SBC V2-004 Development

Updated design to include the following changes.

• Correction of reset circuit.
• Addition of speaker circuit.
• Add solder jumpers for bypassing DS1210.
• Move status LED to corner of board as per other ECB boards.
• Align serial connector pinout and functionality to SBC Z180 Mark IV
• Add max232 solder jumpers for TTL level output.
• Add onboard super capacitor.
• Incorporate ppide.
• Update to Kicad 5.
• Add jumper settings to silkscreen.
• Move reset switch to edge of board and remove reset jumper.
• Add jumpers to configure battery backup source.
• Add cpu clock divider to support MSX.
• Default to hard Kontron reset mode.
• Add User input button on UART Ring Indicator line (for recovery mode in ROMWBW)

Other ideas to be considered:

• RAM access over ECB-BUS.
• Renumber all parts.

Most recent Kicad files can be found here: https://github.com/b1ackmai1er/SBC-V2-004

Version V:

Version: R:

Sound circuit sourced from TRS-80 circuit:

CPU-Clock switching sourced from ZX-TURBO circuit: