RVPC: The 1-Euro RISC-V computer with VGA and PS/2


33 points by unwind on 2024-05-15 | 12 comments

Automated Summary

The article introduces a 1-Euro RISC-V computer project, called RVPC, with VGA and PS/2 support, aiming to provide an accessible educational tool for learning RISC-V architecture. The device, CH32V003 in SO8 package, has six GPIOs, using two for PS2, three for VGA, and the last one for an audio buzzer. The development focuses on integrating PS2 and VGA into Vmon, with available software resources and retro games. The target resolution is 320x200, and the board will be available as a soldering kit when completed, for just 1 Euro. Prototypes are expected soon, and those interested in software development can reach out to the author.


AstroJetson on 2024-05-15

/sigh, I just tossed a stack of PS2 keyboards and two monitors that took VGA into the electronic recycle station. "Nothing does PS2 anymore, and everything is HDMI" now ring hollow in my head.

So I'm going to buy a $1 computer and $30 worth of adaptors to play with it. :-)

DrNosferatu on 2024-05-15

What about a little more expensive version with enough memory to handle VGA mode 13h?

PS: If I’m not mistaken, this would mean a minimum of 256K video memory - so, say, another 256K for general RAM. So perhaps a 512K or 1MB system.

brucehoult on 2024-05-15

There is not a lot of pricing room between a $1 board with 10c 48 MHz 2 KB RAM chip (as here) and a $5 board with 1 GHz 64 bit 64 MB RAM board running Linux (Milk-V Duo).

That gap is pretty much filled by boards using e.g. the ESP32-C3 with 400 KB RAM, running at 160 MHz. You cvan find quite a few of those for around $1.80.


snvzz on 2024-05-16

>to handle VGA mode 13h?

While VGA is the interface used for the analog video signal, no attempt is being made to emulate the old "VGA controller".

DrNosferatu on 2024-05-15

The manufacturer’s similar chips max out at 64K - still it would make a more beginner-friendly project:

Color makes a big difference in impact!

snvzz on 2024-05-16

>The manufacturer’s similar chips max out at 64K

Perhaps these should be considered. 64KB is a world better than the 2K in the selected variant (CH32V003) in that micro-controller family.

brucehoult on 2024-05-16

As pointed out in my other comment, you can add vast amounts of extra functionality for very little cost, up to a Linux-running board with 64 MB RAM for $5.

But that's not the point. The point is: what is the cheapest stand-alone usable computer you can make?

"Usable" in the same sense as a ZX80 or Altair 8800 or Apple I of course, not in the sense of a modern computer.

If you pay 50c for the CPU instead of 10c then you just increased the total cost by 50%.

snvzz on 2024-05-16

>If you pay 50c for the CPU instead of 10c then you just increased the total cost by 50%.

True. But is the difference actually 5x? CH32V003 shouldn't be the only option.

DrNosferatu on 2024-05-16

I guess you could always get the Agon Light, but that’s 50€!

The ESP32-C3 can be had for under 2€.

…and a killer app for such a nano computer would source ports of people’s favorite retro games ;)

DrNosferatu on 2024-05-15

Perhaps the ESP32-C3?

poulpy123 on 2024-05-15

What do you plug on VGA and PS/2 nowaday ?

snvzz on 2024-05-16

A PS/2 Keyboard and a VGA monitor.

Alternatives include e.g. a PS/2 compatible USB keyboard via passive adapter, and a HDMI monitor through an OSSC (Open Source Scan Converter).