Hardware
This page exists to answer questions about what features exist in each version of BlueSCSI V2 hardware, and to call out hardware design decisions.
Features Removed:
- USB-C power port
- Micro SD slot
Design Decisions:
- The 2023.09a board revision was deemed too expensive to move forward with as a long term solution, due to increased production cost, so a few things were removed and changed for affordability reasons
- Moves Pico to the edge to use built-in micro USB port (Pi Foundation really needs to upgrade this to USB-C)
Features Added:
- Initiator Mode
- I2C connectivity
- Dual SD Slots, one Micro and one Full Size (Use only one at a time)
- USB-C power port onboard
Features Removed:
- Option Switch Jumpers (these have been basically unused)
Design Decisions:
- The termination switch chip was discontinued, changed to using LVTH245 plus a discrete mosfet switch. LVTH handles 8 lines of termination and the mosfet handles the last one (SCSI uses two banks of 9 signals, and most chips these days only do 8 or 16 bits at a time).
Features:
- External LED jumpers
- Onboard power and activity LEDs
- Option Switch Jumpers
- Switchable Termination
- Power Isolation Jumper (allows for USB power to the Pico without any draw from the host system)
- Term Power Back-Feed
- Single SD slot, Full Size
- SCSI Bus Reset Button
Design Decisions:
- Using Raspberry Pi Pico instead of embedding the RP2040
Features Added:
- PCB is now only as wide as the DB25 connector
Features Removed:
- S1 and S2 Option Switch Jumpers (these have been unused in the code)
Design Decisions:
- Some Macs have their DB25 port too close to the Display output or other things
- Make the whole thing narrower to try and stop collisions
- Micro SD slot moved further into the PCB, less of the card sticks out now
Features Added:
- About 30% shorter
Features Removed:
- Switchable Termination (termination is now always on)
- SCSI Bus Reset Button (using too much space)
Design Decisions:
- Many people commented that the prior DB25 was too long. This version removes some features, but decreases the length substantially.
Features:
- Switchable Termination
- Option Switch Jumpers
- Single Micro SD slot
- SCSI Bus Reset Button
Design Decisions:
- Kept switchable termination on this model to increase possible use cases
- Using Raspberry Pi Pico instead of embedding the RP2040
Features Added:
- I2C connectivity
Features Removed:
- Option Switch Jumpers (these have been basically unused)
- SCSI Bus Reset Button (impossible to get to inside a PowerBook)
Design Decisions:
- Updated to allow SMD-soldering the Pico directly onboard
- Termination switch chip was discontinued, same design decision as Desktop in that regard
Features:
- Onboard Power and Activity LEDs
- Solder pads for external LED
- Switchable Termination
- Option Switch Jumpers
- Single Micro SD slot
- SCSI Bus Reset Button
Design Decisions:
- Using Raspberry Pi Pico instead of embedding the RP2040
Features:
- Onboard Power and Activity LEDs
- Switchable Termination
- Option Switch Jumpers
- Single Micro SD slot
- SCSI Bus Reset Button
Design Decisions:
- Using Raspberry Pi Pico instead of embedding the RP2040
