ROM subroutines: input integer number

ROM subroutines

Input integer number

addr	code	mnemonic	action	comments
EE0...D0	E072 EA00	SETH $72, 0000	$72 <== EA00	set the address of buffer (in system RAM)
D4	E772 0060	INCL $72, 0060	$72 <== $72 + 60	set the address of buffer (in system RAM)
D8	E371 0016	SETL $71, 0016	$71 <== 16	save 20₁₀ to the first byte of buffer (max string length)
DC	A171 7200	STBI $71, $72, 00	($72) <== $71	save 20₁₀ to the first byte of buffer (max string length)
E0	0005 0A72	TRAP 5/0A, $72	call system function: input string	input string with number
E4	E772 0002	INCL $72, 0002	$72 <== $72 + 1	get first symbol to $71
E8	8171 7200	LDBI $71, $72, 00	$71 <== ($72)	get first symbol to $71
EC	3171 712D	CMPI $71, $71, 2D	compare $71 and 2D; result - $71	compare with '-'
F0	E373 0001	SETL $73, 0001	$73 <== 1	+1 to sign
F4	E374 0000	SETL $74, 0000	$74 <== 0	0 to string index
F8	4A71 0003	BNZ $71, 0003	branch to 104 if $71 <> 0	bypass for positive numbers
FC	2573 7302	SUBI $73, $73, 02	$73 <== $73 - 2	-1 to sign
100	E774 0001	INCL $74, 0001	$74 <== $74 + 1	1 to string index
104	E371 0000	SETL $71, 0000	$71 <== 0	0 to result
108	8275 7274	LDBU $75, $72, $74	$75 <== ($72 + $74)	get current symbol from buffer
10C	3176 750D	CMPI $76, $75, 0D	compare $75 with 0D; result - $76	compare with enter code
110	4276 000A	BZ $76, 000A	branch to 138 if $76 = 0	exit if enter (end of string)
114	2575 7530	SUBI $75, $75, 30	$75 <== $75 - 30	form decimal digit value
118	4075 0009	BN $75, 0009	branch to 13C if $75 < 0	if < 0 - error
11C	3176 7509	CMPI $76, $75, 09	compare $75 with 09; result - $76	compare with 9
120	4476 0007	BP $76, 0007	branch to 13C if $76 > 0	if > 9 - error
124	1971 710A	MULI $71, $71, 0A	$71 <== $71 * 0A	result * 10₁₀
128	1875 7573	MUL $75, $75, $73	$75 <== $75 * $73	current digit * sign
12C	2071 7175	ADD $71, $71, $75	$71 <== $71 + $75	add to result
130	2174 7401	ADDI $74, $74, 01	$74 <== $74 + 1	next bufer index
134	F1FF FFF5	JMPB FFFFF5	branch to 108	repeat cycle
138	9F6F 6F00	GOI $6F, $6F, 00	return using $6F	(finish subroutine)
13C	E373 0020	SETL $73, 0020	$73 <== 20	code of space symbol
140	4274 0004	BZ $74, 0004	branch to 150 if $74 = 0	end cycle
144	0005 0273	TRAP 5/02, $73	call system function: print symbol	print space under every correct symbol
148	2574 7401	SUBI $74, $74, 01	$74 <== $74 - 1	decrease couner of spaces
14C	F1FF FFFD	JMPB FFFFFD	branch to 140	repeat cycle
150	2176 6F00	ADDI $76, $6F, 00	$76 <== $6F	store return address and call print string ROM subroutine
154	9F6F 7030	GOI $6F, $70, 30	call $70+30; return - $6F	store return address and call print string ROM subroutine
158	075E 3F3F 3F07 0D0A	.^???...	7 symbols: 'BELL', '^??' '?', 'BELL", CR/LF	text to print (length=7 - first byte)
160	216F 7600	ADDI $6F, $76, 00	$6F <== $76	restore return address
164	F1FF FFDB	JMPB FFFFDB	branch to D0	repeat from the very beginning

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E-MMI software