Hackaday Europe 2026

Retro-PC

whoami

Jeroen Domburg
Sprite_tm
Espressif
spritesmods.com

I like gaming!

Let's build a powerful gaming PC!

Let's not build a powerful gaming PC!

Let's build a powerful retro-gaming PC!

What era?

1995'ish
486 CPU
2d video chip
8-16MiB RAM
Sound card

What is 'valid' retro?

What I want

Original silicon where important

No mechanical parts

New peripherals

Component-level design

Is this retro?

Design

First approach

Elan SC520

5x86-133
Last 486 ever made ('5x86' = 486++)
i486DX4-100: 1994
SC520: 2000

Lessons learned

Large BGAs SUUUUCK
Uncertainty kills motivation

My retro-computer:The old

Single-Board Computer
i486DX4-100 / AM486DX5-133
C&T F65545 VGA

My retro-computer: The new

FPGA chipset (ECP5 LFE5UM-45)
USB-C powered
ESP32-S3 'peripheral controller'
SDRAM memory

Bringup

CPU needs to:

Read unit of data (8b/16b/32b)
Write unit of data (8b/16b/32b)
Handle interrupt
...
That's it!

What about

LOCK, PLOCK, BRDY, BLAST, PCD, PWT, CACHE, HITM, INV, WB/WT, KEN, FLUSH, HOLD, HLDA, BOFF, AHOLD, EADS?

Not strictly needed

Cache
Bus master
Multi-processor

Build a chipset!

Bitstream loader
Bus interface
SDRAM controller
MiSTer ao486: PIT, PIC
MiSTer TSConf: RTC
IDE, KBC
ESP32: hard disk, KB-USB

Specs!

AM486DX5-133/i486DX4-100

64MiB SDRAM

HD/CDROM image on uSD-card

SVGA output

USB keyboard/mouse

Sound Blaster 16/Pro

NE2000 network card

MIDI via TinySoundFont

Configurable via OSD

Resource usage

FPGA LUT/FF: 34%
FPGA BRAM: 55%
ESP32: 2M/16M flash

Newer CPUs?

Pentium 1: 64-bit, 50-66MHz
P2-3: GTL+ logic, OoO transactions, 66-133MHz
P4: AGTL+, quad-pumped bus

Super Socket 7: AMD K6-II, Cyrix MII, ... up to 550MHz

So What?

Because I can!

Shoulders of giants
ao486, bochs, yosys, ...

Because we can!

https://codeberg.org/Sprite_tm/vapourdeck
ESP code, bios, Verilog, schematic, pcb, ...

(keynote-ish bits go here)

Example

VapourDeck!

https://codeberg.org/Sprite_tm/vapourdeck

Image code, verilog, schematic, pcb

Thanks for listening!

Jeroen Domburg / Sprite_tm

jeroen@spritesmods.com

@sprite_tm@social.spritesmods.com

https://codeberg.org/Sprite_tm/vapourdeck