Great info on the 2732 chips.. thanks a lot!!
----- Original Message -----
From: "Mark De Smet" <de-smet@xxxxxxxxxxxxxxx>
To: <stella@xxxxxxxxxxx>
Sent: Monday, September 03, 2001 12:57 AM
Subject: Re: [stella] EPROMs
>
> > Well, I just got back from the Hamfest in Shelby, North Carolina.. Among
> > other things I picked up an EPROM programmer with a 28-pin ZIF socket,
> > that can program 2700-series EPROMs. Unfortunately, the guy didn't have
> > any EPROMs left, but I did find another guy who had some.
> >
> > Now, I freely admit, I don't know the slightest thing about EPROMs, so
> > don't laugh if this sounds like a stoopid question, but..
> >
> > 2 of the chips I got are labelled `M2732AFI 21V Fast', and appear to be
> > brand new. Are these things fully compatible with the standard 2732? I'm
> > assuming that EPROMs are like RAM, and will run just fine at a slower
> > speed than they are rated, but what about the programming
voltage/timings?
> >
> > The rest of the chips I got are 27C128's. I assume the C means CMOS. I
> > haven't yet found a data sheet for these, but somebody on this list can
> > probably give me the short answer: Will these 27C128's (a) work in a
> > programmer designed for regular 27xx series, and (b) assuming I get them
> > programmed, will they work in a 2600 cartridge? (Yes, I have 74xx
inverters)
>
> A Quick tutorial about 27 series eproms. They are all the same with a few
> differences:
>
> The numbers that follow 27 show the size in kilo-bits.
>
> If there is a -number after, that indicates the speed, ie 25 is 250ns
> This is useually the time between address valid, /CE and /OE = 0V to data
> output valid. 250's worked for me, and I doubt you can get something
> slower. Faster shouldn't be a problem.(unless you go to fast) I've gone
> down to 120 w/o a problem
>
> The letter mixed in there can lead you the programming voltage. If
> talking about 2732's, there are generally 3 types, 2732, 2732A and 27C32.
> All three have different programming voltages. 2732 IIRC is 21.x V, 2732A
> is 12.5V, and I think 27C32 is also 12.5V, but not sure(I wouldn't tell a
> programmer that you have a 2732A if you are using a 27C32 though)
>
>
> To your questions: as long as you wire them correctly(data to data, power
> to power, OE to OE etc...), there will be no damage to the VCS. However,
> if you use a 2732A in a programmer that is configured for 2732, then you
> will most likely destroy the chip(possibly damage to programmer, but I
> doubt it) This is because the programmer will be using a programming
> voltage above that rated for the eprom. Unless your programmer is very
> old, it should be able to handle all of the above types, with the
> appropriate setting. Usually via the pc(either through pc program, or
> terminal w/ serial link), you choose the chip type. Find the correct
> setting for the chip you are using. Be sure to match both the 27 series,
> the size, and the programming voltage type. If you match those, you
> shouldn't have any problems. If there are leading letters(which usually
> denote a manufacture), try to match those as well, but if you can't it is
> ok to try a setting for a different manufacturer. The only difference
> that is likely between manufacturer's is the write timing etc. If there
> is no match, then the programming won't work quite right, but no damage
> will be done.
>
> A quick sample of manufacturer's prefixs:
> TMM - toshiba
> D - Intel
> TMS - TI
> AM - AMD
>
> Hope that helps,
> Mark
>
>
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