• HP-35[?] - first scientific calculator
• HP-80[?] - first business calculator
• HP-45[?] - first scientific calculator with a shift key
• HP-65[?] - first keystroke programmable, with cardreader
• HP-70[?] - lower-cost version of HP-80
• HP-55[?] - programmable with timer but no cardreader
• HP-46[?] - printing version of HP-45
• HP-81[?] - printing version of HP-80
• HP-21[?] - smaller/cheaper HP-35 successor
• HP-22[?] - smaller/cheaper HP-80 successor
• HP-25, 25C[?] - inexpensive scientific programmable
• HP-27[?] - business/scientific, no programming
• HP-67[?] - HP-65 successor
• HP-28[?] - first RPL[?] programmable with graphics
• HP-48[?]
• HP-49G[?]

• 124 S[?] Dual Power Solar Desktop Calculator

• EL-520R[?]
• list more Sharp calculators here

• Sinclair Scientific
• list more Sinclair calculators here

• TI-30[?]
• TI-58[?]
• TI-58 C[?]
• TI-59[?]
• TI-81[?]
• TI-82[?]
• TI-83[?]
• TI-85[?]
• TI-86[?]
• TI-89
• TI-92[?]
• TI-99/4A[?]

See also:

• abacus, slide rule, pocket computer[?]