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Solving the global IC shortage by reusing old stuff!
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Merge pull request #2 from AndersBNielsen/R1B2 
Solder jumpers instead of 0402 resistors, redundant 0805 decoupling caps
2022-11-24 22:56:30 +01:00
build Removed build output and .DS_Store files 2022-04-12 12:39:32 +03:00
hardware Solder jumpers instead of 0402 resistors, redundant 0805 decoupling caps 2022-11-24 22:44:36 +01:00
software_linux Removed build output and .DS_Store files 2022-04-12 12:39:32 +03:00
.gitignore R1B2 gerbers, start+stop bits in modem driver 2022-10-18 11:00:00 +02:00
abn6502rom.s Solder jumpers instead of 0402 resistors, redundant 0805 decoupling caps 2022-11-24 22:44:36 +01:00
assemble.sh BASIC interpreter support, PS/2 serial code, scrolling support, cleanup. 2022-09-18 14:02:18 +02:00
burncrom.sh Wireless nRF24L01+ bootloader added! 2022-04-03 14:13:47 +02:00
crom.s R1B2 gerbers, start+stop bits in modem driver 2022-10-18 11:00:00 +02:00
defines_abn6502.s BASIC interpreter support, PS/2 serial code, scrolling support, cleanup. 2022-09-18 14:02:18 +02:00
License.md PCB Silkscreen annotations added 2021-10-30 14:18:58 +02:00
memmap.cfg BASIC interpreter support, PS/2 serial code, scrolling support, cleanup. 2022-09-18 14:02:18 +02:00
README.md R1B2 gerbers, start+stop bits in modem driver 2022-10-18 11:00:00 +02:00
userland.s R1B2 gerbers, start+stop bits in modem driver 2022-10-18 11:00:00 +02:00

README.md

ABNielsen.com 6502 Single Board Computer R1

This is a 6502-based complete single board computer intended to help during the global IC shortage. Why use new chips when you can reuse scrap?

Complete hardware overview of R1:

Watch the video

Video about the wireless bootloader:

Watch the video

Check out the NEW project on HackADay if you want to read more and see some pretty pictures :)

https://hackaday.io/project/184725-abn6502-sbc-r1

For R1 I got rid of the Padauk MCU without increasing the chip count!

Build instructions:

  1. Send gerber files from /hardware to your favorite board house
  2. Build the project using assemble.sh - this will also try to burn the main ROM using Minipro. Dependencies: [CC65] (https://github.com/cc65/cc65) and a way to burn the ROM's.
  3. Source the IC's - the spirit of this project is to contribute as little as possible to the global IC shortage and get used chips locally or from Ebay/AliExpress/etc.
  4. Burn the ROMs. I use a TL866II Plus variant for the actual ROMs.
  5. Solder away
  6. For the PS/2-keyboard I use the 6522's Shift Register, PB6, and a 74xx74 flip flop. See my R1 Hardware overview at 7:46: https://youtu.be/w5cA64xof2I?t=466 This is now included on the board - instead of a PS/2 connector which can be harder to source I went with a USB-A-connector.
  7. Enjoy!

Optional: Setup SSH keys with a Raspberry Pi, connect an nRF24L01+ compatible module to it and compile the wireless bootloader code in /software_linux

Also optional: Microsoft BASIC can be enabled by cloning the msbasic Github repo into the same folder you cloned this repo.

git clone https://github.com/mist64/msbasic.git

Then uncomment ;BASIC := 1 (Remove the ";") and run assemble.sh - this will let you run BASIC by pressing F4. To change settings for BASIC, values can be changed in defines_abn6502.s

Also, please note that the current code assumes VRAM starts at $0800 rather than the default $2000 in the schematic - resistors will have pads for configuring in the next build, but for now it requires jumpers.

License: Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) https://creativecommons.org/licenses/by-nc/4.0/