- Battery and power
- Four N cells or the 82120A NiCd pack. HP warns not to put a fully flat pack in the calculator to charge it, since that can lock up the keyboard. Old alkalines left inside leak, and corrosion in the 41 spreads into the flexible circuit behind the ports, so the battery bay is the first photo to ask for.
- Memory
- Continuous Memory, with all 319 registers kept while it's off. If it shows MEMORY LOST every time it powers up, suspect the batteries or the contacts.
- Display
- The same 12-character alphanumeric LCD as the 41C, built from 14-segment characters. Later Halfnut units have a black frame under the display glass.
- Keys
- One gold shift key and an ALPHA key. Lockups and changed memory point to poor contacts, which HP's service manual tests for by tapping the case.
- Cards, ports and modules
- All four ports are free, because the memory is built in. They take application pacs, the Time Module, the 82180A Extended Functions/Memory module, the HP-IL module, a printer or the separate HP 82104A card reader, which goes in port 4.
- Original, reissue or clone
- V is the Roman numeral five: five times the 41C's memory. A 41CV starts up with 273 data registers where a 41C shows 17, which is the quick test if the label is unclear. HP's serial label is on the bottom near the ports, and clones like the SwissMicros DM41X run the same software.
Check the listing photos against this list, and ask the seller about anything you can’t see. A missing piece should come off the price.