>Thanks to Bryan Christopher Turner for original pinout
>Several pins has been added by Johan Borg johbo050@student.liu.se
Pin # / What it does
1 / R6
2 / R7 used for battery level detection in the TI89
3 / R8 -"-
4 / R8 -"-
5 / LCD FS normaly a pulse every 11ms (90Hz)
6 / LCD BS normaly ~740 kHz
7 / LCD ? 50/50 45Hz
8 / LCD RS norm pulse every 88uS (11.5kHz)
9..12 / LCD data
13 / Gnd
14 / Vcc
15 / reset?
16 / CS4/ (memory at $C0 0000, note that this signal was found because of what appears a bug
17 / CE1/ (ROM at $40 0000) ; in some keypressed-detecting code, which generates a
18 / CE odd byte ; write to somewhere in this area for some keys,
19 / CE even byte ; might be bad if you use this signal for access to extra ram)
20 / R/W
21 / CE2 (RAM chip select)
22 / D1
23 / D4
24 / D10
25 / D3
26 / D9
27 / D2
28 / D8
29 / D1
30 / CE3/ (ROM at $20 000)
31..38 / A1..A8
39..40 / A18..A19
41 / Vcc
42 / Gnd
43 / D4
44 / D12
45 / D5
46 / D13
47 / D6
48 / D14
49 / D7
50 / D15
51..59 / A17..A9
60 / ? (seams to output exactly the same thing as pin 51/A17
61 / A20
62 / link out (tip) (to base of transistor in Q1)
63 / link out (ring) (to base of transistor in Q1)
64 / link in (tip) (connected to pullup resistor, connected to port via D10 and L2)
65 / link in (ring) (connected to pullup resistor, connected to port via D10 and L3)
66 / Vcc
67 / Gnd
68 / OSC2/2 used for voltage multiplier generating ~16v for the LCD
69 / pin 68 inverted used for voltage multiplier generating ~16v for the LCD
70..73 / LCD constrast LSB-MSB
74 / low=LCD on
75..80 / R0-R5
81
82 / ON key
83 / C0
84 /
85 / Gnd(?)
86 / Vcc(?)
87 / OSC 2 in
88 / C1
89 / OSC 2 out
90..91 / C2..C3
92 / OSC 1 out
93 / C4
94 / OSC 1 in
95
96..98 / C5..C7
99 / used as the input for battery level detection. (can be set to output by using 600000:6,4
100 / output-pin, controlled by $600000:7,5 used for LSB in contrast on TI-92, unused on TI-89
Rx = keyboard ROW address line
Cx = keyboard COLUMN line
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