CW2DMK, MxZVM, and Bill Vermillion

Z-80 Replacement for the Model III

Ted over at Microcore Labs has been developing a modern Z-80, which he calls MCLZ8, which can plug directly into a Model III.

MCLZ8, is a Zilog Z80 emulator which can be used as a drop-in replacement for the original Z80. It uses a Teensy 4.1 microcontroller board which contains an 800Mhz microcontroller and a small PCB to perform the voltage translation between the motherboard and the microcontroller. The MCLZ8’s Z80 emulation passes the exhaustive ZEXALL opcode test suite and the speedy microcontroller allows the ability to simultaneously mimic the Z80’s local bus interface.

You can read about his project here.

Some videos of the MCLZ8 in action are here.

Catweasel Tools Updated to v4.9

Quentin Barnes has released v4.9 of the Catweasel Tools originally written by Tim Mann. Many updates to this version were written by Tim!


  • The main new feature of this release is the -R option for cw2dmk. It provides the ability to replay a previously saved log as input to cw2dmk rather than reading from physical media. This will allow users of cw2dmk to pass along strange or unexpected media read behaviors to the maintainers as files without having to mail diskettes.
  • Catch errors when writing to files. Report and exit when errors are seen.
  • Add -X min_retry feature to cw2dmk, accepting the same syntax for min_retry as for -x max_retry.
  • Add QUIRK_IAM to -q option in cw2dmk.
  • Add QUIRK_EXTRA_DATA to -q option in cw2dmk.
  • Various minor cleanup of code and the cw2dmk usage message.

You can download from Github..

TRS80GP v2.4.7 Released

TRS80GP has been updated to v2.4.7. Release Notes:

New Features:

  • Orchestra-90 support (No stereo; mixed to MONO).
  • Added menu entry to unload symbols from previous .bds file/symbol loads.

New Command Line Options:

  • -haste option faster than turbo but graphics emulation compromized.


  • FDC 0xd8 command modified so SuperUtilty boots with Percom doubler.
  • Add slight jitter on Model III disk emulation to handle problems with perfect 200ms rotations colliding with 60Hz interrupt.
  • Improved display of IDAM and DAM CRC errors in disk image debug tools.

Visit the TRS80GP Web Page for the download and information, or here for the emulator.