Mini IBM PC (working clone!)

Mini IBM PC - working clone. It uses the FabGL VGA module and a 5" color VGA LCD display. The IBM PC is finely emulated at 2x speed (compared with the original one). The emulated graphic card is CGA or Hercules (automatically switching, afaik), the emulated audio is the IBM PC internal speaker. It can be controlled with a PS/2 keyboard and PS/2 mouse.

B.O.M.:

FabGL ESP32 Module (like this one: https://pt.aliexpress.com/item/1005008391040472.html)
5" display (like this one: https://pt.aliexpress.com/item/1005008129581910.html)
FAT32 formatted SD Card (a small 1 Gb SD card is more than enough)
power plug;
USB cable (for ESP32 power);
3 mm red LED;
2x5 mm square red LED;
680 ohm (more or less) resistor
two on/off switches (see picture)
two DB15 male VGA connectors
some ribbon cable;
(optional) 3.5 mm audio jack
(optional) small speaker

I took the Luiz Pacheco's 3D awesome project, modifying it a litte bit to fit my needs (I also had some little issues with the original project: i.e. the display didn't fit inside the bezel).

The FabGL is an open source project by Fabrizio Di Vittorio:

The project also requires PS/2 Keyboard and PS/2 Mouse, a FAT32 formatted SD Card, a DIY VGA cable and +5v PSU.

How to start:

The ESP32 need a sketch (of course!). For this project, we'll use the PC emulator sketch.

from Arduino IDE: file -> preferences -> additional boards manager URLs -> add: https://dl.espressif.com/dl/package_esp32_dev_index.json Library manager -> download the FabGL 1.0.9 (NOT A NEWER ONE!) Board manager -> download the Esp32 by Espressif Systems 1.0.6 (NOT A NEWER ONE!)

Note: I specified the releases that surely work. I've had troubles compiling with newer versions because of some changes into the source code. If you want to try the newest release, be prepared to face some compile errors.

board: ESP32 Dev Module Tools -> Partition scheme = Huge App (IMPORTANT!)

Download the project from: https://www.github.com/fdivitto/fabgl and expand it somewhere in your disk. It will create the folder "FabGL-master"
Open the sketch PCEmulator.ino from the folder FabGL-master \ Examples \ VGA \ PCEmulator
Compile and upload the sketch. Note: if you experienced some missing or wrong functions/include/etc., maybe you're using some wrong release of the above software.

For your convenience, I've uploaded a ZIP file containing my SD Card image. Just unzip all the files into the root of a FAT32 formatted SD card. The first item of the list that will appear after booting the ESP32 ("MS-DOS 6.22 + CGA Games") is already on the SD card, the other options will be downloaded from the fabGL site if selected. Note: "MS-DOS 6.22 + CGA Games" will load two hard disks, C: with system and utilities, and D: with some CGA games. The keyboard setting is Italian; you can change it editing the AUTOEXEC.BAT file. Simply type the command "EDIT C:\AUTOEXEC.BAT" and change "KEYB IT" according with your region (i.e. "KEYB US", "KEYB FR", etc.). Remember: you're working under MS-DOS 6.22, so just change your configuration (AUTOEXEC.BAT and CONFIG.SYS accordingly).

The FDD and HDD images can be created/modified using WinImage (https://www.winimage.com/winimage.htm)

Build the VGA cable using two DB15 VGA connectors (male), some ribbon cable and two switches ON / OFF (see below about the switches). Be sure to make the the cable long enough to let you easily open the case without the need to disconnect it every time.

USE +5V power only!

I glued everything inside with hot glue; I used double sided mounting tape for the monitor - it's glued to the cover, the two square holes aligned. The back part of the monitor hosts perfectly the buttons PCB: just glue it or put two screws. I use to put a screw and warm it with the solder iron until it melts the plastic.

I put two red LEDs for the HDD and FDD (always on, not representing the HDD/FDD activity) connected in series with a 680 ohm resistor.

Everything is powered directly to the +5V plug, don't use a different voltage or it can burn the ESP32 and the LEDs (the monitor accepts at least up to +12v).

NOTE ABOUT THE TWO BLACK SWITCHES ON THE FRONT MONITOR:

I added these switches to simulate a color, green or amber monitor (actually the amber is more yellow than amber). The schematics for the VGA cables using the buttons can be found inside the image section (rather bad schematics, but I'm too lazy to use some fancy tool).

Printed with Creality Ender 3 Pro, using supports and 25% infill (NOTE: 100% infill and no support for the buttons), white and black PLA+

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