Macintosh Hard Disk 20

Resources

Wiki
Mac GUI – excellent description and some repair hints
User Manual
Nisha Firmware Specification
Nisha Operation Summary
Firmware, HD Diag tools, documentation

Hard Disk 20 was the first hard drive from Apple. It communicated over floppy disk drive interface and was quickly replaced by SCSI standard disks, like SC20 HDD.

Internals

Controller Board

Hard Drive

Rodime RO552 – thanks to the proprietary communication interface, this drive was manufactured for Apple only. This makes finding replacement drives extremely hard, as they don’t exist outside of full Hard Disk 20 devices.

HDD Board

Disassembled HDD Mechanics. Unfortunately the drive was in such a bad condition, that it was not possible to make it work.

Power Supply

Reassembly

Some Dirt

This drive was in a very bad condition, probably submerged in water for a long time. The electronic boards seem to be restored fine, but the disk drive could not be revived.

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s