EPROM cards

EPROM cards can only be used in slot 3. They are designed to be used for long term storage of important data or programs. Unlike RAM, EPROMs will retain information even when removed from the Cambridge Z88. Thus, in addition to providing a means to make back-up copies of valuable data, EPROMs provide a convenient means for transferring data between Cambridge Z88s.

One important fact to note about EPROMs is that data cannot be change once it is recorded into them. If you record a file onto EPROM and then make some changes you will be able to record a complete new copy of the file, but this will use up more space within the EPROM. The space occupied by the original version will not became available again. When an EPROM becomes completely full in this way you will only be able to re-use it by erasing ALL the data which it contains. EPROMs cannot be partially erased.

EPROMs may be inserted or removed at any time, except when they are actually being read or written to. They do not consume much power except when being written to, at which time the Cambridge Z88's screen will be switched off to conserve power.

Note - It is important to remove any EPROM card from the Cambridge Z88 if you have to re-power a Cambridge Z88 which has been left without power. Otherwise there is a small risk that data on the card may be corrupted. If the EPROM becomes corrupted it will need to be fully erased and all the data will be lost. An EPROM may not be recognised by the Cambridge Z88 when you type CARD within the Index. It will be shown once you have saved a file to it. If a new EPROM will not catalogue, then try installing it again. If this fails, try erasing the EPROM.

EPROM eraser

The EPROM eraser will erase all the data stored in the EPROM by exposing the integrated circuit through the round window in the card to ultra-violet light.

WARNING

If the internal light can be seen when there is no card present the EPROM eraser is faulty and should be retuned.

The EPROM eraser produces an intense ultra-violet light which can only be activated by inserting a Cambridge Z88 memory card into the eraser; this safety feature prevents any escape of ultra-violet light.

REMOVE FROM MAINS SUPPLY WHEN NOT IN USE.

Never touch the ultra-violet light source. It gets hot in use and may cause bums; also it is made of quartz and will cloud over due to moisture from the skin.

To erase an EPROM

1. Connect the eraser to the domestic mains supply. The plug should be fitted with either a 1 Amp or a 3 Amp fuse.
2. Fully insert the EPROM card into the slot on the front of the eraser, with the round hole uppermost. The card is correctly inserted if the white label on the end of the card is visible and the printing "32K EPROM" or "128K EPROM" is upside down.
3. The action of inserting the card switches the eraser on. The red indicator light on top of the eraser should light and the EPROM will be exposed to ultra-violet light for approximately twenty minutes. After this time the ultraviolet light is automatically switched off and the red light will go out.
4. After the red light goes out, you can remove the card from the eraser. DO NOT REMOVE THE EPROM BEFORE THE RED LIGHT IS OUT. The EPROM card should now be blank and ready for re-use. Removing the card resets the timer, so to erase another card, simply insert it; the red indicator light will again be illuminated, and the process can be repeated.

The ultra-violet light source decreases in efficiency with use and eventually a single 20-minute exposure may not completely erase all the data in the EPROM. In this case it may be a good idea to repeat the process a second time to be absolutely sure that it is thoroughly erased.

There is no means of erasing selected individual parts of data from the EPROM. When the EPROM is exposed to the ultra-violet source all data is affected in the same way.