Invisible Software

Invisible LAN Boot ROMs


A boot ROM lets you set up a diskless workstation on the network. By installing a boot ROM in the network board, you can make your computer load DOS from a network file server, instead of a local disk drive.

We are making available boot ROM images that work with many NE-1000 or NE-2000 compatible Ethernet boards. This is the first time Invisible Software has ever released boot ROMs for use with boards manufactured by other companies. Of course, these boot ROMs will also work with NE-1000 and NE-2000 compatible boards manufactured by Invisible Software.

Note: As a practical matter, boot ROMs only support DOS. It is possible, but usually not practical, to run Windows 3.X on a diskless workstation. It is not possible to run Windows 95 on a diskless workstation.

Ethernet Board Requirements

Your Ethernet board must meet the following requirements to use a boot ROM:

Caution: Even if your board meets all the above requirements, it is still possible that it won't work with our boot ROM. This is because of variations in the design of different boards and controller chips.

Boot ROM Image Files

Download the appropriate boot ROM image file, as indicated in the following table.

File Description
Boot ROM image file for NE-1000 compatible Ethernet boards.
Boot ROM image file for NE-2000 compatible Ethernet boards.

When you unzip the file, you will find a ROM image file that is exactly 16K bytes in size. The ROM image file contains a byte-for-byte binary image of the 16K EPROM chip.


You need one of the following two types of EPROM chip: 27128 or 27C128. Each of these chips is organized as 16K by 8 bits. (That is, the chip holds 16K bytes of data.)

Programming the EPROMs

To program the EPROMs, you need a special device called an "EPROM programmer". The function of the EPROM programmer is to transfer the contents of the ROM image file into the EPROM chip.

You must have a programmer that is capable of reading binary image files. Sorry, but we cannot provide our boot ROMs in any other file format.

Warning: There are two different types of EPROM chips. Some are programmed at 12.5 volts, while others are programmed at 21 volts. You must know which type of EPROM chip you have, and you must set your programmer to use the correct voltage. If you program at an incorrect voltage, the EPROM chip may be physically damaged.

Testing the Boot ROM

After programming your EPROM, plug it into the network board. Make sure that you align the notch on the EPROM chip with the notch on the socket.

When you start your computer, you should see the message "Invisible Network" on your screen for a few seconds. Then, you should see a second message with the board's I/O address, IRQ level, and serial number.

Assuming that the boot ROM starts up OK, try running the NETDIAG program. This will verify that the boot ROM is able to communicate on the network.

Finally, if NETDIAG runs OK, try loading the Invisible LAN operating system, and then try accessing some files on a server.

Software Documentation

For instructions on setting up the Invisible LAN software to support diskless workstations, go to our On-Line Manuals section and get the "Invisible LAN DOS User Manual".


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