AgonLight (CPC core)

[Matej]

There is new opensource 8bit RaspberryPI like SBC computer based on real fast eZ80 (128kb flash, 8kb sram), 20MHz, 512kb Ram and powerful GPU (32bit risc mcu) - 640 x 480 / 64 colors and sprites, scrolling. And BBC basic + build in dos. And there is expansion slot too Gpio and Uext. And use cheap ps/2 mechanical keyboard. There is also CP/M ported to it.
Price is 50usd/euro simple version(AgonLight2) and 100usd/euro for first version.

Maybe there can be way to:
1.) emulate in esp32 gdp - CPC plus video
2.) do AgonLight Amstrad-BUS (2x or 4x interface/cartridge for sound, gfx etc) or playcity soundcard with 2x cannon 9 for sega gamepads/joysticks.
3.) implement Basic + DOS
And to have CPC core on it.

Or when even not this maybe do new games, demos, apps CPC -> AgonLight conversions etc. Its very cheap and fast nice little Z80 computer.

Here is homepage:
https://www.thebyteattic.com/p/agon.html?m=1

GitHub:
https://github.com/TheByteAttic/AgonLight

European Manufacturer(50euro version):
https://www.olimex.com/Products/Retro-Computers/AgonLight2/o...

Facebook:
https://m.facebook.com/groups/970092390358810/

YouTube:

https://youtu.be/KWRallh_hfc

[TotO]

Here the good link: https://www.olimex.com/Products/Retro-Computers/AgonLight2/open-source-hardware
The price do not include VAT and shipping fees. (75 EUR)

[GUNHED]

Price is 50usd/euro simple version(AgonLight2) and 100usd/euro for first version.

Can you please explain the differences between the two versions?

[Matej]

Price is 50usd/euro simple version(AgonLight2) and 100usd/euro for first version.

Can you please explain the differences between the two versions?

First one green from ByteAttic and NL computer museum is made from higher priced parts but on other hand purple one made by Olimex have USB(ps/2 protocol) instead of PS/2 also LiPo battery connector also second expansion port called - Uext something like Arduino Shield not only GPIO. Olimex produce lot of UEXT boards - soundcard, rs232, wifi... First one got higher priced capacitors but as voltage is low both are perfect. Watch that Youtube video. Olimex is lower price as they got lot of SMDs and parts in warehouse also automatic SMD maschines. They produce ARM sbc Olinuxino also Notebook with ARM... On other hand first version got higher priced parts capacitors, higher voltage protection when You connect to GPIO etc. They are better for hardware experiments or development. It is opensource author ByteAttic will be happy to have more manufacturers. There is one in Bulgaria, Australia one in NL.

PS: Want see FutureOS like or SymbOS on AgonLight

[TotO]

Anyway, the second version replace the first.

[Neurox66]

Mine AgonLight2 from Olimex will arrive tomorrow

[SerErris]

This is quite an interesting little project.

But as it is the same for BBC basic - it actually can only be compatible with the CPC on Basic level. 

So regarding our beloved CPC family this will not be able to emulate a CPC in a good way.

It starts with the Video screen not beeing in RAM but actually only living in the video processor (ESP32). So you could not write directly to screen RAM (nor could you read from it), you would need to tell the ESP to read or write to the video RAM and deliver that information backup to you. That would be slow. 

Also all the stuff working on the CRTC/GA level in hardware will not run, and the ESP is not a processor like an ARM that could emulate a CRTC/GA to the Z80 here. So whatever software is running that wants to play with CRTC and GA would not work.

However you could rebuild a CPC if you want, components are there (and you could maybe even use a ARM or maybe even an ESP to emulate the CRTC/GA), but not this board. 

The ESP stuff is just a assumption. I do not know enough about ESP and if it could listen to 7F00 port etc. and to react on signals send to it.

Potentially it could actually do what the GA is doing, and even what the CRTC is doing (as this is more or less a counter). But I am not sure if you could integrate it that way.

[GUNHED]

PS: Want see FutureOS like or SymbOS on AgonLight

Yeah, that would be something!

Probably it's more easy to adapt SymbOS for it. Back the day when the T-Rex was still sold Prodatron had SymbOS running on it and there was a 2nd SymbOS underneath it for... kind of driving the hardware level. Prodatron can explain that way better of course.
However the double SymbOS system on T-Rex was really cool! Sadly they stopped selling the hardware (as far as I know).

About FutureOS: It would be much of work to do that. Kind of a major rewrite, but still a fascinating idea to me.

Thank you for the information you provided.

[Bread80]

As SerErris says, this could never be fully compatible with a CPC, but it could be compatible with anything which only accesses the machine through the Firmware. This could potentially give you a significantly faster Amstrad BASIC, along with faster 'serious' software, including development tools, if that's you thing.

If I was to implement this I'd rewrite the Firmware to send commands to the ESP32. I.e. it would send a command to write a character or draw a line. That would have the added advantage of the main CPU not having to do all the graphics itself, freeing up more CPU cycles for user software (e.g. BASIC). I think you might have to forgo the firmware indirections because there's probably no good way to intercept that stuff back from the ESP32.

All in a all a good, fun, project for anyone with a lot of spare time.

BTW another interesting project would be to take the open source design and rework it to be more CPC compatible. I'm not really sure what that would entail though. For example, how easy is it to create something with the same port addresses? And would you be able to, maybe, sniff the bus for screen writes?

[SerErris]

And still some things might be pretty hard to implement, but that depends on what you can do with the ESP. For instance can you read from the video ram? Can you write to the video ram - even if that is indirect it is fully required to achieve even basic graphics skills. 

And for obvious reasons all the draw routines need to get changed and if you want to keep even Basic compatible, you would need to reimplement the broken screen memory layout if you want to calculate the screen memory position on your own. It is actually not required for any new program, as the basic graphics functions, simply would work in a different way, but if anyone programmed a basic program that would directly write to the screen, that would simply fail. 
However the likelyhood of that happening is pretty low - the draw functions are the fastest way you can get even for a single pixel, they are faster, than doing a pure basic implementation.