Recent content by noglin

@joevt: reverse engineering it and making your own driver based on it, that's very cool. Kudos. Out of curiosity, if you don't mind me asking, how did you go about that? I suppose MacsBug and looking at the driver entries with some custom made macros for mapping records/structs and reading disasm?

joevt, aha that would explain why I recalled SNES not looking worse on 5200. Thanks! "Power Mac 8500/8500 has a few options for video input", was this configurable in the Apple Video Player? I found the chip that is on the video input module, attaching it for future references.

Actually, I think I had this part the wrong way about the RAM accesses: - I think the typical time it should take is 32 cycles, and then when a page misses, that's when it gets very expensive, because it will miss in TLB and must search in PTE, but then after those 168 cycles it won't have to do...

Some insights: - the L2 cache is (as expected) not split. Data can use all of the 256kB. - I have not checked N-way yet (I think allocating 2x128kB, write both, and then read interleaved from both would tell if it is N-way) How I approached the micro benchmark: - this is on a 5200 with 8kB data...

Thanks everyone! I actually managed to find one by chance on marktplaats, boxed new. Once I have it home I'll post picture here as well in case it might be useful if anyone would pursue building this.

NJRoadfan, We are probably saying more or less the same thing. "mixes the output of the video data frame buffer and the graphics data at the output stage" Yes. Although I say this is happening on the Valkyrie chip. I might be wrong, but I don't think so. Here is why I believe it is happening...

This is very likely the infamous 5XXX/6XXX specific issue. I *think* that issue is actually with the CPU itself, a hardware bug in how atomics are handled, and will cause the machine to crash in a particular situation when there is an atomic operation and the address is residing in L2 (or is not...

There is detailed information about L1 (as it is part of the CPU), i.e. N-Way (on 603 it is 2-way), cache policies, that it is LRU, what bits from physical address are the tag, and what bits in the EA/PA are the index, etc. As L2 is not part of the CPU, information about it is unlikely to be...

Where does that overlay function reside if not on the Valkyrie chip?

That's interesting! I had not researched this aspect very much as my main goal was to figure out if I could use the Valkyrie for upscaling what I am drawing in a 320x240x16. That makes sense. Although I don't recall feeling it was "less resolution" on e.g. SNES plugged into my 5200 vs SNES...

I presume the following is what happens: - video card writes to the back-buffer (a) - system software gets a hint that the video card is done and tells Valkyrie to change current back buffer (from a to b) - video card starts write to back buffer (b) whatever is in the completed buffer is what...

So I actually have a quite deep understanding of this now. Thanks to the references and comments in here. I'll share it and hopefully it will help others that might be curious and need a summary rather than the code/technical references: The video card takes the analog signal and converts it to...

Thanks! Do you know if these are considered rare? I would prefer to wait and see if I can get one within EU to avoid the customs processing fees, but might just need to bite the bullet.

Thanks! I suppose the opposite would work as well? Put a 630 series in a 5200?

Thanks nixontheknight for confirming! Are those the only ones?