What Does It Do?
The Lo-tech XT-CF-lite rev.2 is a bootable storage adapter for IBM PC, PC/XT, PC/AT and compatible hardware - the board acts as a fixed disk controller, able to replace an aging MFM hard drive and controller. Thanks to the XTIDE Universal BIOS, the device can provide the maximum 8GB storage that is accessible by MS-DOS from a single storage media card (either CompactFlash or Microdrive).
Can SD Cards be used?
CompactFlash to SD card adapters that support 8-bit transfer mode should work. This has not however been tested.
Can I Solder Surface Mount Components At Home?
Yes, you'll need:
- A temperature controlled soldering iron
- Fine multi-core solder (0.5 or 0.7mm)
- Quality syringe flux (like Edyson FL22)
- Desoldering Braid (to remove excess solder)
- Isopropyl Alcohol (to clean off flux residues)
A suggested soldering order is:
- Resistor networks RN1 and RN2
- CompactFlash header
- SMT ICs (note IC orientation; the bevelled edge is indicated on the silk-screen)
- Capacitors C1-C7
- IC socket (note orientation; the notch is printed on the silkscreen)
- 8-pin header JP1
- Capacitor C8
The board should be cleaned before capacitor C8 is fitted.
BIOS, Flashing and Reflashing
Is an EEPROM Programmer Needed?
No, the board ROM can be flashed in the host system from DOS using the Lo-tech XT-CF flash utility.
What BIOS does the Card Use?
The card uses the XTIDE Universal BIOS, from R566. The same BIOS configuration options are needed as for the Lo-tech ISA CompactFlash Adapter, except that the XT-CF-lite rev.2 can be set to either 300h or 320h.
- BIOS type should be set to 'XT-CF' (8088/8086 CPU) or 'XT-CF (BIU)' (V20/V30/286 CPU)
- Card IO Port should be set in the BIOS to 300h or 320h, matching the configuration set on the card at JP1
- The BIOS base address option (C800h or D800h) can be changed via JP1 without re-flashing the BIOS
- Pre-configured XTIDE Universal BIOS R566 Binary File for Lo-tech ISA CompactFlash Adapter
- This is the 'standard' 8KB BIOS image, and should be used in most installations.
- There is 24KB free, meaning additional option ROMs (for other devices) can also be hosted in the ISA CompactFlash Adapter
- To add other ROM images, append the required binaries using MS-DOS "COPY /B" command, then write the entire file using the Lo-tech XT-CF flash utility
- Pre-configured BIOS based on R566 (FFh padded with BIOS at CC00h) Binary File for Lo-tech ISA CompactFlash Adapter
- This is a 24KB ROM image, with the first 16KB padded with bytes of FFh.
- This image enables the use of the adapter in machines that are hard-wired to have 8- or 16KB at C800h provided by a ROM on the system board, and as such cannot have this ROM address provided by a device in an expansion slot.
- Machines needing this version include the Tandy 1000 RL/HD
If building from source, run XTIDECFG.COM to configure the IDE_XT.BIN file, select controller XT-CF and 300h, then save the file. Then exit to DOS and use FLASH to write it to the card (see below).
How is the BIOS Programmed?
The BIOS cannot be programmed with the XT-IDE Universal BIOS XTIDECFG utility; instead the Lo-tech XT-CF flash utility should be used once the BIOS image file has been configured and saved (to disk) using XTIDECFG.
Can the Board be Re-Programmed, i.e. BIOS Upgraded?
Yes, the specified flash ROM chips can be re-programmed around 1,000 times.
First BIOS Flash Attempt Fails
- Check the ROM enabled jumper on JP1 is fitted.
- Check the soldering and orientation of IC2 and IC6
BIOS Re-flashing Fails
In some systems, the first flash is performed successfully but further flashing fails. This is typically caused by BIOS ROM shadowing, which later machines used to run ROM code from fast RAM instead of slower ROM chips. This can be resolved by either disabling ROM shadowing in the BIOS, if the option is provided, or by JP1:
- Remove JP1 ROM enable (position 3), then power on the machine
- Once completely booted, install a jumper on JP1 position 3 (with the machine running). The jumper connects the ROM-CS signal generated by one of the '688's; the signal is isolated from the host system and therefore this cannot damage the host.
- Next run the flash utility, and the flash should be successfully programmed.
- Machine hangs during POST or won't POST with the adapter installed
- BIOS cannot be flashed onto card, or flashing causes system lockup or hang
- BIOS flashing was successful, but the XTIDE Universal BIOS never appears in the POST
For these issues:
- Check the soldering, especially for shorts around the CompactFlash header. Some pins appear shorted when soldered due to the solder mask - see high-resolution photo
- Some machines, such as the IBM PS/2 Model 30-286, are not compatible with the CARDSEL/ZWS signal generated by IC3
- Remove IC3 (for example using a hot-air rework tool). Note that activity LED will also be disabled.
- If the XTIDE Universal BIOS never appears during the POST:
- try alternate BIOS images:
- ensure that the system ROM is scanning for option ROMs (original IBM PC 5150 and original Tandy 1000 ROM do not scan for option ROMs, for example)
- ensure selected BIOS location is is available (and toggle JP1 position 1 to change the address)
CompactFlash Cards are Not Detected
- Check the soldering and orientation of the ICs and CompactFlash header
- Try a different CompactFlash card. A small number of cards do not correctly support 8-bit transfer mode.
SD Cards are Not Detected
Use of CompactFlash to SD cards has not been tested and is therefore not supported. Some adapters may however work.
MicroDrive Performance is Sluggish
Seagate ST1 microdrives sleep after 2 seconds of inactivity. Therefore, there is a brief pause whenever the media is accessed.
The Machine Hangs at 'Booting C'
This occurs because the boot sector written by the CompactFlash card manufacturer is not compatible with 8088 CPU in most cases. This can be resolved in one of two ways:
Wipe the boot sector using the Lo-tech WIPEDISK utility and then start over - boot from a floppy (press A when the XTIDE Universal BIOS message appears) then run FDISK to create a primary and active partition, then reboot again from a floppy and run FORMAT /S to copy on the DOS files. Note that this method will completely erase all data on the device.
If using MS-DOS 6.22, boot from a floppy (press A when the XTIDE Universal BIOS message appears) then run FDISK /MBR. This will re-write the executable boot-sector code, leaving the partition table and partition data intact.