Decapping fundraisings

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Locutus73
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Decapping fundraisings

Postby Locutus73 » Tue Feb 13, 2018 2:56 pm

Hi,
I love videogames and computing since, well, something like 35 years. I started with a VIC20 in my childhood and never ended. I love emulation and, recently, I discovered the FPGA emulation/simulation/reimplementation/replication world I find very fascinating.
Since I’m in good company, I was wondering: why don’t exist coordinated fundraisings aimed to decap most famous CPUs and chipsets (i.e. 68000, ECS/OCS/AGA, SNES, ecc.)? This would help both the developing of more accurate emulators and transistor level accurate FPGA replicas.



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Re: Decapping fundraisings

Postby Sorgelig » Tue Feb 13, 2018 3:23 pm

I know one man who does chip decapping and converting to verilog. Actually it's his hobby. The chips he's reversing aren't those listed above.
He wants at least $10000 for reversing Z80 which surprisingly still has no FPGA replica yet. Keep in mind that reversing decapped chips even such "simple" as Z80 is very time consuming and pretty boring if you do this for chips you don't like.
I don't know where you can rise such funds.

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Re: Decapping fundraisings

Postby Locutus73 » Tue Feb 13, 2018 4:18 pm

Let me be clear: I’m not talking about something actual I can do (rise funds) or asking someone else to do. For now, I’m just theoretically speculating. I mean: I see many successful fundraising kickstarter campaigns, many based on gimmicks and gadgets. I also see very organized, long living, profound open (as thought) source projects based on voluntary free (as beer) coding work offered by high skilled motivated developers. I mean, a project like MAME (started by a fellow countryman of mine), wouldn’t be alive and in good shape after 20 years without so much work, effort and money spent by many many people. All these efforts are aimed to preservation of systems we love (mostly for nostalgic reasons) and to let us revive old good times spent in front of flickering TV sets. Now, open source software can live thanks hours of free coding offered by enlightened developers, but, to me, offering experience and free time is not different to offering real money. I think that the definitive documentation needed for preservation would be produced by decapping and imaging the integrated circuits of old hardware, but this is a task that needs special tools not so widespread as good thinking/developing brains. So I was imaging a widespread opensource decapping project: something aimed to produce open source documentation, with a credible backing, a robust sharing platform (GitHub?), good legal basis (no intellectual properties infringement), and a solid, trustable, fund raising platform. I know that this would cost money, but, after all, anything costs money, even time spent by open source developer is time subtracted to real moneymaking job (i.e. a second job in the free time). I don’t think figures like $10000 are unreachable considering the retrocomputing/gaming user base, and the definitive achievements: a decapped integrated circuit would be the definitive documentation for any future implementation. Verilog implementation wouldn’t be needed: I mean, Verilog implementation would be a direct consequence/benefit of this project as long as better emulation, and could come in a second moment by great people like you. The same preservation spirit of MAME would drive something like this. I think open source decapping image repository, open source accurate emulation and open source HDL accurate functional emulation and/or transistor level replica would be the perfect triad incarnation of timeless old hardware preservation. I don’t even know how to start such a project, but sometime a simple idea is the seed of great accomplishments.



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Re: Decapping fundraisings

Postby Sorgelig » Tue Feb 13, 2018 4:37 pm

If you don't need verilog but just decapping, then you have more luck.
High resolution shots of 68000 and some Amiga chips are floating on internet.

There are many better implementations of said chips in verilog, but authors usually don't want to make them opensource. I envy your optimism on open source. I'm more pessimistic since i'm in this area some time already.

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Re: Decapping fundraisings

Postby alexh » Tue Feb 13, 2018 5:05 pm

The problem associated with decapping old chips and turning them into verilog is that they used lots of "nasty" tricks which cannot be directly implemented in an FPGA today. The circuits have to be interpreted and somewhat re-designed. It is essential that the decapping take place but it is not a 1:1 copy what is there process.

For example someone found the original schematics of some of the Atari ST Chipset. They had been implemented through schematic capture. I believe these schematics could be turned via an automated method directly into a verilog representation *but* the verilog wouldn't work / synthesise. Not until it had been re-designed.
Last edited by alexh on Tue Feb 13, 2018 5:08 pm, edited 1 time in total.

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Re: Decapping fundraisings

Postby ijor » Tue Feb 13, 2018 5:08 pm

I'm not sure about the Amiga chipset, but most classic CPUs and lots of custom chips are already decapped. See, for example, http://www.visual6502.org/

I made several decap contributions myself, including reverse engineered schematics of both the Atari 8-bit (complete) and the ST (partial) custom chipset.

alexh wrote:For example someone found the schematics of the Atari ST Chipset.


Not the full chipset. Only the MCU-GLUE STe combo and Blitter.

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Re: Decapping fundraisings

Postby Locutus73 » Tue Feb 13, 2018 5:16 pm

Sorgelig wrote:If you don't need verilog but just decapping, then you have more luck.

Let me be clear: I don’t mean we don’t need Verilog, I’m very fascinated by FPGA emulation/replica, I feel a basic pleasure in its elegant rawness. But I think that decapping based documentation would be the definitive base for preservation, HDL transistor level recreation and cycle accurate emulation (and in a few decades, transistor level software recreation).

Sorgelig wrote:High resolution shots of 68000 and some Amiga chips are floating on internet.

I didn't know. But does it exists an organized, well coordinated repository for all this work? I see many organized projects in the emulation world (MAME, Higan, Libretro, ecc.), but the FPGA emulation/replica and documentation world seems to be rather scattered. MiSTer resembles me the most organized project, even being mostly a one-man show for now; reading other threads I think that porting MiSTer to other boards would make it gain the status of platform transcending the binds to a specific hardware implementation.

Sorgelig wrote:There are many better implementations of said chips in verilog,

What do you mean by “better implementations of said chips”? Verilog implementations of the original functions better optimized and performing than the original integrated circuit design or higher fidelity transistor level replica of the original designs than available open source implementations?

Sorgelig wrote:but authors usually don't want to make them opensource.

I see high level of drama in sagas like the jwdonald’s and pgate1’s ones. I mean: I’m not against closed source, I have my own software company, me, my partners and my employees live thanks to the earnings produced by closed source software. However, if you spend so many time in a spare time/hobby project, and you don’t find a way to monetize it in a reasonable time and if events dictates the non-profitability of your project, why don’t open source your job and make it outlast yourself and your interest? If your hobby can buy you a new house good for you, but if it can’t, admit it and don’t thrash it.

Sorgelig wrote: I envy your optimism on open source. I'm more pessimistic since i'm in this area some time already.

I'm not so optimist in general; but I see great minds and resources at work in the retrocomputing/gaming world, and good photographic documentation seems to me the natural next step, the holy grail of preservation, along with functional documentation (in the form of open source emulators) and formal hardware description (in the form of HDL implementation/replica).

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Re: Decapping fundraisings

Postby Locutus73 » Tue Feb 13, 2018 5:27 pm

alexh wrote:The problem associated with decapping old chips and turning them into verilog is that they used lots of "nasty" tricks which cannot be directly implemented in an FPGA today. The circuits have to be interpreted and somewhat re-designed. It is essential that the decapping take place but it is not a 1:1 copy what is there process.

Ok, but collecting decapping photographic documentation is not tied to what can be or can’t be done now. This documentation would be definitive: once you picture the transistors you have the perfect schematics of the integrated circuits; I don’t think you can go further. In a few decades, this documentation could even lead to transistor level 1:1 software replica; see DICE http://adamulation.blogspot.it/

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Re: Decapping fundraisings

Postby ijor » Tue Feb 13, 2018 6:21 pm

Locutus73 wrote:... and a solid, trustable, fund raising platform.


Forgot to comment about that. I am not fan of the fund raising of these kind of projects. The decapping cost is affordable (I paid a a couple from my own pocket), and some people have the equipment to do it for free. Then of course that it takes an amazing amount of time to do the actual reverse engineering. But that's "just time". And even when time costs a lot of money, I don't like to be paid for my time for these kind of hobby projects. Neither I like to pay others. Paying people to do what we can do with time is kinda corrupting and tainting these projects, IMHO.

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Re: Decapping fundraisings

Postby Locutus73 » Tue Feb 13, 2018 7:00 pm

ijor wrote:Forgot to comment about that. I am not fan of the fund raising of these kind of projects. The decapping cost is affordable (I paid a a couple from my own pocket), and some people have the equipment to do it for free.

It was my understanding that decapping was very expensive and required non domestic high-specialized equipment. I mean, software development, even the most qualified and refined, can be done at home and good developers are not a rare resource in the retro community (mostly nerd and geeks like us :D ). I believed that decapping skilled people with access to the needed equipment was rarer and that decapping skilled people loving retrocomputing/gaming and with access to the needed equipment maybe was extremely esoteric. But I might be wrong.

ijor wrote: Then of course that it takes an amazing amount of time to do the actual reverse engineering. But that's "just time".

Time is money :D

ijor wrote: And even when time costs a lot of money, I don't like to be paid for my time for these kind of hobby projects. Neither I like to pay others. Paying people to do what we can do with time is kinda corrupting and tainting these projects, IMHO.

I’m not so idealist, I mean, I’m a software capitalist, my company sells closed source software and support. I don’t believe in corruption by money rightfully earned; I think they are a necessary resource for projects sustainability. Fundraising doesn’t mean that anyone is making money, funds could be all spent for project costs. In addition, eventually I don’t find unethical to make money even in open source projects; many consultant earn their livings working on open source projects. Funds could be spent for the work of decapping technicians with the needed skills, but not interested in the project.

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Re: Decapping fundraisings

Postby ijor » Tue Feb 13, 2018 7:52 pm

Locutus73 wrote:It was my understanding that decapping was very expensive and required non domestic high-specialized equipment. I mean, software development, even the most qualified and refined, can be done at home and good developers are not a rare resource in the retro community (mostly nerd and geeks like us :D ). I believed that decapping skilled people with access to the needed equipment was rarer and that decapping skilled people loving retrocomputing/gaming and with access to the needed equipment maybe was extremely esoteric. But I might be wrong.


Decapping is not extremely expensive. It is not very cheap, but it is affordable. There aren't that many (that I know at least) in the retro community that have access to the equipment. May be a handful, but so what? You don't need that many. And even then, as said, paying for the service is affordable. Did you check the link to visual6502.org I posted above?

Decap (and I mean not decap in the strict sense of just exposing the die, but actually all that is required to producing the microphotographs) is the easy part. The hard part is the reverse engineering. And for that you need only time. Yeah, lots and lots of time. But no equipment.

This is at least for the old school chips present in the kind of platforms we usually call retro. If you want to decap something like, say, the latest generation consoles, then that probably has costs at a different level.


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