XT-CF-Lite V4

Description

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).

Picture

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

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

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-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