This is the first run of boards for the G80-S Micro Computer. There were two minor issues with these boards: First is that the silkscreen is slightly oversized, causing an overlap on the top side of the board. Second is that SIO/DART IEI line was left disconnected, and will require a resistor to VCC if Z80 SIO/DART interrupts are desired. However, if interrupts from the SIO are not desired, then this is not a problem. Just a note, G-Monitor v0.25b does not use interrupts from the SIO/DART. These boards come with the resistors/capacitors when available. You might check availability before purchasing.
In order to move these boards, they have been discounted to $8.
NOTE: You will need to either have a programmer capable of programming the GAL22V10 PLD or you will need to purchase the option that includes the PLD. Without this PLD you will not be able to use this computer.
To build this board you will need the following components:
2 – MAX232
1 – GAL22V10 – Programmed with G80-S JEDEC File
1 – Z80 Microprocessor
1 – 28C256 EEPROM
1 – “Narrow” 32k SRAM (UM61256 or Equivalent)
1 – Z80 DART or Z80 SIO/0
1 – i8255 PIO
1 – 6x6x6mm Tactile Switch
2 – Male DB9 Sockets
1 – XO Oscillator of your frequency choice (Software designed for 6mhz)
1 – XO Oscillator 1.8432mhz
16 – 100nf Capacitors (0805 Footprint) *included while available*
5 – 10k Resistors (0805 Footprint) *included while available*
Optional (but recommended) Components:
3 – DIP-40 0.600″ Sockets
1 – DIP-28 0.600″ Socket
1 – DIP-28 0.300″ Socket
1 – DIP-24 0.300″ Socket
2 – DIP-16 0.300″ Sockets
1 – 40-Pin Header 2.54mm
1 – 26-Pin Header 2.54mm
1 – Computer Peripheral Power Supply Connector
1 – Resistor Between IEI and VCC: 10K Should work.