PDP-8 mSeries Tester wrs 2013_09_20 Parallel Port Pin Name Tester Usage 1 C0- Control 0 SPARE_PIN_1 2 D0+ Data 0 RESET_N 3 D1+ Data 1 CS_N 4 D2+ Data 2 SCK 5 D3+ Data 3 chip A SI 6 D4+ Data 4 chip B SI 7 D5+ Data 5 chip C SI 8 D6+ Data 6 chip D SI 9 D7+ Data 7 chip E SI 10 S6+ -Ack chip D S0 11 S7- +Busy chip E SO 12 S5+ +PaperEnd chip C SO 13 S4+ +SelectIn chip B SO 14 C1- -AutoFd SPARE_PIN_14 15 S3+ -Error chip A SO 16 C2+ -Init SPARE_PIN_16 17 C3- -Select SPARE_PIN_17 18 thru 25 ground In register order: Parallel Port Pin Name Tester Usage 1 C0- Control 0 SPARE_PIN_1 14 C1- -AutoFd SPARE_PIN_14 16 C2+ -Init SPARE_PIN_16 17 C3- -Select SPARE_PIN_17 2 D0+ Data 0 RESET_N 3 D1+ Data 1 CS_N 4 D2+ Data 2 SCK 5 D3+ Data 3 chip A SI 6 D4+ Data 4 chip B SI 7 D5+ Data 5 chip C SI 8 D6+ Data 6 chip D SI 9 D7+ Data 7 chip E SI 15 S3+ -Error chip A SO 13 S4+ +SelectIn chip B SO 12 S5+ +PaperEnd chip C SO 10 S6+ -Ack chip D SO 11 S7- +Busy chip E SO Wiring for Microchip MCP23S17 16-bit GPIO expander Pin Name Usage Chip A Chip B Chip C Chip D Chip E 1 GPBO I/O pin 2 GPB1 I/O pin 3 GPB2 I/O pin 4 GPB3 I/O pin 5 GPB4 I/O pin 6 GPB5 I/O pin 7 GPB6 I/O pin 8 GPB7 I/O pin 9 VDD 3.7v 10 VSS Ground 11 CS-N PPort D1+ 12 SCK PPort D2+ 13 SI PPort D3+ D4+ D5+ D6+ D7- 14 SO PPort S3+ S4+ S5+ S6+ S7+ 15 A0 PPort D0+ 16 A1 PPort D0+ 17 A2 PPort D0+ 18 RESET-N PPort D0+ 19 INTB n.c. 20 INTA n.c. 21 GPA0 I/O pin 22 GPA1 I/O pin 23 GPA2 I/O pin 24 GPA3 I/O pin 25 GPA4 I/O pin 26 GPA5 I/O pin 27 GPA6 I/O pin 28 GPA7 I/O pin last line.