Not yet used one myself as I have plenty of spinning rust here. IDE-CF or SD are popular though. Advantages is that they are cheap, quiet and you can replace them easily if needed which I'd imagine negates any downside. Another option is DOMs(Disk On Module). Like SSDs they are solid state drives. Downside of of most solid state storage is if they get corrupt there is usuasly no chance of recovery. Not a big deal if you think ahead and have backups.

Ok, but about the total corrispondency "Hard disk=Compact Flash" ?

The majority of folk don't seem to have issues on all the forums and chat rooms I've been on. Yes there are few and it's usual with cheaper grade stuff. Best to get industrial CF cards. They are a bit pricier but are of better quality. IDE-SD adapters are available as well. https://i.ebayimg.com/images/g/k1oAAOSwiOVc42Ru/s-l1600.jpg

With respect to Amigas what systems are we talking about here?

AlessandroB wrote:

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?

No Amiga experience, I'm afraid. As for CF, I sometimes see odd behaviour, such as a specific card not working with a specific HDD controller, but in general they seem to work reliably hassle-free with PCs I'm using them with. The only differences I experience vs real HDD is that they don't make a lot of noise, heat and vibrations, and that they are much faster, and more reliable (than >30 year old HDDs, a new HDD will beat CF, particularly under heavy load, but I don't imagine such loads on ancient PCs, and new HDDs aren't an option there anyway).

I prefer CF to SD as CF uses the IDE interface natively, so there is no additional conversion needed. SD has a different protocol so it needs intelligence, which adds latency (not significant in this application) and risk of compatibility issues. Plus the damned things are so small I keep losing them - and I use them for my Raspberry Pis. CF=old PC, SD=Pi. That way I don't mix them up 😉

All Amiga models suffer to sone cf. Specially when you put two cf on the same channel or put a cf+CD-ROM

AlessandroB wrote:

Frend gift me this computer: Olivetti M290-20

I had this model in the early 90's. A fine little machine. A few years ago I asked parents if I could pick it up (assuming it was in attic). Unfortunately I learned that my parents tossed in a dumper not long after I had moved out of the house. 🙁

finally they brought me this famous Olivetti 286. It's really small and beautiful from life. It's aesthetically new, I think I opened it for the first time since it was bought. From a quick glance mount:

CPU: AMD N80L286-16/S
VGA: WD90C11A-LR
RAM: solder onboard (i think 1 Mb), 2 slot empty
Chipset: VLSI
Battery: Litium coin
Slot free: 2xISA

finally they brought me this famous Olivetti 286. It's really small and beautiful from life. It's aesthetically new, I think I opened it for the first time since it was bought.

Excellent.

Found a little slide-show of this trim wee beast on Ytube.
https://www.youtube.com/watch?v=VUFytwFE-8w

I tried to turn it on and on the monitor it writes me: CMOS Timer Error UNRECOVERABLE POWER-UP ERROR. I think it's a battery problem (which is still its original) but does anyone have experience with this mistake?

AlessandroB wrote:

I tried to turn it on and on the monitor it writes me: CMOS Timer Error UNRECOVERABLE POWER-UP ERROR. I think it's a battery problem (which is still its original) but does anyone have experience with this mistake?

Yes, I've seen quite a few systems that didn't POST with a faulty Real-Time Clock.
A missing or discharged CMOS battery may cause spurious data in the tiny CMOS RAM that's part of the Real-Time Clock (RTC).
Another issue is compatibility, i believe. In case of Dallas Clocks, there are different models out there that have different specs.
Replacing an old Dallas Module by a newer random model might cause the PC to display error codes, as well.
IMHO, it's best in that case to repair such a Dallas chip or at least keeping it and using a newly made replica instead.

PS: A POST card is helpful in some situations (works on ATs and modern PCs, but not XTs).
By checking the BIOS error codes, someone can narrow down the damage.

Edit; I merely was speaking in general here.
I'm not stating that the Olivetti has a Dallas module (I don't know that model).

a CR2450 is installed for luck and not a dallas.