Just For Fun

Just out of curiosity I've done a little add-on board with a PSRAM (specific for the ESP32) and a microSD socket. I've called it uHat (micro Hat) as it is fitted over the uTerm2-S board using the AUX (J6) connector like an hat:

The uHat add-on allows to run an interesting application of the FabGL library that requires the SD and the PSRAM.

There is a FabGL library application (inside the FabGL library examples) that emulates a PC XT. There are a few options, but the most interesting is probably that one with Windows 3.0.

Because the SD on the uHat uses different GPIO, before compiling the PCEmulator.ino application you have to change the parameters at the line containing the “FileBrowser::mountSDCard” call as shown in the following image (yellow line):

And here the emulator in action:

Tanks to Michel Bernard the Z80-MBC2 can be completely emulated with the uTerm2-S + uHat (this emulator is based on the FabGL lib too). You have to use the same SD of the real one. The User key of the Z80-MBC2 here is emulated with the DFLT key.

In the Files section I've uploaded the ready to use version for the uTerm2-S (changes for the uTerm2-S + uHat are marked with the “J4F:” string inside comments):

I've prepared an “easy link” to order a small lot (min. 5 pcs) of PCB here.

If you are looking for a assembled unit ready to use now there is a professional seller that can sell both and ship worldwide.

The link to the seller is this one.

An “User Group” was created on Facebook (it is the same used for the Z80-MBC2).

The FabGL library was developed by Fabrizio Di Vittorio.

The Z80-MBC2 emulator was developed by Michel Bernard.

All the project files are licensed under GPL v3.

If you use this material in any way a reference to the author (me ☻) will be appreciated.

Schematic.
A280821_SCH.pdf.

BOM file.
A280821_BOM_v1.ods.

PCB Gerber files.
A280821_GBR.zip.

PCB Reference.
A280821_PCB_Ref.pdf.

PCB Values.
A280821_PCB_Values.pdf.