8-bit ISA interface for Compact Flash cards
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).
| SW1.1 | SW1.2 | SW1.3 | I/O Address |
|---|---|---|---|
| ON | ON | ON | 0x300 |
| ON | ON | OFF | 0x320 |
| ON | OFF | OFF | 0x360 |
| OFF | ON | ON | 0x380 |
| OFF | ON | OFF | 0x3A0 |
| OFF | OFF | ON | 0x3C0 |
| OFF | OFF | OFF | 0x3E0 |
| SW2.1 | EEPROM Enable |
|---|---|
| OFF | EEPROM disabled |
| ON | EEPROM enabled |
| SW2.2 | EEPROM Write Enable |
|---|---|
| OFF | EEPROM write disabled |
| ON | EEPROM write enabled |
| 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 |
Notes:
- 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
| Component Type | Reference | Description | Quantity | Possible Sources and Notes |
|---|---|---|---|---|
| PCB | XT-CF-Lite V4 PCB | 1 | Todd Goodman or your favorite PCB manufacturer | |
| 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-CD74HCT688E, 771-74HCT688N, 595-SN74LS688N, 595-SN74LS688NE4 |
| IC | U4 | 74LS32 quad 2-input OR gate | 1 | Mouser 595-SN74ALS32N, 512-DM74ALS32N, 595-SN74AHCT32N |
| IC | U5 | 74LS04 hex inverters | 1 | Mouser 595-SN74ALS04BNE4, 595-SN74ALS04BN, 595-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 |