15 August 2023, 21:40 | #1041 | |
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I mean a redesign of the chipset to be 32bits access too, would have been possible, right? (or there was timing problems or anything else?) |
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15 August 2023, 21:42 | #1042 | |||||
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BTW I did buy a mouse for my PlayStation, thinking it would be useful playing more sophisticated games. But I never did because nothing suitable came my way. That mouse is going to be rewired for the Amiga. Quote:
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16 August 2023, 00:07 | #1043 | |
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Some would argue both of those can be true. |
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16 August 2023, 04:20 | #1044 | |
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16 August 2023, 05:29 | #1045 | |
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The idea was to write chipram from fast CPU faster... as at some point it generally is faster to do more stuff in software rather than let blitter and copper duo have some fun. Exactly because blitter and copper are 16bit and run at constant speed. But doing most of the work in FAST then copying it to CHIP still takes a lot of time. Hence 32b access to CHIP RAM during CPU mem access slot makes perfect sense as it doubles the throughput with relatively low cost of ICs. Things I described as possible was not only theoretically possible, they were made into AAA chipset. And more. Obviously the biggest compatibility issues were with "more" part but on register level ECS compatibility was retained (but not timings). Either way I'd love to see AAA instead of AA... It probably would not save commodore but at least we'd have even better machines to turbo charge after 30 years... and pretty possible without the need for 3rd party RTG. |
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16 August 2023, 08:32 | #1046 |
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Yeah, I agree because we would so have another essence of the Amiga, a different touch of hardware combinations/limitations and so another taste of the very particular magic which can be created.
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16 August 2023, 08:41 | #1047 | |
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Classic Amiga chipset has added complexity with DMA slot issues. Before X86's UEFI era, the IA-32 PC starts with 8086's 16 bit real mode, and 386 OS can switch to 386's protected mode. A similar approach was used for AMD's X86-64 Long mode. The assumption is legacy software wouldn't be aware of the new mode, hence the hardware legacy mode default. The alternate timeline of Amiga's evolution would be like the PC with hit-the-metal MDA/CGA/EGA/VGA legacy but with Amiga's hit-the-metal OCS/ECS/AGA legacy. Beyond either VGA or AGA, it's Windows GDI/GDI+/DirectX or Amiga's RTG. Windows 7/2008 Direct2D(DirectWrite) has replaced legacy GDI/GDI+. In modern times, PS5's Zen 2 CPU has additional customizations to replicate Jaguar's timings and latency in a backward compatibility mode. PS5 and PS4 Pro's 36 CU GPUs have strict topology design issues with PS4's 18 CU design. PlayStation 4 and 5 are the closest to old-school hit-the-metal. PC has graphics APIs that have resource tracking to support many hardware performance levels from laptops to workstations/servers. This is also applicable to Xbox's evolution. Like the PC's DirectX, Xbox Series X's 52 CU doesn't follow Sony's strict 4X/2X scaling from Xbox One X's 40 CU, and Xbox One's 12 CU scaling. Xbox One X/Series X has a virtual machine GPU hypervisor that can target hardware performance profiles of lesser Xbox One and Xbox Series S machines. Xbox One X dev kit has a 44CU GCN variant that can replicate the retail Xbox One X (40 CU), Xbox One S (12 CU higher speed), and Xbox One(12 CU original) performance profiles and this hypervisor technology was carried over to Xbox Serise S/X. With lots of money and skills, backward compatibility can be solved. Last edited by hammer; 16 August 2023 at 08:49. |
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16 August 2023, 09:18 | #1048 | ||||
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My Amiga 3000's stock SKU has a 1MB Chip, 1 MB Fast RAM, and Kickstart 2.04 ROM configuration. 1 MB Fast RAM's DRAM chips can be moved into Chip RAM slots since they are not ZIP RAMs. When Commodore's 2 MB Chip RAM configuration was being shipped, CPU-driven 3D games were also in vogue, hence the need for Fast RAM. When 3D games matter, a 2 MB CHip RAM configuration cuts A1200/CD32's raw hardware performance in half. Quote:
Apple Mac II has 16 colors with 640×480p or 256 colors with 512×384p without tricks like HAM modes. https://en.wikipedia.org/wiki/Macintosh_II To work around the "No New Chips" directive, Amiga 3000's designers wasted four 80ns 256K chips for Ambre flicker fixer for the framebuffer to create flicker free 16 colors with a 640x512 display. The 32-bit Chip RAM is wasted with 16-bit ECS. Quote:
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16 August 2023, 09:26 | #1049 | |
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ET4000AX with 386DX-based PC has 32-bit system RAM + 16-bit ISA bus + ET4000AX's discrete high-speed 16-bit VRAM or 32-bit DRAM depending on SKU. ET4000AX's raster processing on video memory is NOT being disturbed by the CPU's I/O access. 386DX-33 has 33 Mhz 32-bit system memory. 486SX-33 has 33 Mhz 32-bit system memory. 486DX2-66 has 33 Mhz 32-bit system memory. 486DX-50 has 50 Mhz 32-bit system memory. ET4000AX by itself is useless. For the 1992 to 1993 era, A1200 needs at least 33 Mhz 68020 / 68030 with 32-bit Fast RAM to counter fast 386DX-33 and 386DX-40-based PCs. I support DP's argument on CPU-accelerated A1200 game bundles for 1993. Last edited by hammer; 16 August 2023 at 09:32. |
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16 August 2023, 09:55 | #1050 | |
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Did you miss AGA 256 color mode vs HAM6 vs HAM8 comparison? [ Show youtube player ] Results: 47.23 fps for AGA's 256-color mode. 39.91 fps for AGA's HAM8 mode. 39.94 fps for AGA's HAM6 mode. The Alice is showing its bottleneck. HAM mode incurs a performance penalty. ET4000AX's raster operations have a 32-bit core at 65 Mhz with a 32-bit 40 Mhz video memory clock. On raster operations, ET4000AX is less bottlenecked compared to Denise or Lisa. At least Lisa has a 32-bit design at a lowish clock speed https://bigbookofamigahardware.com/b...uct.aspx?id=23 A3000+ According to Dave Haynie "The Amiga 3000+ was the first computer based on the Pandora chipset (which was later dubbed AA, then AGA). Revision 0 of this system first booted successfully in February of 1991, thanks due to a chip revision that got the display logic actually working. This is revision 1, which completed the audio subsystem, and moved to surface-mount components. As the name suggests, this system was being designed as a drop-in replacement for the existing Amiga 3000 motherboard. In addition to the features everyone knows from the Amiga 3000, and from later computers such as the Amiga 4000, the Amiga 3000+ sported the AT&T DSP3210 digital signal processor as a coprocessor. You can see quite a bit of support circuitry for the DSP in the upper lefthand corner of this board. There was an audio CODEC here, designed to allow 16-bit, 2-channel recording and playback. This was very cutting edge at the time, such chips, common today, where just becoming available. In addition, there was a separate mono CODEC with hardware phase correction, which supported modem protocols up to V32. The actual DSP was located above and to the right of the CPU. Note: this is the real Amiga 3000+, very rare. Most of the Amiga 3000+ type systems out, whether boards or whole computers, are actually the scaled-down "AA3000", which was after the A3000+ had been cancelled, by the Bill Sydnes administration, as a product." - Dave Haynie A3000's 32-bit Chip RAM design was in place for this AGA evolution upgrade that was completed in Feb 1991! Lisa is ready for A3000's 32-bit RAM! AGA could have been Xmas Q1 1991 player! You're defending fools like Bill Sydnes administration. Last edited by hammer; 16 August 2023 at 10:04. |
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16 August 2023, 10:28 | #1051 | ||
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...and more complex features like sprites, copper, dual playfield, overscan etc., that were much more difficult to accurately reproduce than the simple CRTC in a PC CGA/EGA/VGA card. This was a big stumbling block because many Amiga games and demos relied on exact operation of the hardware, whereas most PC programs avoided doing fancy stuff that might be incompatible on some graphics cards.
Another example of a platform with this issue is the Amstrad CPC. Though it uses the same CRTC as the PC, coders on the CPC pushed the envelope much more to get fancy effects that relied on exact operation of the graphics hardware. But at least 3 different CRTC chips were used at various times along with 2 different gate arrays, with the result that some demos only work properly on machines with certain chip combinations. PCs had issues too. But there was one fundamental difference - PC gamers didn't care so much about compatibility. If an older DOS game didn't work it wasn't a big deal, because they were mostly only interested in playing newer games. Ironically, the fact that hardware wasn't always 100% compatible was just accepted as part of life in the PC world, whereas Amiga fans tended to overreact when some game or demo didn't work 100% on a new model. Quote:
However the Amiga didn't really get that far during its official lifespan, and as a retro platform it is expected to have original hardware (or an exact emulation of it). Quote:
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16 August 2023, 11:14 | #1052 | |
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Commodore needed a more advanced low end model to replace the aging A500, not expensive big box machines. Zorro III was a disappointing compromize (sorry Dave, but it needs to be said). The eventual replacement for the A2000 would have PCI slots as well as Zorro II. |
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16 August 2023, 17:15 | #1053 |
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AAA was capable of being low end position and high end as well. All depends on configuration. But the last cog was always CPU and there just wasn't any relatively cheap and powerful enough to handle new more or less 3D titles, even with new chipset with abundance of chipmem, great bandwidth, chunky pixels in hardware and of course 32b blitter(s). And it was designed to handle 030 but 040 was kind of problematic. So... yeah, that's why fixed, tightly integrated chipset is great for consoles, not so great for computers.
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16 August 2023, 21:45 | #1054 | ||
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But of course that wasn't good enough for fans, who wanted more 'realism' - thus the push for texture mapped 3D, more detailed objects, lighting effects, higher frame rates and higher resolution. Hardware could be 1000 times more powerful and still not enough to sate this appetite. Quote:
The original Amiga chipset was 'tightly integrated' in that the CPU shared memory with the chipset in an interleaved fashion that didn't slow it down much. However as soon as you included FastRAM this integration vanished. Now the CPU is independent of the chipset and can go as fast as it wants - which is a good thing for computers, especially when the chipset can do stuff like blitting and line drawing independently while the CPU is doing other things. But of course the CPU has to slow down when accessing ChipRAM to feed graphics data into the chipset, which was a problem for code that used the CPU to render graphics. The answers to that were to a) improve ChipRAM write bandwidth, and/or b) offload rendering to a chipset which could do it faster. If you specify that the chipset's capabilities are fixed then increasing write bandwidth is your only option. That was the initial technique used by PCs, until graphics chips with hardware 3D were developed. Today we also see this on the Amiga, where an insanely powerful CPU can produce graphics performance we could only dream of back in the day, despite the slow 2D chipset. And current systems are not even as efficient as they could be. With proper write caching a fast CPU would be able to render at full video frame rate without significant loading. |
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17 August 2023, 01:21 | #1055 | ||||||
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The Amiga chipset has hardware extensions for 2D scrolling games since the 68000 CPU couldn't deliver 7.1 mips for 7.1 Mhz clock speed and memory bus. Amiga chipset compartmentalized most 2D visual effects processing within the custom chips domain, hence it's easier to change the CPU (within certain limits) when compared to Atari ST/STe. Quote:
In modern computing, PS4 has timing backward compatibility issues between CPU and GPU, hence the reason for spending extra silicon budget for PS4 timing matching on PS4 Pro and PS5. PS4's game design assumptions will be PC laptop friendly. "Resource tracking" is a major feature of PC's graphics API management. Quote:
Doom is both a tech demo and a game. A500/A600's recent Grind also serves both as a tech demo and a game. Dread couldn't work on 68K with enabled caches due to cache coherent incompetence issues. Quote:
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Intel didn't play with Motorola's 68000 vs 68020 instruction set changes. Intel's 386 approach has compartmentalized backward compatibility in real mode 86 and 286 protected mode. DOSbox has CPU cycle settings to approximate hardware performance profiles for certain early DOS games that used hardware's performance as a timing method. Games that are PC clone aware have game design factors in faster PCs. Windows 3.0 offered API and driver abstraction for TIGA i.e. Texas Instruments convince Microsoft that the internal interfaces to its Windows operating system had to be adaptable instead of hard-coded since all versions of Windows prior to Windows 3.0 were "hard-coded" to specific graphics hardware. Quote:
The major issue for DOS gaming on 1st generation Core series PCI slot-equipped PC hardware is sound cards since modern PC BIOS doesn't allocate the necessary IRQs, hence SBemu project was created. https://github.com/crazii/SBEMU Due to NVIDIA's dominance and Shader Model 6 wave intrinsics, this pressured AMD to follow NVIDIA's wave size 32 on RDNA architecture i.e. API abstraction has limits. AMD lost GCN's wave64 argument while it's a win for NVIDIA's CUDA's wave 32 size. PC Direct3D12 and Shader Model 6.6 are closer to the metal, and this is driven by maximizing the game's performance which is influenced by game consoles and NVIDIA's CUDA hardware architecture. Last edited by hammer; 17 August 2023 at 02:17. |
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17 August 2023, 01:50 | #1056 | ||
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Before Bill Sydnes's administration, AGA itself was a quick development fork from AAA R&D since Commodore recognized the competition's advancement. Bill Sydnes has a "PC Jr" mentality and promoted ECS beyond its useful competitive life span. Dave Haynie is responsible for big box Amigas and it's up to Commodore's upper management to allocate human and material resources for A500's replacement. In the big corporate world, employees must follow management directives. Don't argue against the "boss" e.g. Elon Musk firing engineers who disagree with him in Tesla. In SpaceX, major shareholders installed mechanical engineer Gwynne Shotwell as president and chief operating officer to balance Elon Musk's direction. Tesla's major shareholder installed economist Robyn Denholm as chairwoman is less engineering competent when compared to Gwynne Shotwell. Quote:
A2000's Zorro II is 16-bit and it's obsolete since A1200's expansion connector is a 32-bit data bus with a 24-bit memory address from 68EC020 CPU and Budgie is a cutdown 32-bit Super Buster. A1200 is effectively a cutdown A3000+ AGA. Last edited by hammer; 17 August 2023 at 02:19. |
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17 August 2023, 03:02 | #1057 | |||
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Throwing RTX 4090 on CyberPunk 2077's raytracing overdrive needs pixel construction ticks from DLSS. Sub-pixel density for geometry is useless, hence the hardware accelerated geometry culling. Quote:
Again, raytracing is the compute power blackhole. Quote:
A1200 needs 32-bit Fast RAM to enable full performance for 68EC020 and AGA chipset. Imagine if the 68020/68030 CPU has 1 IPC 32-bit SIMD DSP extension for pack_INT8 and pack_INT16 operations. Only a few instructions are needed for 3D software render while the slower scalar instructions can handle the host OS processing. Modern X86-64's fastest instructions are the AVX SIMD extensions. Itanium's VLIW attempted to bring MIMD style into general-purpose compute processing vs the hardware OOOE instruction-level parallelism. |
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17 August 2023, 08:45 | #1058 | |||||
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Perspective parallax is a different effect which is inherent to 3D. But Doom didn't do a particularly good job of it. The textures of the mountains in the background are very poor, and appear to be very close, unlike eg. the distant mountains in Shadow of the Beast. The PlayStation had a similar problem with with games like Tomb Raider. Fog or darkness was often applied to hide the limited depth, but It wasn't uncommon to 'hit the sky' at the walls of an 'outside' room. Quote:
This was the PC's problem too. Clone cards used various CRTC chips just like the CPC did. With EGA and VGA it was even more of an issue because CRTC functionality was embedded into custom gate arrays. Many cards were not fully compatible with the original IBM adapters. Some specified 'full register compatibility' as an advantage over other cards that weren't, but sensible coders avoided doing tricky stuff that might break on some cards. Quote:
TIGA was actually the impetus for Microsoft to make Windows graphics card agnostic, a smart move that 'accelerated' the development of more powerful graphics chips because the designers didn't have to worry about being compatible at the hardware level. Graphics card manufacturers then provided drivers as binary 'blobs' that further discouraged banging the hardware directly, giving them total freedom to design it however they liked. |
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18 August 2023, 02:01 | #1059 | |
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Unless I'm mistaken, most textmode software used abstraction to communicate with the display so I think MDA is an exception to the need for hardware compatibility. That's why early non-IBM-compatible MS-DOS machines could still use most textmode software. |
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18 August 2023, 02:50 | #1060 | ||
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IBM PC compatible Quote:
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