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Playstation backwards compatibility patent was published on Januray 14th

Shizumapower

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Still new to making threads, hopefully I'm not repeating /reposting.

From what I can understand, this is the Patent filed in 2017 and has recently been published.

There is quite a lot to digest and understand here, click the link for full article:



Backward compatibility through use of spoof clock and fine grain frequency control
Sep 12, 2017 - SONY INTERACTIVE ENTERTAINMENT LLC
An application runs at a first operating frequency if the application is designed for a current version of a system and runs at a second operating frequency if the application is designed for a prior version of the system that operates at a lower frequency than the first operating frequency. The second operating frequency may be higher than the operating frequency of the prior version of the system to account for differences in latency, throughput or other processing characteristics between the two systems. Software readable cycle counters are based on a spoof clock running at the operating frequency of the prior version of the system, rather than the true operating frequency. It is emphasized that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.
Latest SONY INTERACTIVE ENTERTAINMENT LLC Patents:
Skip to: Description · Claims · References Cited · Patent History · Patent History


 
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jshackles

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Interesting!

In the case of video game consoles, the operation is typically at a set clock frequency, and the software applications are tested for proper operation at this set frequency. Sometimes, it is desirable to run applications created for the original, less powerful console on a more powerful console. This ability is often referred to as “backward compatibility”. In such cases, it is desirable for the more powerful device to be able to run the application created for the less powerful device without detrimental effects of differences in latency or processing speed.

It is most definitely desirable.

Another interesting tidbit:


It is noted that the software application may have access to a cycle counter, e.g., a counter of cycles of operation of the CPU or GPU, or alternatively a counter that increments at a slower rate, for example the counter may increment every time the CPU or GPU has completed 16 clock cycles. As the frequency of the CPU and GPU is fixed on the original console, the application may be relying on the consistency of this timing. For example, the software application may be making assumptions regarding the ratio of clocks between CPU and GPU. Alternatively, the application may be using the GPU cycle counter to calculate the time to the next vertical blanking interval and then modify the rendering operations being performed so as to ensure that all rendering is complete prior to the start of vertical blank.

When this same software application is run at a higher frequency on the more powerful console, many errors may arise from its use of the cycle counter. For example, as at a higher frequency the number of cycles between vertical blanking intervals would be greater, the calculation concerning available time before the start of the next vertical blanking interval would be incorrect, leading to improper decisions as to what rendering is performed and potentially fatal errors.

Therefore, aspects of the present disclosure also provide a system and method of replacing the true cycle counter with a spoof clock which returns a number that corresponds to the frequency of the less powerful console. Whether reading the cycle counter returns the true cycle count, or whether instead it returns the value of the spoof clock, depends on the use case and would be configured by the operating system. Embodiments of the present disclosure provide a system configured to operate in two modes. The first mode is a normal mode in which the system operates at a normal frequency of operation, and the second mode is a compatible mode in which the system operates on the assumption of compatibility between the system and other ones (e.g., old versions of the system). The system is configured to be activated and operated in the normal mode. However, when an application or a title originally designed for the older versions of the system is run, the system may be configured to switch to a suitable operating frequency for the loaded application.

In layman's terms, this means that Sony will essentially lie to the software running in BC to make it think it's running at the correct speed and the correct number of clock cycles, hence the spoofing.




To be fair, this looks really similar to how the PS4 Pro runs boost mode, but hopefully we see this used to allow the PS5 to run even older software (PS1, PS2, etc).
 
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DynamiteCop!

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Interesting!



It is most definitely desirable.

Another interesting tidbit:




In layman's terms, this means that Sony will essentially lie to the software running in BC to make it think it's running at the correct speed and the correct number of clock cycles, hence the spoofing.




To be fair, this looks really similar to how the PS4 Pro runs boost mode, but hopefully we see this used to allow the PS5 to run even older software (PS1, PS2, etc).
Yeah basically the system will clock itself to the level of a PS4 or a Pro when operating the particular code associated, kind of similar to how the Pro and One X work now with unpatched games, they disable a number of compute units.
 

stranno

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To be fair, this looks really similar to how the PS4 Pro runs boost mode, but hopefully we see this used to allow the PS5 to run even older software (PS1, PS2, etc).
Yes, its the "Boost stuff". Nothing to do with real back-compatibility support: full emulation or virtual machines.

Since Playstation 5 will be, quite probably, just a more powerful Playstation 4, running OrbisOS again, i think that the back-compatibility will be limited to Playstation 2, again. But who knows.
 
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Shizumapower

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Interesting!



It is most definitely desirable.

Another interesting tidbit:




In layman's terms, this means that Sony will essentially lie to the software running in BC to make it think it's running at the correct speed and the correct number of clock cycles, hence the spoofing.




To be fair, this looks really similar to how the PS4 Pro runs boost mode, but hopefully we see this used to allow the PS5 to run even older software (PS1, PS2, etc).
So... could we see our digital library converted to PS5 day one? That is big (my backlog is ridiculous).
 

MoreJRPG

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Can't say I'm surprised. It's suicide not to have this backwards compatible with PS4
 
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jshackles

Gentlemen, we can rebuild it. We have the capability to make the world's first enhanced store. Steam will be that store. Better than it was before.
Jul 2, 2013
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Oregon
Yeah basically the system will clock itself to the level of a PS4 or a Pro when operating the particular code associated, kind of similar to how the Pro and One X work now with unpatched games, they disable a number of compute units.
But in this case (as far as I understand from reading the briefing) rather than disabling those compute units completely, they'll actually be running and performing calcs. But then lying to the underlying software / middleware.

In theory, that means faster processing / loading of assets but that will depend entirely on how the original software was created. If it's a PS1 game that was "coded to the metal" (as the phrase used to be) then you won't see any performance gains using this method. If the software is a bit more modern and expects multiple compute units or multi-threading, then this method should allow for some performance gains as the back end processing could be done much faster.