Trying out a cheap Chinese FPGA Board

SlithyMatt · Post by **SlithyMatt** » Tue Mar 29, 2022 4:37 pm

I bought an (allegedly) Altera Cyclone IV-based FPGA development board direct from China via Wish for a whopping US$32! I just started a new video series where I explore this board (and possibly others) and see just how cheaply a simple single-board computer can be sourced and built, leaning on open source VHDL components to build something that will likely be 6502-based, if not a full-on X16 clone.

TomXP411 · Post by **TomXP411** » Tue Mar 29, 2022 9:55 pm

Is this board big enough for a simple computer emulation?

It's $95 on Amazon right now, and it has a DE-9 (presumably serial) port, VGA port, and a PS/2 port.

https://www.amazon.com/Cyclone-Development-downloader-Infrared-Controller/dp/B085X2N2S2

Scott Robison · Post by **Scott Robison** » Tue Mar 29, 2022 10:13 pm

On 3/29/2022 at 3:55 PM, TomXP411 said:

Is this board big enough for a simple computer emulation?

It's $95 on Amazon right now, and it has a DE-9 (presumably serial) port, VGA port, and a PS/2 port.

I believe it is. Memory would be the biggest thing it might not have enough of, but I think it has plenty of logic elements.

TomXP411 · Post by **TomXP411** » Tue Mar 29, 2022 10:59 pm

On 3/29/2022 at 3:13 PM, Scott Robison said:

I believe it is. Memory would be the biggest thing it might not have enough of, but I think it has plenty of logic elements.

Specs say 8MB of SDRAM (64 Mbits, to be precise.)

I can think of various ways to slice that up, but it's certainly enough to support most 8-bit systems.

Scott Robison · Post by **Scott Robison** » Tue Mar 29, 2022 11:00 pm

On 3/29/2022 at 4:59 PM, TomXP411 said:

Specs say 8MB of SDRAM (64 Mbits, to be precise.)

I can think of various ways to slice that up, but it's certainly enough to support most 8-bit systems.

There you go then. I didn't have a datasheet.

TomXP411 · Post by **TomXP411** » Tue Mar 29, 2022 11:03 pm

Yup... here's a Multicomp core that uses that FPGA. It might need modification for this dev board.

https://github.com/douggilliland/MultiComp/tree/master/MultiComp_On_RETRO-EP4

For reference: Multicomp is an FPGA computer core that's designed to be modular: you can build a Z80 or 6502 system (the MiSTer implementation is switchable) and it can run CP/M, BASIC, or user ROMs. In a lot of ways, it's the purest "retro" system there is, since it's just RAM, ROM, and a text interface.

TomXP411 · Post by **TomXP411** » Wed Mar 30, 2022 5:09 am

So after chatting with @Wavicle, I'm kind of torn. I could spend about $300 and set up a second DE10-Nano for FPGA development, or I could buy one of those EP4CE6 boards. The DE10-Nano has a Cyclone V with an ARM SOC, so it's really much more powerful than the IV on this dev board. On the other hand, this board is simpler, has VGA and DE9 serial, and it's got that cool LED segment display, so it would be more along the lines of one of my build targets (an Intel SDK-80/85 clone.)

Ah, who am I kidding? If my goal is MiSTer development, then I I should do the DE10.

OTOH, The De10-Nano is out of stock everywhere... so you see my dilema. ?

lydon · Post by **lydon** » Wed Mar 30, 2022 6:45 am

On 3/30/2022 at 1:00 AM, Scott Robison said:

There you go then. I didn't have a datasheet.

I found this datasheet: https://ark.intel.com/content/www/us/en/ark/products/210472/cyclone-iv-ep4ce6-fpga.html

It has 6000 LE and 33KB of RAM (270Kb as in bits).

The C64 core (MiSTer, complete with cpu, sid, cia, vic) uses just over 6000 LUTs.

Check my MiSTer2MEGA65 Explained video for a comparison of the DE10-Nano (100000 LE) and the MEGA65s (200000 LE) FPGA resources.

paulscottrobson · Post by **paulscottrobson** » Thu Mar 31, 2022 6:47 am

On 3/29/2022 at 10:55 PM, TomXP411 said:

Is this board big enough for a simple computer emulation?

It's $95 on Amazon right now, and it has a DE-9 (presumably serial) port, VGA port, and a PS/2 port.

https://www.amazon.com/Cyclone-Development-downloader-Infrared-Controller/dp/B085X2N2S2

Yep. You could probably build an X16 on it ...... they're pricey now though (Unless Matt is Australian). I have an earlier generation board and it was more like half that. They're usually figurable because circuit diagrams are fairly universal and the parts are standard parts. However, the documentation is in Chinese

TomXP411 · Post by **TomXP411** » Thu Mar 31, 2022 9:33 am

On 3/29/2022 at 11:45 PM, lydon said:

I found this datasheet: https://ark.intel.com/content/www/us/en/ark/products/210472/cyclone-iv-ep4ce6-fpga.html

It has 6000 LE and 33KB of RAM (270Kb as in bits).

The C64 core (MiSTer, complete with cpu, sid, cia, vic) uses just over 6000 LUTs.

Check my MiSTer2MEGA65 Explained video for a comparison of the DE10-Nano (100000 LE) and the MEGA65s (200000 LE) FPGA resources.

Is this a RAM chip (circled in red)?

If so, that would explain the confusion between the specs on Amazon and the FPGA's core specs. The 64Mbits RAM would be that chip.