8085 Program to find factorial of a number in 8085

Program to find factorial of a number in 8085

Here is a program to find factorial of a number in 8085

MVI B, 03H
MOV C, B
DCR C
LOOP1:
MOV E, C
SUB A
LOOP2:
ADD B
DCR E
JNZ LOOP2
MOV B, A
DCR C
JNZ LOOP1
STA 8000H
HLT

Advanced Code

MEMORY	LABEL	MNEMONIC	HEX CODE	COMMENT
4200		LXI H,4100	21	Load the number to the HL pair
4201			00
4202			41
4203		MVI C,M	4E	Copy the number to register C
4204		MVI E,M	5E	Copy memory content to E
4205		DCR E	1D	Decrement E
4206	LOOP1	INX H	23	Increment memory
4207		DCR C	0D	Decrement C
4208		MOV M,C	71	Copy content of C to memory
4209		JNZ LOOP1	C2	Jump on non-zero to label LOOP1
420A			06
420B			42
420C		LXI H,4100	21	Load the number whose factorial is to be found in HL pair
420D			00
420E			41
420F	LOOP2	MOV A,M	7E	Copy memory content to accumulator
4210		INX H	23	Increment memory
4211		MOV B,M	46	Copy memory content to B
4212		MOV C,A	4F	Copy accumulator content to C
4213		MVI A,00	3E	Initialize A with 0
4214			00
4215	GO	ADD B	80	[A] ß [A] + [B]
4216		DCR C	0D	Decrement C
4217		JNZ GO	C2	Jump on non-zero to label GO
4218			15
4219			42
421A		MOV M,A	77	Copy accumulator content to memory
421B		DCR E	1D	Decrement E
421C		JNZ LOOP2	C2	Jump on non-zero to label LOOP2
421D			0F
421E			42
421F		STA 4500	32	Store accumulator content to memory
4220			00
4221			45
4222		HLT	76	Program ends