Lt. Kernal Hard Drive System
Specific System Requirements – Lt. Kernal HD
Lt. Kernal Hard Drive
The Xetec Lt. Kernal Hard Drive system is well suited for running Color 64. It supports up to nine Logical Units (LUs), each containing fifteen “users” that function similarly to subdirectories. This structure allows for as many as 135 distinct storage areas.
Color 64 cannot use Lt. Kernal and RAMDOS simultaneously if an REU is installed alongside the hard drive.
Hardware Requirements
When operating on a Commodore 64, the HIRAM connector must be properly installed as described in the Lt. Kernal documentation. Without the HIRAM connection, the system will not function correctly.
If you are using a Commodore 128 in 64 mode, the ribbon cable connecting the computer to the Host Adapter automatically handles the HIRAM signal.
Run the CONFIGURE utility and verify that the NMI TRAP setting is disabled (set to 0) for Commodore 64 mode. If NMI TRAP is not set to 0, callers may experience line noise during modem communication.
In the BOOTMAKER program, ensure that you answer “Y” to the Lt. Kernal configuration prompt. Failure to do so may result in garbled modem communication.
Accessing Logical Units
Color 64 accesses Lt. Kernal storage using the “ldlu” and “i” drive commands.
The syntax for the ldlu command is:
l<device><LU><USER>
Example: To access LU 2, USER 5 on device 8: l825
For users 10 through 15, hexadecimal values A through F are used.
Example: LU 3, USER 11 on device 8: l83b
For LUs 2 through 9, you must also include an initialization command in SETUP.
Example: To initialize LU 3: i3
When combined: l83b!i3
Separate individual disk commands with an exclamation point (!).
Faster Disk Access
If your Lt. Kernal uses DOS version 7.1 or later, faster disk access can be achieved by merging optional enhancement routines into specific overlays. These merges are not required for normal operation.
Merge the following files:
- lkf.init → √bbs.init
- lkf.msgs → √bbs.msgs
- lkf.xfer → √bbs.xfer
- lkf.ovl → √bbs.ovl
- lkf.nw1 → √bbs.nw1
- lkf.nw2 → √bbs.nw2
These routines replace the standard free blocks routine with a custom Lt. Kernal command. They assume the Lt. Kernal is configured as device 8.
The “lkf” merges are intended only for systems running Lt. Kernal DOS 7.1 or later.