Table of Contents

Display details

To be honnest, even I do not know, nor care about these details (Cyrille). Don't bother about this and just download the graphics.cpp file in the HP sdk where you will find 4 functions:

DrawGraphic (draws a 43*6 graphics in the dot matrix area)

DrawText (displays text in the 43*6 graphics in the dot matrix area)

DrawNumber (displays numbers in the number area).

(Someone else needs to double check this.)

"Hardwired" display indicators (non-changeable)

Segment Address Value
Big equals 0xfffb420c 0x80
360 0xfffb4214 0x80
RPN 0xfffb4214 0x40
RAD 0xfffb421c 0x80
RCL 0xfffb4224 0x80
STO 0xfffb422c 0x80
BEG 0xfffb4234 0x80
Battery symbol 0xfffb423c 0x80
Tiny equals 0xfffb4244 0x80
Input 0xfffb424c 0x80
Shift 0xfffb4204 0x80

Programmable LCD segments

Here's what I worked up on the main digit and exponent area.

Digit Segment Address Value
(leading negative) c 0xfffb4228 0x40
0 a 0xfffb4210 0x80
0 b 0xfffb4210 0x40
0 c 0xfffb4218 0x80
0 d 0xfffb4210 0x100
0 e 0xfffb4218 0x40
0 f 0xfffb4220 0x40
0 g 0xfffb4220 0x80
0 h 0xfffb4228 0x100
0 i 0xfffb4228 0x80
1 a 0xfffb4210 0x200
1 b 0xfffb4218 0x100
1 c 0xfffb4218 0x200
1 d 0xfffb4218 0x400
1 e 0xfffb4220 0x100
1 f 0xfffb4220 0x200
1 g 0xfffb4220 0x400
1 h 0xfffb4228 0x400
1 i 0xfffb4228 0x200
2 a 0xfffb4210 0x800
2 b 0xfffb4210 0x400
2 c 0xfffb4218 0x800
2 d 0xfffb4210 0x1000
2 e 0xfffb4220 0x800
2 f 0xfffb4228 0x800
2 g 0xfffb4218 0x1000
2 h 0xfffb4220 0x1000
2 i 0xfffb4228 0x1000
3 a 0xfffb4210 0x4000
3 b 0xfffb4210 0x2000
3 c 0xfffb4218 0x2000
3 d 0xfffb4218 0x4000
3 e 0xfffb4220 0x2000
3 f 0xfffb4228 0x2000
3 g 0xfffb4220 0x4000
3 h 0xfffb4220 0x8000
3 i 0xfffb4228 0x4000
4 a 0xfffb4210 0x10000
4 b 0xfffb4210 0x8000
4 c 0xfffb4218 0x10000
4 d 0xfffb4210 0x20000
4 e 0xfffb4218 0x8000
4 f 0xfffb4228 0x8000
4 g 0xfffb4220 0x10000
4 h 0xfffb4228 0x20000
4 i 0xfffb4228 0x10000
5 a 0xfffb4210 0x40000
5 b 0xfffb4218 0x20000
5 c 0xfffb4218 0x40000
5 d 0xfffb4218 0x80000
5 e 0xfffb4220 0x20000
5 f 0xfffb4220 0x40000
5 g 0xfffb4220 0x80000
5 h 0xfffb4228 0x80000
5 i 0xfffb4228 0x40000
6 a 0xfffb4210 0x100000
6 b 0xfffb4210 0x80000
6 c 0xfffb4218 0x100000
6 d 0xfffb4210 0x200000
6 e 0xfffb4220 0x100000
6 f 0xfffb4228 0x100000
6 g 0xfffb4218 0x200000
6 h 0xfffb4220 0x200000
6 i 0xfffb4228 0x200000
7 a 0xfffb4210 0x800000
7 b 0xfffb4210 0x400000
7 c 0xfffb4218 0x400000
7 d 0xfffb4218 0x800000
7 e 0xfffb4220 0x400000
7 f 0xfffb4228 0x400000
7 g 0xfffb4220 0x800000
7 h 0xfffb4220 0x1000000
7 i 0xfffb4228 0x800000
8 a 0xfffb4210 0x2000000
8 b 0xfffb4210 0x1000000
8 c 0xfffb4218 0x2000000
8 d 0xfffb4210 0x4000000
8 e 0xfffb4218 0x1000000
8 f 0xfffb4228 0x1000000
8 g 0xfffb4220 0x2000000
8 h 0xfffb4228 0x4000000
8 i 0xfffb4228 0x2000000
9 a 0xfffb4210 0x8000000
9 b 0xfffb4218 0x4000000
9 c 0xfffb4218 0x8000000
9 d 0xfffb4218 0x10000000
9 e 0xfffb4220 0x4000000
9 f 0xfffb4220 0x8000000
9 g 0xfffb4220 0x10000000
9 h 0xfffb4228 0x10000000
9 i 0xfffb4228 0x8000000
10 a 0xfffb4210 0x20000000
10 b 0xfffb4210 0x10000000
10 c 0xfffb4218 0x20000000
10 d 0xfffb4210 0x40000000
10 e 0xfffb4220 0x20000000
10 f 0xfffb4228 0x20000000
10 g 0xfffb4218 0x40000000
10 h 0xfffb4220 0x40000000
10 i 0xfffb4228 0x40000000
11 a 0xfffb4214 0x1
11 b 0xfffb4210 0x80000000
11 c 0xfffb4218 0x80000000
11 d 0xfffb421c 0x1
11 e 0xfffb4220 0x80000000
11 f 0xfffb4228 0x80000000
11 g 0xfffb4224 0x1
11 h 0xfffb422c 0x2
11 i 0xfffb421c 0x1
negative exponent (-) 0xfffb421c 0x2
12 a 0xfffb4214 0x4
12 b 0xfffb4214 0x2
12 c 0xfffb4224 0x4
12 d 0xfffb421c 0x4
12 e 0xfffb4224 0x2
12 f 0xfffb422c 0x4
12 g 0xfffb422c 0x8
13 a 0xfffb4214 0x10
13 b 0xfffb4214 0x8
13 c 0xfffb421c 0x8
13 d 0xfffb421c 0x10
13 e 0xfffb4224 0x8
13 f 0xfffb422c 0x10
13 g 0xfffb4224 0x10
14 a 0xfffb421c 0x40
14 b 0xfffb4214 0x20
14 c 0xfffb421c 0x20
14 d 0xfffb4224 0x40
14 e 0xfffb4224 0x20
14 f 0xfffb422c 0x20
14 g 0xfffb422c 0x40

Digit zero at the left. Digits 12, 13, and 14 are the small exponent digits.

Individual LCD character segment legend

Segment Position
a Top center horizontal
b Top left vertical
c Center horizontal
d Top right vertical
e Bottom left vertical
f Bottom center horizontal
g Bottom right vertical
h Decimal point
i Comma

Contrast control

LCD contrast seems to be controlled by the low 4 bits of SUPV_MR (0xfffffd18). Be sure that you write the access key to the high byte so that changes to SUPV_MR will be accepted.