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--- sd:int_12h_string_services [2026/04/14 06:09] – created - external edit 127.0.0.1
+++ sd:int_12h_string_services [Unknown date] (current) – external edit (Unknown date) 127.0.0.1
@@ Line 1: / Line 1: @@
+= INT 12h String Services
+== Catalog
+<code>
+; ============================================================================
+; INT 12h - STRING SERVICES
+; A library of string functions intended to support programming in assembly,
+; or to be used by a higher level language implemented in assembly.
+; February 7th, 2026, 10:20AM -- passed all 85 tests on the SD-8516
+; ============================================================================
+; Function dispatch via AH register:
+;   AH=00h: strlen - Get string length
+;   AH=01h: strcpy - Copy string
+;   AH=02h: strcmp - Compare strings
+;   AH=03h: strcat - Concatenate strings
+;   AH=04h: atoi - ASCII to integer
+;   AH=05h: itoa - Integer to ASCII
+;   AH=06h: strupr - Convert to uppercase
+;   AH=07h: strlwr - Convert to lowercase
+;   AH=08h: strchr - Find character in string
+;   AH=09h: strncpy - Copy n characters
+;   AH=0Ah: strncmp - Compare n characters
+;   AH=0Bh: strcmpi - Compare strings (case-insensitive)
+;   AH=0Ch: conv_ch_to_uc - Convert single char to uppercase
+;   AH=0Dh: conv_ch_to_lc - Convert single char to lowercase
+;   AH=0Eh: test_uc_lc - Test if char is uppercase
+;   AH=0Fh: isnum - Test if char is digit (0-9)
+;   AH=10h: isalpha - Test if char is letter (A-Z, a-z)
+;   AH=11h: puthex - Print byte in AL as hex
+;   AH=12h: putbase - Print number in B in base CL
+;   AH=13h: print_fld_hex
+;   AH=14h: beginswith (Test if string starts with prefix)
+;   AH=15h: endswith (Test if string ends with suffix)
+;   AH=16h: strstr (Find substring in string)
+;   AH=20h: htoi (hex ascii to int)
+;   AH=21h: itoh (int to hex ascii)
+;
+; ============================================================================
+</code>