Epson I+ - Manual (Page 80)

You can also execute the commands directly from the diagnostics
diskette, without loading diagnostics. For example, if you are logged onto
drive C, and you want to prepare your hard disk for moving, follow these
steps:
1. Insert the diagnostics diskette into drive A.
2. At the C) prompt, type:
A: HDSIT
3. Press Enter.
To use the System diagnostics program, DIAGSYS, you must always
boot the system with the diagnostics diskette in drive A. If you attempt to
start this program in any other way, the tests may produce strange results.
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