WTB: EPROM Emulator for 2716

Hi Dimiter,

Didi wrote:
> On Oct 1, 11:46 pm, Jon Kirwan <j...@infinitefactors.org> wrote:
>> On Fri, 1 Oct 2010 13:12:17 -0700 (PDT), TXMarsh
>>
>> <timothyma...@gmail.com> wrote:
>>> Hi Paul... thanks for the reply.  I'm in the US (Texas).  From what I
>>> can tell most emulators that did 512 also did smaller eprom emulation
>>> but sometimes they only emulated down to 2732s... but some do emulate
>>> 2716s... so kinda depends on the exact model.  Not a real expert on
>>> 2716s v. 2732s but there may be some fundamental difference (besides
>>> size).
>> My recollection is that that was a nice period of time where
>> most of the time most of the different sizes were voltage and
>> pin compatible.  But that might very well have been at or
>> above the x32 size.  The x16 might be different in some way.
>> I'd have to go to a datasheet again, to know.  Memory fails.
>>
>> Your point is wise to hold in mind, lacking specifics, while
>> looking around.
> 
> There was no difference between the 16 and 32 from a read point of
> view, just A11 was added. I think on the 2716 it was the programming
> voltage pin, but this may be wrong (I have not been designing eprom
> programmers which would program these for well over 20 years :-) ).
> But I am quite sure the 32 can "drop in" replace a 16 if the data
> are written in its upper half (Vpp for the 16 is held at 5V
> during read and this is where A11 is).

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

On Oct 2, 4:39=A0am, D Yuniskis <not.going.to...@seen.com> wrote:
> Hi Dimiter,
> ....
> 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: =A0make sure you know *which* chip you are trying to
> emulate.

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.

> As an aside, it is amusing to look back at the die for these
> devices. =A0Intel 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 =A0:-/

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

http://www.tgi-sci.com
------------------------------------------------------
http://www.flickr.com/photos/didi_tgi/sets/72157600228621276/

TXMarsh wrote:

> Hi Paul... thanks for the reply.  I'm in the US (Texas).  From what I
> can tell most emulators that did 512 also did smaller eprom emulation
> but sometimes they only emulated down to 2732s... but some do emulate
> 2716s... so kinda depends on the exact model.  Not a real expert on
> 2716s v. 2732s but there may be some fundamental difference (besides
> size).

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.

-- 
********************************************************************
Paul E. Bennett...............<email://Paul_E.Bennett@topmail.co.uk>
Forth based HIDECS Consultancy
Mob: +44 (0)7811-639972
Tel: +44 (0)1235-510979
Going Forth Safely ..... EBA. www.electric-boat-association.org.uk..
********************************************************************

In article <044f1cca-f61e-43ba-b707-a9b97e3c75bb@28g2000yqm.googlegroups.com>,
Didi  <dp@tgi-sci.com> wrote:
>On Oct 1, 11:46=A0pm, Jon Kirwan <j...@infinitefactors.org> wrote:
>> On Fri, 1 Oct 2010 13:12:17 -0700 (PDT), TXMarsh
>>
>> <timothyma...@gmail.com> wrote:
>> >Hi Paul... thanks for the reply. =A0I'm in the US (Texas). =A0From what =
>I
>> >can tell most emulators that did 512 also did smaller eprom emulation
>> >but sometimes they only emulated down to 2732s... but some do emulate
>> >2716s... so kinda depends on the exact model. =A0Not a real expert on
>> >2716s v. 2732s but there may be some fundamental difference (besides
>> >size).
>>
>> My recollection is that that was a nice period of time where
>> most of the time most of the different sizes were voltage and
>> pin compatible. =A0But that might very well have been at or
>> above the x32 size. =A0The x16 might be different in some way.
>> I'd have to go to a datasheet again, to know. =A0Memory fails.
>>
>> Your point is wise to hold in mind, lacking specifics, while
>> looking around.
>>
>> Jon
>
>There was no difference between the 16 and 32 from a read point of
>view, just A11 was added. I think on the 2716 it was the programming
>voltage pin, but this may be wrong (I have not been designing eprom
>programmers which would program these for well over 20 years :-) ).
>But I am quite sure the 32 can "drop in" replace a 16 if the data
>are written in its upper half (Vpp for the 16 is held at 5V
>during rd and this is where A11 is).

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! ]

>
>Dimiter


--
-- 
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

Hi Dimiter,

Didi wrote:
> On Oct 2, 4:39 am, D Yuniskis <not.going.to...@seen.com> wrote:
> 
> 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.).

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!)

> 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.

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.

>> 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  :-/
> 
> 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... :-).

<frown>  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..."

> So my memories likely cover a limited area, although
> most of them are surprisingly vivid.

[watch your mail...]