Overlooked?

[kkilopik90]

The question of the first commercially available personal computer has had several answers: Kenbak, Altair, Apple. One machine, offered in 1974 for $795, with 200 bytes of RAM, 4K bytes of ROM, a high level language with intuitive UI and floating point math library, including keyboard, display, and magnetic storage. Did Kenbak offer those? Altair did, but only with the addition of expensive terminals, interface boards and third party software.

This amazing machine was also pocket-sized and battery powered. Yes, it's the HP-65 programmable calculator. Don't stop reading because you think it isn't a real computer. It is fully programmable with conditional branching and subroutines and powerful instructions. Floating point multiply in a single instruction? Try that on your 8008. Its built in display is numeric, not as intuitive as text but much moreso than blinking lights. It gained a huge following and grew software libraries and user groups. So why is its place in computing history not larger?

 

[durgadas311]

It is true that what were called "programmable calculators" were very much like personal computers in a lot of ways, especially to those of us that could not afford "the real thing". But the HP-65 was by no means the first. Wang and HP were competing in the programmable calculator market long before the HP-65. Wang's 300-series (mid 1960s) were programmable, and then after HP-9100s leapfrogged over them they came out with the Wang 700 series and so forth. These were expensive machines, but they were "personal" in the sense that the user/customer had the entire machine to themselves - they were not sharing. However, as a young enthusiast at the time, there was something different - more compelling - about the things we called "computers".

I had not looked at the Kenbak before. It looks to be the equivalent of a programmable calculator CPU without the even most basic I/O. I'd consider it a stretch to call it a "personal computer", but that's just my opinion.

 

[krebizfan]

Didn't we have this discussion before? The HP-65 and before that the HP-35 were products that followed Bill Hewlett's dream of having a desktop calculator that could fit in a slide rule pouch. So it might qualify in an early portable context but those were not general purpose computers any more than the desktop calculators were. Many of the smaller minis were designed as single user personal computers even if the pricing kept them out of the home. The MCM-70 came out in 1973 and had a one line display and keyboard and tape storage all in a single unit before the HP-65. The calculator style trainers like the KIM-1 were just a bit later.

The early 70s was when the easy personal computer was available. Don Lancaster's TV Typewriter gave a good design for an inexpensive terminal with associated cassette storage. Attach that to a CPU board and a prototype was ready.

 

[commodorejohn]

I had not looked at the Kenbak before. It looks to be the equivalent of a programmable calculator CPU without the even most basic I/O. I'd consider it a stretch to call it a "personal computer", but that's just my opinion.

There's a certain argument to be made that it's approximately equivalent to a bare-bones Altair, but it has no expansion bus (and, for that matter, no provision for extending the address space beyond 8 bits, IIRC.) Even in the early-'70s hobbyist world, that was a huge oversight; without extensive modification, you'd never get it to do anything more than trick lights-and-switches programs (the literature included programs for playing simple games by means of translated I/O patterns, which raises so many questions you have to wonder why the need never occurred.)

Blankenbaker is (was?) a nice guy, though - happy to answer questions about the thing when I briefly toyed with developing an emulator for it.

 

[exemple]

Technically speaking, yes. "All computer is calculator, but not all calculator is computer". The 65 might be stepping into computer territory, but I think other models such as the 41c series have a more objective fit into this category. Especially when it comes to I/O and networking. Yes, I'll call the HP-IL interface a network interface, although local one. Expandability? Also yes given the amount of original memory, clock, programs, etc. available. Heck even the manual refers to it as a "computer", because really, that's what it is.