Amigo

Amigo - Amiga 1000, in Verilog 2001, from schematic

Copyright 2010, Jason S. McMullan

The aim of the Amigo is to create a schematic-level capture of the digital components of the Commodore Amiga 1000.

My personal reason for this project is to have a functional Verilog simulation that can be used to:

• Validate emulators
• Convert into FPGA (a la Minimig)
• Assist in debugging old Amiga hardware
• Regenerate the Amiga 1000 schematic from Verilog

The last point seems to be the most important for me. All of the Amiga 1000 schematics I have been able to obtain online are very blurry, almost to the point of unreadability.

My hope is that the 'Amigo' will be able to be used to generate a faithful and readable schematic one day.

• Jason S. McMullan

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Progress so far:

• Selectable Wishbone cores for emulating the Motorola 68000

  • ao68000 (from OpenCores)

    • True Motorola 68000 emulation, but Icarus Verilog 0.9 appears to hate it.

  • ucore (from OpenCores)

    • MIPS32 core, which I am using for debugging under Icarus.

  • Any other Wishbone complaint 32-bit CPU core should be pluggable, via the 'Motorola_16_to_w32.v' module and a small amount of glue logic for interrupts.

• Amiga 1000 Daughterboard logic appears to be complete

  • $E00000 mirror of $F80000 does not exist, could be due to erroneous PAL logic. Will verify against my reference hardware.

Things to do:

• Create wrappers for Minimig's OCS cores (Paula, Agnus, Denise), to leverage the Minimig work for Amigo.

• Decide upon (for REAL!) whether to make the first pass of the Amigo 1000 a Rev A or a Rev C machine.

  • This affects mostly the part numbering (ie U6U or U6S for the M68000, etc).
  • It is most likely I will be doing a Rev A, as that appears to be what I have as my reference hardware.

• Finish out the Amigo capture, including pullup resistors, ferrite beads, etc.

• Decide what to do about the analog components (ie RGB to NTSC conversion circuity). Icarus Verlog doesn't (as of 0.9.x) support Verilog-AMS, so I may have to put that off.