Amiga OCS/ECS demos that work without extra memory (only 512kb chip)
category: offtopic [glöplog]
Just got my HxC and installed it in my Amiga 500. Unfortunately it seems like my 512kb slow-mem expansion is broken, so until I can get that fixed or find one I can buy, I'm stuck with the built-in 512kb chip.
Are there any good demos that can run on that config? So far of the ones I've tried, Substance/Quartex is the only one I've found.
Are there any good demos that can run on that config? So far of the ones I've tried, Substance/Quartex is the only one I've found.
http://www.pouet.net/groups.php?which=1521
Should work.. as I didnt have more memory in my machine when being involved working with gigademo2 atleast.. ;)
Should work.. as I didnt have more memory in my machine when being involved working with gigademo2 atleast.. ;)
Looked into this some years ago to determine if I ever do something with OCS again if one ought to be using extra-mem or not.
Turns out demos started to require extra memory at TheParty1991 (which was at the end of the year), about. Odyssey and Hardwired requires it while Voyage doesent. Demos before this should work. Enigma, Mental Hangover and all those old cool multipart megademos etc.
A little bit disappointing that so many of the famous old OCS-demos require extra-mem. Makes trying to do without a bit pointless. And if you're allowing expansions why not go real fast mem Amiga 3000 OCS or something. C64 scene is better this way since expansions never caught on.
Turns out demos started to require extra memory at TheParty1991 (which was at the end of the year), about. Odyssey and Hardwired requires it while Voyage doesent. Demos before this should work. Enigma, Mental Hangover and all those old cool multipart megademos etc.
A little bit disappointing that so many of the famous old OCS-demos require extra-mem. Makes trying to do without a bit pointless. And if you're allowing expansions why not go real fast mem Amiga 3000 OCS or something. C64 scene is better this way since expansions never caught on.
So now that we're discussing memory, can someone explain the different types found in the Amiga. As I was never fortunate enough to own one, I never got to know the intricate details of the different RAM types.
most sceners had an extra half meg of "trapdoor ram" by the end of 1990, so there kind of a global shift to embrace it after that. I think a few games had started supporting it before then. (Unreal springs to mind though I could be wrong)
Gawd, what a fucked-up architecture! :)
The half-meg expansion was more or less standard equipment for any Amiga owner, everyone I knew had one.
So it's not comparable to C64 memory expansion from a "standardized platform"-viewpoint, it's more like the C64 diskdrive, not part of the standard package you bought, but something almost everyone bought sooner or later.
So it's not comparable to C64 memory expansion from a "standardized platform"-viewpoint, it's more like the C64 diskdrive, not part of the standard package you bought, but something almost everyone bought sooner or later.
As far as I remember, practically everybody had the 512kB trapdoor extension around 1989.
No ram expansion = l@m3r!
Hehe. OK then! Lets decide here and now: "Real" OCS is _with_ half-meg expansion.
What about HD? Much less common, back in the day.
What about HD? Much less common, back in the day.
A500 = Half-meg trapdoor, 2 x floppy drives
Two floppy drives were very useful to me back in the days.
HDs were very rare!
HDs were very rare!
my dad had an HD for his Amiga 500 which also had a 286 PC Cpu in it for running MS-DOS stuff!
A600 all the way, guys! :)
trc_wrm: consider it from another viewpoint. The chip ram did not only allow you to store data for your images (think modern graphics card), but also for the other chips, e.g. for sound. Plus you could run code from there (now think modern graphics card again). Basically a unified memory pool and hardware accelerated 2d bitmap graphics in 1985. I would argue that this was anything but fucked up :-)
Of course space was an issue, so people started upgrading their Amiga by 512k pretty early. Those were so called "fake-fast" memory extensions, as there weren't any faster but cheap and much appreciated extra space. And then there was real fast mem which was much faster than chip-mem. Thats basically the mem type for anything >2mb.
Of course space was an issue, so people started upgrading their Amiga by 512k pretty early. Those were so called "fake-fast" memory extensions, as there weren't any faster but cheap and much appreciated extra space. And then there was real fast mem which was much faster than chip-mem. Thats basically the mem type for anything >2mb.
Also, don't forget, AAAAMMIIIIIIGGGGGAAAAAAHHHHHH!!!111
Aparently you can blag the hardware into using the fake fast as chip ram too by addressing it from $80000 and up.
And this is the wacky funny Hippie story how they did it Amiga History - original developer/architecture team reunion
If you're going to support that 512KB upgrade, you might as well support the realtime clock too. I hate it when clocks aren't realtime.
Reminds me of some good times.. going to a local computer market, and seeing a (then pretty rare) 2.5" hard disk, and my friend deciding it was time for that upgrade for his A600.. then walking a mile to the bank and back. Then walking 3 miles home, fitting it, getting it set up, and finally installing some game (monkey island perhaps) that came on a ton of disks.. and no more disk swapping! That HDD was 20MB, and i was jealous for the next year with my mere 2x floppies :D
Reminds me of some good times.. going to a local computer market, and seeing a (then pretty rare) 2.5" hard disk, and my friend deciding it was time for that upgrade for his A600.. then walking a mile to the bank and back. Then walking 3 miles home, fitting it, getting it set up, and finally installing some game (monkey island perhaps) that came on a ton of disks.. and no more disk swapping! That HDD was 20MB, and i was jealous for the next year with my mere 2x floppies :D
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Aparently you can blag the hardware into using the fake fast as chip ram too by addressing it from $80000 and up.
Not just a matter of "addressing it from a different address", it requires an ECS Agnus (fatter or superfat Agnus), thus making it non-OCS and consequently non-cool.
The standard platform everyone coded for back in the day was 0.5MB chip+0.5MB trapdoor RAM, because these were by far the most popular setup package all the stores and mailorder chains sold in 1990. But even before that, most users just couldn't get by on just 0.5MB RAM, so many demos would at least require that you had it to store OS data+buffers in, so that at least 400KB or so of chipmem was free for the demo.
Demos up until 1987/8 by contrast assumed you had no fastram, and this can make some demos load and start in fastram, including the chipmem data, causing the classic "garbage on screen and in speakers".
Regardless of when the demo was made, anything trackloaded doesn't require fastmem. With very few exceptions. The reason is that the OS doesn't need to be preserved, so you have the full 512KB chipmem for the demo. This means that all megademos and trackmos should run ok, and the only reason they don't is because some demopart or the loader is kickstart-specific.
As for AmigaDOS loaded demos, you would have to go pretty early, to demos made in 1987/8. This means kickstart 1.2 or 1.3 is most compatible with them, but many demos don't have kickstart ROM calls in them. Remember to run the "add22K" command and disconnect any external floppies to yield as much free RAM as possible. (If you run my ChipMap command, it should say $28000-$7ffff is free to be sure.)
Most cracktros work on anything because they're small and have to not crash so that people could play the game after being bragged to. ;)
Summary: Cracktros, Megademos, trackmos, and demos made 1985-1988 should be successful on a stock A500 without fastmem.
Demos up until 1987/8 by contrast assumed you had no fastram, and this can make some demos load and start in fastram, including the chipmem data, causing the classic "garbage on screen and in speakers".
Regardless of when the demo was made, anything trackloaded doesn't require fastmem. With very few exceptions. The reason is that the OS doesn't need to be preserved, so you have the full 512KB chipmem for the demo. This means that all megademos and trackmos should run ok, and the only reason they don't is because some demopart or the loader is kickstart-specific.
As for AmigaDOS loaded demos, you would have to go pretty early, to demos made in 1987/8. This means kickstart 1.2 or 1.3 is most compatible with them, but many demos don't have kickstart ROM calls in them. Remember to run the "add22K" command and disconnect any external floppies to yield as much free RAM as possible. (If you run my ChipMap command, it should say $28000-$7ffff is free to be sure.)
Most cracktros work on anything because they're small and have to not crash so that people could play the game after being bragged to. ;)
Summary: Cracktros, Megademos, trackmos, and demos made 1985-1988 should be successful on a stock A500 without fastmem.
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Regardless of when the demo was made, anything trackloaded doesn't require fastmem.
If you, by "fastmem", mean trapdoor ram/fakefast/slowmem then I call massive bullshit on this claim. (even when including "with very few exceptions")
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the "add22K" command
my nitpick memory might be failing me, but isn't it add21k? :) (or add44k if you're on aga)
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Regardless of when the demo was made, anything trackloaded doesn't require fastmem.
That is indeed utter nonsense! FAKE FAST LOCATED, need I say moar? Lots of trackmos actually utilise (fake) fast memory! And most of them use horribly bad approaches to detect extra memory (mirror tricks etc.)! :D
