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Agon Light 2 and Other Modern 8-Bit Computers


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I'm not sure if this is the right forum for this,  but it seems like the closest match.  I've ordered quite a lot of hardware for "retro" computers and video game consoles in the past 8 years or so.  I've ordered things from all over Europe, Spain, Germany, France, UK, Poland, Ukraine, the Czech Republic, Croatia, Russia.   I'm sure I missed some.  I've ordered from China, and Japan of course.  And a little bit from South America - Argentina, and Brazil. But today I got my first package from Bulgaria.   It's the Agon Light 2 from Olimex, based on the open source computer designed by Bernardo Kastrup of the Byte Attic. https://www.thebyteattic.com/

 

The past several years there have been many "homebrew" 8-Bit computers that are trying to capture the same energy and excitement that many of felt in the heyday of 8-Bit computers in the late 70's and early 80's.   The list is actually quite long and I am not going to attempt to list them all here, but some of the better known examples are: The Commander X16, the Mega 65, the Spectrum Next, and the X65.  All of these depend to one extent or another on the power and versatility of an FPGA.  This gives these computers impressive specifications,  but they are not exactly cheap.  And then there are the others like Zeal 8-Bit Computer, or the RC-2014 that are a bit more modular.  It can be fun to put these systems together, but a lot of time energy and money are required to put a usable system together.   Myself,  I can appreciate all of them, but the Agon Light Stood out to me because of its' low cost and almost plug and play nature.  Also give it's cost, (€50 from Olimex) the specifications are pretty impressive:

 

Zilog eZ80F92 micro-controller running at 18.432 Mhz

512K of RAM

The VDP and sound system run on an Essprisif ESP32-PICO-D4 running at 240Mhz with 8MB of PSRAM

PS2 Keyboard input

VGA Out at up to 640*480 at 64 colors

A microSD Card Slot for storage.

 

To me the best thing about this was that it has a built in OS or you can boot right to BBC BASIC.  For some reason this spoke to me.

 

 

Agon Light 2.jpg

Front.jpg

Back.jpg

Edited by mutterminder
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12 hours ago, john_q_atari said:

Looks cool. Seems like it is about $100 USD for the computer and case as shown in your post shipped to the US. Looks like mouser is out of stock on the board. Please share in the future your impressions after using it and what you personally end up using it for.

With shipping of €24 and a Paypal fee of €4.50 it did come to about $98.  This wasn't an option when I ordered it,  I would now order it from Mouser since they allow backorders. Even that, for me, would be at least $72 for the board alone, once tax and shipping are added on. If you are ordering other things as well,  then you could divide the shipping, so I guess it wouldn't be too bad.  They don't carry the metal case yet, but there are a couple of 3-D printed cases out there.  That being said, the metal case is nice.

Edited by mutterminder
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I was able to play around with this system a bit yesterday and today.  I have a few observations.  With regard to the Olimex Agon Light 2 - It seems to be a high quality PCB and I was pleased with its' construction.  The metal case is well made as well and the cutouts match well with the I/O connections.  It comes loaded with VDP V1.02 and MOS V1.02.  Since it did not come with a µSD card, it did not initially boot to BBC BASIC. It was necessary to prepare a µSD card with BBC BASIC and some other user files.  MOS (Machine Operating System) supports an autoboot function with an Autoexec.txt file.  If you want to boot directly to BASIC you can put it in the Autoexec.txt.

 

There were a few lessons learned for me while setting this up.  First, I would say that it is not exactly plug and play, at least not in the form offered by Olimex.  It could be, and I think an enterprising individual could sell the Agon Light in an all-in-one kit for about $100. This would include the PCB, a case, a keyboard, and a preloaded µSD card.

1. The Agon Light 2 needs a PS/2 compatible keyboard, but the keyboard connector is USB A.  I have several PS/2 keyboards around the house so thought I - "I'll just get a PS/2 to USB A" adapter. So I used a PS/2 female to USB Male adaptor.  I checked the pin-out, and it seems like this should work, but none of the four keyboards I tried would work in this way.  I finally did locate an older PS/2 compatible USB keyboard, and that one works. There is a spreadsheet https://docs.google.com/spreadsheets/d/1-6_sz6l-vJW5rFg3M0Y6bwC0hmFS7U6PPNjIZ9plrM8/edit#gid=0  maintained by the community, listing keyboards that have been found to work.

2. There are newer versions of the VDP, MOS, and BBC BASIC.  V1.03, V1.03, and V1.04 respectively. It matters what order you update them in.  Make sure to update the MOS before the VDP.  The newer VDP runs at a higher communication rate that is not supported by MOS 1.02.

3. When installing BBC BASIC make sure to install the test and examples directories that are include in the source code zip file from the release of BBC BASIC you install onto the µSD card.  The syntax of some of the commands has changed from earlier versions.

Edited by mutterminder
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Hi, 

 

Just received mine as wel. (It arived last week, but I was ar Revision so)
Played around with it for a hile, stil having issues upgarding. if i upgrade the vdp to 1.03rc3 i cant reach the mos animor, wich i need to upgrade the mos to 1.03rc4

I have been looking around fro a comunity but have not yet found anything.

 

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If anybody is interested the keyboard I am using is the Kensington Pro Fit USB/PS2 Washable Keyboard P/N K64407.  I picked this up when the kids were little because it is washable and they would spill their drinks and get food in the keyboard. It's still available on Amazon but the listing doesn't really promote the fact that it is PS2 compatible, and it doesn't come with an adapter. Fortunately, for the Agon Light 2, you don't need one.

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On 4/15/2023 at 5:57 AM, Jobj said:

So again, i managed to screw up my MOS 

Im afraid i have to order one of those expencive cables, becouse it no longer boots into BASIC, so flash command does not work ether 
 

You don't need to get into BASIC to run the flash program, just to MOS.  I thought I had messed up my MOS once.  I updated the VDP before I updated the MOS and I didn't get a MOS prompt (*).   So I went back to an earlier VDP, then I got the MOS prompt back, then I updated to the latest MOS before updating to the latest VDP.  I haven't tried the firmware update from 2 days ago yet, so we'll see how that goes.

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Can I ask a stupid question? What can I play on it?

 

I know it has a Zilog processor, and it supports BASIC. What does that mean to me? Can I play old Apple ][e games, Atari, Commodore games, etc?

 

 

I built an SC131 CP/M system kit, and it's really cool... but it's mostly useless to me because I can't even get the old Zork games to run on it.

 

 

Thanks!

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If what you want to do is play games, mostly what you have is potential. There is not yet an big software library.  Outside of the example and demo programs that are distributed with BASIC, I have not seen much software yet.  The only two games I know of are at text version of "The Oregon Trail" written in BBC Basic, and a Sokoban game written in Z80 assembly. There is port of CP/M to the AGON which I have not yet tried, but what I have found out about it seems to imply that it still needs a lot of work. It could potentially run a lot of CP/M text based programs, however I'm not sure how stable it is.  There is also a version of Forth available, but again I have not yet tried it. Perhaps if I run across a Forth program I want to run, I'll give it a try.  

 

Since it runs BBC BASIC, there is a large library of legacy programs, that could potentially be run on it with minimal conversion. If you're not a programmer yourself, you might want to hold off purchasing one, until there are more in the wild. Like I said, there is a lot of potential in this little computer. It may or may not ever be realized.  But given the low cost of entry, there could be many people who decide to check it out.  Heck, I've spent more on a single modification to my Atari 8-Bit. With wide distribution there could be wide support as well. The... potential is there.

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12 hours ago, mutterminder said:

If what you want to do is play games, mostly what you have is potential. There is not yet an big software library.  Outside of the example and demo programs that are distributed with BASIC, I have not seen much software yet.  The only two games I know of are at text version of "The Oregon Trail" written in BBC Basic, and a Sokoban game written in Z80 assembly. There is port of CP/M to the AGON which I have not yet tried, but what I have found out about it seems to imply that it still needs a lot of work. It could potentially run a lot of CP/M text based programs, however I'm not sure how stable it is.  There is also a version of Forth available, but again I have not yet tried it. Perhaps if I run across a Forth program I want to run, I'll give it a try.  

 

Since it runs BBC BASIC, there is a large library of legacy programs, that could potentially be run on it with minimal conversion. If you're not a programmer yourself, you might want to hold off purchasing one, until there are more in the wild. Like I said, there is a lot of potential in this little computer. It may or may not ever be realized.  But given the low cost of entry, there could be many people who decide to check it out.  Heck, I've spent more on a single modification to my Atari 8-Bit. With wide distribution there could be wide support as well. The... potential is there.

 

Ok, that makes sense. I saw it on Twitter, I follow Byte Attic guy on there. It seemed really cool, and I've been hugely interested in small form factor PCs (older ones, especially kits). I was a MUMPS/Delphi/C/C#/VB programmer for a little over 15 years, but I honestly just don't know that I have the time (or the interest)... but definitely enjoy the nostalgia... they do seem really cheap, and pretty high quality. I'll probably pick one up. I like that it has built in VGA... that's huge.

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23 minutes ago, Gemintronic said:

I've already tried to get into tiny systems like this having bought and sold off a Maximite.  I think the next big thing might look like a Raspberry Pi Pico with HDMI/DVI and headers pre-soldered.  Top that off with a BASIC compiler and joystick support and you've hit the sweet spot.

The Pi Pico is a powerful little microcontroller. I thought it was pretty cool when it came out, one of the first demonstrations of it capabilities was a BBC Micro emulator connected through VGA. The Pico DVI Sock is less than $10 so it is an interesting option.  I didn't know there was a BASIC compiler out, I'll have to look into it.

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10 minutes ago, mutterminder said:

The Pi Pico is a powerful little microcontroller. I thought it was pretty cool when it came out, one of the first demonstrations of it capabilities was a BBC Micro emulator connected through VGA. The Pico DVI Sock is less than $10 so it is an interesting option.  I didn't know there was a BASIC compiler out, I'll have to look into it.

 

Actually, I was just wishing for such a combo.  Although some hope is out there.

 

https://geoffg.net/picomite.html

 

https://www.adafruit.com/product/5710

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On 4/21/2023 at 6:03 AM, Gemintronic said:

 

Actually, I was just wishing for such a combo.  Although some hope is out there.

 

https://geoffg.net/picomite.html

 

https://www.adafruit.com/product/5710

The Picomite is an interesting computer as well.  It looks like mostly an off-shoot of the Colour Maximite, and the Colour Maximite 2, which is a much more capable machine. It seems that neither are available right now due to the chip shortage.  MMBasic seems to be a very powerful version of BASIC, so I'm thinking of turning one of my Pi Picos into a Picomite VGA, as this looks fairly easy to construct, and PCBs are available. https://www.tindie.com/search/?q=picomite  Colour Maximite 2 PCBs are also available, however the CoreH743I modules are at least $100, so putting one together is going to cost more than a Picomite VGA or Agon Light.

 

It doesn't look like MMBasic has yet been update to support DVI output so I don't know if the Picomite DVI will be a thing.  The biggest problem I see with using the Pi Pico in this application, is the relatively small amount of RAM.  With only 264K, there is not enough for a full screen buffer, much less an HD screen buffer, so you have to limit the number of bits per pixel, limit the resolution, or create the graphics 1 line at a time like the Atari 2600.  Still if you use a 320*240 resolution you could do 256 colors with only 76K.

 

Since these are not 8-Bit computers, perhaps they need their own topic.  Even though they clearly appeal to nearly the same group of people.

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I’ve built two versions of the PicoMite VGA - the officially released version and the PicoGame that supports two joysticks/game pads. There’s a lot of activity for the PicoMite on www.thebackshed.com forum. One member just posted a Frogger clone that looks pretty good https://www.thebackshed.com/forum/ViewTopic.php?FID=16&TID=15842

 

 The version of Micromite Basic on the PicoMite is very advanced and almost as full featured as the Color Maximite 2, although the graphics output is more similar to the original Color Maximite due the limited memory on the Raspberry Pico.

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8 hours ago, Forrest said:

I’ve built two versions of the PicoMite VGA - the officially released version and the PicoGame that supports two joysticks/game pads. There’s a lot of activity for the PicoMite on www.thebackshed.com forum. One member just posted a Frogger clone that looks pretty good https://www.thebackshed.com/forum/ViewTopic.php?FID=16&TID=15842

 

 The version of Micromite Basic on the PicoMite is very advanced and almost as full featured as the Color Maximite 2, although the graphics output is more similar to the original Color Maximite due the limited memory on the Raspberry Pico.

I guess now I have to build one of these too.

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The V3 card on Tindie https://www.tindie.com/products/land_boards/raspberry-pi-pico-card-with-vga-sound-kbd-v3/ is functionally the same as the official boards listed at the bottom of the page at https://geoffg.net/picomitevga.html

 

The V1 and V2 boards on Tindie are slightly different with digital I/O ports driven by one or two chips.

 

The boards are easy to build. 

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