CompactFlash IDE Daughterboard for MPU302

The IDE-CF daughterboard plugs into MPU302 to add additional drives to CP/M-68K. BIOS version MPUBIOS_v2 will detect the presence of the IDE-CF daughterboard automatically and assign four 8-megabyte drives, D: thru G:. Older version of MPU302 may not have the most recent BIOS, please refer to CPM BIOS Update section of MPU302 Software Updates for instruction on BIOS update.

photo above shows the major features of the CF IDE daughterboard. The CompactFlash connector and DIN41612 are keyed so they can be connected only one way. The 5V power to MPU302 and daughterboard is supplied via the 2.5mm power plug. The center lead is 5V while the barrel is ground. When the daughterboard is plugged into MPU302, 5V power must come in via the 2.5mm plug. This is because 5V is shorted to ground when the 2.5mm plug is not inserted. The 4-pin header and 5-pin header are for serial port and SPI port, respectively.

Schematic was created with IVEX WinDraft.

Gerber files. IVEX WinBoard is used to created the pc board. The boards were manufactured by Seeed Studio.

Part list

DIN41612 connector definition.

Above is a high-resolution bare pc board for reference

1. Solder C7, the 10uF SMT capacitor. The end marked with black line should align with the taper end (marked with '+') of the silkscreen.
2. Solder resistor R1, R2. Both are 4.7K 1/8W resistor.
3. Solder U2, 74AHC00 or 74HC00.
4. Solder C1-C4, bypass capacitors
5. Solder P1, the 44-pin CF adapter. Lay the adapter flat in the same plane as the pc board with pins centered on the pads. Solder just one pad, inspect the alignment and make adjustment as needed. Solder rest of the pads, top and bottom.
6. Solder U1, the DIN41612 connector. Rotate the connector so the polarized tabs line up with the silk screen. Click on the inset photo for detailed reference. Solder just one pin, inspect the connector for proper seating and perpendicular to the board before complete the soldering.
7. Solder J1, the 2.5mm power jack. The power jack fits rather loosely so solder just one terminal, inspect for proper alignment before complete the soldering.
8. Solder the 4-pin header strip and the 5-pin header strip.

Completed board