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JAC
Joined: 24 Jul 2005
Posts: 3469
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 Posted: Sat Apr 29, 2006 2:11 pm Post subject: Eprom Tester: Back burner project ( of many ). |
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Eprom Tester.
Continuing my desire to be able to TEST this old stuff, I have decided to make an eprom tester. The general concensus seems to be to start with the 1702. The non-user friendly voltages arent a problem.
What I need is your thoughts on what I should do in the test.
I have some ideas of the hardware layout, and of course "modern" eproms can be supported through firmware upgrades. I'll incorporate a LCD for easy reading. Seperate UV erasure box needed, or some bug lights 
Put your thoughts below................. |
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debs3759
Joined: 18 Jan 2006
Posts: 9477
Location: Northampton, Divided Kingdom
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| Posted: Sat Apr 29, 2006 2:24 pm Post subject: |
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I haven't looked at any eprom datasheets yet, so my questions might be stupid ones
Do most eproms have a standard pin-out? Do they use the same voltages? When did eproms include a device and/or manufacturer code as standard?
I'd like to see the device/manufacturer codes used to help identify an eprom, so that an unknown device can be plugged in and identified, if that can be done.
If there are some that have standard interfaces and some that don't, then I'd like to see a way to adapt a device fr testing the various types.
If there is a way to get beyond just determining the device class and actually display exactly what it is, then that would be even better, but I imagine that's the same as with CPUs, where coding can only determine a limited amount of info.
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Debs |
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JAC
Joined: 24 Jul 2005
Posts: 3469
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| Posted: Sat Apr 29, 2006 2:27 pm Post subject: |
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| The datasheet for the 1702 is on my other desk, so from memory I think -48V for programming strobes. |
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JAC
Joined: 24 Jul 2005
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| Posted: Sat Apr 29, 2006 3:09 pm Post subject: |
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I cant see it being possible to produce a universal tester able to identify devices debs  pin outs are different, timing cycles are different and memory sizes are different. What is possible is to select the DUT ( device under test)... then the appropriate test can be carried out. I have my own ideas as what to do in a memory test, but I'd liek to hear other suggestions. |
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CPUShack
Joined: 16 Jun 2003
Posts: 34259
Location: State of Jefferson, USA
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JAC
Joined: 24 Jul 2005
Posts: 3469
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| Posted: Sun May 07, 2006 8:27 am Post subject: |
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Finally found some spare time to test some ideas before bringing in a microcontroller and a PCB.
I seem to have many 2708 eprom.. very strange.. anyway.. first victim up. Works well.. -5V +5V and 12V just to read the chip & +25V pulse to program, so not too bad.
Last edited by JAC on Tue May 30, 2006 5:07 am; edited 1 time in total |
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JAC
Joined: 24 Jul 2005
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Sergey
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| Posted: Sun Sep 14, 2008 10:25 am Post subject: |
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Can you possible give me hint, how is best to generate negative voltage?
I don't know, if ICL7660 can handle the current required for 2708 |
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JAC
Joined: 24 Jul 2005
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| Posted: Sun Sep 14, 2008 11:57 am Post subject: |
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| 7660 should be ok. I used a +5/-5V DC DC converter attached on another circuit. |
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