30 July 2009, 20:16 | #221 |
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30 July 2009, 20:24 | #222 |
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When it comes to coin-op conversions the most important thing would be that it does not losing the speed of the original... gameplay first then graphics and sound.
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30 July 2009, 20:36 | #223 | |
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30 July 2009, 20:40 | #224 |
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Sorry Goldrunner, it even got worse after you left... Come back!
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30 July 2009, 20:55 | #225 | ||||
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It actually slows down for every plane you switch on the Amiga. It's still much more efficient than the 68k. Quote:
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Frank *Don't take my word for it. Google for Jay Miner's comment on the ST. |
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30 July 2009, 22:08 | #226 | ||
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As for games. Take another look. It had a lot of the same releases as the Amiga and ST. Take a look here for some screenshots. Doom is also an especially good port, and more capable than the Amiga's version, thanks to the Arch's RISC based 32bit CPU. If anyone is interested in seeing what the hardware spec of the Archimedes was you can see one of the later popular model's specs here. As you will notice the 256 colours on screen from a palette of 4096, 8 channel stereo sound, with 8 voices at 42 kJz or 4 as 83 kHz, 46 built in screen resolutions plus freely programmable additional ones possible, 4MB ram, 12MHz RISC CPU (8 MIPS), native HDD support etc made it a pretty impressive system. Such a shame it was never a commercial success outside of UK schools. |
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30 July 2009, 22:58 | #227 | |||
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But seriously, I agree they were all general purpose computers to an extent - although only because they had a keyboard. Of all the 8-bit machines I would say only the BBC Micro was truly general purpose. Quote:
Oooo got to think now ... I coded the "chop chop" game that ran in between levels on the Megadrive version, so the same logic code was used in the Amiga version for that. Megadrive had loads of hardware sprites which was ideal for a game like Golden Axe along with a hardware character based scrolling background plus lots of buttons. I THINK the Amiga version was actually a close port of the ST version although I probably used the blitter to speed things up. I would need to wade into the source to work it out. As for which was the closest to the coin-op, back then coin-op conversions were "watch the screen and make this computer do it" so no access to code or graphics from the coin-op at all. So all game logic was created from scratch, I remember I preferred playing the Amiga version but the disc access was irritating. But back to the topic Last edited by Graham Humphrey; 30 July 2009 at 23:59. Reason: Back-to-back posts merged |
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30 July 2009, 23:27 | #228 |
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30 July 2009, 23:36 | #229 | |
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I didn't even know there was a Golden Axe 2-3 As far as the Amiga/ST goes I was also guilty of Gauntlet II, Hotrod, T2 (sorry), Motorhead (sorry squared) then just Amiga MKI, MKII and Primal Rage. It was MKI that used a combination of hardware sprites and blitter for one of the characters, which caused the timing issues. I gave up for MKII and just used the blitter as I recall. My A500 rang it fine, but the testers at Probe kept getting screen issues which I couldnt replicate until I went down to London and saw it for myself. Only way to solve it was to stop using one pair of sprites or reduce the screen width by 16 pix. What has happening was a 16 colour sprite kept loosing 2 of its planes, so dropping to 4 colour because there was no DMA space for it. The soft-sprite engine in these games was based on 16 x 16 pixel "tiles" which were all compressed. The 68000 would decompress a character into a buffer and the blitter would cookie cut it onto the screen generating a mask on the fly whilst the 68K decompressed the next tile etc. Nice parallel processing when the 68K could scrounge a clock cycle or 2 from the blitter. The Amiga was very nice, you could also do LOADS of voodoo with the floppy disc controller too. ST was boring by comparison. |
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30 July 2009, 23:37 | #230 |
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30 July 2009, 23:56 | #231 | |
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- ARM CPU - Decent memory bandwidth (25.6mb/sec - though video DMA grabs a large chunk of this) - Chunky 256 colour mode The rest is inferior. I've done some coding for the Arc recently and I've not at all enjoyed the fixed palette in 256 colour mode, the CPU driven 8 voice sound (ever wonder why no games used all 8 voices?), the hardware scrolling that's only accurate to every _other_ pixel and that you're not supposed to use anyway, and the flakiness of RiscOS in general. |
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30 July 2009, 23:58 | #232 |
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Please please please can we keep this thread somewhere vaguely close to the topic at hand?
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31 July 2009, 00:28 | #233 |
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Filled/wireframe 3D games should always run faster on Amiga over ST and yes that includes Elite 2!
Yes the Amigas custom hardware was primarily designed for 2d graphics but Jay Miner loved those 3D flight simulators! That is why the Amigas Blitter chip can draw polygons so the CPU dosen't have to! The Amiga Blitter can draw lines at 1 million pixels a second and fill them at 16 million pixels a second in parallel to the CPU calculating the next set of coordinates. Elite 2 uses curved lines which the Blitter dosen't support but if it had used the Amigas fill mode it would run faster than the ST version. I remember Braben saying he didn't use the Blitter in an interview for an Amiga magazine.The only reason it ran faster on an ST is because it was a direct port. I bet the sound is crap though compared to the Amiga version? Did everyone not know the blitter had this ability ? I don't know a lot about the STE blitter but the Amiga Blitter has 4 DMA channels which can be combined in 256 different ways, it's pipelined, has 2 barrel shifters, has hardware line drawing and polygon filling. How does the STE Blitter compare to this as I know it was a lot newer than the Amiga 1985 Blitter? |
31 July 2009, 00:39 | #234 | |
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I really liked your conversion of Golden Axe. I'm sure there were strict deadlines and with no support from Sega it didn't make things easy. With a bit more more time how much better do think you could have made it ? I'm sure you could have found a way to make use of hardware sprites. Just look how Shadow of the Beast used them. What did your Mortal Kombat team make of Elfmania ? |
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31 July 2009, 01:12 | #235 | |
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Like the amiga it has signed src y/dst y modulos. Unlike the Amiga it has srcx and dstx signed modulos. Not exactly a feature but something required for interleaved ST video format. It has 16 words of on chip RAM (Halftone) which can be used to apply a pattern for every word on a line. They can be anded with the the src data. This can also be used as an indirect addressing mode. The four bits shifted out of the src word act as a look up onto this data. There are three end masks (first/middle/end) which affect which bits are written to on a line. The Amiga IIRC masks off bits from the source (A I think..). Combine both and it's trivial to hflip rasters or scale them by a fixed number of pixels. Quite nice for art packages. Very fast magnify mode. Unlike the Amiga it has access to the whole 24 bit range. On an STE this could be 4 meg of (chip )RAM , chip registers and ROM. On a Falcon that's 14 meg of chip RAM. Blits can be much bigger than on the Amiga. X/Y count max out at 65536. There is a barrel shifter. Shifting is completely free. It runs 1 to 3 bus cycles (4 cycles) depending on whether the operation is R/M/W. Ie an and will take 12 cycles, a copy 8 and a clear 4. This is less efficient than the Amiga but the ST blitter always has 160,000 cycles available to it per VBL in hog/nasty mode. This means it's faster by far at clearing/filling memory than the Amiga (even with DMA switched off on the Amiga) and due to bitplane contention not much slower at copying. Masking is obviously slower. There is an optimisation where the last line of the src need not be read which can speed some blits up. If if the src data is aligned to a 16 pixel boundery. Combined with the end masks you can do a bit aligned copy where it costs 12 cycles for the start /end (depending on which bits you want to preserve) and 8 for the middle word masks. The Amiga has to use the C channel for this if you want to protect bits in the destination. 6 cycles on the Amiga not including contention if my memory serves. See the HRM for details in case my memory is fuzzy. I think for a truly generic pixel bitblit (dest = src with bits on the first/last word needing to be preserved) they're probably on par with each other. Assuming bits on the dest need to be preserved. The ST one is pretty much a straight implementation of raster op with some extensions. The amiga is quite a bit faster at masking but not 3x faster. More like 1.5 on a five/six bitplane screen due to contention. It takes 24 cycles to mask on the ST. It doesn't have the nice collision detection feature the Amiga one has. On the plus side sceners worked out how to gourad shade with it on the Falcon Like the Amiga it will flat out kill the 68k at bit aligned operations. It's fast enough to throw around a 5 plane screen at (320*200) in a VBL. IE 40,000 bytes per frame with an arbitrary shift. Try that on an 8 mhz 68k It does what it does very well. Much better than the 68k. Last edited by frank_b; 31 July 2009 at 20:56. |
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31 July 2009, 01:14 | #236 |
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The STE wasn't the first machine on the ST to have a blitter. I believe the mega ST had one in 1987 so it's not that new. There are sockets on most STs for adding a blitter. I have an STFM and an STF with a blitter fitted.
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31 July 2009, 02:18 | #237 |
2nd era...
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I've never played on an Atari ST.
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31 July 2009, 04:51 | #238 |
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neither did I, however this is exceptionally reminiscent of schoolyard fights when I was but a tiny lass - and yes I mean fights. Be it Moncton, New Brunswick or Lee, New Hampshire... kids could get violent back in the 16-bit wars.
SNES ruled my neighboorhood in the States, there'd be statistics fights and I remember crying once because everyone was mean to the poor Genesis' 64-color pallette. Yeah, I got teased over on-screen colors. I can't stress how serious I am AND We had CD first! Sure... it had mostly crap FMV games but it had Dark Wizard, Snatcher and the Lunar games. 32X was... a mostrous pile of crap, but it did give us Knuckles Chaotix - which was amazing. ... OK sorry - derailment, I guess what I'm saying is I feel like I'm back in those days - only now I'm with the Big Kids picking on the poor ST fans that love their system just as much. I'm an Amiga gal, but I feel for you ST fans. I was there once. *Hugs her CDX* And fuck the Super Nintendo. :P |
31 July 2009, 06:10 | #239 |
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The SNES was a great system! I still have mine and boot up Super Mario Kart regularly. Much better than that horrible Megadrive/Genesis...
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31 July 2009, 07:40 | #240 |
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In ST Turrican 1 or 2 only title music is sampled, rest is generated and not so good, I felt cheated...
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