I've been working on this for a while now and its getting dangerously close to being finished. I designed an Arduino style shield for the electronics so you can plug it directly on to a working project to look at the debug output or create a status display.

The interface is TTL level serial through the normal Arduino TXD/RXD pins. The code is configured for PAL and NTSC generator controlled by a jumper setting. The font is 8x10 (allegedly from a terminal ROM but looks like a PC character set to me). Its kept in RAM so I can implement downloadable soft character sets.

There are two outputs for the 'white' portion of the signal so I can general normal and bright white pixels. The generation code supports attributes for normal, bright, inverse, flashing and underlined characters as well as double height and double width. The display is 80x24 for terminal output with an extra line for the status at the bottom.

I have to complete the coding for the PS/2 keyboard input - It wasn't on my strip board prototype. I put a USB socket on the board so you don't have to have a big chunky USB/PS2 adaptor hanging off the side.

I'm going to port my 65C02 emulator to another 70MIP PIC with 16K of RAM (32K ROM) and see if I can write enough of an Acorn MOS ROM emulator to get BBC Basic to boot using the VT 220 shield for I/O. Should give create a 65C02 emulation equivalent to a real device at about 10Mhz.

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Andrew Jacobs
6502 & PIC Stuff - http://www.obelisk.me.uk/
Cross-Platform 6502/65C02/65816 Macro Assembler - http://www.obelisk.me.uk/dev65/
Open Source Projects - https://github.com/andrew-jacobs

Wow, that looks beautiful, Andrew...

What kind of monitor is that? I thought getting 80 x 24 on a "TV" was quite difficult without aritifacting and such.

Its a cheap (£90) 19" HDMI LCD TV/Monitor from a local electrical store.

_________________
Andrew Jacobs
6502 & PIC Stuff - http://www.obelisk.me.uk/
Cross-Platform 6502/65C02/65816 Macro Assembler - http://www.obelisk.me.uk/dev65/
Open Source Projects - https://github.com/andrew-jacobs

Do this works because it's a digital "HD" TV? I assume you're not using RF to talk to it? Not really sure how modern TVs et al work nowadays compare to the old silver and black boxes with the Channel 3 or 4 selector.

It generates a PAL or NTSC analogue video signal. You need a TV with an AV input, usually three RCA sockets (yellow, white and red). I used to use an old Sony portable TV with a CRT but thats now permanently connected to the bird box cam.

_________________
Andrew Jacobs
6502 & PIC Stuff - http://www.obelisk.me.uk/
Cross-Platform 6502/65C02/65816 Macro Assembler - http://www.obelisk.me.uk/dev65/
Open Source Projects - https://github.com/andrew-jacobs

Lovely piece of work.

That does indeed look like a VT220 font, see here for an example : http://www.flickr.com/photos/99021790@N00/4290889550

If the PC font is similar... well, we know which one came first, right?

Are you planning on selling these or offering instructions for building? It's just the ticket for my UK101 clone (and the Raspberry Pi I have stashed away somewhere).

Cheers

JonB

Indeed... Very minimal. Very impressive!

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65Org16:https://github.com/ElEctric-EyE/verilog-6502

I suspect that's because it is a PC font. This: http://www.vt100.net/dec/vt220/glyphs is what the VT220 looked like.

Can you elaborate, please, Andrew?

I purchased my first flat screen TV recently and it has an HDMI input, a USB input, and what it calls "component" video inputs labeled Y (green), Pb (blue), and Pr (red). I have no idea if "component" video is analog or digital. My cable decoder drives the display using the Y (green) input and an Audio input, so it seems that the Y (green) connector must be composite video & sync signals, yes, no?

Component video is analog. The Y input contains the brightness information (luma), so if you just hook up the Y, you get a grayscale picture. The color information is sent separately over the Pb/Pr connections.

In composite video, all three are mixed, with Y in a lower frequency, and Pb/Pr in a higher frequency modulation, all over the same signal.

If you get a color picture just using the Y input, it must be working in composite mode.