This is a tested and working project

JACC64 512K - Just Another Cartridge for the C64. This holds 32 x 16K ROM images, selectable via DIP switch. It has a reset button and a power LED. It is designed to use an SST39SF040 EEPROM or compatible. When burning the EEPROM, simply combine 32 x C64 standard 16K ROM images sequentially into a file and burn that.

BOM (THT)

• 1 x 5mm LED
• 1 x 6mm Tactile Push Button
• 1 x 330Ω Axial Resistor - 1/4 watt. (LED brightness, anything between 330Ω - 1KΩ is fine)
• 6 x 10KΩ Axial Resistor - 1/4 watt
• 2 x 1N4148 Diodes
• 1 x 100nF Ceramic Capacitor
• 1 x 5-pole DIP switch
• 1 x SST39SF040 EEPROM (or compatible)
• 1 x 32pin DIP Wide IC Socket (optional)

You should also be able to use any (E)EPROMs smaller than the SST39SF040 providing they are 32pin, JEDEC compatible and read at 5V. Programming voltage is irrelevant for this solution.

Obviously you can't hold 32 games if it's smaller, but make sure the DIP switch is set appropriately for the pull-up resistors.

GitHub

https://github.com/oddsocks1024/JACC64-512K

Cartridge Case

https://www.pcbway.com/project/shareproject/JACC64_512K_C64_Cartridge_Case_49b9f140.html

https://www.thingiverse.com/thing:7089362