Texas Instruments TI-84 Plus Manual Book page 136

You cannot send memory backups between the TI-84 Plus product family
and the TI-83 Plus product family.
Receiving from a TI-83 Plus Silver Edition or TI-83 Plus
The TI-84 Plus product family and the TI-83 Plus product family are
compatible with a few exceptions.
Receiving from a TI-83
You can transfer all variables and programs from a TI-83 to a TI-84 Plus if
they fit in the RAM of the TI-84 Plus. The RAM of the TI-84 Plus is slightly
less than the RAM of the TI-83.
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