DECISION COMPUTER INTERNATIONAL CO., LTD. 8255/8254 LAB CARD Card Type Data acquisition Chip Set NEC 8255 I/O Options Digital I/O ports (2) Data Bus 8-bit ISA [Image] CONNECTIONS Function Label Function Label Breadboard (see pinout BB1 Unidentified CN3 below) Digital I/O port 1 CN1 Unidentified CN4 (see pinout below) Digital I/O port 2 CN2 (see pinout below) BB1 PINOUT Function Row Function Row Channel 1A bit 7 1 Channel 1C bit 6 21 Channel 1A bit 6 2 Channel 1C bit 5 22 Channel 1A bit 5 3 Channel 1C bit 4 23 Channel 1A bit 4 4 Channel 1C bit 3 24 Channel 1A bit 3 5 Channel 1C bit 2 25 Channel 1A bit 2 6 Channel 1C bit 1 26 Channel 1A bit 1 7 Channel 1C bit 0 27 Channel 1A bit 0 8 Not used 28 Not used 9 Channel 1B bit 7 29 Clock signal 0 in 10 Channel 1B bit 6 30 Clock signal 1 in 11 Channel 1B bit 5 31 Clock signal 2 in 12 Channel 1B bit 4 32 Gate signal 0 13 Channel 1B bit 3 33 Gate signal 1 14 Channel 1B bit 2 34 Gate signal 2 15 Channel 1B bit 1 35 Clock signal 0 out 16 Channel 1B bit 0 36 Clock signal 1 out 17 Not used 37 Clock signal 2 out 18 I/O write register 38 Not used 19 I/O read register 39 Channel 1C bit 7 20 Note:The breadboard is designed to prototype designs. All holes in a given row are electrically connected. Rows marked not used may be utilized by the designer for extra connections. CN1 PINOUT Function Pin Function Pin Ground 1 Channel 1C bit 6 21 Ground 2 Channel 1C bit 7 22 Ground 3 Channel 1C bit 4 23 Channel 1A bit 3 4 Channel 1C bit 5 24 Channel 1A bit 1 5 Channel 1C bit 1 25 Channel 1A bit 2 6 Channel 1C bit 0 26 Clock signal 0 in 7 Channel 1B bit 7 27 Channel 1A bit 0 8 Channel 1C bit 2 28 Gate signal 0 9 Channel 1B bit 6 29 Clock signal 0 out 10 Channel 1C bit 3 30 Clock signal 2 out 11 Channel 1B bit 5 31 Clock signal 2 in 12 Channel 1B bit 0 32 Clock signal 1 in 13 Channel 1B bit 4 33 Gate signal 2 14 Channel 1B bit 1 34 Clock signal 1 out 15 Channel 1B bit 3 35 Gate signal 1 16 Channel 1B bit 2 36 Channel 1A bit 5 17 +5V power 37 Channel 1A bit 4 18 -5V power 38 Channel 1A bit 7 19 +12V power 39 Channel 1A bit 6 20 -12V power 40 CN2 PINOUT Function Pin Function Pin Ground 1 Channel 2C bit 7 21 Ground 2 Channel 2C bit 6 22 Ground 3 Channel 2C bit 5 23 Ground 4 Channel 2C bit 4 24 Ground 5 Channel 2C bit 0 25 Ground 6 Channel 2C bit 1 26 Ground 7 Channel 2C bit 2 27 Ground 8 Channel 2B bit 7 28 Ground 9 Channel 2C bit 3 29 Ground 10 Channel 2B bit 6 30 Ground 11 Channel 2B bit 0 31 Ground 12 Channel 2B bit 5 32 Channel 2A bit 0 13 Channel 2B bit 1 33 Channel 2A bit 1 14 Channel 2B bit 4 34 Channel 2A bit 2 15 Channel 2B bit 2 35 Channel 2A bit 3 16 Channel 2B bit 3 36 Channel 2A bit 4 17 +5V power 37 Channel 2A bit 5 18 -5V power 38 Channel 2A bit 6 19 +12V power 39 Channel 2A bit 7 20 -12V power 40 USER CONFIGURABLE SETTINGS Setting Label Position » Counter 0 uses internal clock source JP1/A Closed Counter 0 uses external clock source JP1/A Open » Counter 1 uses internal clock source JP1/B Closed Counter 1 uses external clock source JP1/B Open » Counter 2 uses internal clock source JP1/C Closed Counter 2 uses external clock source JP1/C Open BASE I/O ADDRESS Setting JP2/A JP2/B JP2/C JP2/D JP2/E JP2/F 000h Closed Closed Closed Closed Closed Closed 010h Closed Closed Closed Closed Closed Open 020h Closed Closed Closed Closed Open Closed 030h Closed Closed Closed Closed Open Open 040h Closed Closed Closed Open Closed Closed » 2A0h Open Closed Open Closed Open Closed 3B0h Open Open Open Closed Open Open 3C0h Open Open Open Open Closed Closed 3D0h Open Open Open Open Closed Open 3E0h Open Open Open Open Open Closed 3F0h Open Open Open Open Open Open Note: A total of 64 base address settings are available. The jumpers are a binary representation of the decimal memory addresses. JP2/A is the Most Significant Bit and jumper JP2/F is the Least Significant Bit. The jumpers have the following decimal values: JP2/A=512, JP2/B=256, JP2/C=128, JP2/D=64, JP2/E=32, JP2/E=16. Open the jumpers and add the values of the jumpers that are open to obtain the correct memory address. (Open=1, Closed=0) WAIT STATES Setting JP3/A JP3/B JP3/C 0 Closed Open Open 1 Open Closed Open 2 Open Open Closed DIAGNOSTIC LED(S) The function of the LED is unidentified.