XT-CF-Lite V4


XT-CF-Lite V4 is a remake of James Pearce's XT-CF-Lite card, which in its turn is a simplified version of his CPLD based XT-CF card, and shares some ideas with XT-IDE card. This card allows connecting a Compact Flash (CF) card to computers with ISA bus and using it as a mass storage device. The card also supports BIOS extension ROM.
The main difference from the original XF-CF-Lite is using through hole components except of CF connector. Other differences are:
  • 8 KiB EEPROM (28C64) or 8 KiB EPROM (27C64) instead of a flash ROM.
  • Slightly different activity LED circuit (saves one IC).


DIP Switches Settings

SW1 - I/O Address Selection

 SW1.1  SW1.2  SW1.3  I/O Address
 ON  ON  ON  0x300
 ON  ON  OFF  0x320
 ON  OFF  ON  0x340
 ON  OFF  OFF  0x360
 OFF  ON  ON  0x380
 OFF  ON  OFF  0x3A0
 OFF  OFF  ON  0x3C0
 OFF  OFF  OFF  0x3E0

SW1.4 - Not Used

SW2.1 - EEPROM Enable

 SW2.1  EEPROM Enable
 OFF  EEPROM disabled
 ON  EEPROM enabled

SW2.2 - EEPROM Write Enable

 SW2.2  EEPROM Write Enable
 OFF  EEPROM write disabled
 ON  EEPROM write enabled

SW2.3 - SW2.7 - EEPROM Address Selection

 SW2.3  SW2.4  SW2.5  SW2.6  SW2.7  EEPROM Address
 ON  ON  ON  ON  ON  0xC0000
 ON  ON  ON  ON  OFF  0xC2000
 ON  ON  ON  OFF  ON  0xC4000
 ON  ON  ON  OFF  OFF  0xC6000
 ON  ON  OFF  ON  ON  0xC8000
 ON  ON  OFF  ON  OFF  0xCA000
 ON  ON  OFF  OFF  ON  0xCC000
 ON  ON  OFF  OFF  OFF  0xCE000
 ON  OFF  ON  ON  ON  0xD0000
 ON  OFF  ON  ON  OFF  0xD2000
 ON  OFF  ON  OFF  ON  0xD4000
 ON  OFF  ON  OFF  OFF  0xD6000
 ON  OFF  OFF  ON  ON  0xD8000
 ON  OFF  OFF  ON  OFF  0xDA000
 ON  OFF  OFF  OFF  ON  0xDC000
 ON  OFF  OFF  OFF  OFF  0xDE000
 OFF  ON  ON  ON  ON  0xE0000
 OFF  ON  ON  ON  OFF  0xE2000
 OFF  ON  ON  OFF  ON  0xE4000
 OFF  ON  ON  OFF  OFF  0xE6000
 OFF  ON  OFF  ON  ON  0xE8000
 OFF  ON  OFF  ON  OFF  0xEA000
 OFF  ON  OFF  OFF  ON  0xEC000
 OFF  ON  OFF  OFF  OFF  0xEE000
 OFF  OFF  ON  ON  ON  0xF0000
 OFF  OFF  ON  ON  OFF  0xF2000
 OFF  OFF  ON  OFF  ON  0xF4000


  • Make sure that selected I/O and EEPROM addresses do not conflict with other devices
  • Addresses 0xC0000 - 0xC6000 will conflict with EGA/VGA BIOS extension
  • Addresses 0xC8000 - 0xCA000 might conflict with XT Hard Disk BIOS extension
  • Addresses 0xE0000 and up might conflict with system BIOS on newer motherboards
  • It is recommended to disable EEPROM write once XT IDE BIOS extension is programmed and configured

SW2.8 - Not used

Bill of Materials (BOM)

 Component Type  Reference  Description  Quantity  Possible Sources and Notes
 PCB    XT-CF-Lite V4 PCB  1  Order from Sergey or make your own
 Capacitor  C1 - C6  0.1 uF ceramic, 5.08 mm lead spacing  6  Mouser 810-FK28X7R1H104K
 Capacitor  C7 - C8  10 uF ceramic, 5.08 mm lead spacing  2  Mouser 810-FK24X5R1C106K
 Note: Can be replaced with tantalum or electrolytic capacitors
 LED  D1  3 mm (T-1) LED indicator  1  Mouser 604-WP3A8GD
 Connector  P1  Compact Flash Card connector  1  Mouser 517-N7E50-Q516RB-40
 Connector  P2  2x1 pin header  1  Mouser 649-78229-102HLF
 Resistor  R1  330 Ohm, 1/4 W  1  Mouser 291-330-RC
 Resistor  R2  470 Ohm, 1/4 W  1  Mouser 291-470-RC
 Resistor  R3  1 kOhm, 1/4 W  1  Mouser 291-1K-RC
 Resistor  R4  5.6 kOhm, 1/4 W  1  Mouser 291-5.6K-RC
 Resistor  R5  10 kOhm, 1/4 W  0  Note: Do not install
 Resistor Array  RR1  10 kOhm, 6 pin, bussed resistor array  1  Mouser 264-10K-RC
 Resistor Array  RR2  10 kOhm, 10 pin, bussed resistor array  1  Mouser 266-10K-RC
 Switch  SW1  4 positions DIP switch  1  Mouser 506-54356402
 Switch  SW2  8 positions DIP switch  1  Mouser 571-54356405
 IC  U1  28C64 EEPROM or 27C64 UV erasable EPROM  1  Mouser 556-AT28C64B15PU
 Note: Atmel AT28C64B is the recommended part
 IC  U2, U3  74LS688 magnitude comparator  2  Mouser 595-CD74HCT688E771-74HCT688N595-SN74LS688N595-SN74LS688NE4
 IC  U4  74LS32 quad 2-input OR gate  1  Mouser 595-SN74ALS32N512-DM74ALS32N595-SN74AHCT32N
 IC  U5  74LS04 hex inverters  1  Mouser 595-SN74ALS04BNE4595-SN74ALS04BN595-SN74AHCT04NE4
 IC Socket  U1  28 pin 600 mil (wide) DIP socket  1  Mouser 517-4828-6000-CP
 Note: U4 socket is only required for BIOS extension ROM function
 IC Socket  U2, U3  20 pin 300 mil (narrow) DIP socket  2  Mouser 517-4820-3000-CP
 IC Socket  U4, U5  14 pin 300 mil DIP socket  2  Mouser 517-4814-3000-CP
 Bracket    ISA card bracket - Keystone 9202  1  Mouser 534-9202
 Screw    Screw, 4-40 thread, 1/4" length  2  Mouser 534-9900