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Vintage Computers Any vintage computer systems, calculators, video games etc., but with an emphasis on 1980s and earlier equipment.

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Old 30th Nov 2023, 6:48 pm   #21
SiriusHardware
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Default Re: EPROM questions

There are people having trouble reading Intel 2716s on all sorts of programmers in this thread over on vcfed,

https://forum.vcfed.org/index.php?th...eprom.1241971/

...seems you are not alone and the problem is not limited only to you and your STAG programmer.
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Old 30th Nov 2023, 7:21 pm   #22
Mark1960
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Default Re: EPROM questions

I’m curious if this might be because programmers have a slower read cycle than the systems the 2716s are from. Maybe there is a change in the charge from each data cell as it is being read, reading correct data in 500ns but not for a longer read cycle.
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Old 30th Nov 2023, 8:53 pm   #23
ScottishColin
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Default Re: EPROM questions

If anyone's able to turn the source code here into a 2k .bin file I'll try that too.

But not for a week or so as I'm away and on the way back picking up the 8032, two printers and a disk drive. Can't wait

https://github.com/LenShustek/Nestar...'s_Toolkit

Colin.
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Old 1st Dec 2023, 11:28 am   #24
SiriusHardware
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Default Re: EPROM questions

The link in your post above comes up 'not found' for me.

I don't know if you spotted it but one of the respondents in the vcfed thread said he had been able to read the 2716s which would not read as actual 2716 devices by selecting device type 28C16 instead -

If it works, this will only work for reading them, not for programming as the programming regime for 28Cxx devices is completely different.
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Old 1st Dec 2023, 3:25 pm   #25
ScottishColin
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Default Re: EPROM questions

That should have been the same link as in post 18 - try that one.

I'll retry the Intel 2716 when I'm back.

Colin.
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Old 1st Dec 2023, 5:54 pm   #26
SiriusHardware
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Default Re: EPROM questions

I doubt it, you'll be otherwise engaged

That first link in post #18 does work for me - apparently you can't copy a URL link from a post and paste it into another post, as you may possibly have done in #23 - I got zapped by that same quirk several weeks ago.
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Old 8th Dec 2023, 7:14 pm   #27
ScottishColin
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Default Re: EPROM questions

Confirmed that the Intel D2716 reads just fine on my Stag PP39 if I configure it as a (Motorola) 2816.

Colin.
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Old 8th Dec 2023, 7:32 pm   #28
SiriusHardware
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Default Re: EPROM questions

Well, at least that is a workaround for you although I can't even begin to explain why it does work and the 'native' 2716 reading mode doesn't.
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Old 22nd Dec 2023, 11:35 pm   #29
Alan Bain
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Default Re: EPROM questions

I may be missing something, but I don't suppose you've hit the awful TMS2716 problem. Some very old programmer documentation calls them 2716s which is even more confusing since they need three supply rails unlike 2716s from any other mfr. For reading purposes (obviously not programming) 2516 often selects a more standard configuration for reading a non TMS chip.
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Old 21st Jan 2024, 7:28 pm   #30
mm1234
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Cool Re: EPROM questions

The 39M100 module that I believe is being used with the Stag PP39 is interesting because it has the ability to test access times of EPROMs. No other module for the PP3x or PP4x can do this.

The procedure is documented on page 5.6-01 of the PP39 manual here.

With a known good EPROM you turn the pot on the module to min, use Set 7 to verify. If it fails turn the pot towards max and try again. Repeat this until it passes when you press Set F7 and you measure the pulse length with a scope.

Alternatively you calibrate the module with a scope for a certain access time adjusting the pot using Set F7 and then use Set 7 to check that the EPROMs verify ok.

I do not know if the setting is used for Read from EPROM also, normally the pot should be always set to max if this feature is not used.

Is the pot turned fully clockwise pointing to "max" ?

If the EPROM really was manufactured in 1977 and not just marked with a "Copyright 1977" then it will be really slow and the max delay for the module may not be large enough.
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