COMMODORE 64C - BASIC ROM + KERNAL ROM REPLACEMENT ADAPTER (251913-01)

DESIGNED FOR 251913-01 BASIC+KERNAL ROM REPLACEMENT for 4X ROM.

Hello,

This is a tested and working circuit board.

This adapter is suitable for Commodore 64C (Short board) 28pin Basic and Kernal ROM (251913-01). It has the capacity of 4 kernal ROMs and 4 BASIC ROMs that can be selected according to needs.

This PCB is exclusively designed to fit under the metal keyboard holders on the commodore 64C motherboard. (PCB ASSY NO. 250469 PCB NO. 252311 REV.4)

You can find and download many different ROM files for your C64, from internet.

This adapter lets you to use max. 4 different BASIC and KERNAL ROMs in one 27C512 eprom.

You can download a sample binary EPROM image file from the bottom of this page.

This ROM adapter is also compatible with JiffyDOS ROM, you can buy and use JiffyDOS 64 KERNAL ROM Image

http://store.go4retro.com/jiffydos-64-kernal-rom-overlay-image/

27C512 MEMORY MAP

(You can use a HEX editor to design your custom EPROM image file.)

$ 0000 - $ 1FFF - BASIC ROM

$ 2000 - $ 3FFF - Kernal ROM

$ 4000 - $ 5FFF - BASIC ROM

$ 6000 - $ 7FFF - Kernal ROM

$ 8000 - $ 9FFF - BASIC ROM

$ A000 - $ BFFF - Kernal ROM

$ C000 - $ DFFF - BASIC ROM

$ E000 - $ FFFF - Kernal ROM

Ps. In order to use this ROM adapter, your Commodore 64's 251913-01 ROM have to be desoldered and socketed.

Ps. If you only need 251913-01 ROM replacement for one ROM, you don't need this adapter, you can directly insert the 27C128 EPROM into the socket on the motherboard. Pinout 251913-01 and 27c128 are the same.

If you need a PCB for 24-pin ROMs (901226-01 BASIC ROM and 901227-03 KERNAL ROM), you can find it here.

https://www.pcbway.com/project/shareproject/C64___BASIC___KERNAL_ROM_REPLACEMENT_ADAPTER_REV_3.html

COMPONENTS:

27C512 (or W27C512) (FOR 4X ROM)

2 PCS 10K 1/4 WATT RESISTANCE

2 PCS. 14 PIN 2.54mm ROUND MALE HEADER

2 PCS 2PIN 2.54mm MALE HEADER

2 PCS 2.54mm JUMPER CAP

2 PCS 28 PIN WIDE DIP IC SOCKET (ONE FOR C64C MOTHERBOARD )

And you will need an eprom programmer to program 27c512

In terms of device and software safety; please turn your Commodore C64C off before switching between ROMs.

In order to protect your electronical devices, always turn off your Commodore C64C before connecting or unconnecting any device.

Gerber files and component list are subject to change without notice. Before paying for the PCBs, be sure to update your orders!

As you can see I have uploaded many projects and I am still working on new projects. If you have any questions, please look for answers online. Unless I specify explicitly, all my projects are tested and confirmed to work under normal circumstances before being shared. I'm sorry I didn't have enough time to answer all the questions.

Use this PCB at your own risk !

Have fun

Thank you.

C64istanbul