原文
A 6502 based laptop design
Yes, I know I'm crazy, but I figured why not. I'm enjoying working the PC6502 project but having a little tower of PCBs on the sofa isn't the best. It's very simple, these are the specs
- 65C02 running at 8MHz
- 46K RAM
- BASIC in ROM
- 65C22 VIA (for timers and some IO)
- 9" DIsplay (with built in font/simple graphics)
- Built in keyboard
- Compact Flash for storage
- 10000mAh battery built in
- USBC powered/charged
- Serial Console
- 1 internal expansion slot
Assembled front view
Assembled rear view
Assembled LHS view
Assembled RHS view
Assembled closed front view
Assembled closed rear view
Lower parts (main board, battery, keyboard) in it's case
Screen with BASIC code
First bring up
- 2025-11-12 - Initial commit with work in progress PCB, Schematics complete.
- 2025-12-30 - PCBs arrived!
- 2026-01-01 - Initial power up of PCBs gives all the correct voltages
- 2026-01-03 - Bring up of board with simple ROM/RAM/Console working.
- 2026-01-04 - VIA working, ACIA working, comms to/from the keyboard in basic working. Begun integrating keyboard into firmware
- 2026-01-05 - Keyboard now integrated into firmware, so you can type on the keyboard and don't need the console for input
- 2026-01-09 - Compact flash working, Beeper also now working. Also runs from battery just fine.
- 2026-01-16 - Connected a 4.3" 800x480 RA8875 based display and got that working. I failed to get the LT7683 based display working.
- 2026-01-17 - work on a number of case related things that did not quite work in actual life.
- 2026-01-18 - Tweaked CPLD to slow down FTDI read/writes. Also begun work on bios, added start beep and begun work on load/save functions
- 2026-02-08 - Added more commands, notably SAVE,LOAD and DIR for compact flash
- 2026-02-13 - Added more graphics commands :)
- 2026-02-14 - Assembled the case
- add in larger display (going to try a 10.1" RA8889 based 1024x600, fall back is a 9" RA8875 based 800x480)
- Fix buggy keyscan code on MEGA644P
The memory map is fairly stable at the moment, everything seems to be working fine.
| Start | End | Size (Dec) | Size (Hex) | What is it | Notes |
|---|---|---|---|---|---|
| 0x0000 | 0xBEAF | 48816 | 0xBEB0 | RAM | This includes Zeropage and other bits BASIC may need (more below) |
| 0xBE00 | 0xBFFF | 512 | 0x200 | peripherals | This is where the peripherals are mapped (see below) |
| 0xC000 | 0xFFFF | 12288 | 0x3000 | ROM | holding EhBASIC, eWoz monitor, bootstrap and vectors |
| Start | End | Size (Dec) | Size (Hex) | What is it | Notes |
|---|---|---|---|---|---|
| 0xC000 | 0xFAFF | 15104 | 0x3B0 | EhBASIC | EhBASIC 2.22p5 |
| 0xF000 | 0xF2FF | 768 | 0x300 | eWozMon | Enhanced Wozmon |
| 0xF300 | 0xFFF9 | 3322 | 0xCFA | Bootstrap | startup messages and also input/output/load/save functions |
| 0xFFFA | 0xFFFF | 6 | 0x0A | 6502 Vectors |
| Start | End | Size (Dec) | Size (Hex) | What is it | Notes |
|---|---|---|---|---|---|
| 0x0000 | 0x02FF | 768 | 0x300 | RAM | This includes Zeropage and other bits BASIC may need |
| 0x0300 | 0x07FF | 1280 | 0x500 | RAM | This is going to be for the compact flash reading/writing |
| 0x0800 | 0xBDFF | 46592 | 0xB6B0 | ROM | BASIC RAM available |
| Address | subAddr range | RW | What is it | Notes |
|---|---|---|---|---|
| 0xBE0O | 00-FF | RW | Expansion slot | |
| 0xBF00 | 00-9F | Unused Currently | ||
| 0xBFAO | 0-0 | W | Beeper | just write 0xFF and 0x00 to turn on/off the speaker |
| 0xBFBO | 0-7 | RW | Compact Flash | |
| 0xBFCO | 0-F | RW | 65C22 | on board VIA |
| 0xBFDO | 0-F | 0-1 | Display | |
| 0xBFEO | 0-F | RW | 65C21 | internal keyboard |
| 0xBFF0 | 0-1 | RW | Console | FTDI USB console port |
I've Added a some extra commands to EhBASIC and they are as follows;
- BEEP P,L - Pitch (P) is 0-255, length (L) = 0 to 255
- 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
- ELIPSE - X,Y,RX,RY,C,F - Draws an elipse, X is 0-799, Y is 0-479, RX is X radius, RY is Y radius, C is colour and F is fill
- LINE X,Y,EX,EY,C - Draws a line, X is 0-799, Y is 0-479, EX is X end point (0-799), EY is Y end point (0-479), C is colour
- 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
- SQUARE - X,Y,EX,EY,C,F - Draws a square, X is 0-799, Y is 0-479, EX is X end point (0-799), EY is Y end point (0-479), C is colour and F is fill
- WOZMON - Jumps to wozmon, Q will exit WOZMON and return to basic (Handy for check chunks of memory)