Talk:EPROM

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Is the table in this article up to date? I can't believe the largest EPROM is only 512kb. sjorford →•← 10:02, 21 Mar 2005 (UTC)

The table isn't really inclusive. It only lists one family of devices. There are larger ones, but I've never heard of one > 20 megs. Certainly, the common ones are all pretty small. - Bryce —Preceding unsigned comment added by 66.81.40.136 (talk • contribs)

Contents 1 First EPROM 2 how does it work 3 Erasure 4 Electrically programmable rom? 5 What does the UV actually do? 6 Re-programmable EPROM?

[edit] First EPROM

The first EPROM was the 1702 (256x8 = 2k memory) used to store the firmware or boostrap of the first microcomputers or programmable calculators. —Preceding unsigned comment added by Cl barbot (talk • contribs)

[edit] how does it work

How does an EPROM work? I think that there is missing that part. Explanation of EPROM memory cell work.--Čikić Dragan 16:28, 2 February 2006 (UTC)

I don't know the details but i belive there is a "floating gate" on the transistors which can be charged using a higher voltage than that used for normal operation and discharged using UV light. Plugwash 01:26, 8 July 2006 (UTC)

[edit] Erasure

It says it can be programmed electrically, but can only be erased by UV light. Does that mean that once the chip has been programmed, you are unable to overwrite the settings with electrical signals? Does the chip need to be erased via UV light to change any programming?

Yes, EEPROMS are the only ones that can be erased electrically —Preceding unsigned comment added by 67.177.254.247 (talk • contribs)

Not quite, when erased an EPROM will go into a blank state (all zeros or all ones depending on its design), you can then electrically flip bits out of the blank state but you can't flip them back again. Plugwash 01:28, 8 July 2006 (UTC)

[edit] Electrically programmable rom?

Please note this: I read in some books that EPROM means Electrically Programmable ROM, and not Eraseable Programmable ROM. If other users confirm this, please correct the article. —Preceding unsigned comment added by 151.56.233.30 (talk • contribs)

which books? i've certainly never seen this before and proms are also programmed electrically. Plugwash 01:17, 8 July 2006 (UTC)

[edit] What does the UV actually do?

I understand the basics of the programming side, the floating gate, but how exactly does the UV erase the data? Maury 12:16, 1 August 2006 (UTC)

[edit] Re-programmable EPROM?

Can I reprogram the EPROM after erasing it or how many time could I reprogram it?