the manual should cover that, read it yet?
it is not a computer at all posted to computer repair help. forum
is is Point of Sale terminal, old name Cash Register.
age 2008 , only clue is setting date example, RTM)
so is 14 years old.
not problem stated at all and wants more memory to do what not told, my wild guess is the P O S terminal has amnesia.?
it forgets, and you did not read page 3 in the manual these words
This POS terminal uses a
nickel metal hydride battery pack for memory protection.The battery
pack must be replaced at least every three years at the user's expense.
this is RECHARGEABLE battery when fails memory dies.
until replaced. just line on PCs the coin cell dies, same pain
rtm
https://www.manualslib.com/manual/324826/Sharp-Up-820f.html?page=3&term=memory&selected=4#manual
there is no memory upgrades here, but if do, ask the maker for support. and my be super costly that, a new main board.
the list of options from sharp are: this model.
For your UP-800F/810F POS terminal, the following options are available:
For details, contact your authorized SHARP dealer. Do not try to install any options yourself.
1. External printer model TM-T88III/T88IV, TM-U220/230 or TM-U295*
2. Remote customer display model UP-P20DPB
3. Remote drawer model ER-03/05DWB
4. Remote coin case model ER-48CC2, ER-48CC3 or ER-58CC
5. Remote coin case cover model ER-01CV1-5, ER-02CV1-5 or ER-03CV
6.
RAM memory board model UP-S04MB2 (says extra)
7. Magnetic card reader model UP-E13MR3
8. EFT interface model UP-I04EF
9. Contactless clerk keys model UP-R10CL2
* The external printer TM series are not SHARP products
there may be 2 choices. now. ask maker SHARP for SUPPORT
UP-S04MB2 / S08MB2 Expansion memory board (4MB / 8MB)