Comparison of pack types
Finding out the size
These are the most common memory packs. Psion made them in several sizes: 8, 16, 32, 64, and 128k. Some other companies made larger ones. Note that the CM model organiser cannot use packs larger than 64k.
Datapacks of 8 and 16K were first produced for the Series One Organiser. The Series II uses essentially the same design and so those old packs can be used with it. Larger packs have a different internal addressing mechanism and these cannot be used on the Series One. Very large packs, those of 128k and larger use yet another addressing method, which is why the old CM model cannot use these properly.
Datapacks contain an EPROM (Erasable Programmable Read-Only Memory) chip. Such chips can be written to by using a high voltage, and once that is done the data contained on it is very safe. Writing to a datapack will cost considerable battery power and is very slow.
Information stored on a datapack will last for many years without the need of a power supply. Unfortunately, the organiser cannot remove data from a datapack. If you delete any file or record it is merely marked as deleted, and the space it uses is NOT freed up for re-use.
Once a pack is full, it can be erased completely by shining ultra-violet light through the small window in the EPROM chip for about half an hour. Psion has made datapack formatters for this purpose, but any EPROM Eraser that is large enough to contain a datapack circuitboard can be used. This is a standard piece of electronic equipment and so it should be possible to get one for a reasonable price from a good electronics parts supplier. A 'black-light' like those used for checking bank notes and stamps will not work. I have heard from someone who manages to erase them by using a sunbed, but this takes much longer because it is not the right frequency or intensity. Leaving one out in the sun for several weeks apparently also works, provided you do not do it behind a window since glass blocks most of the right UV wavelength (253.7nm).
When the organiser first notices an empty pack, it will try to 'size' the pack. It scans it to find out whether it is really empty, finds out what the size is and prepares it for use by writing a header and a MAIN file on it. This process takes only a few seconds. If the organiser stops with the error 'PACK NOT BLANK' then the pack has not been fully erased and you will have to try to erase it again.
|32kB DataPak - PCB view.||32kB DataPak - component view.|
Psion made these only in the 32k size. Some other companies have produced larger rampacks, usually 64k, and Widget Software has even made packs of sizes 128k, 256k, 512k, 1Mb. Note that the CM model organiser cannot use rampacks properly.
Rampacks contain a normal dynamic RAM chip. These chips need a constant power supply to keep the data safe, so they contain a small battery for when the packs are removed from the organiser. This battery should last approximately five years. If the pack's internal battery is empty, then the data will be lost as soon as the pack is removed from the organiser. Writing to a rampack is very fast and costs very little of the organiser's battery power.
Unlike a datapack, if you delete any file or record from the rampack the space it uses is freed up for re-use. This makes a rampack ideal for storing temporary data that changes often, or developing procedures.
Rampacks are sensitive to power surges, so always ensure that the organiser is switched off when you insert or remove a rampack or when connecting the organiser to a peripheral like the comms link. This is especially true if the rampack's battery is running low.
It is possible to replace the battery in a rampack, even without using a soldering iron though we do not really recommend you do this. If you do want to use this very rough solution, it is at your peril and we are not responsible for any damage done.
|32kB RAMPak - PCB view.||32kB RAMPak - component view.|
Flashpacks are sometimes called flashram packs or flash datapacks, and they generally come in the sizes 128k and 256k. Note that the CM model organiser cannot use flashpacks.
Flashpacks contain a flash EEPROM (Electronically Erasable Programmable Read-Only Memory) chip. These chips are very much like the EPROM chips of a datapack, except that they can be formatted electronically instead of by using UV light. Writing to a flashpack consumes less power and is faster than writing to a normal datapack. The data stored on it is just as safe.
Like a normal datapack, the organiser cannot remove data from a flashpack. If you delete any file or record it is merely marked as deleted, and the space it uses is NOT freed up for re-use. Once a pack is full, it can be formatted completely by using a menu option (see below) and there is no need for a separate formatter. Special flashpack formatters have nevertheless been produced.
Flashpacks were a later development so the organiser cannot use them without extra software, the flashpack driver. This is normally present on a flashpack so that it will be loaded into the organiser automatically when you press ON in the organiser's main menu. Without this software the flashpack can be read but not written to.
When the driver is loaded (by pressing ON in the main menu), FLASH should appear as a menu option. The flash driver will stay in memory permanently, even if any flashpacks are subsequently removed. To remove it you must choose the REMOVE option in the FLASH menu. You must remove any other software drivers first, for example the comms link and any bootable packs, before the flashpack driver can be removed (otherwise a 'bad device call' error occurs). You can check for the presence of a flash driver in OPL by testing whether bit 2 of $2178 is set (i.e. whether (PEEKB($2178) AND 4)<>0 ).
There are normally two ways of formatting a flashpack with the organiser. You could either choose the FORMAT B: or FORMAT C: options in the FLASH menu, or use the new OPL command FLSHFORM:("B",0). The first parameter is the slot to format, the second is zero for no display, or non-zero for the standard formatting display.
The organiser will refuse to format the pack unless you have two flashpacks inserted. This is because it will need to copy the flashpack driver to the formatted pack from the other one. If this is not the case, a 'Device Missing' error will occur. During the formatting process a counter is displayed indicating its progress. Formatting consumes a lot of power, and you should consider connecting the organiser to a power supply.
Note that all the flashpacks you use should have the same version of the flashpack driver installed. If not, then you must use the newest version to format the older packs.
If you have only one flashpack and need to format it, there is one way to do this. You need the developer kit, a comms link and a copy of the flashpack driver software. With these you can make a pack image of an empty pack (containing only the driver) and transfer this into the flashpack. Alternatively you can copy it onto a freshly formatted datapack so that from then on you can format it using only the organiser.
Important note: All the flashpacks you use should have the same version of the flashpack driver installed. If not, then you must use the newest version to format the older packs.
|256kB FlashPak - PCB view.||256kB FlashPak - component view.|
Here's a table highlighting the differences between the pack types:
|Writing power drain||High||Low||Medium|
|Formatting||UV formatter||Not needed||Organiser|
|Price per pack||Cheap||Medium||Expensive|
|Price per kB||Cheap||Expensive||Medium|
Generally commercial programs were sold on ordinary datapacks. Nearly all program packs can be erased and reused as ordinary datapacks, but there are a few exceptions.
Some of the first program packs produced by Psion, in particular the Concise Spelling Checker, are on packs containing an ordinary PROM chip, and these can obviously not be erased (there is no window in the chip). There are also some program packs which are wired differently, so that they cannot be written to and so could not be properly used after being erased. The only ones we know of are the program packs made for the series 1, since that machine did not have a write protection system. These packs clearly have 'PROGRAM PAC' written on the circuit board.
|Programme Pack - component view.|
You can find out what the size is of a program pack or datapack by looking at the number on the chip. There should be a number on it that starts with the digits 27. The other two or three digits indicate the size of the memory (in KiloBits!); 64 for 8k, 128 for 16k, 256 for 32k, 512 for 64k and finally the odd number 011 for a 128k pack.
Flashpacks generally only come in two sizes and these are easy to recognise. The 256K flashpack has two square memory chips surface mounted on the circuit board (see the picture above). A 128K flashpack is simply missing one of these chips.