Nothing much to do there CPU wise. A 286/16 is limited to your basic shooters, platformers and what not that came out pre -91. Adventure games and most RPG's are not that demanding from that era and should work fine. The only real limit comes from the more CPU hungry games like flight simulators, Wing Commander series etc.

I have an M240, the M290's 8086 predecessor and am working on similar stuff. I've already made an SB1.0 (Snark Barker project to build replica, was fun and it works), and just today received PCBs for Lo-Tech 1MB RAM card and XT-CF adapter. The latter is speed-wise probably the most important, as the original MFM HDD is very slow and noisy - plus old HDDs are rather failure-prone. As you have a 16b ISA bus, you don't need XT-IDE/XT-CF and can just grab a generic ISA IDE controller and use that for hooking up a CF card.

As for CPU, I'm going to add a NEC V30 for a bit of a boost. Your 286-16 gives you less options. There exist in-socket upgrades to 386SX and even 486(SLC) CPUs - but they are as rare as hen's teeth and command big prices. An IBM PS/2 models 50/60-specific upgrade currently on eBay is being offered for EUR 499, which is unfortunately par for the course. Tbh I'd be happy with what you have.
Also, given the non-standard system layout (passive backplane with big SBC-type CPU board including I/O) you can't realistically replace the motherboard even if you wanted too.

What you could look for:
- very late 286 games could use EMS. Getting an EMS card would help there.
- replace the EGA adapter with a VGA one.

256k VGA is built in. https://translate.google.com/translate?sl=aut … etti-m290-20%2F

Nice wee system. Fit a network card to for some good old irc fun. Take the ram to it's max, just because and fit a maths co-pro. With 3megs of ram total it will run GeoWorks nicely or just a basic win3.x setup.

A Harris 20 or 25 may be possible but you have to change the osillator.

About the CPU... i have seen that Harris and Intersil made a 20/25Mhz 286 CPU, it was easy for me to replace... it makes sense to do it?

About the integrated VGA... is good for 286 DOS games? from monkey island 2 to wing commander, because thare are only two isa slot, one for ide controller and one for sound card... no space left for VGA, or is better to use a isa vga and the internal ide controller?

Replacing the CPU is easy - but it won't run any faster unless you also change the clock oscillator. Big question there is what else that oscillator feeds. If the ISA bus runs off a simple 1/2 divider, putting a faster CPU in means overclocking the ISA bus. If the ISA bus has its own 14.3MHz clock crystal, you have no such problem and so long as chipset and RAM can handle the higher speed you can try 20MHz or 25MHz (with 40 resp 50MHz crystal). In any event it will involve some soldering...

If the VGA is the one mentioned on that link, a WD90C11, it's one of the better ones - no high-colour support (but with a 286 and 256kB video memory that's not really an option anyway), but relatively fast, certainly for its age.

I'd stick with the on board controller. Fitting a network card you have the option of fitting an eprom with xt-ide bios in its boot rom socket to access larger drives.

Wing Commander will be slow as it's more suitable for 386s. .Monkey Island 2 should run fine.

Caluser2000 wrote:

I'd stick with the on board controller. Fitting a network card you have the option of fitting an eprom with xt-ide bios in its boot rom socket to access larger drives.

Wing Commander will be slow as it's more suitable for 386s. .Monkey Island 2 should run fine.

Wing Commander runs acceptably on my 286-12. Having a zero wait main board helps tremendously, as does having a fast VGA (ET4000)

That's cool. I'll try it on my Zenith Z286LP Plus.

https://drive.google.com/drive/folders/197ZQb … FKHGPLK-ry4pKqO

I have this controller and this vga, i thing are better than the original on the mainboard or not?

Performance of the OAK VGA probably is about the same. The ide controller, in my opinion, would be a waste and better off on a late 386 or 486 system. A sound card and nic are better options seeing as you only have two isa slots.

So, no big chance to make this computer run much better... only swap to harris25mhz make a really improvement...

It is possible to run it to 30/35/40Mhz???

Wouldn't even try. Better off with a generic faster system to play around with. Except the system for what it is, a nice 16-bit mid-range x86. This is how good it can look

Ok, i have also a 386sx20, 486DX2, PentiumII 133->566, Pentium4 3,6Ghz

AlessandroB wrote:

About the CPU... i have seen that Harris and Intersil made a 20/25Mhz 286 CPU, it was easy for me to replace... it makes sense to do it?

About the integrated VGA... is good for 286 DOS games? from monkey island 2 to wing commander, because thare are only two isa slot, one for ide controller and one for sound card... no space left for VGA, or is better to use a isa vga and the internal ide controller?

Add a socket and get the Make it 286 to 486slc upgrade 😉

http://www.cpushack.com/2014/08/30/improve-te … 86-286-upgrade/

AlessandroB wrote:

because thare are only two isa slot, one for ide controller and one for sound card... no space left for VGA, or is better to use a isa vga and the internal ide controller?

Actually, with only two ISA slots, I would not touch the system at all and leave it as is. Add a sound card and let it be the 286 it is. I mean, it's an Olivetti, not just some cheap no-name clone from Asia. If you want to build an uber-286, use a cheap clone board with 8 ISA slots as a basis. This will get you much further.

derSammler wrote:

AlessandroB wrote:

because thare are only two isa slot, one for ide controller and one for sound card... no space left for VGA, or is better to use a isa vga and the internal ide controller?

Actually, with only two ISA slots, I would not touch the system at all and leave it as is. Add a sound card and let it be the 286 it is. I mean, it's an Olivetti, not just some cheap no-name clone from Asia. If you want to build an uber-286, use a cheap clone board with 8 ISA slots as a basis. This will get you much further.

I Agree, but, what the target use for this system in your opinion?

Most games up to 1990 should run fine on it, also simpler stuff like adventures that are a bit newer (Day of the Tentacle e.g. still runs nicely on a 286).

With DOS 5.0, Windows 3.0, and such games, you have a very nice 286. No need to try to reach 386 performance.

Back in the early 1990s we had an IBM PS/2 with 386-16 and one of my best friends had a 286-12, so a tiny bit slower than your Olivetti. We used to play Origin games on both, particularly Ultima 6 and Martian Dreams. At one point I bought Wing Commander and enjoyed it on the 386-16, but although it ran on the 286-12, it was too slow to be playable. I never liked them, but my friend was into all the ...Quest games, particularly Space Quest and Police Quest. I believe everything up to Space Quest V and Police Quest 3 ran fine on the 286.

Apart from games there's not a lot of stuff out there that specifically needs/wants a 286, so you should basically see this as something that can run XT stuff, but run it better (faster CPU, wider bus) with easier compatibility with more modern peripherals (AT keyboards, regular IDE controllers). The biggest improvement is probably HDD speeds - which will be even more apparent if using IDE-CF adapter - and after that the ability to use 16b ISA VGA cards.

That said, I sort of agree with the idea that the 286 is in retrospect the least interesting of the generations of older PC stuff, particularly as most of the advantages it was supposed to have only really materialized with the 386. But one 286 is still a lot better than no 286, and if you see it as a turbo-charged, slightly less archaic XT, it's not going to disappoint.

Also, pretty pointless but cool & cheap upgrade that seriously increases one aspect of performance (and improves SimCity, the one game to extensively use it): install an 80287XL FPU.

Thank you, your reasoning is really complete and exhaustive, I will keep it original, as it comes from the company. I take this opportunity to ask you something: in the Amiga forums (which I frequent a lot) it is said that the compact flashes are not 100% the substitute of the hard disks because they do not behave in the same way, it is as if some functions were missing therefore in some cases they can work, in other cases they give incompatibility. Is this experience valid also in the PC field?