Can hold one or more programs (64K or 128K EPROM) and start it using a program list.
Supports:
https://www.pcbway.com/project/shareproject/UC1___Ultimate_Cartridge_1.html
Open Hardware Cartridge for the Commodore 64, simple to build, uses jumpers.
https://github.com/SukkoPera/OpenC64Cart
https://ezcontents.org/floppy-disk-notcher-addon
This version costs 1$ https://cults3d.com/en/3d-model/tool/floppy-disk-notcher-add-on
Free version https://www.thingiverse.com/thing:6185377
https://www.thingiverse.com/thing:5328855
https://retrorepairsandrefurbs.com/2021/07/04/commodore-1541-5-25-fdd-repair-modification/
You can use Azimuth head alignment for adjusting the tape drive, basically adjust the signals so that they are inside the three bars
https://csdb.dk/release/?id=143459
alternative version https://csdb.dk/release/?id=49944
Copy-H should have alignment as well https://csdb.dk/release/?id=162750
will power the 1530 drive and create audio interface so it's easy to use the casettes with PC for recovery https://www.load64.com/1530usb/
You can use Audacity for recording
AudioTap can be used to convert wav to tap file or tap to wav
Final Tap can be used to verify, clean and optimize the recording
https://www.load64.com/smf/index.php?topic=12.0
can be used for disk and tape recovery, this list has other interesting devices as well https://github.com/wagiminator/C64-Collection
For 1530 and 1531 datasette
Square belts
1 x 75mm Thickness 1.2mm
1 x 55mm Thickness 1.2mm