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WTB: EPROM Emulator for 2716

TI threw a monkey-wrench into the works with their "2716". The predecessor -- 2708 -- required multiple supplies. Intel (and the rest of the Japanese suppliers) introduced

*the* 2716 as a "5V only" part (still needed Vpp for programming but could *run* the chip off 5V alone -- no need for multiple supplies).

Folks quickly realized that they did NOT want TI's parts (purchasing agents who thought 2716 == 2716 soon learned that this was not the case... recall that 2716's were approaching the $50/ea price at one point so a naive purchasing agent could easily screw himself by "finding" a bunch of "2716's" at a "real good price" :> ). So, TI had to come up with a "TI" 2716 -- though they already had used the 2716 P/N. Hence the 2516 was born. (i.e., a TI 2516 is the same as an intel 2716)

Not content with shooting themselves in the foot with *their*

2716, TI then went on -- in their infinite stupidity -- to shoot themselves in the *other* foot by coming out with a 2532 THAT WAS NOT EQUIVALENT to the rest of the world's 2732!

Point being: make sure you know *which* chip you are trying to emulate.

As an aside, it is amusing to look back at the die for these devices. Intel had these *tiny* die while folks like Hitachi had these big monstrosities (though functionally equivalent). Yet, they (Hitachi) managed to make a good show of it (financially). Probably had Milo Minderbinder on their sales staff :-/

--don

Reply to
D Yuniskis
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Hi Don,

I think I remember there was some sort of a mess with these but I am not sure how far it went (did it affect read etc.). Perhaps I never saw an abnormal TI part, I think I remember the 25 instead of the 27 though. Of course I do remember the 2708 with its +5, +12 and -5 volts but I never really used it nor did I make a programmer capable of programming it. I also remember the 1702... but only its existence, never used or considered it.

But I did have a Hitachi EEPROM with a 2716 pinout in my hands in the early to mid 80-s. Did not have to UV erase it, had to program it in the programmer. But during these years I was quite disconnected from the real world, at this side of the iron curtain there was no access to the market and I had to run TGI (thinking of it as a private company was itself a diagnosis rather than anything else) on part donations from friendly state owned labs etc... :-). So my memories likely cover a limited area, although most of them are surprisingly vivid.

Dimiter

------------------------------------------------------ Dimiter Popoff Transgalactic Instruments

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Reply to
Didi

If I recall (hard to be sure without looking at the data-sheets) there are a few pins that moved around between those two sizes. Which means that you would have to wire an adaptor up to be able to use it.

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Paul E. Bennett...............
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Reply to
Paul E. Bennett

2716 retro? What about the 2708 ? When the price dropped I immediately bought stock, without really knowing what I would do with them. [ By the way I'll part from them for the price I originally payed ( euro 10), purchaser pays shipping. If only they find a good home! ]

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Albert van der Horst, UTRECHT,THE NETHERLANDS
Economic growth -- being exponential -- ultimately falters.
albert@spe&ar&c.xs4all.nl &=n http://home.hccnet.nl/a.w.m.van.der.horst
Reply to
Albert van der Horst

IIRC, the "AC" differences between the parts wasn't significant (i.e., the range of access times was big enough to absorb any small differences between vendors).

The bigger problem (for us, looking for "static" RAM parts that could be used to emulate ROMs) was the variations of "static" parts that were available as 2716 contemporaries. E.g., pseudo-statics vs. "real" statics; low power vs. not-so-low power. You had to read datasheets carefully... :-( (and remind purchasing agents that *you* are the engineer, not them!)

First design I was involved with used 1702's (i4004 based). I recall white ceramic with gold lead frames (?). Much classier looking than the drab gr[ae]y ceramic that the 2716's came in.

Hard for me to really imagine that! Though I can recall working with folks in the UK ~20 years ago who couldn't buy many of the parts that I took for granted. And, anything they *could* buy was considerably more expensive ("dollars == pounds" was the mantra we used -- despite the current exhange rate).

I've (more recently) found dealing with products for second/third world markets to be an unpleasant reminder of how much I (we?) take for granted in this regard. "No, you can't use that BGA part because they won't be able to service it..."

[watch your mail...]
Reply to
D Yuniskis

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