Alice Averlong🏳️⚧️So my roommate bought that weird Hand386 portable PC that popped up on aliexpress. Let's tear it down (nondestructively for once, since I'm borrowing it).
first off, lemme get the spoilers out of the way: It's real, it runs DOS/Windows 95, and it can run Doom (badly) and VGAPride.
It's easy to open (this image came out blurry, but I'm just using it for navgiation)
We've got two terminal connectors on the left, plus a 3.5mm audio jack. The right has a USB port and a barrel jack power connector.
First off, the CPU. This is surprising! It's an DM&P ALi M6117D.
This is a modified version of the chip made by ALi/ULi, licensed to DM&P. ALi's chip division was bought by Nvidia in 2006.
This is a modified version of the chip made by ALi/ULi, licensed to DM&P. ALi's chip division was bought by Nvidia in 2006.
So the M6117D is a 386SX-compatible system on a chip.
It's a static 386SX Core (apparently licensed from Intel?) plus ram controller, peripheral controllers, IDE support. It runs at 25-40mhz, and up to 16 megabytes of RAM
It's a static 386SX Core (apparently licensed from Intel?) plus ram controller, peripheral controllers, IDE support. It runs at 25-40mhz, and up to 16 megabytes of RAM
Chip info here:
Also, I was wrong. Apparently it goes up to 64 megabytes of RAM:
Next to the CPU, we've got four DRAM chips. AMIC A420616AS-50F, 2-megabyte chips.
So we're looking at 8 megabytes.
So we're looking at 8 megabytes.
Then we've got our VGA chip: A Chips&Technologies 65535.
This is a fully integrated chip with built in CRT controller/flat panel support, RAMDAC, and and clocks.
It supports up to 1280x1024 resolution with enough VRAM, or 640x480 16bpp truecolor.
This is a fully integrated chip with built in CRT controller/flat panel support, RAMDAC, and and clocks.
It supports up to 1280x1024 resolution with enough VRAM, or 640x480 16bpp truecolor.
For VRAM, a Sharp LH6A4260K-60, which I'm pretty sure is a 512 kilobyte chip, but I can't be sure.
The really surprising chip is this, a Yamaha OPL3 YMF262-M...
Yeah, this thing has real OPL3 sound. Assuming this chip is genuine, of course.
Yeah, this thing has real OPL3 sound. Assuming this chip is genuine, of course.
There's two SST39SF512 half-megabyte flash chips.
The left is labeled VIDEO and the right is labeled BIOS.
The left is labeled VIDEO and the right is labeled BIOS.
The last interesting thing about the top of the PCB is that there's another speaker, labeled SP1.
There's two stereo speakers as well, so I suspect this is just used for PC Speaker, and was easier than merging the audio in with those other speakers
There's two stereo speakers as well, so I suspect this is just used for PC Speaker, and was easier than merging the audio in with those other speakers
So here's another blurry navigation-picture for the other side of the PCB. The interesting thing here is that they've got the keyboard on a separate PCB.
So over by the USB port, we've got a CH375B.
This is an 8-bit IO chip for USB, specifically for storage.
(it's also an 8051-based core! there's always an 8051)
This is an 8-bit IO chip for USB, specifically for storage.
(it's also an 8051-based core! there's always an 8051)
There's three 74HC139s, which are dual 2-to-4 line decoders.
This maybe is used for wiring up one of the expansion ports to the ISA bus?
A YAC512-M. This is a DAC used by the OPL3 to create the analog output of the audio chip.
Assorted power regulation/charging circuitry that I'm not going to go into.
So the keyboard PCB is also the display converter PCB. It stars a Realtek RTD2660, which is a standard video controller. It takes in analog video and drives LVDS displays with it. It's an all-in-one chip that's used on a bunch of cheap monitors, and it's also an 8051!
Next to it we've got a P25Q40H half-megabyte serial flash chip. This is presumably used to store configuration info for the RTD2660.
The other chip on the keyboard/video board is an HM82C42. I can't find any info on this specific version, but it's almost certainly an Intel MCS-48 acting as a PS/2 keyboard controller.
The keyboard is a rubber membrane onto the PCB, like a remote control. It's functional but feels pretty crap.
It's a 60 pin connector. 8-bit ISA is 62 pins, 16-bit ISA is 98 pins.
So if they just merged some grounds, 60-pins is totally doable.
The other connector is 12 pins:
This one is PS/2 and VGA. An adapter is included with the device.
This one is PS/2 and VGA. An adapter is included with the device.
Storage is on a 2 gigabyte CF card. It's got Dos 7.1, Windows 95, and a few games pre-installed on it, plus a driver for the CH375 USB storage chip
Games included:
Doom, Wolf3d, XianJian QiXia Zhuan (aka Chinese Paladin), Tyrian, Raptor: Call of the Shadows, and Uncharted Waters: New Horizons
Daikoukai Jidai II
Doom, Wolf3d, XianJian QiXia Zhuan (aka Chinese Paladin), Tyrian, Raptor: Call of the Shadows, and Uncharted Waters: New Horizons
Daikoukai Jidai II
there's also the SBVGM audio player, which includes "Funky Stars" and the whole soundtrack of PlanetX3
LP🔸Light up the night@foone Does it *have* any digital audio? Because I've only seen literally the OPL3, so hypothesized it was synth-only (time to dust off the MIDI sound efffects that I think fraggle might have uncovered in DOOM, or at least boosted).
DrYak@LionsPhil no, unless you bitbang some PWM out of the PC Speaker (like lots DOS of MOD-trackers, and some games - e.g. RealSound - used to do). But that will sound very bad on a piezo.
Also: this is a 386*SX* (16bit, no cache) so Doom is already stretching it.
@dryak Yeah, and you can't really do that concurrently with something else. I remember a (third-party) Win3.11 PC speaker digital audio driver with two operating modes: one was completely blocking while a sample played, and worked about as well as that vaguely famous DOS golf game that did it; but the multitasking-friendly interrupt-driven mode was a crackly mess because you are asking too much to go context switch your only core during such realtime-sensitive hackery.