I got Dr. Zeissler's 286-20 with a nice ET4000 videocard.
I never had a 286 myself, nor an ET4000.
I went from a 8088 machine at 9.54 MHz to a 386SX-16.

I like the 286 because it has a lot of performance, while still having to work within the limits of the 16-bit segmented memory model. Like the 8088, the 286 was not explored much by the demoscene. So I may want to do some more experiments on that. And unlike the 8088, you can use a GUS in this machine. A 286-20 with ET4000 and a GUS makes an excellent demo platform, which can rival Amigas. It's interesting to see just how close you can get it to the 386/486 demos of the day.

my 😀 YOUR 286-20 is a very fast machine!
Perhaps your upcoming Demoeffects will run on my A2386-25 in my Amiga.

dr.zeissler wrote:

Perhaps your upcoming Demoeffects will run on my A2386-25 in my Amiga.

Probably 😀
What PC videocard do you have in the Amiga?

ET4000 😀 but only the 256color model. But I still have the same one I sold to you, but this card is very oversized.

Scali wrote:

I never had a 286 myself, nor an ET4000. I went from a 8088 machine at 9.54 MHz to a 386SX-16

386SX are much similar to 286.

dr.zeissler wrote:

ET4000 😀 but only the 256color model. But I still have the same one I sold to you, but this card is very oversized.

Well, that should be good enough 😀
I plan to only do EGA or VGA effects for 286, it won't be fast enough for more than 256 colours anyway 😀

Tertz wrote:

386SX are much similar to 286.

In terms of performance in 16-bit code, yes.
However, for a coder, the big difference is that a 386SX can also run 32-bit code. I like the challenge of writing 16-bit code only, and still doing things that people did with 32-bit code on 386/486.

Scali wrote:

Tertz wrote:

386SX are much similar to 286.

In terms of performance in 16-bit code, yes.

Hence, in a code wich is done to run on 286 you may don't notice a difference.

I like the challenge of writing 16-bit code only, and still doing things that people did with 32-bit code on 386/486.

Sound like we may will see demos for 286 😀 like saw for XT recently. The problem may be in that top Intel 286 was 12.5 MHz and demos should be done for this clock, as maximum.

Tertz wrote:

Sound like we may will see demos for 286 😀 like saw for XT recently.

Yup, I actually started targeting 286 before I went to 8088: http://www.pouet.net/prod.php?which=62165
With the things I've learnt on 8088, I'd like to revisit the 286.

Tertz wrote:

The problem may be in that top Intel 286 was 12.5 MHz and demos should be done for this clock, as maximum.

I think that is somewhat up to the viewer.
Certain effects can be designed to run 'acceptably' on a 12.5 MHz, but smoother on a 16/20/25 MHz 286.
My idea is to try to get as close to 386/486 as possible, so the faster the better 😀

some oldskool-stuff would be very nice:
https://www.youtube.com/watch?v=qW8G6zOyPq0
https://www.youtube.com/watch?v=o1tWNRd-4j8
https://www.youtube.com/watch?v=eonlhPhv01s

dr.zeissler wrote:

some oldskool-stuff would be very nice: https://www.youtube.com/watch?v=qW8G6zOyPq0 https://www.youtube.com/watch?v=o1tWNRd-4j8 […]
Show full quote

some oldskool-stuff would be very nice:
https://www.youtube.com/watch?v=qW8G6zOyPq0
https://www.youtube.com/watch?v=o1tWNRd-4j8
https://www.youtube.com/watch?v=eonlhPhv01s

Yea, with EGA/VGA those effects are not too difficult.
It's more interesting to try to do them on 8088+CGA though 😀

As I said on "pouet", after the ultimate XT-Demo (8088mph) we would like to see,

- the ultimate Tandy-1000 Demo (because 8088mph does not support tandy-gfx and the soundcapabilities)
- the ultimate 286/10-20 EGA-Demo SB or DAC suppport
- the ultimate 286/386 VGA-Demo (SB/GUS?)

😀

PS: it's all about the "cool 2d/color-effects", not about 3D stuff...bäh!

dr.zeissler wrote:

- the ultimate Tandy-1000 Demo (because 8088mph does not support tandy-gfx and the soundcapabilities)

Yes, I would probably go for PCjr though. I've done some experiments with its audio chip. The biggest difference with a regular PC is the lack of a DMA controller, which means that floppy access locks up the PC if you use the BIOS routines.
So one thing I've been thinking about is having some kind of 'background loader' that allows floppy access while you can still at least can keep the music playing and some static graphics displaying, and hopefully even some simple animation.
Once that problem is solved, the PCjr can do pretty much everything that 8088+CGA can, and more.

dr.zeissler wrote:

- the ultimate 286/10-20 EGA-Demo SB or DAC suppport
- the ultimate 286/386 VGA-Demo (SB/GUS?)

I would probably lump those two together as a single platform.

dr.zeissler wrote:

PS: it's all about the "cool 2d/color-effects", not about 3D stuff...bäh!

Well, I'm more of a 3d coder than 2d I guess.

I like my 286 for what it is, a pure 16 bit x86 system and nothing else. I look forward to trying out any demos that are made for this class of system.

I think its prefectly fine to target 286 machines the in the 16-20 MHz range with VGA + music demos, 16 MHz seems to be the most common of all 286 speeds and 20 MHz is at least not rare. If you would write VGA + music demos with an Intel 8-12 MHz 286 as the target I have a feeling that they would be somewhat less impressive.

For those who dont have a fast 286... buy one! My Harris 286-16 MHz with Neat chipset is the retro system I use the most of all my retro computers, I have a 20 MHz Harris 286 aswell but that system needs a case.

286 systems are quite varied depending on who manufactured them or assembled them. I'm happy with my OEM 1990 Zenith z286lp plus at 12.5mhz. It was quite a common speed for 286s in the late 80s early 90s and certainly appears to perform nearly as quickly as my old original 286/16 clone.

Screen shot in Win3.1 which runs surprisingly well running Trumpet WinSock utils. With the software I have to be brutally honest Win3.1 has more functionallity than GeoWorks 2.x and certainly as stable.

Scali wrote:

286? VGA? Adlib? Sounds like a great system for 1991 donut 😀

Sound is great through a CT1740 btw.

Mark me down as interested in some more 286 demo action!

I tried "mo'slo" and "at-slow" last night to slow down my 16Mhz rocket and found them both lacking. According to 'checkit', I achieved a speed equivalent to 1.29 times a PC-XT at one point, but - consistent with my previous experiences with software slow down utils - the results were inconsistent and the system was unstable.

So it looks like the turbo function is my best bet - this appears to under clock the CPU to 8Mhz which helps with some games. My other option is to run the relevant games in CGA mode instead of EGA - I don't know why but this causes them to run at a playable speed. But they don't look as good of course. 😜

Yea, there's quite some variety in speeds. The early ATs at 6-8 MHz are still quite slow. Faster than an 8088 or V20 at 10 MHz, but not exactly blazing 😀
16-20 MHz is quite a different type of machine. Especially as the VGA cards got better, and the systems as a whole got better. Faster chipsets, memory etc.
They started to become competitive with Amigas at that point. Which is what I find interesting.
They are somewhat of a 'missing link' as well. Programming-wise they're still very similar to the 8086, with segmented memory, 16-bit registers and all. But performance-wise they're becoming quite capable machines at last.

Currently been reading Jan '89 PC Mag. It has a good review on various 286/12s. Looking at the ads some earlier 16-20s even sported intergrated IDE. Can't get over the price Zenith was asking for their z248/12 Model 80 VGA system but it did appear have some i/o magic not seen on a lot of clone systems at that time. Never heard the term "Superset Bus" or "Slushware" before which are unique to Zenith systems. This seems to confirm what I'm experiencing with my later wee system.

The 286 had a pretty good run really - from '82 to... 92? My machine was built in mid '91 - almost 486 territory - and it would have been a very cheap and usable workhorse for the family who owned it (they left all their documents on there so I know quite a bit about them 😈)

I had another play around with "AT-slow" last night and got a better result using the /c switch, which allows you to specify the Mhz you're aiming for. "at-slow /c6 /2" worked well and made both California Games and Double Dragon playable.

Next job is to spray paint the drives a dark gray - their current colour isn't working for me.