I’m excited to announce a very cool project for retromaniacs:
- RetroShield is an 8-bit microprocessor daughtercard for Arduino Mega.
- A real 8-bit microprocessor executes programs,
- while Arduino Mega emulates RAM, ROM, and peripherals.
- Hardware/Arduino Software for 6 microprocessors released (see below for hw/sw details):
- MOS: 6502
- Motorola: 6809
- Intel: 8031 - 8085
- RCA: 1802
- Zilog: Z80
- Upcoming microprocessors (bold chips at hand):
- Fairchild: F8
- Intel: 4004, 4040, 8008, 8080, 8088, MCS-48 (the whole line-up :))
- Intersil: 6100 or 6120, Harris HD6120 (PDP-8)
- Motorola: 6800, 6801/6803, 68008
- National: SC/MP, SC/MP II
- Signetics: 2650, 8X300
- Texas Instruments TMS9900
- Commodore SID
- Let me know if you want anything else to be added to the list.
- Donations are welcome.
- Hardware Specs:
- Microprocessor runs at about 110~170kHz.
- RAM : ~6 KB (available in Arduino Mega, expandable to 128 KB via expansion
- ROM : >200 KB (available in Arduino Mega)
- Peripherals: UART, PIA, Timers, etc. (emulated by Arduino)
- Project goal is to make a simple platform to keep microprocessors alive
- No need to build complex circuits, or burn EEPROMs :)
- If you have the chip, you can bread-board it in one night.
- Existing Arduino shields can be used to extend the capabilities, i.e. SDCard, LCD.
- You can learn how microprocessors interface w/ memory or peripherals.
- Run some of the great older software avaliable.
- Open source hardware/software.
|6502 / W65C02S||Apple-1 (6502+6521)
KIM-1 (6502 + 6530)
|MON,BASIC,Cassette (Steve W)
KIM-1 (MOS Technology, Inc)
|6809||6809E + FTDI||Simon6809 (Lennart Benschop)|
|Z80||Z80 + 8251||Microsoft Basic (MSFT, Grant Searle)
EFEX (Mustafa Peker)
|8031||8031 + UART||PAULMON2 (Paul Stoffregen)|
|8085||8085A + 8251||MON85 (David Dunfield)|
|1802||1802 + UART||MCSMP (Charles J, Yakym)
Tiny BASIC (Tom Pittman)
RCA BASIC3 (Ron Cenker)
|Motorola 6801 / 6803||next|
2019/08/12: Released updated PCB’s for 1802 and 8031.
- For 1802, connected Q directly to Arduino to decode uart (rev A design required a jumper cable from Q to Arduino).
- For 8031, 8031 couldn’t drive an LED directly, so I rerouted the LED to the available Arduino GPIO.
- Bit the bullet and ordered PCB Assembly service to solder SMT parts on PCB’s to make it easier to build this thing.
My hope is people will be able to contribute hw/sw so we have many flavors to experience.
Links to Arduino Code for each microprocessor:
- RetroShield 6502 Software
- Apple I Monitor + BASIC + Cassette Interface
- KIM-1 thru TTY
- RetroShield 6502 even works with Monster 6502
- RetroShield 6809 Software
- Simon6809, educational monitor w/ assembler/disassembler
- RetroShield Z80 Software
- Z80 Basic Ver 4.7b, Microsoft BASIC, heavily modified by Grant Searle.
- Efex Monitor (work in progress)
- RetroShield 1802 Software
- Membership Card Serial Monitor Program Ver. 1.5 by Charles J, Yakym.
- Tiny BASIC by Tom Pittman Copyright 1982
- RCA Basic Level 3 v1.1 by Ron Cenker, Copyrighted 1981
- IDIOT monitor by Lee Hart
- RetroShield 8031 Software
- PAULMON2 v2.1 by Paul Stoffregen
- RetroShield 8085 Software
- RetroShield 6502 Theory of Operation
- RetroShield 6809 Theory of Operation
- Theory of Operation for Z80, 1802, 8031, 8085 will be completed as needed (frankly same concept as 6502 and 6809).
- PCB/Kits are available for sale at my store
- your purchase helps support more microprocessors
- Copyright 2019 Erturk Kocalar, 8Bitforce.com
- Hardware is released under Creative Commons ShareAlike 4.0 International.
- Software is released under the MIT License.
- Distributed as-is; no warranty is given.