A Simple EPROM Programmer for the Motorola D2 Kit. Add 2K of firmware using a handful of components that fit right on the D2 board. Frank W. Summers. , , , , , , 27C, , 27C, , 27C, 27C, , , EPROM series. EPROM and CMOS. ON-BOARD EPROMS. ·-··~)epar:;t-;; -socket or (31< of EPRO~1s. /\ddressable by DIP swi tch to any 14K or br. bound,lry al)()vc.

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Stored charge on these isolated gates changed their properties. However, these require many weeks lead time to make, since the artwork for an IC mask layer must be altered to store data on the ROMs.

2708 / 2704 EPROM reader / programmer

This page was last edited on 8 Novemberat Like EPROM chips, such microcontrollers came in windowed expensive versions that were used for debugging and program development. This is simple and inexpensive.

We must simply set the A1 digital port connected to pin 22 of the EPROM to zero, and read only the values between 0 and All articles with unsourced statements Articles with unsourced statements from October Commons category link from Wikidata Wikipedia articles with GND identifiers. Rarely do you get to SEE the result of these process changes. In a production environment, it is cheaper to have a single production line making dies that can be used in more then one device, then having an entire seperate production line just to make a product that may not be the most popular.


This certainly was not an uncommon procedure, even Intel regularly sold EPROMs as swhether to use a die with an imperfection, or to simply meet demand.

Later documentation simply has Pin 19 listed as GND. Photons of the UV light cause ionization within the silicon oxide, which allow the stored charge on the floating gate to dissipate. Views Read Edit View history.

EPROM | The CPU Shack Museum

To erase the data stored in the array of transistors, ultraviolet light is directed onto the die. In other projects Wikimedia Commons. The effects of this process on the reliability of the part would have required extensive testing so they decided on the window instead.

This prompted larger capacity devices to introduce a “signature mode”, allowing the manufacturer and device to be identified by the EPROM programmer. Erasure, however, has to be accomplished by non-electrical methods, since the gate electrode is not accessible electrically.


Sorry, your blog cannot share posts eeprkm email. The design was altered to work with the new, smaller process, and it was significant enough to warrant a new copyright.

This page describes a EPROM Programmer for type EPROMS

This quality mark was used to signify that products met the eerpom conditions:. Retrieved from ” https: Archived PDF from the original on Please write us about any error, missing part or comments!

We are in the process of creating the burning part needed in our circuit board, the PIC software and the corrispondent burning utility in Python. EPROMs are particularly nice as due to the fact that they need a window to allow UV light in for erasure, you can also have a clear shot of the die in most cases. An insulating layer of oxide is grown over the channel, then a conductive silicon or aluminum gate electrode is deposited, and a further thick layer of oxide is deposited over the gate electrode.


Intel sought to remedy this with the release of the 87C 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. EPROMs had a limited but large number of erase cycles; the silicon dioxide around the gates would accumulate damage from each cycle, making the chip unreliable after several thousand cycles.

First, the National Semiconductor die looked suspiciously like the Intel die. Facebook Twitter Google Email Print. It was soon found that small-volume production was economical with EPROM parts, particularly when the advantage of rapid upgrades of firmware was considered. National also using a die.

When the high voltage is removed, the electrons are trapped on the electrode.