Hackers' Pub

Syntax	Description	Examples
`"` keyword `"`	Finds the string within quotes, including spaces. Case-insensitive. (Escape quotes inside with `\"`)	`"Hackers' Pub"`
`from:` handle	Finds content written by the specified user.	`from:hongminhee` `from:hongminhee@hollo.social`
`lang:` ISO 639-1	Finds content written in the specified language.	`lang:en`
`#` tag	Finds content with the specified tag. Case-insensitive.	`#HackersPub`
condition condition	Finds content that satisfies both conditions on either side of the space (logical AND).	`"Hackers' Pub" lang:en`
condition `OR` condition	Finds content that satisfies at least one of the conditions on either side of the OR operator (logical OR).	`#HackersPub OR "Hackers' Pub" lang:en`
`(` condition `)`	Combines the operators within the parentheses first.	`(#HackersPub OR "Hackers' Pub" OR "Hackers Pub") lang:en`

Tube🌱Time @tubetime@mastodon.social

5/2/2025, 1:49:16 AM

Public

here are four EPROM cells. the critical element is a transistor (circled) that has a floating gate -- a control electrode with no external connection! modern flash memories also use floating gates, but the construction is quite different.

the basic structure is a select transistor with a gate that is common to the entire row (two tan horizontal lines). the middle light blue region is VCC -- delineated by the faint crenulations. circled in green is a stubby tan bar that is the floating gate.

diagram of the memory cell, showing a y-decoder, x-decoder, output sense, and the basic cell, consisting of a FAMOS device (a FET with a floating gate) and a select transistor.

Tube🌱Time @tubetime@mastodon.social

5/2/2025, 1:49:49 AM

Public

the first EPROM devices were intended to be erased using X-rays, but ultraviolet light turned out to be a more practical method (X-rays can damage chips).

Once programmed, the information pattern in the memory can be erased (restored to the all "1" state) by ultraviolet light before packaging or by exposure to X-ray radiation as described in Section I. The ability to erase before packaging allows for complete testing of the memory chip prior to shipment, which is a distinct advantage over once-programmable ROMs. Erasure of information in packaged devices by placing them in a commercially available X-ray generator allows for correction of programming errors as well as unpredictable future pattern modifications.

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