In my first 6303 based computer I used floppies for secondary storage. Even though it worked very well floppies are relatively small, fragile, slow and, above all, they are outdated. Today there are easier and more convenient ways of storing large amounts
Enhance the storage capabilities of your Zeal 8-bit computer with our Compact Flash card interface!
Compact Flash Interface for Zeal 8-bit computer
PIC 2 CF
XT-CF-Mini Bootable 8-bit ISA CF Card Interface
Compact Flash 128mb 256mb 512mb CF Card 1GB 2GB 4G Memory Card for CNC IPC Numerical Control Machine PCMCIA Adapter (2GB Compact Flash to PCMCIA) : Electronics
PixelFlash CF Card Reader - Compact Flash Card Reader, USB 3 Card Reader for Computer - Tactical SuperSpeed CompactFlash Memory Adapter, Rugged Anti-Scratch Exterior Classic - No-Bend Pins, Black : Electronics
CompactFlash - Wikipedia
An 8-bit IDE interface @ Retroleum
This bootable expansion card provides a Compact Flash card interface to 8-bit ISA systems such as PC/XT. Typically paired with a 64MB or 1GB CF card.
XT-CF-Mini Bootable 8-bit ISA CF Card Interface - XT-IDE
Enhance the storage capabilities of your Zeal 8-bit computer with our Compact Flash card interface!
Compact Flash Interface for Zeal 8-bit computer
An 8-bit IDE interface @ Retroleum
SC504 – Compact Flash (Z50Bus)
Z80 8-bit Compact Flash Card Interface