Programming Bipolar PROMs

Glen Slick glen.slick at
Mon Sep 27 14:05:26 CDT 2021

On Mon, Sep 27, 2021 at 11:20 AM Brent Hilpert via cctalk
<cctalk at> wrote:
> The 82S23 programming algorithm is in the 1975 Signetics Bipolar Memories databook (also on bitsavers).
> Looks like it may be a little more complex than that for the 188.
Page 91, timing diagram on Page 92


1. Terminate all device outputs with a 10K Ohm resistor to Vcc.

2. Select the address to be programmed, and raise Vcc to Vccp = +10 ± 0.5V.

3. After 10us delay, apply Iout = 65 ± 3mA to the output to be
programmed. Program one output at a time.

4. After 10us delay, pulse the /CE input to logic low for 0.3 to 0.5us.

5. After 10us delay, remove Iout from the programmed output.

6. After 10us delay, return Vcc to 0V.

7. To verify programming, after 50us delay, raise Vcc to Vcch = +5.5 ±
0.2V, and apply a logic low level to the /CE input. The programmed
output should remain in the high state. Again, lower Vcc to Vccl =
+4.5 ± 0.2V, and verify that the programmed output remains in the high

8. Raise Vcc to Vccp = +10 ± 0.5V and repeat steps 3 through 7 to
program other bits at the same address.

9. After 10us delay, repeat steps 2 through 8 to program all other
address locations.
Page 24, timing diagram on Page 25

Same as above, except different timing in step 4.

4. After 10us delay, pulse the /CE input to logic "0" for 1 to 2 ms.

(of course in case of typos above, refer to the manuals)

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