I wanted build a simple and elegant way to switch between the different character ROM sets, and the different monitor ROMs that are available for the MZ-80K.

There are 3 character ROM images available:

1. •80K_ENG_CG.ROM
   

2. •80K_ENG(fixed)_CG.ROM
   (a version that I fixed some small issues)
   

• 80K_JPN_CG.ROM

  (which I copied from my Japanese MZ-80K2E
   and have made available on my FTP site)

and 3 monitor ROM versions available:

• MZ80_MON_STD.ROM

• MZ80_MON_NEW.ROM

• MZ80_MON_V44.ROM

I burnt all the character ROM images to a single 27128 EPROM, and did the same for the monitor ROM images. Using two of Jim Brain’s 2364 adaptors wired to two 16 position rotary switch I now have a simple multi PROM system that allows me to easily switch between ROM images at will.

The extra long wires allow me to have the dual rotary switches outside the case for easy access.

neoncluster.com