010000: 237777	   lac 017777 i
010001: 550407	   sad d4			" Skip if we have more than four argument words
010002: 610052	     jmp nofiles		" Only four argument words, so no arguments
010003: 217777	   lac 017777			" Move five words past the argument word count
010004: 350406	   tad d1			" so that AC points at the first argument
010005: 350407	   tad d4			" and save the pointer in name
010006: 050010	   dac name
010007: 020003	   sys open; name:0; 0		" Open file, get fd back
010010: 000000	
010011: 000000	
010012: 741100	   spa
010013: 610035	     jmp badfile		" Negative fd, exit with an error message
010014: 050301	   dac fi			" Save file descriptor in fi
010015: 110104	   jms getc			" Get a character in AC
010016: 550407	   sad o4
010017: 610022	     jmp 1f			" Break the loop when we get a ctrl-D
010020: 110140	   jms putc			" Write the character on stdout
010021: 610015	   jmp 1b			" and loop back
010022: 210301	   lac fi			" Close the file descriptor in fi
010023: 020011	   sys close
010024: 777774	   -4
010025: 377777	   tad 017777 i			" Subtract 4 from the count of argument words
010026: 077777	   dac 017777 i
010027: 550407	   sad d4			" Is the value 4, i.e. no args left?
010030: 610064	     jmp done			" Yes, so exit
010031: 210010	   lac name			" Still an argument, so move up
010032: 350407	   tad d4			" to the next filename argument
010033: 050010	   dac name
010034: 610007	   jmp loop			" and loop back to cat this file
010035: 210010	   lac name			" Get the pointer to the filename
010036: 050041	   dac 1f			" Store it in 1f below
010037: 210410	   lac d8			" Load fd 8 which is stderr
010040: 020005	   sys write; 1:0; 4		" Write the four words of the filename
010041: 000000	
010042: 000004	
010043: 210410	   lac d8
010044: 020005	   sys write; 1f; 2		" and then write " ?\n"
010045: 010050	
010046: 000002	
010047: 610024	   jmp loop1			" Now try doing the next argument
010050: 000040	1: 040;077012			" String literal: " ?\n"
010051: 077012	
010052: 210410	   lac d8
010053: 020005	   sys write; 1f; 5		" Write "No files\n" to stderr
010054: 010057	
010055: 000005	
010056: 020016	   sys exit			" and exit
010057: 156157	1: <no>; 040;  <fi>;<le>;<s 012
010060: 000040	
010061: 146151	
010062: 154145	
010063: 163012	
010064: 210404	   lac noc			" Is the number of characters left zero?
010065: 741200	   sna
010066: 020016	     sys exit			" Yes, exit
010067: 510406	   and d1
010070: 751200	   sna cla
010071: 610074	     jmp 1f
010072: 110140	   jms putc			" Store the character in the buffer
010073: 610064	   jmp done			" and loop back
010074: 210404	   lac noc			" Get the number of characters in the buffer
010075: 744020	   rcr				" Divide by two to convert to words
010076: 050102	   dac 1f			" Save in the write's word count below
010077: 210405	   lac fo			" Load fd 1, stdout
010100: 020005	   sys write; iopt+1; 1:..	" Write the leftover buffer and exit
010101: 010304	
010102: 010000	
010103: 020016	   sys exit
010104: 000000	getc: 0
010105: 210176	   lac ipt			" Load the pointer to the next word in the buffer
010106: 550177	   sad eipt
010107: 610123	     jmp 1f			" We've reached the end of the buffer, so read more
010110: 050174	   dac 2f			" Save the pointer
010111: 310411	   add o400000			" Flip the msb and save into ipt
010112: 050176	   dac ipt
010113: 740010	   ral				" Move the msb into the link register
010114: 230174	   lac 2f i			" Load the word from the buffer
010115: 741400	   szl				" Skip if this is the second character in the word
010116: 660511	     lrss 9			" It's the first char, shift down the top character
010117: 510412	   and o177			" Keep the lowest 7 bits
010120: 741200	   sna
010121: 610105	     jmp getc+1			" Skip a NUL characters and read another one
010122: 630104	   jmp getc i			" Return the character from the subroutine
010123: 210301	   lac fi			" Buffer is empty, read another 64 characters
010124: 020004	   sys read; iipt+1; 64
010125: 010201	
010126: 000100	
010127: 741200	   sna
010130: 610136	     jmp 1f			" No characters were read in
010131: 350200	   tad iipt			" Add the word count to the base of the buffer
010132: 050177	   dac eipt			" and store in the end buffer pointer
010133: 210200	   lac iipt			" Reset the ipt to the base of the buffer
010134: 050176	   dac ipt
010135: 610105	   jmp getc+1			" and loop back to get one character
010136: 210407	   lac o4			" No character, return with ctrl-D
010137: 630104	   jmp getc i			" return from subroutine
010140: 000000	putc: 0
010141: 510412	   and o177			" Keep the lowest 7 bits and save into 2f+1
010142: 050175	   dac 2f+1
010143: 210302	   lac opt			" Save the pointer to the empty buffer
010144: 050174	   dac 2f			" position to 2f
010145: 310411	   add o400000			" Flip the msb and save back into opt
010146: 050302	   dac opt			" This also has the effect of incrementing
010147: 741100	   spa				" If the bit was set, we already have one
010150: 610154	     jmp 1f			" character at 2f+1. If no previous character,
010151: 230174	   lac 2f i			" merge the old and new character together
010152: 250175	   xor 2f+1
010153: 610156	   jmp 3f			" and go to the "save it in buffer" code
010154: 210175	   lac 2f+1			" Move the character up into the top half
010155: 660711	   alss 9
010156: 070174	   dac 2f i			" Save the word into the buffer
010157: 450404	   isz noc			" Add 1 to the char count, never skipping
010160: 210404	   lac noc			" Have we reached 128 characters, 64 words?
010161: 550413	   sad d128
010162: 741000	     skp
010163: 630140	   jmp putc i			" No, so return (more room still in the buffer)
010164: 210405	   lac fo			" Load fd1 (i.e stdout)
010165: 020005	   sys write; iopt+1; 64	" and write out the 64 words in the buffer
010166: 010304	
010167: 000100	
010170: 210303	   lac iopt
010171: 050302	   dac opt			" Set opt pointing back to base of buffer
010172: 150404	   dzm noc			" Set the number of chars in the buffer to 0
010173: 630140	   jmp putc i			" and return
010174: 000000	2: 0;0				" Current input and output word pointers
010175: 000000	
010176: 000000	ipt: 0				" Current input buffer base
010177: 000000	eipt: 0				" Pointer to end of data read in input buffer
010200: 010201	iipt: .+1; .=.+64		" 64 word input buffer and pointer to it
010301: 000000	fi: 0				" Input file descriptor
010302: 010304	opt: .+2			" Current output buffer base
010303: 010304	iopt: .+1; .=.+64		" 64 word output buffer and pointer to it
010404: 000000	noc: 0				" Number of output characters
010405: 000001	fo: 1				" Output file descriptor, fd 1 is stdout
010406: 000001	d1: 1				" Octal and decimal constants
010407: 000004	o4:d4: 4
010410: 000010	d8: 8
010411: 400000	o400000: 0400000		" Msb toggle bit
010412: 000177	o177: 0177			" ASCII mask
010413: 000200	d128: 128			" 128 words in the output buffer