 15, a space is typed instead. Unless a space is typed, register 10 is
		incremented.
PDN	40	(4-7, 10-15)		This routine will print, with zero suppression, the four-digit decimal number in registers
		4 through 7.
BCD	11	(1-7,10-15)		This routine converts the 12-bit binary number in registers 1-3 into decimal, and prints the
		four digits with zero suppression.

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