How much of a nerd are you if you’re the one that dropped the stack of punch cards?
Lessons learned - always use TWO rubber bands to hold your stack of punch cards together. Old rubber bands can break. Also, draw an X down the side of the stack. Makes it easier to re-order the cards after you pick them up.
People LOVED those old HP calculators. They were not just objects. I still have an affection for them. The physical quality was also something you don’t get today. It felt solid in your hand, and the ‘tipping’ keys were a pleasure to press. I don’t know why they can’t make them like that today.
I still prefer RPN logic, and I have some HP emulators on my computer. I use RealCalc in RPN mode on my phone. It’s not programmable, but you can see that whoever wrote the app really cared about creating a good calculator.
I love my HP-48GX. The thing’s a tank, it has a snappy response, and it’s fully programmable in a nice little RPN programming language.
Yes. Old HP calculators still have a fanbase.
Ever use a Timex Sinclair 1000?
Or an Atari 400?
http://oldcomputers.net/atari400.html
had one. loading programs (especially games) from cassette was “fun.”
“PBPBPBPBPBPBPB…PBPBPBPBPBPBPB…PBPBPBPBPBPB…PBPBPBPBPB…”
5 minutes later it’d drop a bit at the end and you’d have to start over.
Ah the Commodore 64, what a fond memory I had with it. Amazing video chip and a fantastic sound chip made great video games. I wrote bunches and sold one to the Compute! magazine.
Our very first computer in the house was the TI 99/4A. It’s what got me hooked. 
I think this is the answer: a hand-held device, reasonably priced for consumers, that could be programmed. I never had one, but I remember gathering in awe around our geometry teacher as he demonstrated it.
This is the best answer. It was a general purpose computer intended for the consumer market using a motherboard with various memory and I/O cards that could be added. Based on the Intel 8080 several other small computers became available around the same time using processors such as the TI6800 and MOS Technology 6502 (later Commodore). Other commercial computers could be purchased before then but not in the same price range or intended to be generally expandable. The Altair was the archetype for the S100 Bus which was adopted by numerous other small manufacturers and served as a standard until the IBM PC emerged. The first of these machines didn’t typically include a video display and relied on independent terminals, often just old teletypes. Apple broke ground by integrating a keyboard and video display in their computers though other companies offered the same thing around the same time like the Processor Technology SOL20. The Altair gets the credit though for marketing to the consumer market and for contracting Bill Gates to produce BASIC that would run on the small machines allowing them to be a little more useful.
I did hours of calculations for updating budgets for my plant and for other managers using the Bowmar Brain. At the time, around 1973-4, I could not imagine the advances that came along just a few years later. Of course, first, I had to learn ‘basic’, taking on ‘online’ course from our Buffalo plant, where they had a computer of some kind, using punchtape inputs, etc. etc. that we would input from New Jersey and then receive an answer to our program by fax? Hard to remember for sure. My engineering buddies already knew Fortran, I think, maybe some other stuff. There were a bunch of tedious computations we had to make back then, and we gradually managed to get them onto some form of PC, and, eventually, every location had their own.
Slight Hijack: a great way to revisit the old days is to read through the early days of Byte magazine when the hobbyist and techie was still the target audience.
Byte Magazine at Internet Archive
And, yes, I was probably carrying an early issue while sorting through my card deck of PL/I programs.
Whoa, slow down there buddy. 
Any particular reason for the exclamation point?
Following the links from this lead you to the Olivetti Programma 101, first displayed at the 1964-65 World’s Fair. It was an Assembly Language-like Programmable Desk Calculator (the designation was changed somewhat surreptitiously from “computer”, which kept this division from being sold to GE). According to Wikipedia, 40,000 units were sold at $3,200-$3,500 a pop, so this was a popular device that predates most of the others in this thread, including the Honeywell, the Kenbak, and the Altair
Guinness Book of World Records grants the 1950 2-bit Simon the title of “First Personal Computer”.
It uses 5-bit paper tape or five front panel switches as input, and the output was five lamps on the front panel connected to the output registers. There were a series of articles in Radio-Electronics magazine starting in 1949 describing how to build it, but it was manufactured in 1950 and retailed for $600. This article (which also describes why all the other computers mentioned in this thread aren’t the “first”), mentions that over 400 Simons were sold by 1959.
The guy who designed it, Edmund Berkley, was ahead of his time:
[QUOTE=Edmund Berkley, 1950]
Some day we may even have small computers in our homes, drawing their energy from electric-power lines like refrigerators or radios … They may recall facts for us that we would have trouble remembering. They may calculate accounts and income taxes. Schoolboys with homework may seek their help. They may even run through and list combinations of possibilities that we need to consider in making important decisions. We may find the future full of mechanical brains working about us.
[/QUOTE]
I question whether a programmable calculator is truly a computer. Yes, you could numerical computations on one, but could you make a word processor or even an editor?
Just for bragging rights, I once programmed an HP-95 calculator to find the largest prime number. I believe it was 9999999967 = 10^10 - 33. I also did a more serious calculation of the number of maps between two finite semi-lattices to refute someone else’s conjecture.
Only a true nerd understands that such measures are limited if you’re handing your deck through a service window to a trainee computer operator whose sole joy in life is floor-sorting a trainee computer programmer’s (i.e., your) source code deck. Because he didn’t test well enough to be a programmer, and his career field choices after that were “computer operator” or “cook”.
Why are all of you (except the clowns) thinking that the answer has to be a digital computer? Analog computers for the home were available in the 1950s.
Here’s a .pdf for the Heath Electronic Analog Computer Kit, 1956.
ETA: Exapno beat me to it. Shoulda refreshed.
I know we’ve decided the OP meant recognizable PC progenitors, not computers in general.
But I can’t resist pointing out that Heathkit sold an analog computer kit real early, like 1956. A Google for [heathkit analog computer] will show a bunch of links and a few pix of various models.
I’m not finding pix of the one I’m thinking of that was sold in the mid-late 60s more for “personal” than industrial and classroom use. It as about 2 feet square by 8-10" deep and had two large dials that resembled circular slide rules.
Because, as I said above, we want to make the answer something other than “a rock”.
More to the point, we know what a computer looks like now. It’s an all-electronic stored-program computer, fundamentally similar to what we use now and dissimilar to the dead-ends and strange off-shoots which cattle-pathed off into obscurity most of a century ago now.