Liam Proven wrote: > Microprocessors are what created the PC. No µP = not a PC.
So, if I get this right, the term "PC" to means something like the "personal computer" of today (children of IBM PC or Apple Macintosh) or at least perhaps something as old as an Apple II, a Commodore PET. Perhaps even an Altair or IMSAI, though these are a bit different than an Apple II or a PET or TRS-80 because they required additional "stuff" to make them comparable the Apple, Commodore, or Radio Shack machines. You'd have to add some sort of display and a controller card for the display, a keyboard of some sort, and at least an output port for an external printer, and perhaps a serial port to make it roughly equivalent to an Apple II or a TRS-80. I find it had to make distinctions in some cases, because some machines tend to bend the rules a bit. How about the Hewlett Packard 9830 "calculator"? It had BASIC in ROM, and came up in BASIC when powered-on. No microprocessor, though. Instead, it had a TTL implementation of a somewhat scaled down version of HP's 2100 minicomputer CPU. It had a 40-character LED dot matrix display, a digital cassette tape drive, and you could sit a fast thermal printer on top of it and plug it right into a connector on the back of the machine. It had ROMpack slots for additional functionality, and I/O expansion slots that could provide connections to external hard disk subsystems (that could be shared among multiple 9830's), a plotter, a punched paper tape reader, and a punched card reader, among others. It was expensive. But, it was intended as a single-user computer. For the most part, this sounds like some early personal computers. Some HP 9830s were bought new by people with the means for their home use as a "personal computer, and for the time, a quite capable one at that. This one is a little tricky because of its lack of a microprocessor. But, it still seems to be pretty PC-ish to me. I assume by the definition that since a Tektronix 4051 has a Motorola 6800 inside, it's a PC, right? The 4051 had no multi-user capabilities, and was fully intended for one person to sit down in front of it and do whatever it was they wanted to do, be it playing a game (there were a lot of games for the machine), or do some data acquisition, visualization and manipulation, or even mundane stuff like inventory, payroll, receivables, payables...you get the picture. It was a truly general-purpose computer. That said, what about a Tektronix 4052(1978)? It doesn't have a microprocessor in it, but it was definitely designed as a personal computing device with a graphics display and built-in mass storage (cartridge tape), just like the 4051. In fact, looking at a 4052, if you ignore the "4052" badge on the machine, you can't tell it apart from a 4051, and from a BASIC programming standpoint, they are the same. While the 4051 was very successful, and absolutely did end up in the homes of individual buyers (base price of $5,995, but there were individuals that had the means to buy one as their own personal computer for at home). The 4051's intended markets were engineering, scientific, and data acquisition/data reduction work. One criticism of the 4051 was that it was a bit too slow on number crunching and drawing graphics, requiring some patience if you are doing some serious numerical processing/graphics. To respond to those critics saying that the 4051 being too slow, Tektronix designed a bit-slice implementation of the 6800 (using the 2901 bit-slice devices, fast bipolar ROM for microcode storage, and a 16-bit wide bus versus 8 bits of the 6800 to speed up double-byte operations), added a few tweaks to the instruction set to address more memory than the 6800 could natively address(separate RAM and ROM space, so RAM could be 64K, and ROM could be 64K, but banking of the ROM made even more space available), and hooked in the rest of the 4051 (storage tube graphical display, cartridge tape unit, keyboard, GPIB, and ROMPACK slot) such that it was for all intents and purposes, a faster 4051. With no microprocessor. Of course, it cost more than the 4051. However, like the 4051, some 4052's did sell to individuals to get themselves a powerful personal computer at home. The 4052 was much more powerful than any Apple II, Atari 400/800, TRS-80, or Commodore PET/VIC-20/64. Yes, most of those machines could do graphics, and they were raster bitmapped or tricky equivalents thereof(Atari), but their graphics were primitiS1281ve in comparison to the 4051/4052's 1024x780 point vector storage display. What about a Three Rivers/ICL PERQ 1(1980)? It had a microprocessor in it, a Z-80. However, the Z-80 was relegated to being used as an I/O processor for the hard disk, floppy disk, speech synthesizer, IEEE-488, and RS232-serial port. The main CPU was a bipolar custom CPU that used 74S181 high-speed ALU slices, and a microcoded architecture. The cool thing is that the microcode store was writable! It had up to 2M (256K minimum) of 64-bit wide RAM (with a 16-bit bus), and a built-in 12MB or 24MB hard disk drive and an 8" floppy drive. It also had a 768x1024 bitmapped monochrome (portrait) display, and a graphics tablet. It cost somewhere between $20,000 and $27,500 in base form, with the variance being uncertainties in prices due to varying configurations that have price information available, but not much in the way of actual configuration. Yes, that's a bit much for someone to buy as a personal computer, but it's certainly possible for a person of substantial means. It wasn't a multi-user system, it was intended to be used by a single person sitting at the machine. It plugged into a regular wall outlet. It actually had a GUI, perhaps one of the earliest to exist, and was something that did not exist for the storage-tube Tektronix machines or most certainly not for an HP 9830. I'm absolutely not arguing with Liam's point. I do believe that the microprocessor was the driving force in making possible a device that fits the full definition of a computer, that an average person could buy, take home and unpack and set up in fairly short order, and be up and running with their TV as a display, running BASIC, and a cassette tape recorder for storing and loading programs. A true personal computer, no doubt. I think that in a general sense, it certainly fits that a personal computer is more commonly a microcomputer, and thus, has a microprocessor (perhaps more than one) as its main processing element. With that said, any time that generalities are used, there always seem to be exceptions that sneak their way in and cloud any general definition of a term. I believer that as time goes on, the definition is going to get more and more difficult. With technology advancing as fast as it is, it seems feasible that a small device could be implanted in one's brain that utilizes generation of neural impulses to generate imagery that appears as it is being seen by the eyes, and similarly with sound, and communicates at least initially by recognizing spoken commands (and likely later, just thinking about what you want done), that is connected to (whatever the Internet becomes) full time, with full AI capabilities embedded as part of its operation. I believe one of Elon Musk's companies is working on that and has been for some time. Perhaps that device may well redefine the meaning of a "personal" computer. Perhaps more appropriately the "computer personal" (the computer first, the person secondary). Would I want one? Hell no. -Rick -- Rick Bensene The Old Calculator Museum https://oldcalculatormuseum.com Beavercreek, Oregon USA
