Editing EPROM (section)

== EPROM generations, sizes and types ==
The first generation 1702 devices were fabricated with the [[PMOS logic|p-MOS]] technology. They were powered with V<sub>CC</sub> = V<sub>BB</sub> = +5&nbsp;V and V<sub>DD</sub> = V<sub>GG</sub> = -9&nbsp;V in Read mode, and with V<sub>DD</sub> = V<sub>GG</sub> = -47&nbsp;V in Programming mode.<ref>{{Cite web|url=http://kormus.cz/mvt/datasheety/C1702A.pdf|title=Intel 1702A 2K (256 x 8) UV Erasable PROM}}</ref><ref>{{Cite web|url=http://pdf-file.ic37.com/PdfOld/icpdf_datasheet_8/AM170_datasheet_84155/137654/AM170_datasheet.pdf|title=AMD Am1702A 256-Word by 8-Bit Programmable Read Only Memory|access-date=2018-01-19|archive-date=2018-01-19|archive-url=https://web.archive.org/web/20180119120409/http://pdf-file.ic37.com/PdfOld/icpdf_datasheet_8/AM170_datasheet_84155/137654/AM170_datasheet.pdf|url-status=dead}}</ref>

The second generation 2704 / 2708 devices switched to [[NMOS logic|n-MOS]] technology and to three-rail V<sub>CC</sub> = +5&nbsp;V, V<sub>BB</sub> = -5&nbsp;V, V<sub>DD</sub> = +12&nbsp;V power supply with V<sub>PP</sub> = 12&nbsp;V and a +25&nbsp;V pulse in Programming mode. 

The third generation 2716 / 2732 devices upgraded to an evolved n-MOS technology that required only a single-rail V<sub>CC</sub> = +5&nbsp;V power supply for read operations, and a single V<sub>PP</sub> = +25&nbsp;V<ref name="I2716">{{cite web |title=16K (2K x 8) UV ERASABLE PROM |url=https://amigan.yatho.com/2716EPROM.pdf |website=amigan.yatho.com |publisher=Intel |access-date=18 April 2020 |archive-date=13 September 2020 |archive-url=https://web.archive.org/web/20200913213609/https://amigan.yatho.com/2716EPROM.pdf |url-status=dead }}</ref> programming voltage without pulse.  The unneeded V<sub>BB</sub> and V<sub>DD</sub> pins were reused for additional address bits allowing larger capacities (2716 / 2732) in the same 24-pin package, and even larger capacities with larger packages.
Later the decreased cost of the [[CMOS logic|CMOS]] technology allowed the same devices to be fabricated using it, adding the letter "C" to the device numbers (27xx(x) are n-MOS and 27Cxx(x) are CMOS).

While parts of the same size from different manufacturers are compatible in read mode, different manufacturers added different and sometimes multiple programming modes leading to subtle differences in the programming process. This prompted larger capacity devices to introduce a "signature mode", allowing the manufacturer and device to be identified by the EPROM programmer. It was implemented by forcing +12&nbsp;V on pin A9 and reading out two bytes of data. However, as this was not universal, programmer software also would allow manual setting of the manufacturer and device type of the chip to ensure proper programming.<ref name = "Silicon Signature">{{Cite book | editor = U.S. International Trade Commission | title = Certain EPROM, EEPROM, Flash Memory and Flash Microcontroller Semiconductor Devices and Products Containing Same, Inv. 337-TA-395 | publisher = Diane Publishing | date = October 1998 | pages = 51–72 | url = https://books.google.com/books?id=fkd0fwh9N2UC&pg=PA51 | isbn = 1-4289-5721-9}} The details of SEEQ's Silicon Signature method of a device programmer reading an EPROM's ID.</ref>

{| class="wikitable" style="text-align:center"
|-
! EPROM Type !! Year !! Size — [[bit]]s !! Size — [[byte]]s !! Length ([[hexadecimal|hex]]) !! Last address ([[hexadecimal|hex]]) !! Technology
|-
| 1702, 1702A || 1971 || 2 [[kilobit|Kbit]] || 256 || 100 || FF || PMOS
|-
| 2704 || 1975 || 4 Kbit || 512 || 200 || 1FF || NMOS
|-
|IM6654 ||      || 4 Kbit || 512 || 200 || 1FF || CMOS
|-
| 2708 || 1975 || 8 Kbit || 1 [[Kilobyte|KB]] || 400 || 3FF || NMOS
|-
| 2716, 27C16, TMS2716, 2516 || 1977 || 16 Kbit || 2 KB || 800 || 7FF || NMOS/CMOS
|-
| 2732, 27C32, 2532 || 1979 || 32 Kbit || 4 KB || 1000 || FFF || NMOS/CMOS
|-
| 2764, 27C64, 2564 || || 64 Kbit || 8 KB || 2000 || 1FFF || NMOS/CMOS
|-
| 27128, 27C128 || || 128 Kbit || 16 KB || 4000 || 3FFF || NMOS/CMOS
|-
| 27256, 27C256 || || 256 Kbit || 32 KB || 8000 || 7FFF || NMOS/CMOS
|-
| 27512, 27C512 || || 512 Kbit || 64 KB || 10000 || FFFF || NMOS/CMOS
|-
| 27C010, 27C100 || || 1 [[Megabit|Mbit]] || 128 KB || 20000 || 1FFFF || CMOS
|-
| 27C020 || || 2 Mbit || 256 KB || 40000 || 3FFFF || CMOS
|-
| 27C040, 27C400, 27C4001 || || 4 Mbit || 512 KB || 80000 || 7FFFF || CMOS
|-
| 27C080 || || 8 Mbit || 1 [[Megabyte|MB]] || 100000 || FFFFF || CMOS
|-
| 27C160 || || 16 Mbit || 2 MB || 200000 || 1FFFFF || CMOS
|-
|  27C320, 27C322 || || 32 Mbit || 4 MB || 400000 || 3FFFFF || CMOS
|}

[[File:K573RF1.jpg|thumb|alt=EEPROM 8kbit|K573RF1]]
[[File:K573RF1 (16).jpg|thumb|EPROM 8kbit - detail of 4 bits]]