28pin to 32pin EPROM conversion

Upgrade or replace the ROM.
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Re: 28pin to 32pin EPROM conversion

Post by Forgottenmyname » Sun Jan 13, 2019 2:02 pm

tzok wrote:
Sun Jan 13, 2019 1:29 pm
You can use either PP's TOS based software for this:
http://atari.8bitchip.info/astopensw.php (look for ROMSPLIT)
or use mine, Windows based (first split into 3 parts, 64kB each, then split each into Lo/Hi... or the other way round):
...and remember that CartMan uses Little Endian nomenclature, while Atari ST is a Big Endian machine. So a Low byte in my program is a High byte in Atari ST (so file "tosxxxyy_ROM0_H.bin" should be used to program a "L0" chip and a file "tosxxxyy_ROM2_L.bin" do program a "H2" chip).
Thanks Tzok, will check out both.

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Re: 28pin to 32pin EPROM conversion

Post by tzok » Sun Jan 13, 2019 2:27 pm

But your terminology is confusing, OTP suggests a programmable memory, while ROMs used in STs were not programmable (and that is why the needed less pins), they were not OTP, they were Mask ROMs. OTP EPROMs and Mask ROMs are two different types of memories, and there is no such thing as OTP ROM (this term was sometimes used for PROMs and OTP EPROMs, but never for Mask ROMs). That's all I wanted to point out.

It doesn't matter for who this information is addressed, we should keep things technically correct, to avoid raising of myths. I don't expect you to explain the technical details, but if you use a technical term, use it correctly.

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Re: 28pin to 32pin EPROM conversion

Post by exxos » Sun Jan 13, 2019 2:53 pm

The user needs to only know between chips they can & cannot program. Stating anything more is just confusing.They don't need to know anything else.

They could for example try to re-program a mask ROM in a EPROM programmer. But that won't work for many reasons. All they need to know is they are one time programmable and problem solved. Clearly tells the user it cannot be done. If they want to go read exactly the how's and why's then there's probably 100 page essay on it all somewhere. That is not the aim of the page to go into detail about it all. I'm not going into various "programming" methods either of EPROM or mask or whatever either. Going into exactly the definitions of programming isn't needed either.

If it did not mention they are one time programmable then users may think they can reprogram them, which won't work. Users don't need to know anything more.. They just need to know they can't reprogram the original ROMs and that is exactly what I stated that they are one time programmable. Be It by user or factory . Users will just get more confused if I went into user programmable or fuse blowing stuff. They probably would go looking for a fuse blowing programmer and blank mask ROMs. It happens all the time in fact. Just no use or need to say anything more in depth.

The information has to be in digestible easy to understand chunks. I over simplify a lot of things to make things easier to understand for people. I'm not going to go into all the internal make up if every chip which can hold data and all the programming & construction methods just for people to hardwire chips up. So there a compromise with all this and things have to be explained in a easy way that people can understand.

So I think your not reading it as a novice would read it. Things need to be kept simple as possible as a lot of people are new to all this. They don't need to know masses of details and they probably don't care. They just want to fit the chips as fast as possible without understanding all the technical reasons. The user will know nothing about otp,mask,EPROM etc trying to explain all the differences will do nothing but confuse. This is a simple guide for people who want to just get the job done. Anything more is well beyond the scope of that guide and irrelevant to the topic. Saying chips can be programmed once only is fact, the original Atari ROMs can't be reprogrammed. Its all over simplified but the page is for physically fitting ROMs more than the theory of how it all works.

Thread is now locked as its got well off the topic of installing replacement ROMs. There no need to debate and over complicate something which is a very simple how to guide of fitting chips, not a technical reference document.
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