Editing Psion Organiser (section)

== Datapaks ==

[[File:Psion Organiser Datapak.jpg|thumb|300px|A Psion Datapak. Data is stored in EPROM, so nothing can be electrically erased — deleted records are merely marked as skipped and continue to occupy space.]]

The two slots in the back of the machine are what Psion called '''solid-state drives'''. Drive one came with a real Datapak; drive two came with a '''dummy pak''' fitted to protect the contacts, and Psion's instruction is to keep a real or dummy pak in each slot at all times.<ref name="p1man" />

For the Series 1, Datapaks came in '''8 KB and 16 KB only'''.<ref name="galp1" />

{| class="wikitable styled-table" style="width:100%; text-align:left;"
|+'''8 KB Datapak — manufacturer's specification'''<ref name="p1man" />
! Item !! Specification
|-
| Capacity || 8 KB — 10,900 characters of packed data
|-
| Storage medium || EPROM
|-
| FIND time || Worst case with a full pak, 5 seconds maximum
|-
| SAVE time || 4–8 characters per second, depending on battery age
|-
| Data retention || Mean time to failure 50 years at temperatures up to 100 °C
|-
| Formatting || 30 minutes in a Psion Formatter prepares a pak for re-use
|-
| Life || Can be formatted up to 100 times
|}

Because the storage is EPROM, '''erasing a record does not free the space''' — it is only marked so that the Organiser skips it. The only way to reclaim a pak is to erase the EPROM optically: the '''Psion Formatter''' shines ultraviolet light through the window in the chip for half an hour. The white label on the underside of a pak is there to keep light off the die, and has to be removed before formatting.<ref name="p1man" /><ref name="galp1" />

'''Program packs are different again.''' Most Series 1 software packs use a special board silkscreened "PROGRAM PAC" in which the '''programming voltage (Vpp) line is not connected''', so the pack cannot be written to even though it contains an EPROM. The Link-Up Pack and the Software Pack used ordinary Datapaks so that settings and programs could be saved onto the same pak.<ref name="galp1" />