This might not be the best group to ask, but I figured I would start here. = I need to duplicate a 35-year-old CPU. Are there legal ramifications doing = this?=20 For instance on OpenCores they have a partially-compliant C54x DSP core. I = assume the partial compliance is in part not to run into licensing issues a= nd have TI sue them. However, I need to duplicate the CPU's instruction set= and associated cycle count exactly, so I'm pretty much going to copy the C= PU using the existing documentation. Thanks in advance for the help.
Legal Issues Reproducing Old CPU
Started by ●September 18, 2013
Reply by ●September 18, 20132013-09-18
Am 18.09.2013 06:30, schrieb ditiris@gmail.com:> This might not be the best group to ask, but I figured I would start > here. I need to duplicate a 35-year-old CPU. Are there legal > ramifications doing this? > > For instance on OpenCores they have a partially-compliant C54x DSP > core. I assume the partial compliance is in part not to run into > licensing issues and have TI sue them. However, I need to duplicate > the CPU's instruction set and associated cycle count exactly, so I'm > pretty much going to copy the CPU using the existing documentation. > > Thanks in advance for the help. >IANAL, but AFAIK, reproducing instruction set and cycle count exactly is OK, unless some of the instructions are patented. Patents expire after at most 20 years in any part of the world that I know of, so with a 35-year-old CPU you should be ok. Philipp
Reply by ●September 18, 20132013-09-18
Philipp Klaus Krause wrote:> Am 18.09.2013 06:30, schrieb ditiris@gmail.com: >> This might not be the best group to ask, but I figured I would start >> here. I need to duplicate a 35-year-old CPU. Are there legal >> ramifications doing this? >> >> For instance on OpenCores they have a partially-compliant C54x DSP >> core. I assume the partial compliance is in part not to run into >> licensing issues and have TI sue them. However, I need to duplicate >> the CPU's instruction set and associated cycle count exactly, so I'm >> pretty much going to copy the CPU using the existing documentation. >> >> Thanks in advance for the help. >> > > IANAL, but AFAIK, reproducing instruction set and cycle count exactly is > OK, unless some of the instructions are patented. Patents expire after > at most 20 years in any part of the world that I know of, so with a > 35-year-old CPU you should be ok. > > PhilippI think you need to be careful. While patents do expire (patents from 35 years ago expired after 17 years IIRC), copyrights generally do not. On the other hand it would be unusual for the owners of such old copyrights to pursue legal action against you unless you were making a lot of these devices. Still you're better off getting legal advice from someone who knows more about these issues, especially if you're intending to make significant money from this copying effort. -- Gabor
Reply by ●September 18, 20132013-09-18
On 9/17/2013 10:30 PM, ditiris@gmail.com wrote:> This might not be the best group to ask, but I figured I would start here. I need to duplicate a 35-year-old CPU. Are there legal ramifications doing this? > > For instance on OpenCores they have a partially-compliant C54x DSP core. I assume the partial compliance is in part not to run into licensing issues and have TI sue them. However, I need to duplicate the CPU's instruction set and associated cycle count exactly, so I'm pretty much going to copy the CPU using the existing documentation. > > Thanks in advance for the help. >Is this an educational exercise or a product development case ?
Reply by ●September 18, 20132013-09-18
On 9/18/2013 12:30 AM, ditiris@gmail.com wrote:> This might not be the best group to ask, but I figured I would start here. I need to duplicate a 35-year-old CPU. Are there legal ramifications doing this? > > For instance on OpenCores they have a partially-compliant C54x DSP core. I assume the partial compliance is in part not to run into licensing issues and have TI sue them. However, I need to duplicate the CPU's instruction set and associated cycle count exactly, so I'm pretty much going to copy the CPU using the existing documentation. > > Thanks in advance for the help.Although I am not a lawyer... My understanding is that you can duplicate any hardware that is not patented. Few CPUs involve patents that can not be circumvented by not duplicating the exact circuit. One exception is the ARM7 (at least the 7). It has some feature of some interrupt instruction that requires a piece of hardware that is patented. That is the only example I know of. Since you are looking at duplicating a 35 year old CPU, I think it would be pretty safe. Which CPU is it, if you don't mind? -- Rick
Reply by ●September 18, 20132013-09-18
On 9/18/2013 9:53 AM, GaborSzakacs wrote:> Philipp Klaus Krause wrote: >> Am 18.09.2013 06:30, schrieb ditiris@gmail.com: >>> This might not be the best group to ask, but I figured I would start >>> here. I need to duplicate a 35-year-old CPU. Are there legal >>> ramifications doing this? >>> >>> For instance on OpenCores they have a partially-compliant C54x DSP >>> core. I assume the partial compliance is in part not to run into >>> licensing issues and have TI sue them. However, I need to duplicate >>> the CPU's instruction set and associated cycle count exactly, so I'm >>> pretty much going to copy the CPU using the existing documentation. >>> >>> Thanks in advance for the help. >>> >> >> IANAL, but AFAIK, reproducing instruction set and cycle count exactly is >> OK, unless some of the instructions are patented. Patents expire after >> at most 20 years in any part of the world that I know of, so with a >> 35-year-old CPU you should be ok. >> >> Philipp > > I think you need to be careful. While patents do expire (patents from > 35 years ago expired after 17 years IIRC), copyrights generally do not. > On the other hand it would be unusual for the owners of such old > copyrights to pursue legal action against you unless you were making > a lot of these devices. Still you're better off getting legal advice > from someone who knows more about these issues, especially if you're > intending to make significant money from this copying effort.Copyright does not cover a design, it only covers an expression. If you reverse engineered the chip and were making identical chips, that would be covered by copyright... But just duplicating the functionality, even by constructing a gate level copy of the CPU, would not be covered by copyright. I am also not a lawyer... -- Rick
Reply by ●September 18, 20132013-09-18
rickman wrote:> On 9/18/2013 9:53 AM, GaborSzakacs wrote: >> Philipp Klaus Krause wrote: >>> Am 18.09.2013 06:30, schrieb ditiris@gmail.com: >>>> This might not be the best group to ask, but I figured I would start >>>> here. I need to duplicate a 35-year-old CPU. Are there legal >>>> ramifications doing this? >>>> >>>> For instance on OpenCores they have a partially-compliant C54x DSP >>>> core. I assume the partial compliance is in part not to run into >>>> licensing issues and have TI sue them. However, I need to duplicate >>>> the CPU's instruction set and associated cycle count exactly, so I'm >>>> pretty much going to copy the CPU using the existing documentation. >>>> >>>> Thanks in advance for the help. >>>> >>> >>> IANAL, but AFAIK, reproducing instruction set and cycle count exactly is >>> OK, unless some of the instructions are patented. Patents expire after >>> at most 20 years in any part of the world that I know of, so with a >>> 35-year-old CPU you should be ok. >>> >>> Philipp >> >> I think you need to be careful. While patents do expire (patents from >> 35 years ago expired after 17 years IIRC), copyrights generally do not. >> On the other hand it would be unusual for the owners of such old >> copyrights to pursue legal action against you unless you were making >> a lot of these devices. Still you're better off getting legal advice >> from someone who knows more about these issues, especially if you're >> intending to make significant money from this copying effort. > > Copyright does not cover a design, it only covers an expression. If you > reverse engineered the chip and were making identical chips, that would > be covered by copyright... But just duplicating the functionality, even > by constructing a gate level copy of the CPU, would not be covered by > copyright. > > I am also not a lawyer... >Watch out! How are you going to have the same instruction set without "copying" it? If the instruction set itself is copyrighted (IIRC this was the case for the Intel 8080) you could have ompletely different underlying hardware and still infringe on the copyright. I seem to recall that some people worked around this by simply changing the instruction mnemonics... -- Gabor
Reply by ●September 18, 20132013-09-18
On 9/18/2013 3:01 PM, GaborSzakacs wrote:> rickman wrote: >> On 9/18/2013 9:53 AM, GaborSzakacs wrote: >>> Philipp Klaus Krause wrote: >>>> Am 18.09.2013 06:30, schrieb ditiris@gmail.com: >>>>> This might not be the best group to ask, but I figured I would start >>>>> here. I need to duplicate a 35-year-old CPU. Are there legal >>>>> ramifications doing this? >>>>> >>>>> For instance on OpenCores they have a partially-compliant C54x DSP >>>>> core. I assume the partial compliance is in part not to run into >>>>> licensing issues and have TI sue them. However, I need to duplicate >>>>> the CPU's instruction set and associated cycle count exactly, so I'm >>>>> pretty much going to copy the CPU using the existing documentation. >>>>> >>>>> Thanks in advance for the help. >>>>> >>>> >>>> IANAL, but AFAIK, reproducing instruction set and cycle count >>>> exactly is >>>> OK, unless some of the instructions are patented. Patents expire after >>>> at most 20 years in any part of the world that I know of, so with a >>>> 35-year-old CPU you should be ok. >>>> >>>> Philipp >>> >>> I think you need to be careful. While patents do expire (patents from >>> 35 years ago expired after 17 years IIRC), copyrights generally do not. >>> On the other hand it would be unusual for the owners of such old >>> copyrights to pursue legal action against you unless you were making >>> a lot of these devices. Still you're better off getting legal advice >>> from someone who knows more about these issues, especially if you're >>> intending to make significant money from this copying effort. >> >> Copyright does not cover a design, it only covers an expression. If >> you reverse engineered the chip and were making identical chips, that >> would be covered by copyright... But just duplicating the >> functionality, even by constructing a gate level copy of the CPU, >> would not be covered by copyright. >> >> I am also not a lawyer... >> > > Watch out! How are you going to have the same instruction set without > "copying" it? If the instruction set itself is copyrighted (IIRC this > was the case for the Intel 8080) you could have ompletely different > underlying hardware and still infringe on the copyright. I seem to > recall that some people worked around this by simply changing the > instruction mnemonics...No, the instruction set is a concept and is not copyrightable. The Z80 had the same instructions the 8080 had including the opcodes. They changed the nemonics because they could be copyrighted... possibly. Don't confuse the design with the code. There are also issues with the size of the material "copied". A title of a book is not copyright protected for example. So you will find a NOP instruction in many CPU designs even though the 8080 had one. They even use the same nemonic in many CPU instruction sets. -- Rick
Reply by ●September 18, 20132013-09-18
On 9/18/2013 12:01 PM, GaborSzakacs wrote:> Watch out! How are you going to have the same instruction set without > "copying" it? If the instruction set itself is copyrighted (IIRC this > was the case for the Intel 8080) you could have ompletely different > underlying hardware and still infringe on the copyright. I seem to > recall that some people worked around this by simply changing the > instruction mnemonics...I thought the mnemonics were copyrighted. Not the instruction set. Rob.
Reply by ●September 18, 20132013-09-18
On Wednesday, September 18, 2013 4:30:15 PM UTC+12, dit...@gmail.com wrote:> This might not be the best group to ask, but I figured I would start here. I need to duplicate a 35-year-old CPU. Are there legal ramifications doing this? >Which core ? If you are doing this to keep a legacy product alive, and keep off the chip-sales commercial radar ( ie no product names mentioned ) - then no one will know, and even if they did know, are unlikely to care. Even more direct commercial replacements, of very old devices, seems to be fine, and you are a long way from this. A good example is http://www.tekmos.com/products Here, they even mention vendor names and part numbers, and pitch directly for chip sales, but the vendors do not care, as they no longer have direct commercial offering. -jg
