My retro toolchain

About my toolchains for retro computing.

Tools are very personal choice, what works for me. I use Windows (11 now) as my main workstation and often the command line. I do have Linux desktops for compatibility testing. As I grew up in the 80ties with mini’s like HP1000, PDP-11 + RSX-11M, VAX/VMS, MS-DOS, all command line, many many editors, from line editors to screen oriented (EDT from DEC was great!) with all kind of automation tools and code management, I feel comfortable with what Windows (and Linux) offer me now, it makes me very productive! YMMV, pick your tools as you like it.

Tools development
When there is not a tool available that does easy what I need, I write my own. GUI or command line, depending on the context.
My toolchain consists of Freepascal (commandline) and Lazarus (GUI).
Most tools have to do with manipulating binary data as to be expected. Other areas are compilers and simulators.
Resulting tools run on Windows, Linux and Apple Mac’s. See the, like the Hex format conversion, the KIM-1 Simulator and more.

Assembly toolchain

I have quite a collection of 8 bit computers, 6502, Z80, 6809.
Each processor comes with its own machine language, and for each processor myriads of assemblers have been made, each with its own deviations of the official syntax and way they operate. The simple ones are two-pass assemblers generating binaries and listings and symbol tables. More advanced are made up of an assembler and a linker. Linkers are nice and powerful, but a bit overkill for simple projects. I like command line assemblers, callable from an editor.

Notepad++ Editor
A very powerful text editor, with syntax highlighting, multiple files windows open, good search, plugins like hex editor and external tools support.

  1. Install latest version from the download
  2. Add plugins Hexeditor and NPPEXEC
  3. Add scripts to nppexec such as (requires TASM 2 installed, read below)

    • make6502pap tasm -65 -x3 -g1 -s “$(FILE_NAME)” “$(NAME_PART).pap” “$(NAME_PART).lst” -s “$(NAME_PART).sym”
    • make6502bin tasm -65 -g3 -s -l -fff “$(FILE_NAME)” “$(NAME_PART).bin” “$(NAME_PART).lst” -s “$(NAME_PART).sym”
    • make6502hex tasm -65 -x3 -g0 -s “$(FILE_NAME)” “$(NAME_PART).ihex” “$(NAME_PART).lst” -s “$(NAME_PART).sym”
    • makez80hex tasm -80 -g0 -s “$(FILE_NAME)” “$(NAME_PART).ihex” “$(NAME_PART).lst” -s “$(NAME_PART).sym”
    • etc, see c:\tasm\TASMMAN,HTM
  4. Edit you source
  5. Assembly first time: press F6 choose wanted script
  6. After that Press CTRL-F6 to asemble
  7. The output of the assemble appears at the bottom of the editor in a separate part
  8. Open in Notepad also the listing file
  9. If errors, correct the source
  10. if errorfree, start debugging your code, leave Notepad++ open to edit source and read the listing

This is a command line assembler that supports processors like 6502 and Z80. Output is binary, MOS papertape, Intel Hex, Motorola S-record. Listings and symbol tables (for the KIM-1 Simulator) can be generated. Used from Notepad++ as Tool, no need to start from the command line.

  1. Download TASM 32 here
  2. Unpack in e.g. c:\tasm
  3. Create environment variable TASMTABS=C:\TASM
    (Settings – Related Settings – Advanced system settings – Advanced tab – Environment Variables).
  4. Add c:\tasm to the PATH
  5. Invoke tasm from the command line without arguments for help and/or read TASMMAN.HTM in C:/tasm
  6. Add macro’s to Notepad++, see there.

Test and debug
The output of the assembler can be downloaded to the SBC. Burn an EPROM, download hex or papertape. And test the code.

For KIM-1 programs I always use the KIM-1 Simulator debugger on the PC.
Set breakpoints and watches, trace the code, inspect memory, run the program.
When it is a TTY console program, I sue a terminal emulator, Teraterm.
2400 baud 8 bit, one stop bit, no parity, 5 ms character delay, 20 ms line delay for papertape upload.. Higher baudrates may work.

For CP/M there are many emulators available, choose one that allows file from the PC to be accessed also by the emulator. E.g. the Z80 IDE and CP.M emulator of Hein Pragt.
I only use the assembler and linker of the CC65 package. Mainly for KIM-1 KB9 Basic development, as the source from Pagetable is in this format.

This is how I do it (Windows, can be done also on Linux)

  1. Download and unpack the archive of pagetable in a folder on your PC.
  2. Download and unpack the CC65 package, a C compiler, from which only the assembler and linker is used. I used the Windows binary.
  3. Copy CA65.EXE, LD65.EXE and longbranch.mac from the CC65 package to the folder where you unpacked the MS Basic source.
  4. Change whatever you like in the source. It is quite a complicated construction, with macros for every variant, so look carefully at the listing file what really is produced.
    Start with no adaptations and then go on studying the listing file and testing. The KIM-1 Simulator is a good tool for testing! Load the symbol table file to see what is where.
  5. Assemble and link with this simple batch file makekb9v2.bat, resulting in an object, a binary, a listing file and a symbol label file.
    ca65 -D kb9 msbasic.s -o tmp/kb9v2.o -l tmp/kb9v2.lst
    ld65 -C kb9.cfg tmp/kb9v2.o -o tmp/kb9v2.bin -Ln tmp/kb9v2.lbl
  6. Repeat step 4 and 5 until you are satisfied with the adaptations. The article listed above are a good source of inspiration.

A tool to compare files, text and binary. Open the program, drop binary files from the explorer on it and see the differences highlighted. Essential to compare ROM dumps or to check if assembler source assembly leads to identical binary as the original. Detects subtle syntax differences from sources converted or disassembled, leading to different code.

Still searching for a good multiprocessor tool. With some intelligence, like input files not only binary, but also a symbol file and tips of what is data and what is code. Output should be in assembler format ready to assemble. A multipass operation, where you learn from each iteration symbols and data areas.

For 6502 code I use the online tool at Virtual Disassembler. Drop the binary and copy the code. Choose the output format, like “listing” or “assembler”. You can input a symbol file.