Teardown and review of a new 386 system: Hand386 | Hacker News Reader

Teardown and review of a new 386 system: Hand386

yeokhengmeng.com

97 pointsingve45 comments

A chip with probable silkscreen “HM82C42” was found. Googling does not turn up anything but given the amount of traces going to this chip, I’m going to suspect this is the keyboard controller to the PS/2 interface.

A PC's keyboard controller is also known as an 8042, based on the original Intel microcontroller it used, so 82C42 is obviously a variant of it from a different manufacturer. No surprise that Google doesn't work --- it's gotten increasingly horrible for finding less well-known part numbers and such: https://news.ycombinator.com/item?id=36195600

I suspect someone may have gotten a batch of NOS embedded PC boards with this SoC and decided it would be a good opportunity to sell them to the retrocomputing community. That explains the CF and choice of I/O, as well as the 94-95 datecodes on the ICs.

Indeed, the 82C42 is a keyboard controller. The original 8042 was a microcontroller that had the keyboard controller code burned into the onboard ROM. I am using an 8242 variant right now from VT for a multi-cpu 68k project. There are a few different variants, but the most common one has the standard PS2 keyboard+mouse support.

http://www.bitsavers.org/components/viaTechnologies/VT82C42_...

I think this is a custom board (especially given the lithium battery and USB charging), but they copied the design from an industrial using the M6117. I've seen a ton of devices that use the same pair of an M6117 and a CHIPS F65535 VGA chip. You can still find stocks of both on places like Utsource. I do wish they had just gone with the more modern Vortex86 instead, perhaps someone will design an open hardware equivalent to this device that uses one of them instead.

The 386SX was the slow one back when it was released. The "real" 386 was the DX, with a 32 bit bus. The 486 was so much better, the first Intel to perform close to the Unix workstations I had at university.

My first Linux box was a 386SX laptop with 3 megs of RAM (1 on the motherboard, 2 in an add-in card.) This was back in the Linux 0.99.x days.

I late upgraded to a 486 and it was like night and day!

I mained a 386SX in high school. Windows 3.x really chugged on that thing (only 2 MiB of RAM as I recall), but I learned a lot about Windows programming and x86 assembly.

Then came 1995, college, a Pentium, and something called Linux...

Normally I'm a sucker for weird and wonderful hardware, but I'm trying to figure out what the target audience is, and I'm really coming up short. Anyone got any ideas?

Everything I can think of, there's a better alternative available.

It's probably good for running TOTP authentificator or some kind of crypto wallet software, especially considering the lack of internet connectivity on this device, which makes it more secure for this purpose (though it may output QR codes on the screen, so actually it's kind of unidirectional data diode, rather than fully isolated device). I would install OpenBSD on such computer. Recent supply chain attacks on the dedicated crypto wallet hardware [1] indicate that we must rely on open source software if we strive to avoid low-entropy backdoors in the random number generator in such systems. The probability of a successful supply chain attack on such a gadget, given the number of user-controlled variables, is close to zero.

[1] https://www.kaspersky.com/blog/fake-trezor-hardware-crypto-w...

OpenBSD dropped support for 386 chips nearly 20 years ago. This is a 386SX chip first released 35 years ago. You're not running a crypto wallet on a 386SX. The cryptography would crush it.

It seems to be a pure nostalgia computing device, which has enough of a target market to make a few hundred sales.

But why a 386? Why not a 486 with a better screen?

It's annoying me that I can't get my head around it.

> But why a 386? Why not a 486

This question can go on and on though. Why a 486 and not a P1? Why a P1 and not a P2?

If I had to guess I'd assume it was purely based on part availability, or cost.

The question seems to be why ship Windows95 preinstalled on a platform that can't run it, when highly integrated x86 clones such as the Vortex are available? https://www.vortex86.com/products/Vortex86DX

I assumed that was for the FAT32 and USB support. The stock image just boots up in MS-DOS 7.1 mode and you have to type “win” to go graphical.

Availability. Check out the datasheet on the 'CPU' in the article.

Also top 486s require a heatsink and a fan.

That was true in 1989 but modern x86 reimplementations like the Geode GX1 are much lower powered. The GX1 is discontinued but DigiKey still has > 100k of them in stock...

My guess is that it’s for older industrial equipment. There was another laptop on Aliexpress that made the rounds the other day:

https://arstechnica.com/gadgets/2023/05/brand-new-laptop-rec...

Those who want pre-built DOS-based cyberdeck.

> I'm trying to figure out what the target audience is

Probably it was some sort of terminal for industrial equipment; nothing to write home about by today's standards (and yesterday's too for that matter), but could be used for slow and not critical tasks such as EEprom/chips programmer, serial terminal for known soft/hard protocols and signals. I would find useful having one that accesses a shared directory on the LAN then can read firmware files and program chips or read/write on rs232 or i2c busses, work as serial terminal for debugging etc, and other tasks where a laptop could be overkill.

The 386 is the minimum viable processor for a lot of applications. 386SX class machines are the baseline for the modern x86 architecture: 32-bit internals, real MMU capabilities. It could probably handle a lot of legacy Win32, Win16 and DOS industrial apps. The heat issues could be a concern but lower power and solid state storage could still be a reliability win when replacing aging hardware.

This is what springs to mind for me:

* https://www.cpushack.com/space-craft-cpu.html space shuttle used a 386 * https://www.cpu-galaxy.at/article/cpu_in_space.htm ISS still does too * https://arstechnica.com/science/2019/11/space-grade-cpus-how...

Interestingly, the CPU core used in this seems to have some undocumented instructions that are not present on Intel/AMD (and conflict with SALC there, though this shouldn't be a problem, since it is also an undocumented opcode and rarely ever used).

The linked datasheet only lists a few of those, and it seems there is not even enough information there on how SMM should be implemented: it says that CR0, EFLAGS, EIP and the CS descriptor are saved/restored using some internal registers, and that the SMM code is responsible for everything else - without explaining how exactly to do this.

    F1           enter SMM (ICEBP)
    D6 E6        exit from SMM
    D6 CA 03 A0  load SMM entry point register with EAX
    D6 C8 03 A0  load EAX with SMM entry point???
    D6 FA 03 02  load power control register with EAX

It's called HSM and seems to be described starting around page 31 here: https://www.dmp.com.tw/app/webcamera/pdf/m6117d.pdf

Yes, but pretty much all the information about how the "M1386SX" core handles SMM is contained on that single page, the following ones only describe I/O ports. And it leaves a lot of questions unanswered, like how to access the "GR" registers (something like MSRs on Pentium+?), or the other descriptor caches that aren't saved automatically.

The text is written as if these were standard features of the architecture, or at least documented elsewhere (maybe they were, but can't find anything online now).

It’s brilliant that someone would do this.

There is no problem statement, a series of bad design decision and component choices, and a rather silly price.

It reminds me a bit of the British tradition of shed engineering and it’s great to see people still doing things for the dream

Yup. It's awesome and rubbish at the same time.

Aside from interfacing with ISA cards emulation is probably better - an old mid/high end phone with a portable bluetooth keyboard and limbo x86 (via f-droid) sounds promising.

For laptops, there are some lovely cheap little Chromebooks out there that are near/past their update expiration date and if you want a slight challenge you can get an ARM one like the Asus C101P.

But there's something about having real hardware to do things like this...

Does anyone know if the core ("DM&P Ali M6117") is derived from one of the Intel licensees like Via, or if the patents have expired (mostly likely I guess), or it Intel just don't care?

IIRC the DM&P SoCs are based on Intel-licensed Rise/SiS cores.

The Vortex86 ones are based on RISE, but this is a M6117, which originated at ALI (Acer Labs), which became ULI, which was bought by Nvidia (https://www.nvidia.com/en-us/drivers/uli-m6117c/), and then at some point ended up at DM&P

Edit: and indeed you can see this in the PCB pics, one says ALI under the DM&P lettering and the other has an Nvidia logo in the same spot

Alternate review https://youtu.be/Eiutn-P7HVQ

Not for sale anymore, though.

I'd pay a small sum of money for a clamshell computer with full keyboard and gaming controls[1] (thumbstick, d-pad) as long as I could run Linux with Wine on it.

[1] Do they still make the Pandora? I seem to recall it being overpriced and under-produced.

The Pandora was renamed to Pyra I think. But the solution you are looking for could be the GPD WIN Max 2. it checks all your boxes.

The prices I am seeing in my local market[1] are higher than I want to pay.

I was thinking a few hundred dollars at most, not $3200 :-(

[1] https://www.wantitall.co.za/computers/ysjmnpc-gpd-win-max-2-...

Wow that is more than double the retail price. You usually find them new for $1300. Alternatively, you could look into a used GPD Win 2 (Released End of 2018). In my area, I find them for €350 used.

I always ignore WantItAll when looking for products here, it's clearly just a "re-shipper" of overseas online stores so everything is always pretty insanely priced because you're paying the normal overseas online store "retail" price + the cost of it being shipped to SA + import tax + WantItAll's markup + local courier fee.

I think their market is people who have so much money that they don't care what it costs to get niche items imported, to me it's a bit sickening that said market here is apparently big enough to sustain such a company.

I think their market is people who don’t know better, and advertisers (if you search for x_product South Africa chances are they are one of the top results if it’s not on Takealot).

Shop and Ship (I think it’s called Aramex Global Shopper in SA) type forwarders should have killed wantitall.

I was an original crowd-funder of the Pandora. Waited years (three, I think) for mine to turn up, by which time my interest in that sort of thing had waned, and it was also out-of-date and felt pretty like a first attempt in terms of build quality, etc. It had what I would now consider to be "alibaba" build quality. Not great, but not terrible. I have reasonably high standards for build quality, and I was disappointed. Don't get me wrong, I wasn't thinking Macbook Pro build quality, but was expecting mid-range laptop build quality. This felt like a cheap device in comparison.

I sold mine on eBay at a time that there was still a huge waiting list, so made a fair bit on it - IIRC I doubled my money, having sold it within a week of it arriving.

The pyra website seems to still be working to the same formula, and looks to be taking pre-orders - very much like back whenever the Pandora was a thing!

[1] - https://pyra-handheld.com/boards/pages/pyra/

Unrelated but does anyone know any reasonably priced rPi case with similar form factor ? All I've seen are one-offs. I'd love one to work as serial terminal/debugging tool

The seller had close up photos on one of his listings of the PCB, so a teardown wasn't totally necessary, although I suppose this might be a deeper dive.

I’d rather have something in this form factor that runs modern mainline Linux (as in no weird kernel modules that won’t get merged).

Just a shame this was not a 486 DX/2 66mHz or 100mHz. I refuse to waste time on 386, it just is too underpowered.

I suppose it depends on what you want to run on it, some things run best on a 8088/4mhz, or a 286/386/486... once the Pentium came out and people stopped writing clock cycle dependent code, the CPU didn't really matter.

Demos and dos games with vga graphics

386 is the smallest core you can have that runs modern OS with virtual memory. If you're looking for performance, by today's standards, you might as well ask for a Pentium Pro class CPU, it's not gonna make a significant difference vs a 486 in price and it will be much faster.

<quote> WHAT EXACTLY IS A 386?

The Intel 386 CPU was first launched by Intel in 1985. Known as 80386 or i386, it is the first 32-bit CPU of the x86 architecture. </quote>

It’s really weird. When growing up I used to read about old, mostly disappeared systems as curiosities. Now, I’ve actually grown up with such curiosities…

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