EXDOS by pear
Contents
Brief information
It is a clone card EXDOS. Compact version designed by pear. It includes the Bus Bridge on-board.
Jumper J9 (PWR in version 2) near a power socket:
- Short: card and a EP powered with a common power supply connected to the card,
- Open: card and a computer powered with separate power supplies.
Do not connect the interface to the computer when the power is on !
The original Enterprises power supply does not have enough power to both the computer and the card !
If you want to use a single, common AC adapter should provide 9V voltage and current of about 3 - 4A. In the case of the power supply connected direct to the card's polarity can be any (the card has a diode bridge).
EXDOS v2.0 Compact
Refreshed the EXDOS project. It is more compact, more configurable and more compatible with newer floppy disk drives.
Futures
- power switch with two color LED,
- provides power for two drives (only +5V for 3,5" drives),
- two modes of connect floppy drives - XT or AT style,
- PC full compatible floppy drive connector,
- possibility of powering the Enterprise from one common power supply,
- possibility to change the order of A/B-B/A drives by jumpers,
- support for many types of memory chip.
Configuration
The chip 240B is optional. It is only needed in two situations:
- if you want to connect the original Enterprise drive,
- there are connect more than 2 floppy drives.
When connecting the original Enterprise drive and 5.25 "drives, an additional 12V power supply is required.
Modes of drives connection
XT | Up to 4 drives can be connected (straight tape, drive setup by jumpers) |
---|---|
AT | Two drives can be connected (interlaced tape, fixed DS1 drives) |
In both modes, for proper operation, DD or HD floppy drives with a DD/HD switch are required.
Some new HD drives aren't has a switch by factory and do not support DD disks.
A/B-B/A switch
AB | standard order DS0=A, DS1=B |
---|---|
BA | reverse order DS0=B, DS1=A |
240B jumpers
Use only in XT mode. Do not short them in AT mode !
Label | Purpose |
---|---|
DCR | Disk Change Reset used only with original EP drive |
InUse | used only with original EP drive |
Sel3 | select drive C |
Sel2 | select drive D |