Pin Maps

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Pin Maps

Which pin is which, for every chip family Firestarter drives.

Line pin 1 up with the notch at the socket's lever end. Pin 1 is the end marked by the notch or the dot on the package.

Check the programming voltage before you power anything. The 24-pin UV families run up to 25 V on VPP, and the voltage varies by part. A family listed as having no VPP pin never sees a boosted rail at all.

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Pin 21 is not the same on every 24-pin chip

On the 24-pin UV-EPROM families — 2716, 2732 and relatives — pin 21 is the programming voltage pin, and it carries up to 25 V.

On the 24-pin 5 V EEPROM families it is write enable, and no high voltage reaches the socket at all.

The two layouts are otherwise identical. That is why Firestarter picks the layout from the part number rather than from the pin count.

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The pin maps

TI 2532 (4KB) — non-JEDEC 24-pin UV-EPROM (DIP24_2532)

Programming voltage 25.0 V, read voltage 5.0 V.

VPP pin: pin 21

Pin	Signal	Pin	Signal
1	A7	13	D3
2	A6	14	D4
3	A5	15	D5
4	A4	16	D6
5	A3	17	D7
6	A2	18	A11
7	A1	19	A10
8	A0	20	/CE
9	D0	21	VPP
10	D1	22	A9
11	D2	23	A8
12	GND	24	tied high

JEDEC 2716 (2KB) (DIP24_2716)

Programming voltage 25.0 V, read voltage 5.0 V.

VPP pin: pin 21

Pin	Signal	Pin	Signal
1	A7	13	D3
2	A6	14	D4
3	A5	15	D5
4	A4	16	D6
5	A3	17	D7
6	A2	18	/CE
7	A1	19	A10
8	A0	20	/OE
9	D0	21	VPP
10	D1	22	A9
11	D2	23	A8
12	GND	24	tied high

JEDEC 2732 (4KB) (DIP24_2732)

VPP pin: pin 20

Pin	Signal	Pin	Signal
1	A7	13	D3
2	A6	14	D4
3	A5	15	D5
4	A4	16	D6
5	A3	17	D7
6	A2	18	/CE
7	A1	19	A10
8	A0	20	/OE
9	D0	21	A11
10	D1	22	A9
11	D2	23	A8
12	GND	24	tied high

JEDEC 24-pin 5V parallel EEPROM (AT28C16/AT28C04 family) (DIP24_2816)

VPP pin: none — 5 V only

Pin	Signal	Pin	Signal
1	A7	13	D3
2	A6	14	D4
3	A5	15	D5
4	A4	16	D6
5	A3	17	D7
6	A2	18	/CE
7	A1	19	A10
8	A0	20	/OE
9	D0	21	/WE
10	D1	22	A9
11	D2	23	A8
12	GND	24	VCC

JEDEC 24-pin 5V SRAM (6116/6264-style) (DIP24_6116)

VPP pin: none — 5 V only

Pin	Signal	Pin	Signal
1	A7	13	D3
2	A6	14	D4
3	A5	15	D5
4	A4	16	D6
5	A3	17	D7
6	A2	18	/CE
7	A1	19	A10
8	A0	20	/OE
9	D0	21	/WE
10	D1	22	A9
11	D2	23	A8
12	GND	24	VCC

JEDEC 27256 (DIP28_27256)

VPP pin: pin 1

Pin	Signal	Pin	Signal
1	VPP	15	D3
2	A12	16	D4
3	A7	17	D5
4	A6	18	D6
5	A5	19	D7
6	A4	20	/CE
7	A3	21	A10
8	A2	22	/OE
9	A1	23	A11
10	A0	24	A9
11	D0	25	A8
12	D1	26	A13
13	D2	27	A14
14	GND	28	VCC

JEDEC 27512 (DIP28_27512)

VPP pin: pin 22

Pin	Signal	Pin	Signal
1	A15	15	D3
2	A12	16	D4
3	A7	17	D5
4	A6	18	D6
5	A5	19	D7
6	A4	20	/CE
7	A3	21	A10
8	A2	22	/OE
9	A1	23	A11
10	A0	24	A9
11	D0	25	A8
12	D1	26	A13
13	D2	27	A14
14	GND	28	VCC

JEDEC 2764/128 (DIP28_2764)

VPP pin: pin 1

Pin	Signal	Pin	Signal
1	VPP	15	D3
2	A12	16	D4
3	A7	17	D5
4	A6	18	D6
5	A5	19	D7
6	A4	20	/CE
7	A3	21	A10
8	A2	22	/OE
9	A1	23	A11
10	A0	24	A9
11	D0	25	A8
12	D1	26	A13
13	D2	27	/PGM
14	GND	28	VCC

JEDEC 28-pin 5V parallel EEPROM (28C256 family) (DIP28_28C256)

VPP pin: none — 5 V only

Pin	Signal	Pin	Signal
1	A14	15	D3
2	A12	16	D4
3	A7	17	D5
4	A6	18	D6
5	A5	19	D7
6	A4	20	/CE
7	A3	21	A10
8	A2	22	/OE
9	A1	23	A11
10	A0	24	A9
11	D0	25	A8
12	D1	26	A13
13	D2	27	/WE
14	GND	28	VCC

JEDEC 28-pin 5V parallel EEPROM 8K (28C64 family) (DIP28_28C64)

VPP pin: none — 5 V only

Pin	Signal	Pin	Signal
1	NC	15	D3
2	A12	16	D4
3	A7	17	D5
4	A6	18	D6
5	A5	19	D7
6	A4	20	/CE
7	A3	21	A10
8	A2	22	/OE
9	A1	23	A11
10	A0	24	A9
11	D0	25	A8
12	D1	26	NC
13	D2	27	/WE
14	GND	28	VCC

JEDEC 28-pin SRAM/FRAM 8K (6264/FM1608 family) (DIP28_JEDEC_SRAM_8K)

VPP pin: none — 5 V only

Pin	Signal	Pin	Signal
1	NC	15	D3
2	A12	16	D4
3	A7	17	D5
4	A6	18	D6
5	A5	19	D7
6	A4	20	/CE
7	A3	21	A10
8	A2	22	/OE
9	A1	23	A11
10	A0	24	A9
11	D0	25	A8
12	D1	26	NC
13	D2	27	/WE
14	GND	28	VCC

JEDEC 32-pin UV-EPROM ≤256K (27C010/27C020 family — PGM on pin 31) (DIP32_27C020)

VPP pin: pin 1

Pin	Signal	Pin	Signal
1	VPP	17	D3
2	A16	18	D4
3	A15	19	D5
4	A12	20	D6
5	A7	21	D7
6	A6	22	/CE
7	A5	23	A10
8	A4	24	/OE
9	A3	25	A11
10	A2	26	A9
11	A1	27	A8
12	A0	28	A13
13	D0	29	A14
14	D1	30	A17
15	D2	31	/WE
16	GND	32	VCC

JEDEC 32-pin 5V parallel EEPROM 64K (28C512 family) (DIP32_28C512_EEPROM)

VPP pin: none — 5 V only

Pin	Signal	Pin	Signal
1	—	17	D3
2	—	18	D4
3	A15	19	D5
4	A12	20	D6
5	A7	21	D7
6	A6	22	/CE
7	A5	23	A10
8	A4	24	/OE
9	A3	25	A11
10	A2	26	A9
11	A1	27	A8
12	A0	28	A13
13	D0	29	A14
14	D1	30	/WE
15	D2	31	—
16	GND	32	VCC

JEDEC 32-pin 5V Flash (SST39SF040/AM29F040 family) (DIP32_SST39SF040)

VPP pin: none — 5 V only

Pin	Signal	Pin	Signal
1	A18	17	D3
2	A16	18	D4
3	A15	19	D5
4	A12	20	D6
5	A7	21	D7
6	A6	22	/CE
7	A5	23	A10
8	A4	24	/OE
9	A3	25	A11
10	A2	26	A9
11	A1	27	A8
12	A0	28	A13
13	D0	29	A14
14	D1	30	A17
15	D2	31	/WE
16	GND	32	VCC

JEDEC 32-Pin Standard (DIP32_STD)

VPP pin: pin 1

Pin	Signal	Pin	Signal
1	VPP	17	D3
2	A16	18	D4
3	A15	19	D5
4	A12	20	D6
5	A7	21	D7
6	A6	22	/CE
7	A5	23	A10
8	A4	24	/OE
9	A3	25	A11
10	A2	26	A9
11	A1	27	A8
12	A0	28	A13
13	D0	29	A14
14	D1	30	A17
15	D2	31	A18
16	GND	32	VCC

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Some 24-pin chips need an adapter

The socket has 32 pins. A 24-pin chip fits physically, but on the AT28C04 and AT28C16 families one signal lands in the wrong place — so those parts are marked adapter-required and will not program without a small adapter.

The signal is write enable. On the chip it is pin 21; the socket carries it on pin 30. Dropped straight in, chip pin 21 meets the socket's D7 line. That is harmless — it is a 5 V logic signal, not a high voltage — but write enable can never be asserted, so the chip reads fine and never writes.

To build the adapter: wire every chip pin straight through to the same-numbered socket pin, except these five.

Chip pin	Signal	Goes to socket pin
19	A10	23
21	/WE	30
22	A9	26
23	A8	27
24	VCC	32

Leave socket pins 1, 3, 4, 25, 28, 29 and 31 unconnected.

You cannot damage a chip by wiring this wrong. Neither layout has a programming-voltage pin, so the worst case is a chip that will not read or will not write.

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The shield's own wiring — which Arduino pin drives which RURP signal, and the control-register bits behind them — is in PINOUTS.md in the firmware repository.