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  1. N

    How does the L2 cache work on NuBus (PowerPC)

    Thanks, I can find and fix those things, but before I do, is this type of output useful for dingusppc? Interesting! Is there any value in getting the data from a live system or is taking it out from ROM generally better? Very nice!
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    How does the L2 cache work on NuBus (PowerPC)

    It is odd indeed, adding screenshot from MacsBug (same if I reboot and check as soon as it says "Debugger installed"). I had made a mistake with DecoderInfo and some in NKHWInfo. Now it looks more reasonable. Added some more info 0x00000DD0,4,AddrMapFlags,0x8100183F...
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    How does the L2 cache work on NuBus (PowerPC)

    Thanks for the pointers @joevt! Would this be useful? Let me know if you spot some obvious issues, or if I should grab anything else, wrote a program to do it. Also I can enter privileged access as well in case there is anything elsewhere I should get (I could dump all phys ram if that helps)...
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    How does the L2 cache work on NuBus (PowerPC)

    I wanted to write a more thorough reply but shooting what I have now: I had a quick peek in the Open Firmware dump you had extracted. I can see dbat registers being used, which are not present on 601, so it seems they have code paths in that one for 603 (and/or 604) as well. Perhaps firmware...
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    How does the L2 cache work on NuBus (PowerPC)

    I see thanks folks, this was interesting to read about. Reading the thread it seems to be quite a lot of steps just to get it to work, and that is *if* it works (on a 5200). I think just entering MacsBug and query the info based on NanoKernel locations is still a quicker turn-around. joevt, so...
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    How does the L2 cache work on NuBus (PowerPC)

    Oh I see, yes I was sure the 6100 was not OF so I was a bit confused this morning, but I'm also honestly not exactly sure what OF is, never looked into it more than "open standard for PCI". Reading that thread you sent I'm even more confused "Apple did make a Open Firmware for NuBus Power Macs...
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    How does the L2 cache work on NuBus (PowerPC)

    Hey @joevt that would be a great way to do it. I have a Performa 5200 so that one is not openfirmware though. Interestingly it seems associativity is not reported on OF, although most likely 1 as well.
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    How does the L2 cache work on NuBus (PowerPC)

    An update here, thanks to this source https://github.com/elliotnunn/NanoKernel that I just found out about, amazing project.. I could go into MacsBug and just query the below info, and it confirms what I had found out by empirical tests: - 256kb, shared data and instruction - 32 byte blocks -...
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    nubus pds graphics card for 5200?

    That makes sense! Thank you! Well even if it doesn’t sound that it is plausible, it might still be faster. Valkyrie ends up getting its entries filled up and takes quite some time to empty. If the gfx card on the pds is fast vram it might still win. Hope someone will be able to try it out one...
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    nubus pds graphics card for 5200?

    That makes sense, OK so it won't ack until the PDS device acks it. Disclaimer: I really don't know much about the bus transfers.. I just saw you made your own graphics cards... respect! The extra clock delays for 603 to 040 is the same for the valkyrie chip. The PPC can do 64 bit writes...
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    nubus pds graphics card for 5200?

    5200 developer notes: PDS connects to PrimeTimeII with D32, and directly to the 68040 Address bus. I don't know the 68030 bus protocol but if it is 16mhz and it can transfer in burst mode 32bits per bus cycle, then that is ~60mb/s. If every other cycle it is ~30mb/s With valkyrie I can write...
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    nubus pds graphics card for 5200?

    You are probably right, I don't know much about the LC3/LC1 and how the 030 bus works. Are you saying that an LC3+PDS at best runs at 16mhz? THe thing is, from what I understand from the developer notes, it seems PrimeTime II has its own buffers, so if the PrimeTimeII is on the 68040 bus of the...
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    nubus pds graphics card for 5200?

    Not exactly that one but a few Micron Xceed Color30 which were like 500 eur to 1875 eur, most likely folks trying their luck
  14. N

    Let's see your best disk speeds( PPC )(68k)

    I've done some microbenchmarking for the Performa 5200 (ram/vram/specific instructions etc). If anyone would go this route I can recommend: use mftb for a highly accurate timer, it ticks every 4th bus cycle (and for instruction level micro benchmarks, do isync and sync, wait for mftb to tick...
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    MODTracker audio replay on early 68k macs

    I don't know much about the 68k macs unfortunately, as my first mac was a PowerPC, but I agree, there is definitely a cultural difference. I think one reason is that Apple made so many different machines with many different cpu's and chips. They were heavily pushing that you should use their...
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    nubus pds graphics card for 5200?

    Oh sorry to hear that. A pity it would have been very interesting to hear how it performed. I tried look for the card but it seems hard to find and quite expensive.
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    MODTracker audio replay on early 68k macs

    Nicely done MIST. There is also libmikmod, I used it decades ago for a demo for ppc mac, but there should be a 68k version as well, e.g: https://web.archive.org/web/20100605155536/http://www.algonet.se/~afb/mikmod/ This one might work? oh never mind the player is only Power Macs, but anyhow...
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    nubus pds graphics card for 5200?

    That is very interesting, thanks. Would you consider trying it out it in your 6200? Based on that the PDS slot on the 5200/6200 connects to PrimeTime II, and according to developer notes, PrimeTime II has buffers, it is quite possible that this is faster than the valkyrie chip (that only has 4...
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    How did the PowerPC 603 / 5200 at 75mhz compare to PC:s (486/Pentium)?

    correction: valkyrie has 4 buffered transactions (e.g. 8 pixels in 16bit).
  20. N

    nubus pds graphics card for 5200?

    Thanks, the valkyrie chip that came with the 5200 (and 5300/6200/6300) is actually the exact same chip as in the Performa 630, and it is a pretty slow gfx chip.
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