LT6502,  PC6502,  Retro Computing

LT6502

10 February 2026 /

Building on the PC6502 system I decided to make a laptop 6502 system. I think there’s something nice about having a portable retro system that is fully self contained.

It’s going very well so far. It’s been quite a steep learning curve. I’ve been remembering the 6502 assembly coding I did back in the 1980s, slowly remembering.

It’s been fun to bring the system up one bit at a time, starting EhBASIC, getting teh display working, the beeper and compact flash.

So here is where I’m at;

Here was the test of the comms with the keyboard, a simple “HELLO” from basic, which is being controlled by the console port (left hand side).

Next was getting the boot menu to ask if you wants a Cold, Warm or Monitor boot.

The really big milestone was getting the screen working. This was a lot of work, but so worth it. There were very definitely moments where I didn’t think I could get it working. Getting the scrolling working was probably the hardest. But I got it in the end.

I am really pleased with this, oh and the colour I chose as I find the amber easy on my eyes.

I’ve also been playing with some math functions to generated images.

This shows the colour really well, The screen is 800 x 480 pixels and is 8 bit colour.

I’ve also added a bunch of extra commands to basic;

  • BEEP <0-255> – Beeps at a variable pitch, higher number gives a higher pitch
  • CIRCLE X,Y,R,C,F – Draws a Circle, X is 0-799, Y is 0-479, R(radius) is 1 – 65535, C is 8bit RGB Value (RRRGGGBB), F is fill (0 = no fill, 1 = fill)
  • CLS – Clear screen (both graphic and text mode)
  • COLOUR <0-255> – Sets the colour (text) to 8bit RGB value, in the form RRRGGGBB
  • DIR – Scans the Compact Flash card and shows slot number and name for any files present
  • LOAD <0-2047> – LOAD a file from CF
  • MODE <0,1> – Sets the display mode, MODE 0 is text, MODE 1 is graphics
  • OUTK – Outputs Text to the 8 character display on the keybed, can be a string or value, anything more than 8 characters will result in text shifting. a String will clear the display and then output the characters
  • PLOT X,Y,C – Plots a dot, X is 0-799, Y is 0-479 and C is 8bit RGB Value (RRRGGGBB)
  • SAVE <0-2047>,”” – SAVE current BASIC program into a SLOT and give it a name, upto 16 characters
  • WOZMON – Jumps to wozmon, Q will exit WOZMON and return to basic (Handy for check chunks of memory)

The screen has a clever driver on it and has hardware acceleration for things like circle, line, square, fill, etc. which makes doing these things really quick.

Now I’ve started working on the case, oh boy that’s a real challenge but it’s getting there, slowly.

You can find more info and all the files so far on my git hub here – https://github.com/TechPaula/LT6502

electronics and synth nerd.