Is the Amiga architecture still relevant today?

[ejstans]

Leander stop trying to re-write history.

Firstly if the engineers at Commodore were "allowed" to do what they wanted by their employers, then there's a good chance that Amiga might have survived a lot longer.  Commodore Inc, screwed up.  

There were plans in the early 1990's for hardware and software that would have extended Commodore's technological advantage and made your P100 CPU with 16 meg running Win 95 every bit the boat anchor that it was.

The Hombre (if that's what you're referring to) was basically a wholly new architecture and would not be backward-compatible except through software emulation. And in addition to AmigaOS, it was actually planned to run...Windows!!!

No amount of bug-fixes for that set up would have turned it from the horse-drawn carriage that it was, to the modern motor car that the Amiga still was.

Um, I think you have things backwards here. By this time, the Amiga was technologically ancient. I know because I upgraded my old Amiga 500 to a sparkling "new" Amiga 1200. My friend ditched his Amiga 500+ and bought a 486 instead. His PC ran circles around my Amiga, no matter how hard I refused to believe it...

[ejstans]

i never knew they planned to run windows, but it wouldn't surprise, as Commodore was stupid enough to build PC's instead.
 
In what way did the 486 run circles around your amiga? What were your specs? An A1200 with an 030 and 4-8 meg would have let you do anything a 486 could and Win 3.1 was laughable running on said 486. You'd be a masochist to contemplate running Win95 on it. So i don't see how the 486 was superior.

My spec was an Amiga 1200 with 4MiB fastram and a 40MHz FPU. That's generous too because most people didnt' have any fastram...

[ejstans]

OK so what couldn't you do that the 486 could..

It simply couldn't keep up...

[ejstans]

Doing what? Measured how? Blue screens per minute Vs Guru's per days?

To be honest, I think my Amiga probably crashed at least as often as my friend's PC...No memory protection and all that hardware banging...
 
As for what the PC was doing better. It was faster: my friend was playing around in 3D Studio and could have tezture mapped models moving in semi real time (if I recall correct) and raytracing was blazingly fast. Me in Real3D had like wireframe models and rendering took overnight...Ok, maybe I'm exagerating here, but it was obviously no contest which computer was faster. The graphics were more advanced (SVGA I think?) and of course there was nothing like Wolfenstein or Doom on the Amiga! That's actually another thing: there were much more software, including games, which were of particular interest to us at the time.
 
Now, I mentioned Real3D which is one of the few apps that would have benefitted from a faster CPU. But since "everyone" just had a baseline Amiga 1200 (if that, many people were hanging on the Amiga 500s), those few game companies still developing for the Amiga just targeted those baseline machines. Faster CPU didn't do su much since the game had to be playable without one. I remember the Sierra title "Rise of the dragon" actually had extra animations if you had a faster processor, but does that really make much difference for playability?
 

Having had an '030 A1200 and having to use a 486 running 3.11, and believe i knew many, many other in the same situation, I can't which was more enjoyable to use.

I'd say neither was probably particularly enjoyable to use. I can't exactly remember Win3.11 though, but as I recently dipped back into Amiga, I'm fully aware of the suckage that was Workbench. Give me a shell any time of the day...
 

There's interesting review in Australian Commodore and Amiga review comparing Workbench 3.1 to Win 95 here? http://www.racevb6.com/acar/
 
Its the second last 1995 issue, its a nice read.
 
Comparing a 486 with Win 3.11 is a no contest.
:

It's a bit tilted I'd say...Yeah, such points as Autoconfig, and possibly responsiveness (can't remember exatly), and video, I'll give the Amiga. But usability goes straight to Windows 95, and that's what matter. Not to mention availability of programs...
 
I have to question their technical competence though, as they claim that since Win95 was 32-bit, that meant a byte became 32 bits and made programs bloated...
 
Ahhh, this does bring back memories of when in the mid 90s I got Linux up and running on my new AMD K5 (first PC I bought). My friend (same 486 guy but now upgraded to Pentium 133MHz and Windows 95) commented on X11 and FVWM: "Yuck! It's like the old Amiga Workbench for goodness' sake"...And yeah, it wasn't particularly useful, especially compared with Windows, but all I needed it for was to bring up multiple xterms...

[ejstans]

Engineering is always a compromise. The Amiga was a damn near perfect set of compromises for the technology of the 1980s... But when technology moved on the compromises that made the Amiga great became a millstone around the engineers necks... The 90s killed the 5year old Amiga design as it simply wasn't relavant any more.

What the...was with the slow-mem trapdoor expansion port on the Amiga 500?! Freakin' useless crap. Imagine if people could have added a cheap fastram expansion in the trapdoor slot instead? Would have fixed the major problem with the Amiga which was that it was bandwidth-choked without fastram. Manufacturer's could even have used slower (and cheaper) memory than chipram since the 68k alone would be consuming it.
 
My guess as to the reason of hanging it on the chipbus was to make it possible to upgrade to a newer Agnus and have the memory be chipram. But since that conversion involved cutting traces on the motherboard and bringing out the soldering, I have some doubts that it was really a planned feature...

[ejstans]

@ejstans
 
A500 is a great example of technology compromise Bloodline mentioned.
To be aware of what that actually means you have to know A1000 well in detail.
A500 - It wasn't designed for major upgrade path in mind, since for that purpose there was A2000 launched side by side. That crappy (as you said) trapdoor expansion was not part of Agnus upgrade either, but wise engineering made i.e. slow>chip ram hacks feasible at field service level. If you take a good look on various A500 revisions, you'll see the impact of cost economy on motherboard design - first revisions (Rev3 & 5) had then expensive DIL DRAM covering the whole lower left area for just a mere 512Kb of ChipRAM. In spite of hacks, I don't really belive CBM left trapdoor bus just to allow ChipRAM increase somewhere in future, when RAM price drop occur. It was a best-fitting solution for that time - it wouldn't compromise FastRAM bus; it won't help you with ChipRAM, but it may persuade Amiga development to start using. And it did in great exent, just after Kickstart v1.3 debut.
 
If the crowd was left with true FastRAM only, platform wouldn't attract more audience than A1000 and there would be no A1200 nor else.
AFAIK, A500 trapdoor 512Kb expansion might be the most selling Amiga peripheral.

In what way is slowmem best fitting?! Your explanation just leaves me puzzled. Your last paragraph doesn't make much sense to me. Yes, the 512KiB expansion is probably the most sold peripheral. That's because it dropped in price extremely significantly. After awhile it could be bought for some $20 or so. Sideslot fastram cost like five to ten times this! Which expansion are people going to buy?
 
That's why I said: "imagine if the trapdoor ram had been fastram". There needed be no difference in the actual ram expansion; the only difference is which of the buses it would be on.
 
If the trapdoor had been on the fastram bus than the chipbus, how on earth would that be a bad thing and "not attract more audience than A1000"? Doesn't make any sense! And certainly doesn't seem like a reasonable compromise...

[ejstans]

OK.
I'm not 100% sure, but getting trapdoor to Zorro bus while leaving sidecar open for expansion would involve Buster which is no-go for entry level A500. Moreover, as you already know, all trapdoor expansions above 512Kb were built with so called "Gary adapters" which provided missing address signals needed for bank switching. The most advanced of those were designed to host 4Mb RAM which was used as part-Chip, part-Slow combo, never true Fast. I found this case most convincing on the issue of trapdoor mapped to Zorro bus.

I don't want it to be a Zorro device, just out of the chipmem bus onto the CPU bus so that it can be used in parallel with the custom chips. Making it a Zorro peripheral wouldn't make sense since the point is to make it cheap and I'm guessing the glue logic to support the Zorro protocol is at least partly responsible for making the sideport expansion so expensive.
 

Next, price difference - trapdoor vs sideslot (sidecar, whatever). Of course they were expensive - in 80% of cases they came as a secondary or tertiary feature, alongsinde SCSI/IDE controller or more potent CPU (020/030). A500 made it's fame through gaming which requirred stock 68000 and 1Mb RAM, untill 1991. Who needs 68020 and harddrive, out of productivity purposes ? For that matters, you go for big box Amigas.

This is a silly argument. Yes, gaming on Amiga 500 was restricted to 68k and 1MiB (slow)mem. But had a cheap way to add fastram been available as opposed to slowmem, of course the gaming companies would have taken advantage of it! Fastram means that the Amiga can actually operate the way it was intended: the custom chips can run in parallel with the CPU and provide extra processing capabilities. If there is no fastram, there is not enough available memory bandwidth and the copper and blitter will instead stall the processor! Not too mention the bitplanes...

 

When I said "... was left with true FastRAM only...not attract more audience... " I meant that trapdoor FastRAM was not feasible and that if there were no other alternative, all those pricey sideslot expansions would make A500 just another A1000. Does this makes any more sense at all ?

Okay, so you meant that it was either slowmem trapdoor expansion or no trapdoor expansion...

But I will question that, and maintain that it would make much more sense to have a cheap way of adding fastram so that the CPU would have enough memory bandwidth. Really, lack of bandwidth is probably the biggest short-coming of the architecture!

[ejstans]

@ejstans

The sideport is basicly a direct bus to the 68k (which is all zorro really was), if you want to have both the side port and fastram, you need to have some bus arbitration hardware (ie buster)... The A500 was a cheap device, so opted to have a single zorro slot and a single memory expansion (that was arbitrated by agnus to save costs).

And the (fast) ROM ?

[ejstans]

Ah, ok, I looked at schematics. I basically forgot about DRAM...Agnus had to do the DRAM address translation (+refresh). That does explain it...Still, I think it's a bad compromise. I think it would have been worth it to add DRAM support to eg Gary in order to have cheap fastram...

But of course, that's in hindsight. Maybe Commodore thought cheap fastram sideport expansions would flouris?

[ejstans]

Well, by the time Commodore took control, it was all about saving money! Agnus has a DRAM controler, so they just used that.

Yeah, it's not such a completely bad idea as I thought, and it probably made the Amiga 500 (a little) cheaper. The Amiga 1000 shipped with only 256KiB but an option to upgrade to 512KiB. I guess maybe that's where the idea of the trapdoor expansion came from, even though in the Amiga 500 the extra memory couldn't be used by the custom chips.
 
Anyway, I'm glad the reason for slowmem was sorted out, because when I wasn't considering the DRAM addressing issue, I just thought it insane to tie the trapdoor expansion to the chipbus when it could as easily have (in my mistaken mind) been sitting directly on the CPU bus and been providing a great memory bandwidth injection. But if in penny-saving mode, I guess it made sense to do it that way, although it is a real shame...I mean, it probably wouldn't have costed so much to just clone the existing DRAM controller...
 
Ahhh, anyway, I do maintain that this was not a good compromise! Had they chosen my way, the Amiga of 1987 would have been just about perfect, considering the constraints of the time! :lol:

[ejstans]

The graphics were more advanced (SVGA I think?) and of course there was nothing like Wolfenstein or Doom on the Amiga! That's actually another thing: there were much more software, including games, which were of particular interest to us at the time.{/QUOTE}
 
You never heard of Breathless Amiga clone game of DOOM?
 
It had all features of DOOM, including textures, shades, light effects, jumps, and on basic Amigas it could be even shrinked in pixels down to 160x120 to grant playability, or enlarged if you had had CPU with muscles...
 
On accelerated Amigas Breathless game make use of more horsepower speed and it could even recognize graphics cards connected to amiga AFAIK...
 
Also to gain speed you could change textures from 1x1 pixels to 2x2 or 4x4 or even remove it and revert to solid rendering of surfaces without any textures.
 
A very masterpiece but it existence was just barely known amongst amiga users due to the fallen of Commodore.

No I had never heard of this 'Breathless', especially not in 1993. As it was apparently released in 1996, which is about when my Amiga gave up its ghost, that's little wonder! :p