OSI Superboard II replica

[vbriel]

I've been working on this project for a little while now and have a working wire-wrap prototype. It is based on the WDC65C02 running at 1Mhz using a Parallax Propeller to connect to the 6502 bus for video and ROM emulation. The Propeller also generates the 1Mhz clock signal used for the 65C02. The system is running on 3.3V so a ton of inline resistors aren't needed. I also use 32K of RAM for more programming. Right now I have the 6850 wired up for the serial interface but I may emulate that too in the Propeller. The OSI Superboard II used the 6850 ACIA as the cassette interface but could also work as a serial port to LOAD/SAVE programs. It's just a matter of saving the text that gets listed or sending a text file of the program.



This is my wire-wrap prototype. The Superboard II had a built in keyboard and that's why I really liked this computer. My replica prototype uses tactile switches for the keyboard but I plan to use larger buttons when I make a PCB.



First time I booted up into BASIC. The keyboard wasn't finished, only C and RETURN was wired to get to this point It's still a little ways off from being complete but I only have a little more to do. My goal is to add PS/2 keyboard option, emulate the 6850 in the Propeller and add cassette drivers. Even if I can't add PS/2 or emulate the 6850 I can add the cassette drivers and be ready to make some kits



This project really became a reality when Jac Goudsmit stepped in and helped with the firmware. He got me to realize I didn't need to assert RDY that it could run at full speed. This is showing the TANK game. The source code and the schematics will be released once the project is ready. The source for the Propeller gives users the ability to directly interface to the 6502 bus as ROM and RAM at full speed of 1MHz. Let me know what you think.

Vince

[whartung]

That looks great Vince. I like seeing how others are working to get video working on their projects. It seems on the one hand so insurmountable to me, yet, folks seem to pop out solution after solution.

I just remember back in the day lusting after an OSI machine, but looking back at the specs and stuff, I can't fathom why. They seem today rather primitive compared to other machines of the day. But I was pretty convinced back then that they were exciting stuff.

[vbriel]

Thanks. What always had me with this board was the built on keyboard. It was just so cool to have a SBC with video and keyboard like that. Just the hardware geek in me

Yeah, the display is only 32x32 with only 25x25 being viewable. I have a real Superboard II and the only difference that I can see right now is a slight dot clock gap on the original vs my replica. Functionally, I like not powering up my Superboard II but I used it quite a bit to verify compatibility.

[Twylo]

Oh wow, this is so cool!!

I absolutely love how chips like the Propeller have really opened up vintage hardware replica and simulation projects. It's almost plug-and-play now, it's fantastic!

That keyboard is great, too. I'm sure it's not so easy to type on, but it's a damn cool idea.

But you can't show us a prototype without showing the wiring side. Come on, that's porn for nerds like us! :-)

-Twylo

[vbriel]

Ok, here's the bottom mess: