Eeprom/Flash rom for 2600?

[endrien]

As we all know you can't really buy new eproms anymore. You can only buy eeproms and flash roms. Are there any that can be bought new and fit a 2600 with little or no modification. I'm sure it wouldn't be all that hard to make a custom PCB either if need be.

[Pioneer4x4]

I haven't look in a while, but most eproms have eeproms that are pin compatible.

[+batari]

You can still buy new EPROMs. Take a look at Digikey and you'll see many to choose from. Most are OTP EPROMs which use EPROM technology but lack the quartz window for erasing. These are suitable for 2600 games and aren't terribly expensive if you buy enough of them.

[endrien]

You can still buy new EPROMs. Take a look at Digikey and you'll see many to choose from. Most are OTP EPROMs which use EPROM technology but lack the quartz window for erasing. These are suitable for 2600 games and aren't terribly expensive if you buy enough of them.

Yeah I did notice some on digikeys website awhile ago, thought it was weird. Can you explain OTP EPROMs in a little more detail? How are they erased(Presumably like eeproms?). Also what would I have to search on their site to find a 2732 eprom? I've searched but did not find it.

Edited August 18, 2010 by endrien

[+GroovyBee]

Can you explain OTP EPROMs in a little more detail? How are they erased(Presumably like eeproms?).

 

OTP = One Time Programmable

 

They can be programmed once and you can't erase them.

[endrien]

Can you explain OTP EPROMs in a little more detail? How are they erased(Presumably like eeproms?).

 

OTP = One Time Programmable

 

They can be programmed once and you can't erase them.

So essentially its just like a mask rom?

Edited August 18, 2010 by endrien

[+GroovyBee]

So essentially its just like a mask rom?

 

In terms of physical looks yes, in pin-out maybe but at the Silicon level no.

[A.J. Franzman]

A mask ROM has its binary code physically manufactured into the silicon. An OTP EPROM is exactly the same as a UV-erasable EPROM, but without the UV window. (Maybe you could erase one with X-rays...)

 

The major difference from an end-user standpoint is, that an OTP EPROM has the same shortcoming as a normal EPROM: bitrot. After 20 or more years, it will begin to self-erase.

[endrien]

A mask ROM has its binary code physically manufactured into the silicon. An OTP EPROM is exactly the same as a UV-erasable EPROM, but without the UV window. (Maybe you could erase one with X-rays...)

 

The major difference from an end-user standpoint is, that an OTP EPROM has the same shortcoming as a normal EPROM: bitrot. After 20 or more years, it will begin to self-erase.

Does this happen to all eproms? Wouldn't that mean homebrew games have a short lifespan because 2732's that you buy are used and who knows how old?

Wouldn't it also mean that prototypes should be non working or starting to stop working?

Edited August 19, 2010 by endrien

[A.J. Franzman]

The major difference from an end-user standpoint is, that an OTP EPROM has the same shortcoming as a normal EPROM: bitrot. After 20 or more years, it will begin to self-erase.

Does this happen to all eproms?

Yes, but there are a few variables and some EPROMs can end up holding their data for much longer than others.

 

 

Wouldn't that mean homebrew games have a short lifespan because 2732's that you buy are used and who knows how old?

Not really. The "20 or more years" that I mentioned (which can actually be much longer, probably up to 50 years or so for well-written, high-quality chips) is just the lifetime of the stored data. The chip itself can remain functional for a lot longer -- a regular EPROM could theoretically be written, then used and/or stored until bitrot set in, then erased and re-written for several such cycles, until eventually hermetic seal leakage of the chip's package would lead to internal corrosion and the chip would fail permanently. But even mask ROMs are susceptible to that kind of failure.

 

 

Wouldn't it also mean that prototypes should be non working or starting to stop working?

Yes. In fact, a few makers of VCS cartridges (notably Bomb) are known for using EPROMs which have already begun to lose their data in substantial numbers. Use of EPROMs for making prototypes is why there is such a big push by us fans for those titles and versions that exist as unique examples or in extremely small numbers to be dumped for preservation. Unfortunately, there are some speculator/collectors who think of their unique cartridges as some sort of a trophy that gives them priceless "bragging rights" or a kind of "gold mine" that they can simply hold onto for as long as they want, and never let anyone else touch until some unknown future time when they might be able to sell them for a small fortune. I'm afraid that several of them will be severely disappointed to learn that their cartridges no longer work properly sometime very soon, and therefore won't be worth very much at all in either cash or bragging rights. (Envy me! I have the world's one and only copy of the Pink Panther VCS paperweight!) The rest of the collecting community will then mourn the loss of the irreplacable data.

Edited August 19, 2010 by A.J. Franzman

[endrien]

 

 

 

Wouldn't it also mean that prototypes should be non working or starting to stop working?

Yes. In fact, a few makers of VCS cartridges (notably Bomb) are known for using EPROMs which have already begun to lose their data in substantial numbers. Use of EPROMs for making prototypes is why there is such a big push by us fans for those titles and versions that exist as unique examples or in extremely small numbers to be dumped for preservation. Unfortunately, there are some speculator/collectors who think of their unique cartridges as some sort of a trophy that gives them priceless "bragging rights" or a kind of "gold mine" that they can simply hold onto for as long as they want, and never let anyone else touch until some unknown future time when they might be able to sell them for a small fortune. I'm afraid that several of them will be severely disappointed to learn that their cartridges no longer work properly sometime very soon, and therefore won't be worth very much at all in either cash or bragging rights. (Envy me! I have the world's one and only copy of the Pink Panther VCS paperweight!) The rest of the collecting community will then mourn the loss of the irreplacable data.

 

 

So its not a problem of the chip dying, more just the chip losing the current data that is stored on it. Meaning it can be reprogrammed And work fine again for another 20+ years continuing until the chip corrodes itself?

Edited August 19, 2010 by endrien

[A.J. Franzman]

Yes, if you're talking about a standard EPROM that you can erase before reprogramming it. With an OTP EPROM, you would either have to wait until ALL of the bytes returned to their original state ($FF, I believe), or reprogram it with EXACTLY the same data that was programmed into it previously.