BASIC Engine for ESP32 and FabGL

Hawk

I'll ask this question, as it's been someting I've been looking for for quite a while, but have you considered whether BASIC Engine could be adapted to the ESP32 and the FabGL VGA library?

I have ordered an Orange Pi (_AU$40) and look forward to running BASIC engine on target hardware, but I like the idea of getting kids to make their own computer that they can then program in a modern version of BASIC. The FabGL hardware is very simple, just needing some leaded passive components to get a working system with VGA, PS/2 mouse and keyboard and simple audio.

There have been other attempts to do this. Eris, by Paul Scott Robson was a good attempt. However it didn't get as advanced as BASIC Engine before Paul moved onto other things, and there was not much uptake by others.

R.T. Russell has also released his BBC BASIC code and it is being ported to the Raspberry Pi Pico, but that does not have VGA output or a framebuffer.

The Colour Maximite 2 has a great version of basic, but the hardware is quite expensive (comparatively) and needs a commercial PCB made.

Given that BASIC Engine has moved on to the H3 platforms, I'm not sure whether this would be seen as a backwards step, but the ESP32 platform is very inexpensive and quite capable, not requiring the extra surface mount video controller to get suitable VGA output.

Anyway, this is just some ideas that I've been considering.

uli

Hawk I'll ask this question, as it's been someting I've been looking for for quite a while, but have you considered whether BASIC Engine could be adapted to the ESP32 and the FabGL VGA library?

Yes, I have.

The biggest issue by far that people had when getting on board with the old BASIC Engine design is that they had to build it. I therefore wanted to have something that works out-of-the-box and is readily available for the next generation.

I have looked at the ESP32/VGA route, but the existing low-cost board from TTGO has design issues that make it impossible to use JTAG and VGA at the same time, which makes development very annoying. There is also another issue (that I don't remember in detail) that, combined with the general I/O shortage on the ESP32, makes it impossible to implement some user-facing feature without modifying the board or having a custom design, which is what I wanted to avoid in the first place.

From a feature and performance point of view, the ESP32/VGA system would be a very, very minor upgrade to the original design that would lack virtually everything that is new and improved on the H3 platform, from internationalization to sprite zooming and everything in-between. The H3 route provides several orders of magnitude more bang for the buck.

So, having looked at this approach in great detail, and taking into account that an ESP32/VGA BASIC Engine system would be a pain in the ass to develop for, would not provide any substantial feature upgrades over the ESP8266 design and would have a very bad price/performance ratio, I have decided that I do not consider it worth my time and effort. YMMV.

guidol

The only thing I have created (as a fork) is RunCPM on the ESP32/VGA32 wth FabGL.
With CP/M you havent a "modern" BASIC available (only MBASIC from Microsoft) but there is also a Turbo Pascal version 😉
With the VGA16Controller-Version of RunCPM for VGA32 you could output Escape-Sequences to use some more FabGL-features.

RunCPM on VGA32

painintheworld

I just bought a prebuilt TTGO to play around with. I installed the requisite software to upload files, etc. and got an error, then ran out of time and set it to the side. I really need to try the RunCPM listed above. I’m not familiar with Eris, but will give it a spin soon!

I’ve got a Color Maximite and a CMM 2. I’m not sure why exactly, but my preference is for the original Color Maximite. Given a choice between the CMM 2 and BASIC Engine NG, the NG winds hands down for me. Now that I’m getting pretty close to finally having a dedicated computer room again, I will be able to get to working on some comparison videos between the CMM 2 and BE NG before too long.

Wouldn’t the experience between the original ESP8266 BASIC Engine with video controller and an ESP32 version without a video controller be quite similar? It seems like the video controller is pretty fast. I’m a neophyte with this stuff, however.

Hawk

Thanks for the responses guys.

I've got a TTGO FabGL board as well as a prototype board from Fabrizio himself. I have even breadboarded up the basic computer (VGA and PS/2 keyboard and mouse). I'm also in the process of building a version into an old SD digital tuner case on prototype board as a dedicated computer. What I really like about this hardware design is that it is SO simple. The tools and skills required are at a kids level. No surface mount, no commercial PCBs required. However, those things are possible if a kid wants to improve on their design.
You can decide whether you want passive resistor dividers or active mosfets for level shifters, SD or microSD for storage, what sort of audio amp you want. Do you want to mount it in it's own case, or build it into the keyboard. Custom design your own PCB and case and get it professionally made. None of these changes would impact the OS that is running on the ESP32.
To get BASIC Engine running on the ESP32, there would be limitations regarding resolution and colours based on the memory ans processing speed of the ESP32. This would be similar to the ESP8226. Fabrizio, in his FabGL library has given all the tools to implement a simple framebuffer VGA output.
VGA monitors are still cheap/free and available...at least here in Australia. PS/2 keyboards, while getting more difficult to find are still available. Some new keyboards still handle both USB and PS/2. I even discussed with Fabrizio the possibility of adding SNES controllers to the library. There is still enough control lines to handle those.
The only thing that is missing from this simple idea is a solid "retro" operating system. An operating system that boots to a "Ready" prompt. I thought ERIS was nearly there, but it lacked the SD interface. TinyBASIC is too limited. BBC BASIC hasn't been ported to a framebuffer type SoC.
So that brings me to BASIC Engine. 😃

painintheworld

Isn't Engine BASIC based on Toyoshiki's TinyBASIC?

guidol

painintheworld
see: http://basicengine.org/history.html#_toyoshiki_tiny_basic

painintheworld

guidol umm, yeah, that is what I said in my post, I simply didn't link it.

Hawk

I made this version of a TinyBASIC microcontroller computer.
https://www.instructables.com/Arduino-Basic-PC-With-VGA-Output/
It had most of what I wanted, except enough RAM and SD storage.
I wasn’t aware of a STM32 Blue Pill version, but I had planned to have a go at making one myself. However, the version of TinyBASIC i was using was quite restrictive.

guidol

Hawk
how about TinyBasic on the TTGO VGA32?

https://www.instructables.com/ESP32-Basic-PC-With-VGA-Output/
https://github.com/fg1998/ESP32-Basic-vga

or check here for other emulations:
http://www.retrowiki.es/viewtopic.php?f=86&t=200036016

Hawk

Unfortunately the version of TinyBASIC is too limited. It has no graphical capabilities, and doesn’t offer the structured capabilities of more modern BASICs. When loaded with the interpreter, there is only 14k available for BASIC programs.

Hawk

uli
Thanks for your resopnse Uli, I understand you points you are making. It's difficult to split your effort across multiple releases, and the H3 is the most obvious release for you at the moment. Thanks for taking the time to explain it. I will continue to tinker with BASIC Engine on my Tauon PC-1, and soon my Orange Pi PC. Thanks for all the effort to put into this project.