24 May 2017, 07:53 | #1 |
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The vampire incompatiblity discussion thread
What incompatibility? That word seems to have a different meaning to everybody but all the meanings are bad. Yes, there is some software that only runs on the 080 but that doesn't mean it's incompatible. It just means that all other Amigas are incompatible to new capabilities of new hardware which is a natural thing. The same thing happens all the time with 020+ binaries.
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24 May 2017, 08:48 | #2 |
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It doesn't behave like any 68k cpu == incompatible. (as it is a bizarr mix of them all)
and now with AGA \o/!. and they add more chipmem etc. /o\ why? well ANY changes introduces more possabilities of stuff not wokring. and I cannot se ANY point with it. but THAT is however off topic here.. |
24 May 2017, 10:30 | #3 |
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there was never a 68060 machine by commodore, but everyone wants one - this was a hack by some 3rd party, remember this ?
about the chip ram - i run my emulation allways with 8MB chip ram - another hack , but not a single app refused to work - regarding that hack. |
24 May 2017, 10:51 | #4 |
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the 68060 was still from MOTOROLA.. anyway. they seem to want to break any of those specs I think is static now. for no reason. so. too bad . LOVE the HW but not my path!..
THIS however is out of topic here |
24 May 2017, 10:54 | #5 | ||||
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The 68080 supports all 68k instructions and thus is far more compatible than the 060. Motorola left away several instructions in the 060 because of the constraints on die size and transistor count at the time. Do you really believe they would have chosen to trap those instructions in a later generation 68k processor? That's what I would consider bizarre, to not support all valid 68k instructions without trapping and 680x0.library in place if you can support the instructions in hardware. Quote:
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24 May 2017, 10:55 | #6 |
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24 May 2017, 11:03 | #7 |
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The problem with the 68060 comparison is that the 680x0 series in general is backwards compatible. I can run a 68000 executable on a 68020, I can run a 68030 executable on a 68040, and I can run a 68040 executable on a 68060. All of this is transparent to the user and the application. Some of the features, e.g. missing FPU opcodes in the 040/060, are handled by software traps, which is slow, but works transparently to the user and the application, meaning on my 060 I can run any executable compiled for an 000, 010, 020, 030 or 040, with or without an FPU. This also means that only a minimum CPU ever has to be checked for; if your CPU is <whatever> or higher, the software will work.
The 68080 changes this, and it means that the rule that higher CPUs are backwards compatible can no longer be made. Not being able to transparently run executables for all previous CPUs in the series breaks the sequence, meaning that incompatibilities that were always downwards only are now facing the other way. While this isn't a problem for "future" software that can be compiled with the 68080 in mind, it doesn't fix 30+ years of existing software that uses this rule, and likely vastly outnumber any current and future 68080-specific programs. Until I can take any 68040 or 68060 executable and run it on the 68080, it's not fully compatible. This compatibility could come from an updated core or perhaps a 68080.library-style setup, but executables for any previous 68k CPU should just work from the users' point of view. |
24 May 2017, 11:13 | #8 | |
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Is this really so hard to comprehend? Do you really think that the professional CPU designers making the 080 are too stupid to make their 080 backwards compatible? |
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24 May 2017, 11:19 | #9 |
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Nope, I wasn't calling you or anyone else involved stupid, so stop trying to find some reason to be offended and defensive. You know as well as anyone else that in Amiga terms, 68040 and 68060 systems have FPUs and MMUs as standard. Yes, that may be a silly assumption on the part of developers 20 years ago, but barring a very minor and uncommon exception, it holds true, and 040- and 060-specific compiles of software make that assumption. Until they can be patched to work in real-time via replacement 680x0 and mmu libraries, any software that looks for a CPU and finds a 68080 can and often will assume that it has a FPU, MMU or both, and will fall over as a result.
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24 May 2017, 11:29 | #10 |
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Well, then clearly say "it currently hasn't got an FPU nor MMU" instead of creating the impression there was a general backward compatibility problem. The lack of the FPU and MMU is not a problem of the 080 as such but rather of the fact that we are seeing a work in progress. And you should know that there is a load of EC and LC 040s and 060s in the Amiga world. Bad software is just that, bad software.
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24 May 2017, 11:34 | #11 |
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Sorry to continue the derailing but, Gunnar has also made it clear that there won't be a compatible MMU of FPU for the Apollo Core (68080) either. So it's a dead end for existing demos and some software that expects at least an FPU in 040/060.
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24 May 2017, 11:46 | #12 |
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Maybe someone should start a new thread to discuss this.
I'm not exactly knowledgeable on Amiga hardware, I know some stuff and I fully admit a little knowledge is a dangerous thing but... To my mind and with reading the addition of AGA support to none AGA machines the Vampire must essentially be its own full amiga and all you are doing is placing a new computer within your old case leeching power and peripheral signals from the main board. By this I mean that from my understanding it is absolutely impossible to add AGA support to a none AGA machine as the complete chipset and bus pathways are not designed for it. Only way to add them is to completely replace them and after doing this what is left of your original Amiga but an i/o interface for peripherals. Its only a matter of time I think before the Vampire becomes a stand alone piece of hardware and essentially a new minimig. In many ways the name Vampire is most fitting. I would also go so far as to suggest that this is a key reason why we haven't seen a vampire for the 1200 as they haven't yet developed a new AGA core, if i am correct the Vampire 1200 will follow very quickly once the AGA upgrade for the 500/600 comes along. Wouldn't it be funny if we found out the FPGA was just running a copy of UAE. |
24 May 2017, 12:20 | #13 | ||||
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24 May 2017, 13:20 | #14 | |||||
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I support this motion.
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24 May 2017, 14:42 | #15 | |||
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this is however still out of topic. so this will be last answer in this thread about this. and nees of libs etc. YES. but how hard is it? we now knows how to do it. still to stop have to think about YET ANOTHER cpu. do a replica of one existing and STICK TO IT! Quote:
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I must say: now seing the issue with changing ANY of the chipset specs tells you how little you know how software can work. ok the memorything is the smallest issue. yes. but still. even thinking of the idea to change ANY of the chipsetspecs show that they are not interested in making a compatible machine. do it EXACT as any chosen chipset work and stick to it. (my recomendation is the AGA chipset being the latest one) ANY expansions shuold be reached via RTG, AHI, Warp3D or similiar solution. as changing the chipsetspecs is anyway pointless as software needs to be rewritten anyway. Systemfriendly software. yes. but thing is: we are using a really old OBSELETE macine (for fun) with a lot of software doing lot of crazy things, absolutley not within the specs. and lets not introduce more things that can make this break. more discussion aboit this? please start another thread.. to just. eh keep it on topic? this thread is about A4000 loosing its possability to show AGA modes in WB, this due to batteryleakage from a neglected machine. (sorry. but that is what i call machines with lekageissues..) |
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24 May 2017, 15:02 | #16 |
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24 May 2017, 15:07 | #17 |
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I do not say that the ppl behind 080 are bad on what they are doing. but the 68k is not in development. and THAT was my point.
however.. EOD just wanted to make it clear what I was pointing out. so in short: The Motorola 68k series can be considered STATIC. The Amiga Chipset can be considered STATIC. Let them be. STATIC. do improvments like addons . reachable via RTG, AHI whatever. as software needs to be rewritten ANYWAY so do not introduce a chanse to break anything as there ARE badly written software out there. As there are anyway NO point of changing specs (due to software not being written anyway) a new thread anywhere maybe? |
24 May 2017, 15:34 | #18 |
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Well, if you think that the Amiga has to be mummified / remain mummified, the Vampire cards definitely are not for you. The whole project is about making the Amiga enjoy at least some of the general progress in the technical field that it failed to experience due to Commodore's demise.
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24 May 2017, 15:37 | #19 |
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Nothing to do with mummified.. as addons would require software to be rewritten anyway. introducing more possible issues by changing HW registers etc is just plain stupid as you still have to rewrite stuff..
080 will be the new ppc.. a few software.. nothing more. love the HW but implementation.... :-/ |
24 May 2017, 15:56 | #20 |
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Another thing you make up on the fly...
No hardware registers are changed, new registers for new functionality are being added. For decades the x86 world was scorned for A20 gates and similar pointless legacy stuff. And now every new feature needs to be crippled or left away because of fear of some badly written demo breaking? Your point of view boils down to that Commodore should never have made ECS let alone AGA because some shit software couldn't deal with the changes. And the compatibility level was much worse than what we are seeing now with the enhancements that the Vampire brings. Quite to the contrary the 080 even improves compatibility in many places beyond what we experience with 040 and 060 equipped Amigas due to some clever features: - blitter serialised with the CPU such that the blitter cannot be overrun by too fast a CPU (most frequent problem of shitty demos and games) - turtle mode (throttle CPU speed to roughly A1200 level) - transparent caches (badly written self-modifying code doesn't break as it does on 040 and 060) |
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