CornBitXL™ V2 (Programmable ROM)

$22.00 USD

ROM failure is a common problem in Commodore 64 and related machines. Named in tribute to the KERNAL it’s meant to replace, CornBitXL™ is a 100% compatible ROM replacement for 27128 (16KB) or 27256 (32KB) ROM chips (incl. KERNAL & FUNCTION ROMs for post-breadbin machines, including C128 and PLUS/4). Version 2 adds support for 27256 ROMs.

The first DIP switch selects either 27128 (16KB) or 27256 (32KB) mode. What’s more, the CornBitXL™ has 4 different “slots” activated by the other DIP switches. Use them to have an all-in-one replacement for multiple machines.


The CornBitXL™ is not intended as a facility to transmit copyrighted content. Please do not purchase CornBitXL™ if you intend to use it in a way incompatible with copyright law. Please inquire if you need a specific configuration. I will not program them with content that violates copyright.

If you have the BackBit Chip Tester, the CornBitXL is fully reprogrammable with four 16/32KB ROMs of your choice. This is made possible by the extra pins that hang over on either side. The extra pins only take up a few millimeters of space, so they should not get in the way of other components, but you will have to install CornBitXL into a socket (dual wipe or machined pins).

Default Configuration:
Slot #1: 317053-01 PLUS/4 FUNCTION LOW
Slot #2: 317054-01 PLUS/4 FUNCTION HIGH
Slot #3: 318005-05 PLUS/4 & C16 KERNAL
Slot #4: 318008-01 1551 KERNAL

To reprogram with the Chip Tester, append four 16KB or 32KB binary files into a 64KB or 128KB file, respectively. Then those 4 ROMs will be available with the 2nd and 3rd DIP switches. Make sure to do a binary append.

Additional information

Weight 2 oz
Dimensions 1 × 1 × 1 in


There are no reviews yet.

Be the first to review “CornBitXL™ V2 (Programmable ROM)”

Your email address will not be published. Required fields are marked *