Datapaks Program Packs Rampaks Flashpaks Psion Software Packs Third-Party Software Packs
Datapaks are the most common memory modules for the Psion Organiser II.
The earliest packs were for the Series 1, and were 8K or 16K. Apparently
a 32K pack was produced for the Series 1 too, but I do not own one.
The Series II can use the same 8K and 16K packs as the Series 1, but Psion redesigned the circuit board so that both pack sizes can use the same board.
The Series 1 used a linear addressing method, and this leads to slow access times on larger packs. For the Series II a faster addressing method was devised, namely paged addressing. Shown here are 32K packs of both types, and their circuit differs only in the placement of one zero-Ohm resistor.
A close examination also shows one other difference between the two 32k packs. The second uses a CMOS type EPROM, recognisable from the C in the the chip name (27C256 instead of 27256). This type is more energy efficient, so is less of a drain on the battery. Psion even marked the labels with a P in a circle to indicate this type.
Packs of size 64K and 128K were made by various companies as well as by Psion themselves. If you look carefully, Psion's 64K pack circuit board still supports a configuration with linear addressing, though I do not own such a pack.
Datapaks contain an EPROM chip. Deleting data from these packs did not
free up space. For that they had to be reformatted by shining UV light
onto the EPROM chip for half an hour. Removing the label from a datapak
reveals a small opening over the EPROM chip's window. Psion supplied pack
formatting services for those who did not have a pack formatter themselves,
and also supplied replacement labels.
When I format a pack, I just remove half of the casing in order to keep the label intact.
Most Psion II software was supplied on ordinary datapaks. Such packs could therefore
be re-formatted and used for other data if you wished. There are however some exceptions.
The Series 1 did not have support for a read-only flag on packs, so its software packs usually had a slightly different circuit board that omitted the program voltage line. These packs cannot be written to, even though they still use EPROM chips.
As far as I know, there are only two kinds of software packs for the Psion II that were not ordinary datapaks. The Concise Oxford Spelling Checker used a pack with the same circuitry as a 64K datapack, except that it used a 64K PROM chip. Some Travel Packs are the same. Its successor, the Thesaurus & Spelling Checker, had a custom circuit board with a surface-mounted 256K ROM chip. It has a different addressing method to other packs, but its software allows it to be used on any Psion, even the CM.
Rampaks are memory modules containing a volatile RAM chip. To keep the memory contents intact even when removed or when the organiser is switched off, the pack contains a battery. Psion only produced 32K rampaks, but there were other companies that produced larger sizes. Olivier Gossuin recently made a new 256K Rampak, also shown below, for which part of the casing needs to be cut away to make enough room for the thicker battery.
Flashpaks contain EEPROM chips. These can be formatted electronically by the organiser. All it needed was a software driver that is normally present on the flashpak itself. In order to restore the driver software to the pak after formatting, a second pack with a copy of the driver was needed in the other slot. Psion flashpaks came in the sizes 128K and 256K. The former simply had just one memory chip, the latter had two. The circuitry was designed to also allow the use of chips with double the capacity, but it seems this was never done at the time, presumably due to the cost. Recently Olivier Gossuin has created a new 512K flashpak with such larger chips.
Psion created some software packs themselves, but also published under the Psion brand a few packs created by others.
The bulk of the software available for the Psion II was written by third parties. The first
section below consists of packs aimed at the ordinary consumer.
The datapak that I've described as 'Unknown' is blank, but has a red logo of the Union Jack on it, which seems to be the logo that Mackay Language Software used. This pack probably used to be one of their language Prakpaks.
If you own any software packs not listed here, please let me know. You can contact me at .
Here are some software packs aimed at or specifically tailored for business and industry:
The following software packs are used in conjunction with particular hardware.