The HUD is rendered using function RenderHud: 802E3D2C/09ED2C. This function reads state to determine which HUD elements to display and calls several other subroutines and makes use of the PrintStr() and PrintInt() functions.

RenderHudMarioLives: 802E3744/09E744

PrintStr(0x16, 0xD1, 0x80338380); // "," = Mario
PrintStr(0x26, 0xD1, 0x80338384); // "*" = X
PrintInt(0x36, 0xD1, 0x80338388, *0x8033b260); // "%d"

RenderHudCoins: 802E37A8/09E7A8

PrintStr(0xA8, 0xD1, 0x8033838C); // "+" = coin
PrintStr(0xB8, 0xD1, 0x80338390); // "*" = X
PrintInt(0xC6, 0xD1, 0x80338394, *0x8033b262); // "%d"

RenderHudStars: 802E380C/09E80C

int showX = 0; // 0x1F($SP)
if ((*0x803316d4 == 1) || (*0x8032d5d4 & 0x8 == 0)) {
   if (*0x8033b264 < 100) {
      showX = 1;
   }
   PrintStr(0xF2, 0xD1, 0x80338398); // "-" = star
   if (showX) {
      PrintStr(0x102, 0xD1, 0x8033839C); // "*" = X
   }
   PrintInt(0x102+14*showX, 0xD1, 0x803383A0, *0x8033B264); // "%d"
}

RenderHudHp: 802E3654/09E654

ShowCameraStatus: 802E3B3C/09EB3C

RenderHudTimer: 802E395C/09E95C

The two commonly used printing functions PrintStr and PrintInt accept null-terminated ASCII strings as input. It then uses a lookup table to determine which letter to display. This table is located in segment 02 alongside the letters. It notably contains missing entries for the letters J,Q,X,Z.

PrintStr: 802D6554/091554

void PrintStr(int X, int Y, char *string);

PrintInt: 802D62D8/0912D8 This is more of a generic printf() style function that accepts a format and variable arguments.

void PrintInt(int X, int Y, char *format, ...);

The lookup table for each of the ASCII characters is located at segment address 0x02007700 (80A856 in extended ROM) and contains entries for each 16×16 RGBA texture. The default table has null entries for J,Q,X,Z and uses some symbols for HUD characters.

Before referencing the lookup table, the character in ASCII is converted to an offset within this table by the function at 802D6858/091858.

int convertchar(int ascii)
{
   if (ascii >= 0x41 && ascii < 0x5B) { // 'A' <= ascii <= 'Z'
      return ascii - 0x37;
   } else if (ascii >= 0x61 && ascii < 0x7B) { // 'a' <= ascii <= 'z'
      return ascii - 0x57;
   } else if (ascii >= 0x30 && ascii < 0x3A) { // '0' <= ascii <= '9'
      return ascii - 0x30;
   } else {
      switch (ascii) {
         case 0x20: return -1; break;   // ' '
         case 0x21: return 0x24; break; // '!'
         case 0x23: return 0x25; break; // '#'
         case 0x3F: return 0x26; break; // '?'
         case 0x26: return 0x27; break; // '&'
         case 0x25: return 0x28; break; // '%'
         case 0x2A: return 0x32; break; // '*'
         case 0x2B: return 0x33; break; // '+'
         case 0x2C: return 0x34; break; // ','
         case 0x2D: return 0x35; break; // '-'
         case 0x2E: return 0x36; break; // '.'
         case 0x2F: return 0x37; break; // '/'
      }
   }
   return -1;
}

Hex	A	Index	Seg Addr	T	Hex	A	Index	Seg Addr	T	Hex	A	Index	Seg Addr	T
20		-	-		40	@	-	-		60	`	-	-
21	!	24	00000000		41	A	0A	02001400		61	a	0A	02001400
22	“	-	-		42	B	0B	02001600		62	b	0B	02001600
23	#	25	00000000		43	C	0C	02001800		63	c	0C	02001800
24	$	-	-		44	D	0D	02001A00		64	d	0D	02001A00
25	%	28	00000000		45	E	0E	02001C00		65	e	0E	02001C00
26	&	27	00000000		46	F	0F	02001E00		66	f	0F	02001E00
27	'	-	-		47	G	10	02002000		67	g	10	02002000
28	(	-	-		48	H	11	02002200		68	h	11	02002200
29	)	-	-		49	I	12	02002400		69	i	12	02002400
2A	*	32	02004200		4A	J	13	00000000		6A	j	13	00000000
2B	+	33	02004400		4B	K	14	02002600		6B	k	14	02002600
2C	,	34	02004600		4C	L	15	02002800		6C	l	15	02002800
2D	-	35	02004800		4D	M	16	02002A00		6D	m	16	02002A00
2E	.	36	00000000		4E	N	17	02002C00		6E	n	17	02002C00
2F	/	37	00000000		4F	O	18	02002E00		6F	o	18	02002E00
30	0	00	02000000		50	P	19	02003000		70	p	19	02003000
31	1	01	02000200		51	Q	1A	00000000		71	q	1A	00000000
32	2	02	02000400		52	R	1B	02003200		72	r	1B	02003200
33	3	03	02000600		53	S	1C	02003400		73	s	1C	02003400
34	4	04	02000800		54	T	1D	02003600		74	t	1D	02003600
35	5	05	02000A00		55	U	1E	02003800		75	u	1E	02003800
36	6	06	02000C00		56	V	1F	00000000		76	v	1F	00000000
37	7	07	02000E00		57	W	20	02003A00		77	w	20	02003A00
38	8	08	02001000		58	X	21	00000000		78	x	21	00000000
39	9	09	02001200		59	Y	22	02003C00		79	y	22	02003C00
3A	:	-	-		5A	Z	23	00000000		7A	z	23	00000000
3B	;	-	-		5B	[	-	-		7B	{	-	-
3C	<	-	-		5C	\	-	-		7C	|	-	-
3D	=	-	-		5D	]	-	-		7D	}	-	-
3E	>	-	-		5E	^	-	-		7E	~	-	-
3F	?	26	00000000		5F	_	-	-		7F		-	-

• https://sites.google.com/site/kazemario64/printstr-x-y-string