Build Instructions

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• 1

  Wiring The circuit

  Following Grants schematic wiring up the circuit. Remember check the pinout of the chips you are using as they may be in different places to Grant's - his EEPROM is a 27cxxx type which has a slightly different pinout to the 28cxxx EEPROM I used. 

  If you are using an oscillator can package you can forget the whole clock circuit on Grants schematic and just add power and ground to the can and then the output clock signal wired to the z80 and 68b50. instead of the inverter output.

  Because we are using USB we can forgo the use of the max chip and wire the adapter as Grant suggests in the schematic.

• 2

  Burn the EEPROM

  Burn the 32krom file that Grant provides as a download. Using a programmer - I have had success with TommyPROM https://github.com/TomNisbet/TommyPROM as well as the new version of the tl866ii+ programmer.

• 3

  Connect USB to the serial adapter

  Open you terminal program and use the setting that Grant uses except you will need to change the baud rate to match your speed. using a 8mhz clock will need a baud ratee of around 125000. Press the reset button and you should see the welcome message.

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