Easyflash

Technical Info
ROM	1MB flash (EF3: 8 * 1MB)
RAM	256 Bytes (EF3: 32kb)
Hardware features	activity LED; Reset Button; EF3:; Freezer; External Kernal; USB link to PC; Menu und Freeze Buttons;
Manual	See Easyflash website
CRT ID	32
Programming	See Easyflash website

EasyFlash is a cartridge for the C64 expansion port. In contrast to traditional cartridges, this one can be programmed directly from the C64.

You can easily create various classic computer game cartridges or program collections with it. All what you need to do this is a C64, an EasyFlash, the software available here and an image of the cartridge (*.crt).

The hardware design and all software packages are licensed under Open Source licenses. This means you can do nearly anything with it.

the following was mostly taken from the Easyflash website:

Features

Easyflash 3
Easyflash 3 (short version)

Easyflash 3
Easyflash 3 (long version)

Easyflash

C64 cartridge emulation (also see CRT_ID):
- 8 or 16 KByte (EP)ROM cartridges
- Ocean Type 1
- Easyflash and EasyFlash xbank.

Easyflash 3

as above, with the following additions:

Freezer cartridge emulation (also see CRT_ID):

provides 7 EasyFlash slots, each of them is a full-featured EasyFlash 1
Kernal ROM replacement function (up to eight Kernals saved in the cartridge)
USB link for flashing and data transfer

Hardware Specifications

Easyflash

1MB flash ROM
256 bytes of RAM

Easyflash 2

this mystical piece of hardware does not exist in the wild, in favour of what turned into the Easyflash 3

"It had 2MB Flash, 512k RAM, no USB. Features depending on how the CPLD was programmed, it was used to develop the external Kernal and freezer logic."