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Table of Contents
ISA Backplane
Introduction
About
ISA Backplane board was designed by Sergey Malinov (http://www.malinov.com/Home/sergeys-projects) and is designed to be used together with the Xi 8088 processor board, but it can be used with other ISA SBC boards. In addition to eight parallelly connected ISA slots this backplane includes an ATX power on/off circuit, a Port 80h POST display, a -5V regulator (most ATX power supplies don't supply -5V, but it can be required for some older ISA cards), serial port header, and a prototyping space.
Specifications
- 8 ISA Slots
- Micro ATX compatible form factor
- ATX power control circuit
- -5V regulator
- Port 80h POST diagnostic display
- 5 Power indicator LEDs (standby, 5V, -5V, 12V, -12V)
- Serial DE9M header
- Reset button and header
Hardware Documentation
Current Board Revision: Rev 1.1
Board: isa_blackplane-1.1-brd.pdf
Schematic: isa_backplane-1.1-sch.pdf
Manufacturing Files: isa_backplane-gerber-1.1.zip
KiCAD Files: isa_backplane-kicad-1.1.zip
Note: The only change between Rev 1.0 and Rev 1.1 was a slight re-positioning of the main ATX power connector. The Rev 1.0 files are archived here.
Build Information
Jumpers, Connectors, and Switches
Create a nice graphic of the jumpers/switches on this board!
It is recommended to solder wire bridges instead of J2 - J4 according to your 7-segment LED display and binary to 7-segment decoder type. Please refer to Bill of Materials section for displays' and decoders' selection.
Bill of Materials (BOM)
| Component Type | Reference | Description | Quantity | Possible sources and notes |
|---|---|---|---|---|
| PCB | ISA Backplane PCB Version 1.1 | 1 | Order from Todd Goodman, see RetroBrew Computers Board Inventory | |
| Capacitor | C1 - C51 | 10 uF ceramic, 5.08 mm lead spacing | 51 | Mouser 810-FK24X5R1C106K Note: Can be replaced with tantalum or electrolytic capacitors |
| Capacitor | C52 | 1 uF ceramic, 5.08 mm lead spacing | 1 | Mouser 810-FK24X7R1C105K Note: Can be replaced with tantalum or electrolytic capacitors |
| Capacitor | C53 - C59 | 0.1 uF ceramic, 5.08 mm lead spacing | 7 | Mouser 810-FK28X7R1H104K, 80-C323C104K5R Jameco 25523 |
| Connector | BUS1 - BUS8 | ISA Edge connector, 98 pin | 8 | Mouser 587-395-098-520-350 |
| Connector | J1 - J4 | 3×1 pin header | 4 | Mouser 649-69190-103HLF Jameco 109576 |
| Connector | P1, P2, P6, P7 | 2×1 pin header | 4 | Mouser Jameco 108338 |
| Connector | P3 | ATX power connector | 1 | Mouser 538-46015-2006 Jameco (was 365149) |
| Connector | P4 | 5×2 pin header | 1 | Mouser 649-68602-110HLF |
| Connector | P5 | DE9M, right angle PCB mount | 1 | Mouser 806-K22X-E9P-N, 571-7478404 Jameco 104943, 614441, 614459, 614432 |
| Diode | D6, D7 | 1N4148 | 2 | Mouser 512-1N4148 Jameco 36038, 179215 |
| LED | D1 - D5 | 5 mm LED | 5 | Mouser: Search for T-1 3/4 LED lamps Jameco 790225 (red, diffused), 107393 (orange, diffused), 697549 (yellow, diffused), 697531(green, diffused), 2006764 (blue, diffused) Note: Use different colors for a nicer look  |
| LED Display | S1 | 2 digit 7-segment LED display,0.56“ character height, 18 pin, 15.24 mm (0.6” between pin rows) | 1 | Mouser 604-DA56-51PBWA/A (common anode, blue, expensive), search for more options Jameco 2005366 (common cathode, green), search for more options Note: Pick either common cathode type or common anode type according to the decoder IC you're planning to use. |
| Resistor | R1, R2 | 10 kOhm, 1/4 W | 2 | Mouser 291-10K-RC Jameco 691104 |
| Resistor | R3, R4 | 1.5 kOhm, 1/4 W | 2 | Mouser 291-1.5K-RC |
| Resistor | R5, R6 | 1 kOhm, 1/4 W | 2 | Mouser 291-1K-RC |
| Resistor | R7 - R11 | 470 Ohm, 1/4 W | 5 | Mouser 291-470-RC Jameco 690785 |
| Resistor Array | RR1, RR2 | 470 Ohm, 16 pin DIP, isolated resistor array | 2 | Mouser: 652-4116R-1LF-470 Note: Can be replaced with 16 x 470 Ohm resistors |
| Trimmer Resistor | RV1 | 50 kOhm | 1 | Mouser: 652-3362P-1-503LF Note: This trimmer is only needed if using D346D or D347D decoders (U1, U2) |
| Switch | SW1,SW2 | 6mm Tactile Switch | 2 | Mouser: 653-B3F-1000 |
| IC | U1, U2 | 7 segment decoder | 2 | Note: Please refer to the table below for proper decoder/display configuration 74HCT4511/74HC4511 (common cathode): Mouser: 771-HCT4511N652, 595-CD74HCT4511EE4, 595-CD74HCT4511E, 771-74HC4511N, 595-CD74HC4511EE4, 595-CD74HC4511E Jameco: 822338 CD4511 (common cathode): Mouser: 595-CD4511BE, 595-CD4511BEE4 Jameco: 13493, 895377 74LS47 (common anode): Mouser 595-SN74LS47NE4, 595-SN74LS47N Jameco: 47790, 295582; Unicorn electronics 74LS247 (common anode, similar to 74LS47, but 6 and 9 with tails): Mouser: 595-SN74LS247NE4, 595-SN74LS247N; Jameco: 47247 74LS48 (common cathode): Jameco: 47811 DM9368 (common cathode): Intertex Electronics, or eBay D346D (common anode): Ask your European friend |
| IC | U3 | 74LS688 | 1 | Mouser: 595-CD74HCT688, 771-74HCT688N,595-SN74LS688N |
| IC | U4 | 74LS574 | 1 | Mouser: 595-SN74AHCT574N, 595-SN74ALS574BN, 595-SN74F574N |
| IC | U5 | 74HCT74 | 1 | Mouser: 595-SN74AHCT74NE4, 595-SN74AHCT74N, 771-74HCT74N, 595-SN74HCT74N, 595-SN74HCT74NE4, 595-CD74HCT74E, 863-MC74HCT74ANG |
| IC | U6 | 74LS32 | 1 | Mouser: 595-SN74AHCT32N, 595-SN74ALS32N |
| IC | U7 | 74HCT14 | 1 | Mouser: 595-SN74AHCT14NE4, 595-SN74AHCT14N, 595-SN74HCT14NE4, 771-74HCT14N, 595-SN74HCT14N, 511-M74HCT14,595-CD74HCT14E |
| IC | U8 | 7905 | 1 | Mouser: 512-LM7905CT Note: This IC is optional, and only required if you need -5V voltage, but your ATX power supply doesn't provide it. |
| IC Socket | U5, U6, U7 | 14 pin 300 mil DIP socket | 3 | Mouser 517-4814-3000-CP, 649-DILB14P-223TLF Jameco 37162 |
| IC Socket | U1, U2 | 16 pin 300 mil DIP socket | 2 | Mouser 517-4816-3000-CP, 649-DILB16P-223TLF Jameco 37373 |
| IC Socket | U3, U4 | 20 pin 300 mil DIP socket | 2 | Mouser 649-DILB20P-223TLF, 517-4820-3000-CP Jameco 112248 |
7-Segment Decoders and Matching Displays
The ISA Backplane board supports a variety of 7-segment decoders and common anode / common cathode type LED displays. Please use the following table to determine the proper configuration.
| 7-Segment Decoder Type | Hexadecimal Support | Matching Display Type | J2 | J3 | J4 | Built in current limiters1 |
|---|---|---|---|---|---|---|
| 74LS47, 74LS247 | Limited - Displays distinct figures for codes A-F | Common anode | 2-3 | 2-3 | 2-3 | No |
| 74LS48, 74LS248 | Limited - Displays distinct figures for codes A-F | Common cathode | 1-2 | 2-3 | 2-3 | No |
| CD4511, MC14511, 74HCT4511 | No - Displays nothing (blank) for codes A-F | Common cathode | 1-2 | 2-3 | 1-2 | No |
| Mitel MD4311BE | Yes | Common cathode | 1-2 | 2-3 | 1-2 | No |
| DM9368 | Yes | Common cathode | 1-2 | 1-2 | 2-3 | Yes |
| DM9370 | Yes | Common anode | 2-3 | 1-2 | 2-3 | No |
| DM9374 | Limited - Displays distinct figures for codes A-F | Common anode | 2-3 | 1-2 | 2-3 | Yes |
| D345D | Yes | Common anode | 2-3 | 1-2 | 2-3 | No |
| D346D | Yes | Common anode | 2-3 | Trim2 | 2-3 | Yes |
| D347D | Limited - Displays distinct figures for codes A-F | Common anode | 2-3 | 1-2 | 2-3 | No |
| D348D | Limited - Displays distinct figures for codes A-F | Common anode | 2-3 | Trim2 | 2-3 | Yes |
- No need for current limiting resistor arrays (RR1, RR2), two 470 Ohm resistors should be used to limit current for the decimal point segment.These resistors should be installed between pins 8 and 9 of RR1 and RR2.
- For decoders D346D and D348D the RV1 trimmer should be installed instead of the J3. This trimmer is used to adjust the intensity of the LED display.
Replacement Notes
- It is recommended to use CMOS parts (74HCT, 74AHCT) for U5 and U7
- Other logic can be from any TTL compatible series (74AHCT, 74HCT, 74LS, 74ALS, 74F).
Photo Gallery
File List
| Filename | Filesize | Last modified |
|---|---|---|
| isa_backplane-1.1-sch.pdf | 567.9 KiB | 2016/06/19 02:25 |
| isa_backplane-gerber-1.1.zip | 394.5 KiB | 2016/06/19 02:25 |
| isa_backplane-kicad-1.1.zip | 231.9 KiB | 2016/06/19 02:25 |
| isa_blackplane-1.1-brd.pdf | 1.8 MiB | 2016/06/19 02:25 |
| obsolete_isa_backplane-1.0.zip | 2.2 MiB | 2016/06/19 02:26 |
