here is an interesting machine, an old 4 function model
with percent (no memory) and optional 2 place rounding from around 1974.
the omega 100 is small but chunky. it requires 4 AA cells that clip
neatly into the rear battery compartment whose cover has a small latch to
secure it. its well made and there is an optional 5v mains adapter.
rare indeed for a handheld device is the burroughs panaplex gas
these were high voltage and usually only seen on mains desktop models,
like the ti-3500, or on portable machines like
the compucorp 320g. the panaplex display is
really nice with its friendly orange glow (which doesnt photo well
unfortunately). the keys click but feel positive and of a high quality.
arithmetic works like a desk calculator (ie 3+2- for 3-2=) and a switch
activates 2 place rounding when set to `$'. $ mode affects number
entry when 123 represents $1.23 without entering the decimal
point. this saves time tallying figures and was often a feature of desk
calculators, the only drawback is 123*3 is taken to be
1.23*0.03=0.04 which means care is needed for tallying item multiples.
altogether a really nice machine with its own individual character.