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Architecture of the Playstation 2

copetti.org

11–20 of 59 posts

Re: Architecture of the Playstation 2

#11
post #8

I remember reading some story way back with some ... Sony exec? Someone saying that there were people writing engine code in Excel to be able to track the co processors and get the timing right. Does anyone know of the truthiness of such a story? I'm learning FPGA design and even there, when timing is pretty controlled, people end up recommending design patterns where you gate stuff similar to how you would do it in…

Excel as in microsoft excel!?

Re: Architecture of the Playstation 2

#13
post #8

I remember reading some story way back with some ... Sony exec? Someone saying that there were people writing engine code in Excel to be able to track the co processors and get the timing right. Does anyone know of the truthiness of such a story? I'm learning FPGA design and even there, when timing is pretty controlled, people end up recommending design patterns where you gate stuff similar to how you would do it in…

I bet they were writing Vector Unit assembly in Excel. The VLIW design meant that you literally packed 2 assembly instructions together into a 64-bit word. Each side had it's own subset of execution units it could utilize and would have it's own separate latency for each operation. So, to keep track of everything going on you pretty much had to write out two columns of code containing your own no-op notation to represent the delay cycles between instructions. That would be much more convenient to do in Excel than in a linear text editor.

Re: Architecture of the Playstation 2

#15
post #4

This reminds me of my homebrew days making custom Guitar Hero 2 tracks. There was a great modding community (scorehero.com) around. This was before DLC was a thing, so if I wanted more content, I had to make it myself.

People still hack GH2 a little bit. Clone Hero is also a pretty big thing for ease of use.

Re: Architecture of the Playstation 2

#16
post #8

I remember reading some story way back with some ... Sony exec? Someone saying that there were people writing engine code in Excel to be able to track the co processors and get the timing right. Does anyone know of the truthiness of such a story? I'm learning FPGA design and even there, when timing is pretty controlled, people end up recommending design patterns where you gate stuff similar to how you would do it in…

I bet they were writing Vector Unit assembly in Excel. The VLIW design meant that you literally packed 2 assembly instructions together into a 64-bit word. Each side had it's own subset of execution units it could utilize and would have it's own separate latency for each operation. So, to keep track of everything going on you pretty much had to write out two columns of code containing your own no-op notation to repre…

Hopefully the Vector Unit assembly didn't require more than 16,384 lines of code if they were using Excel 95.

Re: Architecture of the Playstation 2

#17

Earlier quoted context omitted.

I bet they were writing Vector Unit assembly in Excel. The VLIW design meant that you literally packed 2 assembly instructions together into a 64-bit word. Each side had it's own subset of execution units it could utilize and would have it's own separate latency for each operation. So, to keep track of everything going on you pretty much had to write out two columns of code containing your own no-op notation to repre…

Hopefully the Vector Unit assembly didn't require more than 16,384 lines of code if they were using Excel 95.

The bigger VU only had 16k of of memory so that's not an issue, lol.

Re: Architecture of the Playstation 2

#18
post #5

The PlayStation 2 is actually one of the original reasons I got interested in the computer engineering space. The EE chip is a sort of who's-who of optimization techniques - hardware decoding, vector processing, VLIW architecture (for the VUs), memory bandwidth tailored to keeping the huge amount of functional units busy with a constant stream of math to do. At some point I got a port of Debian (BlackRhino GNU/Linux)…

Indeed awsome hardware to code for. It was amusing when the Sony guys joked people are writing their VU assembler in Excel. To make it easier to mentally keep track of the instructions in each pipe.

Re: Architecture of the Playstation 2

#19
> Some time ago, it was discovered that the BIOS of this console could be upgraded using the Memory Card, this function was never used in practice, but neither removed (at during for most of the console’s lifespan).

The author is correct that official uses for the MagicGate-encrypted system updates were few and far between, effectively "never", but there were a couple!

There was a DVD Player installer/updater for early console models that shipped before that software was finalized, and in Japan there was an entire "Browser 2.0" update that enabled a full HDD OSD unlike the bare-bones HDD Utility Disc we got in US/Europe regions! https://youtu.be/dJnLJxVljGw?t=509

The first revision of slim PS2 still has the 40-pin ATA header on the motherboard, and it works if you solder on a connector, so who knows what could have been.

Re: Architecture of the Playstation 2

#20
post #8

I remember reading some story way back with some ... Sony exec? Someone saying that there were people writing engine code in Excel to be able to track the co processors and get the timing right. Does anyone know of the truthiness of such a story? I'm learning FPGA design and even there, when timing is pretty controlled, people end up recommending design patterns where you gate stuff similar to how you would do it in…

I bet they were writing Vector Unit assembly in Excel. The VLIW design meant that you literally packed 2 assembly instructions together into a 64-bit word. Each side had it's own subset of execution units it could utilize and would have it's own separate latency for each operation. So, to keep track of everything going on you pretty much had to write out two columns of code containing your own no-op notation to repre…

The N64 RSP is similar. I've been playing with a N64 RSP assembler that'll understand how instructions can dual issue, and give warnings when two instructions on the same line can't dual issue, so I can for sure see myself using excel back in the day to help manage the complexity.
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