RetroComputers

Grant Searle's FPGA MultiComp Project

FPGA Recreations of 6502, 6809, and Z80 Vintage Computers

• Multicomp on Land Boards Cards - Hardware
• Multicomp on Purchased Cards
• FPGA Support Cards
• MultiComp Wiki Page on GitHub
• Multicomp Github repo

Our MultiComp Retro-Computer Video Series

Cyclone II Video Series

Video Series

Cyclone IV Video Series

Video Series

6800 CPU

My First Computer Build

My first attempt to build a computer was way back in 1977 (before my Ohio Scientific SuperBoard II). The homebrewed computer based on an MC6800 CPU so the CPU has a soft spot in my heart. I never took any pictures of it and the hardware is long gone now. These are the pieces of it I remember.

• Elco? 120 pin edge connector wire wrapped cards with homebrew backplane
• 6800 Processor board running at 1 MHz
• 2K of Static RAM board
• 2716 EEPROM board (may have had 4 sockets total, don't recall for sure)
• Front panel switches and LEDs to enter the address/data and blink lights

I remember getting it to run and I do remember blinking a light back and forth on it. Once I got the SuperBoard II, I stopped working on my own board. I didn't have an assembler so I have assembled code to machine code.

It might be fun to reproduce that board!

6800 SmithBug Builds

This MultiComp build fills a hole in Grant Searle's Multicomp (he hadn't finished a 6800 version).

It also completes the project I started back in 1977 with a lot of built-in features I could never have imagined back in the day.

• MC6800 CPU
• SmithBug ROM supports up to 60KB of SRAM
• 25 MHz
• SRAM size options to match FPGA capacities
  • 4KB SRAM (for small FPGAs)
  • 32KB (Internal) SRAM version (requires EP4CE15 minimum)
  • 60K (external) RAM version
  • 60K RAM version (requires Cyclone V FPGA)
• MC6850 ACIA UART
• Video Display Unit (VDU)
  • Color attributes
  • XGA 80x25 ANSI character display
  • Extended (256) character set
• PS/2 keyboard
• Runs Tom Pittman's Tiny BASIC
  • User Manual

• Build on EP4CE15 card
• Build on EP2C5 card
• Build on EP4CE10 card
• Build on EP4CE6 card
• Build on EP4CE15 Starter Kit card
• Build on EP4CE6 card (RETRO-EP4)
• Build on EP4CE6 card (RETRO-EP4) 60KB SRAM
• Build on EP4CE15 card
• Build on EP4CE15 card 60KB SRAM, 1MB Banked SRAM
• Build on EP4CE15 card Front Panel control
• Build on Cyclone V card 60KB SRAM, 1MB Banked SRAM

Memory Map (60KB SRAM version)

• SmithBug/MIKBUG Wiki page

• $0000-$EFFF - Up to 60KB external SRAM
  • $0000-$EEFF - User RAM area
    • $EF00-$EFFF - Scratchpad RAM used by MIKBUG
• I/O Map
  • $FC18-$FC19 - VDU
  • $FC28-$FC29 - ACIA
    • J3 right side position - PIN_B22 (EP4CE15) of the FPGA swaps addresses of VDU and ACIA port
    • Installed (PIN_B22 to Ground) uses ACIA Serial port
    • Removed uses VDU
• $F000-$FFFF - SmithBUG ROM
  • I/O "hole" opened up at 0xFC00-0xFCFF

6800 with Front Panel Running SmithBug

• Adding a modern version of a Front Panel completes the build of my 1977 6800 Computer
• Hackaday Front Panel page

• Front Panel Operation

6800 FIG-Forth Builds

• Build on RETRO-EP4CE15 FPGA - Runs out of ROM with Front Panel and boots directly to FigForth
• Build on RETRO-EP4CE15 FPGA - Runs under SmithBUG with Front Panel build - Run via J 0100
• 6800 FIG-Forth Builds - Wiki page

6800 FIG-Forth Reference

• 6502.org Forth Forum
• Forth Interest Group
• Silicon Valley Forth Interest Group
• Kim Harris' Forth Course
• MIKBUG on MultiComp - Hackaday page
• FigForth Wiki page
• FigForth FPGA files
• FigForth Software Build
• Starting Forth book - Brodie
• Thinking Forth by Leo Brodie
• The Evolution of Forth - History and internals of Forth
• Journal of Forth Application and Research
• FIG-FORTH internals

SWTPC

• Memory map (Hexadecimal Addresses):
  • 0000-7FFF: RAM
  • 8004-8007: MC6850 ACIA (UART)
  • A000-DFFF: RAM
  • E000-FFFF: SWTBUG Monitor ROM (visible on every 1 k memory location)
• Emulated components:
  • Motorola MC6800 CPU (SWTPC mp-a)
  • Motorola MC6850 UART (SWTPC mp-s)
  • 48k RAM

6800 Software Development Tools

• 6800 Software Development Tools - GitHub Wiki page
• DREAM 6800 Archive Site - CHIP-8 Software

6502 CPU

• Several builds
  • My original Ohio Scientific SuperBoard II
  • MultiComp build of Ohio Scientific SuperBoard II
  • OSI 6502 Build

Ohio Scientific SuperBoard II

This was my first commercial personal computer.

• Manufacturer: Ohio Scientific
• Model 600 Rev B Board Manual
• Model: SuperBoard II ( Model 600 )
• Available: 1978
• Price: US $279 assembled
• CPU: 6502
• RAM: 4K static RAM, 8K max
• CEGMON - Monitor in 4K of EPROM
• Display: composite video, 30 X 30 text
• Built-in keyboard
• Single board design
• I eventually got a Model 610 24KB RAM expansion card with Floppy Disk Controller
• Ports: composite video, cassette
• Storage: cassette
• Microsoft BASIC
• 2K Monitor ROM (CEGMON)
• Compkit 101 - British clone of the SuperBoard II

SuperBoard II Emulator

• OSI Challenger 1P (8Kb) with Debugger - JAVA web based emulator
• OSI Challenger 1P (32Kb) with Disk Support - JAVA web based emulator
• pill_6502: 8-bit 6502 CPU and 6850 ACIA emulation on the STM32 blue pill to run Microsoft BASIC from 1977

Keyboard Layout

• PS/2 Keycodes
• Keyboard matrix

SuperBoard II/ Retro-Tech Refresh

I was looking around for a way to recreate my OSI Superboard and found Grant Searle's design.

• EP2C5-DB - Our creation of a daughtercard which implements Grant Searle's Multi-Computer
• Grant Searle's CompuKit UK101
  • Based on Cyclone II EP2C5 Mini Dev Board
  • Someone built one of the CompuKit clones as a CPM box

Superboard II Documents

• Dave's OSI Repository - Lots of scanned documents up there - large file sizes
• Compukit UK101 Docs on Sourceforge]
  • CEGMON Users Guide
  • Sample Programs and Tapes
• CEGMON – a blast from the past
• Code for the 6502 microprocessor, mostly for the Replica 1 computer
• Nice page on the C1P/Superboard II
• 6502 Instruction Set
• Compukit 101 video
• Ohio Scientific publications
• Enhanced 6502 BASIC
  • Experience porting Enhanced Basic to a 6502 Computer
    • "EhBASIC is about 11 KB"
• 6502.org - the place for retro 6502 projects
• System68
• L-Star: Software-Defined 6502 Computer - Uses a Propeller chip
• Pick-and-mix to create your own custom computer on a low-cost FPGA board
• Daryl's Computer Page
  • Daryl has designed multiple single board computers
• 6502 Assembly Language books - archive.org
• Micro 6502 Journal
• DABUG Monitor ROM

MultiComp 6502 Builds

• Two Builds
  • OSI C1P/SuperBoard II/UK10
  • OSI 6502

OSI C1P/SuperBoard II/UK101 Builds

• Build on RETRO-EP4CE15 card
• Build on ESTF V2 EP4CE22 card
• Build on zrTech EP4CE6 card - 23KB
• Build on zrTech EP4CE6 card - Minimal features set
• Build on EP2C5 card - Grant's original build
• Build on EP2C5 card - 4KB SRAM
• Build on EP2C5 card - NTSC video, 41KB SRAM
• Build on EP2C5 card - NTSC video, 41KB SRAM, 115,200 baud
• Build on EP4CE10 card
• Build on EP4CE6 card
• Build on WaveShare EP4CE6 card
• Build on EP4CE15 card - VGA, PS/2, 40KB SRAM
• Build on EP4CE15 card
• Build on Cyclone V card - 41KB External SRAM
• Build on Cyclone V card - 41KB Internal SRAM
• Build on Cyclone V card - 41KB External SRAM in box
• Build on Cyclone V card - 41KB Internal SRAM in box
• Grant Searle's CompuKit UK101

OSI 6502 Builds

• Build on zrTech card
• Build on EP2C5 card
• Build on EP4CE10 card - 32KB internal SRAM
• Build on EP4CE10 card - 32KB internal SRAM (copy)
• Build on EP4CE6 card - 16KB internal SRAM
• Build on EP4CE15 card
• Build on Cyclone V card
• Build on Cyclone V card - in box

6502 Software Development Tools

• 6502 Software Development
• CP/M-65 - native port of Digital Research's seminal 1977 operating system CP/M to the 6502

6809 CPU

Our Build

• Our FPGA Builds
• BASIC is a port of Microsoft Extended BASIC for the 6809-based Radio Shack Color Computer

Neal Crook's 6809 Multiple OS Build

Neal Crook's build started from Grant Searle's Multicomp and fixed a number of issues with the VHDL code. It also has an SD Card with multiple OS Support.

• Neal Crook's 6809 Wiki of Multicomp FPGA builds - very helpful
• Neal Crook's Multicomp GitHub (with docs)
• Neal did work on the 6809 core that Grant Searle was using
  • Changed reset to active-low, consistently asynchronous
  • Changed clock to rising-edge
  • Clocked the processor on the input (50MHz) clock rather than a divided clock
    • Used the HOLD input to control the clock rate.
  • Added MMU to control extended RAM
• Neal did some Video Display Unit (VDU) Modifications
• Neal's Memory Mapper
• Neal got SDHC working - the original was SD only

Programming

• CamelForth

SD Card

• SD Card image multicomp09_sd.zip - Program SD card using Balena Etcher
  • SD Card Image
• Using the SD Card

6809 Software Development Tools

6809 Assembler

• Motorola 6809 Cross-Assembler
• asm6809 Assembler
• Assembler User's Manual
• 6809 Assembler for Windows - Crossware
• ASSEMBLER as9 SALVAGED
• Motorola 6809 Emulator
• AS09 - 6800/6801/6809/6301/6309/68HC11 Assembler

6809 BASIC

• Microsoft Extended BASIC - Radio Shack Color Computer 2
• 6800/09 BASIC User's Manual 1979 - Technical Systems Consultants, Inc.
• MICRO BASIC PLUS SOURCE
• ExBASIC for the Radio Shack Color Computer
• https://github.com/douggilliland/Retro-Computers/tree/master/6809/tinybasic
• TSC Micro BASIC PLUS

6809 C Compiler

• CMOC Compiler
  • CMOC Compiler Homsepage
• Introl C Compiler

6809 FORTH

• ciforth
  • ci6809 : a 6809 Forth docs

6809 FLEX Operating System

• FLEX User Group
• Flex User's Guide
• Flex Link Loader
• FLEX Assembler User's Guide
• FLEX Software Archive
• Flex Explained

6809 FUZIX Operating System

• FUZIX

6809 Monitors

• assist09
• https://github.com/douggilliland/Retro-Computers/tree/master/6809/exbasrom exbasrom
• [https://github.com/douggilliland/Retro-Computers/tree/master/6809/wozmon WOZMON ported to 6809

Other 6809 Docs

• MC6809-MC6809E 8-Bit Microprocessor Programming Manual (M6809PM/AD) © Motorola Inc., 1981
• Starting FORTH - First book of learning FORTH
• 6809 Assembly Language Programming by Lance Leventhal archive.org
• Upload ROMs without rebuilding
• 6809 Emulation Page
• N8VEM 6809 Board
• ultim809: homebrew 8-bit computer

Z80 CPU

• Multiple Z80 Builds
  • Land Boards Z80 in 3 Chips card
  • Z80 NASCOM BASIC (in FPGA)
  • Z80 CP/M (in FPGA)
  • Z80 Multi-OS (in FPGA)
  • Z80-MBC2 Build card

Land Boards Z80 in 3 Chips

• Hackaday Z80 in 3 Chips
  • 512KB SRAM
• Front Panel For 8 Bit Computers
• Z80 in 3 Chips
• SD_CARD_X49 mounted on CARRIER95TO49MM
• JOYPAD
• rhkoolstar sbc-2g-512 - SD card image
  • Archive of rhkoolstar sbc-2g-512

Z80 NASCOM BASIC (in FPGA)

• Build on A-ESTF V2 EP4CE22 card
• Build on zrTech v2 card
• Build on EP4CE10 card
• Build on EP4CE6 card
• Build on EP4CE6 card (RETRO-EP4)

NASCOM BASIC Notes

• OUT ADDR,DATA
• INP(128) - Reads I/O address 128 (0x80)

Z80 CP/M (in FPGA)

• Build on EP4CE15 card
• Build on EP2C5 card
• Build on EP2C5 card
• Build on EP4CE6 card (RETRO-EP4)
• Build on EP4CE15 card
• Build on Cyclone V card (MPM)
• Build on Cyclone V card (MPM) in a box

CP/M on FPGA - by Grant Searle

• Archive.org copy of Grant's site from 2012
• Archive.org copy of Grant's Multicomp from 2012
• Fit results (EP2C5 FPGA)
  • Two UART Serial interface
  • No Video Display
  • External RAM

CP/M Notes

• CP/M is not case sensitive
• REN NEWNAME.EXT=OLDNAME.EXT - Rename a file from the old to the new name
• ERA FILE2ERA.EXT - Erase a file
• Asterisk is wildcard
• .COM are command files
• PIP/PPIP - copy command (CP/M 2.2, CP/M 3)
  • CP/M 2.2 uses PIP
  • PIP NEWCOPY.EXT=COPYFROM.EXT - Copy from COPYFROM.EXT to NEWCOPY.EXT
  • CP/M 3 uses PPIP
• Drive references A:
  • Drives go from A-???
• LS is a better directory program

CP/M Resources on the Net

• CP/M Operating System Manual
• Digital Research CP/M Site
• A Short History of CP/M
• CP/M Internals
• CP/M Console Command Processor Instructions
• OAK Repository - CP/M Archive - On the Wayback machine
• Intro to Z80 Retrocomputing - Scott Baker's series on the RC2014
• Digital Research Source Code
• CP/M Programming Languages and Tools retroarchive page
  • retroarchive page - mirror
• Multicomp FPGA - CP/M Demo Disk
• BBC BASIC (Z80)
  • BBC BASIC (Z80) Manual

*BYE- Return to CP/M

• Altair downloads

• Grant noted about the SD card interface:

... the SD controller is easy to control - in BASIC POKE the sector number, POKE the write command, 
POKE 512 bytes to the same location to write a sector, 
or POKE the sector number, POKE the read command, and PEEK 512 bytes to read a sector.

Microsoft BASIC Notes

• SAVE "MYPROG.BAS"
• LOAD "MYPROG.BAS"
• SYSTEM -- Return to CP/M
• NAME "OLDFILE.BAS" AS "NEWFILE.BAS"
• NEW - Delete program
• OUT 132,1 -- Output to I/O port 132
• PRINT MEM - Free memory (6809 Extended BASIC)

AZTEC C Compiler

• Compile C code to CP/M executable
• Aztec C Compiler Manual
  • C Vers. 1.06D 8080 (C) 1982 1983 1984 by Manx Software Systems
• Example Code - HELLO2.C

int main()
{
  int i;
  for (i=0; i< 10; i++)
    printf("%d\n");
}

• Compile code to assembly file
  • Creates a .ASM file

CC HELLO2.C

• Assemble Code to object file
  • Creates a .O file

AS HELLO2.ASM

• Link Code with C library to .COM executable file

LN HELLO2.O C.LIB

ALGOL-M Compiler

• Fizzbuzz example

BEGIN

INTEGER FUNCTION DIVBY(N, D);
INTEGER N;
INTEGER D;
BEGIN
  DIVBY := 1 - (N - D * (N / D));
END;

INTEGER I;
FOR I := 1 STEP 1 UNTIL 100 DO
BEGIN
  IF DIVBY(I, 15) = 1 THEN
    WRITE("FizzBuzz")
  ELSE IF DIVBY(I, 5) = 1 THEN
    WRITE("Buzz")
  ELSE IF DIVBY(I, 3) = 1 THEN
    WRITE("Fizz")
  ELSE
    WRITE(I);
END;

END

• To run compiler:

algolm fizzbuzz

• Result is:

ALGOL-M COMPILER VERS 1.1
   0 ERROR(S) DETECTED

• To run ALGOL interpreter

runalg fizzbuzz

• Result is

ALGOL-M INTERPRETER-VERS 1.0


     1
     2
Fizz
     4
Buzz
Fizz
     7
     8

Z80 Multi-OS (in FPGA)

• Build on Cyclone V card (MPM)
• Build on Cyclone V card (MPM) in a box
• Build on Cyclone 10 card in ITX Enclosure

Retrobrew Multi-boot Multicomp Computer Builds

• MultiComputerZ80 build - Lots of extras - mc-2g-1024 Help file
• Multicomp Z80 with b/w Graphics - muellerk page
• mc-2g-1024 Image18 - Multiboot SD card

mc-2g-1024 Images

• Copy image System18.img to your SD-card. Use direct imaging software (dd in Linux, Win32DiskImager in Windows). Copy to the start of the card
  • rhkoolstar mc-2g-1024 is backed up here
• Included OSs are
  • Type Snnn to select OS at multiboot
  • S001 - Dos+ 2.5 Copyright 1986 (c) by C.B. Falconer, CCP+ Ver. 2.2 (CP/M 2.2 compatible)
  • S002 - CP/M 2.2 (c) 1979 by Digital Research
  • S003 - CP/M Version 3.0 BIOS (2016/9/13)
    • CP/M Version 3.0 Operating System System Guide
  • S004 - MP/M II V2.1
  • S005 - Z80 BASIC Ver 4.7b, Copyright (C) 1978 by Microsoft
  • S006 - ZSDOS v1.1 (c) 1986-8 Harold F. Bower & Cameron W. Cotrill, ZCPR2 (c) 1982 by Richard Conn (CP/M 2.2 compatible)
  • S007 - ZCPR compatible system for CP/M+ (CP/M 3.0) by Simeon Cran

• Additional Volumes
  • Inspired by mc-2g-1024 original but modified
  • Sources from here
  • Mount using mount d vol
    • Ex: mount b: 9 will mount ZCPR3 Utilities A-O as drive b:
  • Volume.008 - ?
  • Volume.009 - ZCPR3 Utilities A-O
  • Volume.010 - ZCPR3 Utilities P-Z
  • Volume.011 - Wordstar, DBase, SuperCal
  • Volume.012 - Games
  • Volume.013 - MuMath
  • Volume.014 - Documentation
  • Volume.015 - Languages (TurboPascal, Fortran, BBC BASIC)
  • Volume.016 - Languages (Algol, Aztec C, APL, PLI, FORTH)
  • Volume.017 - Languages (BDS Tiny C, Janis Ada15, MS COBOL, PILOT)
  • Volume.018-253 - User volumes

Retrobrew Computer Builds of the Multicomp Project(s)

• Multi-boot Multicomp build by muellerk builds on Multi-boot Multicomp build by rhkoolstar
• Some folks made a MultiComputer PCB, too - Retrobrewing
• Another board
• Yet another board
• Jeelabs Building a MultiComp-based Z80
• Patch WordStar 3.0 to use ANSI screen commands
• Homebrew Z80
• "The Thing": FPGA + STM32

Notes

• Z80 Protocol Decoder
• Z80 = mc-2g-1024 - Best build
• Z80 Assembly Language books - archive.org

Z80-MBC2 Build

Z80-MBC2 Build Notes

• On card
  • Z80 CPU CMOS (Z84C00) 8Mhz or greater - I used 20 MHz
  • Atmega32A
  • TC551001-70 (128kB RAM)
  • I used AS6C1008-55PIN since it is available on Mouser and Digikey
  • 74HC00
• I added the optional MCP23017 for GPIO
• External cards
  • External RTC
  • External SD card
    • Runs Petit FAT File System - Loads FAT32 SD cards loaded in Windows
  • External USB-Serial adapter
  • SWLEDX8 - LEDs card
    • Custom wiring, no slide switches
• Bare Board on ebay - $8 shipping included
  • Arrived in a couple of days
• Kit for sale
• Enclosure

68000 CPU

• Builds of two platforms
  • AMR - CPU with VGA frame buffer from SDRAM and other peripherals
  • TS2 - Basic 68K CPU with VGA character display

TG68_AMR Design

• TG68 AMR Build
  • 68000 Core
  • SDRAM support
  • VGA Framebuffer
    • Various resolutions
    • Stored in SDRAM
  • PS/2 Keyboard and Mouse support
  • SD Card support
  • *Loads S Records file

TG68_AMR QMTECH Cyclone IV Starter Kit Build

• Build on QMTECH CycloneIV Starter Kit card in MultiComp Box

TG68_AMR QMTECH Cyclone IV Build

• Build on QMTECH Cyclone IV card

• Runs on RETRO-EP4CE15 base card
  • VGA connector
    • 6 bit video (2:2:2)
    • Pixel dithering maps 24-bit video to six bits
  • PS/2 connector
  • FTDI USB to serial converter
    • Genuine FT230XS FTDI USC to Serial chip
    • USB B
    • Tx/Rx LEDs
  • SD or SDHC Card
    • Can do micro SDHC card using SD card adapter

TG68_AMR Links

• AMR's TG68 Experiments - Original design
• My GitHub page
• Hackaday page

TeeSide 2 design with Multicomp parts

• Hackaday Project page
• Built-on Video Display Unit (VDU)
  • Color attributes
  • XGA 80x25 ANSI character display
  • Extended (256) character set
• ROM
• PS/2 keyboard
• 32KB SRAM
• 16KB ROM

TeeSide 2 Memory Map

• 0x000000 - 0x000007 = ROM Vectors (16-bits)
• 0x000008 - 0x007FFF = SRAM (16-bits)
• 0x008000 - 0x00BFFF = ROM (16-bits)
• 0x01004x - VDU base (A0 = 0) (8-bits)
• 0x01004x - ACIA base (A0 = 1) (8-bits)

TeeSide 2 Monitor ROMs

• TSBUG2 Monitor
  • TS2BUG Commands List
  • 2KB organized as 1Kx16
  • Zero Wait-states
• TUTOR Monitor
  • 16KB organized as 8Kx16
  • Zero Wait-states
  • TUTOR Monitor

TeeSide 2 Build on RETRO-EP4CE15 Running TS2 Monitor

• 68000 CPU in VHDL running on FPGA card
• Running on RETRO-EP4CE15 card
• QMTECH EP4CE15 FPGA Card

TeeSide 2 Build on RETRO-EP4CE15 Running TUTOR Monitor

• 68000 CPU running on RETRO-EP4CE15 card
• Running on RETRO-EP4CE15 card
• QMTECH EP4CE15 FPGA Card

TeeSide 2 Build on Cyclone V Running TS2 Monitor

• 68000 running on Cyclone V card
• Running on RETRO-EP4CE15 card
• QM Tech Cyclone V FPGA Board

TeeSide 2 Build on Cyclone V in Box Running TS2 Monitor

• 68000 running on Cyclone V card in box
• Running on RETRO-EP4CE15 card
• QM Tech Cyclone V FPGA Board

TeeSide 2 Software

TeeSide 2 BASIC

• Lee Davidson's Enhanced BASIC
• TinyBASIC68 - Gordon Brandly's Tiny BASIC v1.0
  • Copy/paste S1/S9 records from TBI68K.HEX into ACIA port
  • JUMP 0900 to run
  • Tiny Basic from MECB
  • Includes LOAD and SAVE from/to the Serial port
    • Type LOAD on VDU port
• MANDLEBRT.BAS

TeeSide 2 C Compiler

• GCC_m68k-elf-toolchain
  • GCC Toolchain
  • GCC m68k-elf page
• SIERRA Compiler
• c_example
• SDCard - Test SD Card reads
• ExtRAMTest - Test the 1MB External SRAM on the RETRO-EP4CE15 card
• c_example - Code example
• objcopy docs
• srecord docs
  • p 26 is the docs for srec_cat

TeeSide 2 Assembly

• vasm
• as68k
• Easy68K
• The GNU Assembler
• testser
• FizzBuzz assembly code

TeeSide 2 Operating Systems

• CPM-68k
  • CPM-68k docs
  • cpm-68k

TeeSide 2 FORTH

• Portable FORTH
• MinForth - Alternate Forth

TeeSide 2 Links

• Jeff Tranter's build (BLOG) - TS2 build
  • Test Programs
  • Monitor code
• Educational Computer Board (MEX68KECB)
  • TS2 compatible memory map
  • Motorola MC68000 Software
  • Motorola 680x0 Resources

68000 Software

C Compilers

• Installing binutils and GCC as cross-compiler for the Motorolla 68000
• The LLVM Compiler Infrastructure - 68K backend
  • LLVM Project
  • Getting Started with LLVM

Operating Systems

• Building uClinux for a 68000 Target
  • uClinux Sourceforge
  • 68000 booting uClinux 2.4.x (with 4Gb sdhc card) - YouTube video
  • Minimal hardware requirement for uClinux
  • Linux toolchain for the MC68000 CPU - gcc (Linux - uClinux/MC68000)
• EmuTOS
  • EmuTOS - Free operating system for Atari computers, and more

Other People's 68000 Builds

• comp.sys.m68k Frequently Asked Questions (FAQ) (1996)
• MiniMig TC64
• Hackaday 68000 pages
• 68000 brought to life!
• Kiwi - a 68k Homebrew Computer
• 68 Katy
• Tiny68K - Reference Tiny68K card
  • t68kbug Debugger

DEC (Digital Equipment Corp) Computers

• Computer Simulation and History (simh)
  • Introduction to SimH -- basic usage - YouTube - Stephen's Machine Room
• Herb's DEC items

PDP-4

• PDP-4 on FPGA
• PDP-4/X System Reference Manual

PDP-8

• Two PDP-8 builds
  • Tom Almy's build
  • OpenCores build
• My PDP-8 Hardware GitHub repository

PDP-8 FPGA Hardware used

• RETRO-EP4CE15
• QMTECH EP4CE15 FPGA Card
• PDP-8 Front Panel

Build of Tom Almy's PDP-8 FPGA (Working 2021-May)

This build is based on Tom Almy's book The PDP-8 Class Project: Resoling An Old Machine.

• PDP-8 FPGA - Hackaday page with progress logs
• PDP-8 Almy book on GitHub
  • FPGA Code - Uses VDU and Front Panel
• My PDP-8 Software GitHub repository

OpenCores PDP-8 Build

• Land Board OpenCores PDP-8 Builds - GitHub repository
  • RETRO-EP4CE15_CYCLONE_IV_VDU PDP-8 Build
    • Built in ANSI Terminal with cpu_001 (IOP16B built-in) - Latest build
    • VDU IOP assembly code
      • Hackaday project page for ANSI Terminal
  • RETRO-EP4CE15_CYCLONE_IV
    • Serial only (no VDU)
  • RETRO-EP4CE15_CYCLONE_V
    • WIP - missing pin assignment
• opencores PDP-8 Processor Core and System Overview
  • Quickstart page

Others PDP-8 FPGA

• Highgate's PDP-8 Page
• Another Almy based design - In Verilog
• Yet another Almy based design
• PDP-8 in VHDL
• A FGPA Implementation of the PDP-8
• PDP-8/I on an FPGA
• PDP-8/i cpu with an RF08 disk emulator Uses a IDE disk as a backing store. It boots TSS/8.
• PDP-8 Instruction verification - In System Verilog?
• PDP8 in a Cypress PSoC5
• Scott Baker's PDP8-SOC - Clean VHDL Design

PDP-8 Documents and Programming

• History of the PDP-8
• Maintenance Manual - excellent document (pdf)
• PDP-8 - A Programmer's Reference Manual
  • The Digital Equipment Corporation PDP-8 - Memory Reference Instructions
• PDP-8/X System Reference Manual (pdf)
• Front Panel software
• pdp8online.com
• PDP-8 Assembly Language Studio
  • Conway’s Life Implemented in PDP-8 Assembly Language

PiDP-8

• PiDP-8/I: RECREATING THE PDP-8/I - Obsolescence Guaranteed
• PiPDP-8 Front Panel
• PiDP-8/I software development nexus

PDP-10

• PDP-10 on FPGA
  • Archived on retrobrew site

PDP-11

My PDP-11 (pdp2011) FPGA builds

• PDP-11 ON RETRO-EP4CE15 - Works
• Based on Sytse van Slooten's original design pdp2011

Other PDP-11 FPGA builds

• Dave Richards pdp2011
• PDP-11 in VHDL - W11 build

PDP-11 Software

• System Disk Images
• Disk Images
• PDP-11 Processor Handbook 1981 - on BitSavers
• PDP-11 on BitSavers
• PiDP-11: Replica of the 1970s PDP-11/70 emulated on Raspberry Pi
• PDP11 Assembler
• A brief tour of the PDP-11

RISC V CPU

• RISC-V Core
• biRISC-V - 32-bit dual issue RISC-V CPU

Terminal

Grant Searle Terminal Design

• Uses two Arduino'ish processors to implement an entire terminal
  • NTSC output
  • PS/2 Keyboard input
• Grant Searle's Monitor Keyboard Design

• Older AtMEGA32 version of Monitor Keyboard Design

• My implementation of Grant's small serial terminal design

External Sites

• Grant Searle's Multicomp page
• Neal Crook's 6809 Multicomp Github
• Retrobrewing Multicomp
• mc-2g-1024 multi-boot capability
• System 09 - VHDL 6809 System On a Chip
• Multicomp build on Cyclone IV

BASIC

• BASIC Programming Resources and Chipmunk Basic Archive
• Tiny BASIC
• Itty Bitty Computers & TinyBasic
• TINY BASIC User Manual

PiGFX

• PiGFX Raspberry Pi graphics card / ANSI terminal emulator

• PiGFX is a bare metal kernel for the Raspberry Pi that implements a basic ANSI terminal emulator with the additional support of some primitive graphics functions.
• It can be driven by pushing characters to the raspi UART.

https://raw.githubusercontent.com/fbergama/pigfx/master/doc/scr1.jpg

RetroBrew Computers Site

• RetroBrew Computers Forum
• pagetable - Probably the best C64 technical data out there
  • Github for all things C64
• S-100 Bus FPGA Z80 SBC Board