Advance Gameboy CPU Pinouts (CPU AGB)
1 VDD3 17 D0 33 A0 49 WA4 65 VDD2 81 WD9 97 LDB5 113 CK1
2 IN35 18 A15 34 /CS 50 WA5 66 WD5 82 WD1 98 LDB4 114 CK2
3 TP8 19 A14 35 /RD 51 WA6 67 WD13 83 /WOE 99 LDB3 115 VDD2
4 TP0 20 A13 36 /WR 52 WA7 68 WD6 84 DCK 100 LDB2 116 GND
5 TP1 21 A12 37 PHI 53 /WLB 69 WD14 85 LP 101 LDB1 117 VDD2
6 SO1 22 A11 38 VDD35 54 /WUB 70 WD7 86 PS 102 GND 118 VCNT5
7 SO2 23 A10 39 GND 55 /WWE 71 WD15 87 LDR5 103 VDD3 119 TP9
8 Vin 24 A9 40 SC 56 WA8 72 WD8 88 LDR4 104 SPL 120 TP6
9 /RES 25 A8 41 SD 57 WA9 73 WD16 89 LDR3 105 CLS 121 TP5
10 D7 26 A7 42 SI 58 WA10 74 WA16 90 LDR2 106 SPS 122 TP7
11 D6 27 A6 43 SO 59 WA11 75 WD12 91 LDR1 107 MOD 123 TP4
12 D5 28 A5 44 VDD2 60 WA12 76 WD4 92 LDG5 108 REVC 124 /FIQ
13 D4 29 A4 45 WA0 61 WA13 77 WD11 93 LDG4 109 GNDed 125 /RESET
14 D3 30 A3 46 WA1 62 WA14 78 WD3 94 LDG3 110 GNDed 126 TP2
15 D2 31 A2 47 WA2 63 WA15 79 WD10 95 LDG2 111 GNDed 127 TP3
16 D1 32 A1 48 WA3 64 GND 80 WD2 96 LDG1 112 GNDed 128 GND
SO it looks like pins 6 and 7 are what we're looking for...
I'll pull mine apart and get back with you.
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So probing around, I have found TP30 and TP31 respectively are places to tap into. The board however doesn't have any passive components, so you'll probably need to add a few caps and resistors from these test points.
I'll look at the GBA's schematic for some nintendo-recommended values.
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ok, looks like the suggested prosound for an original gba is to connect to R30 and R31, which are 47k resistors, but unlike the DMG and pokect there are no coupling caps to worry about. So I guess you can locate a few 47k resistors and solder them to TP30 and TP31 and just connect that to a headphone jack.
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sources:
https://dragaosemchama.com/wp-content/u … Manual.pdf
https://chipmusic.org/forums/post/250576/#p250576
https://gbhwdb.gekkio.fi/consoles/gbs/
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It probably wouldn't hurt to slap a massive electrolytic cap on the power rail near the cpu. 1000uF or so.
Positive pin to vcc and negative pin to gnd.
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