# Reading EPROM problem **URL:** \ **Category:** General Guidance\ **Created:** [February 26, 2026, 9:25am UTC](https://forum.arduino.cc/t/reading-eprom-problem/1432812 "2026-02-26T09:25:09Z")\ **Posts on this page:** 13\ **Page:** 1
**Author:** ![tonic27](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/tonic27/32/1129064_2.png) [@tonic27](https://forum.arduino.cc/u/tonic27)\ **Post date:** [February 26, 2026, 9:25am UTC](https://forum.arduino.cc/t/reading-eprom-problem/1432812/1 "2026-02-26T09:25:09Z")
Hi, first time here, also a novice at reading eproms etc. I'm having trouble reading this EPROM, could you please help me with this ? I have selected the chip and tried with galep5 reader. But if fails. ![IMG20260226083617](https://europe1.discourse-cdn.com/arduino/original/4X/e/f/8/ef8315ad2b5397de78655ae578a87ae67f2501da.jpeg) ![IMG20260226083612](https://europe1.discourse-cdn.com/arduino/original/4X/8/c/1/8c1af7a632ad05f85301c8550c0dfaa6b9da8387.jpeg) ---
**Author:** ![J-M-L](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/j-m-l/32/766245_2.png) [@J-M-L](https://forum.arduino.cc/u/J-M-L)\ **Post date:** [February 26, 2026, 10:03am UTC](https://forum.arduino.cc/t/reading-eprom-problem/1432812/2 "2026-02-26T10:03:10Z")
Back to last millennium parallel NOR flash designed for direct interfacing with microprocessors (probably from the 1990s) 🙂 The [datasheet](https://docs.rs-online.com/6547/0900766b808c5287.pdf) as always would be a good source for information ![image](https://europe1.discourse-cdn.com/arduino/original/4X/3/6/c/36c55e7fbaf930269ffc00f21d9eaca20ca39d38.png) You will need 21 pins to set the address plus 8 pins to read the byte and manage correctly CE, OE, WE and RY/BY. An arduino Mega would have enough pins, then it's a matter of respecting the details of the "DEVICE BUS OPERATIONS" section of the doc. Those components were unforgiving of timing or voltage deviations - may be your galep5 reader is not fully sticking to the expectations ? ---
**Author:** ![UKHeliBob](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/ukhelibob/32/215663_2.png) [@UKHeliBob](https://forum.arduino.cc/u/UKHeliBob)\ **Post date:** [February 26, 2026, 10:14am UTC](https://forum.arduino.cc/t/reading-eprom-problem/1432812/3 "2026-02-26T10:14:07Z")
> [@tonic27](#): > > I have selected the chip and tried with galep5 reader @J-M-L At the moment there appears to be no Arduino involved but @tonic27 has not given us any details @tonic27 What is it that you want to do with this EPROM ? ---
**Author:** ![J-M-L](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/j-m-l/32/766245_2.png) [@J-M-L](https://forum.arduino.cc/u/J-M-L)\ **Post date:** [February 26, 2026, 10:21am UTC](https://forum.arduino.cc/t/reading-eprom-problem/1432812/4 "2026-02-26T10:21:16Z")
> [@UKHeliBob](#): > > At the moment there appears to be no Arduino invo true. Since he posted in "programming", I assumed he wanted to program that but may be it's just miscategorization. ---
**Author:** ![tonic27](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/tonic27/32/1129064_2.png) [@tonic27](https://forum.arduino.cc/u/tonic27)\ **Post date:** [February 26, 2026, 10:26am UTC](https://forum.arduino.cc/t/reading-eprom-problem/1432812/5 "2026-02-26T10:26:47Z")
Sorry if I posted it in the wrong place. I simply want to read it to back it up. ---
**Author:** ![UKHeliBob](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/ukhelibob/32/215663_2.png) [@UKHeliBob](https://forum.arduino.cc/u/UKHeliBob)\ **Post date:** [February 26, 2026, 10:32am UTC](https://forum.arduino.cc/t/reading-eprom-problem/1432812/6 "2026-02-26T10:32:05Z")
So not an Arduino problem at all I have moved your topic to a more relevant forum category ---
**Author:** ![van\_der\_decken](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/van_der_decken/32/1006976_2.png) [@van\_der\_decken](https://forum.arduino.cc/u/van_der_decken)\ **Post date:** [February 26, 2026, 5:10pm UTC](https://forum.arduino.cc/t/reading-eprom-problem/1432812/7 "2026-02-26T17:10:41Z")
> [@tonic27](#): > > I have selected the chip and tried with galep5 reader. But if fails. Fails _how_, exactly? Error message(s)? Flashing light(s)? Smoke being released? Provide details or you're just wasting time. Don't make us play 20 questions. ---
**Author:** ![tonic27](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/tonic27/32/1129064_2.png) [@tonic27](https://forum.arduino.cc/u/tonic27)\ **Post date:** [February 26, 2026, 5:23pm UTC](https://forum.arduino.cc/t/reading-eprom-problem/1432812/8 "2026-02-26T17:23:49Z")
Luckily no smoke ! The software (galep) reports wrong expected chip id. I have tried many other chip devices to try to get it to "see the chip" but I'm struggling ---
**Author:** ![gilshultz](https://avatars.discourse-cdn.com/v4/letter/g/67e7ee/32.png) [@gilshultz](https://forum.arduino.cc/u/gilshultz)\ **Post date:** [February 26, 2026, 5:24pm UTC](https://forum.arduino.cc/t/reading-eprom-problem/1432812/9 "2026-02-26T17:24:48Z")
> [@tonic27](#): > > eproms etc. **Welcome!** Part of your problem is it is not a EPROM: It is 16 Megabit (2 M x 8-Bit) CMOS 5.0 Volt-only, Sector Erase Flash Memory. You can find the die data sheet at: [https://www1.futureelectronics.com/doc/SPANSION/AM29F016D-90ED.pdf](https://www1.futureelectronics.com/doc/SPANSION/AM29F016D-90ED.pdf) ---
**Author:** ![tonic27](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/tonic27/32/1129064_2.png) [@tonic27](https://forum.arduino.cc/u/tonic27)\ **Post date:** [February 26, 2026, 5:38pm UTC](https://forum.arduino.cc/t/reading-eprom-problem/1432812/10 "2026-02-26T17:38:34Z")
Thank you for your help with this, as I'm a novice I guess my next question is can it be read and with what ? Thanks ---
**Author:** ![gilshultz](https://avatars.discourse-cdn.com/v4/letter/g/67e7ee/32.png) [@gilshultz](https://forum.arduino.cc/u/gilshultz)\ **Post date:** [February 27, 2026, 3:55am UTC](https://forum.arduino.cc/t/reading-eprom-problem/1432812/11 "2026-02-27T03:55:18Z")
It can be read with most any processor with additional hardware. What are you going to do with the data after you read it? Are you going to store it in something? I suggest you contact galep5 reader people for support on this piece of hardware. Note: By experimenting you could actually change some of the data in that memory device. ---
**Author:** ![GolamMostafa](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/golammostafa/32/239011_2.png) [@GolamMostafa](https://forum.arduino.cc/u/GolamMostafa)\ **Post date:** [February 27, 2026, 5:00am UTC](https://forum.arduino.cc/t/reading-eprom-problem/1432812/12 "2026-02-27T05:00:26Z")
> [@tonic27](#): > > Thank you for your help with this, as I'm a novice I guess my next question is can it be read and with what ? Try the following "Reader Circuit" (Fig-1). I hope you will be able to read data if you read datasheet carefully and terminate the pin signals properly. ![image](https://europe1.discourse-cdn.com/arduino/original/4X/5/5/7/5579e5c9b3bd89592af4331e1fe01b2c2cfc3d6b.png) Figure-1: **Pseudo Codes:** **1.** Intialialize IO lines as needed. **2.** Read dataseet and bring the chip into read mode. **3.** Assert address A21-A16 A15-A8 A7-A0 ```arduino SPI.transfer(A21-A16); //shifht clock pulses (SCK) are automatically generated SPI.transferA15-A8); SPI.transfer(A7-A0); ``` **4.** Assert ST\_CP signal to latch address **5.** Read data and show on Serial Monitor and chcek the validity **6.** Repeat until all the locations are read. **7.** Reference circuit for 74LS595 's signal termination (Fig-2). ![image](https://europe1.discourse-cdn.com/arduino/original/4X/2/c/3/2c3096b8e1d34d5d7d6d188c09676a43c52233a9.png) Figure-2: ---
**Author:** ![system](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/system/32/1140315_2.png) [@system](https://forum.arduino.cc/u/system)\ **Post date:** [August 26, 2026, 5:00am UTC](https://forum.arduino.cc/t/reading-eprom-problem/1432812/13 "2026-08-26T05:00:50Z")
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