My Home Computers 1980-2023

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Introduction

Computers have evolved enormously during my life time. When I started using computers, the size of the RAM was measured in kilobytes and the processor clock frequency in megahertz. Nowadays we use gigabytes and gigahertz instead, i.e. the RAM memories are a million times bigger and the clock frequency is a thousand times higher. Mind-boggling!

My first home computers

My first home computer was the Sinclair ZX-80, which I bought in 1980 with money I earned at my first summer job. I bought it as a kit that I had to assemble myself. In particular I had to solder all the components to the circuit board.

The ZX-80 was programmable in BASIC, but it had only one kilobyte (1024 bytes) of RAM, which was rather limiting considering that the program, the variables and the text on the screen all had to fit into those 1024 bytes of RAM, so it didn't take long before I upgraded it with the 16KB RAM expansion and the ZX-81 ROM, which made it equivalent to a ZX-81 (except for the SLOW mode). The screen shot below shows an example of what you could do on the upgraded ZX-80, but it was created much later, in an ZX-81 emulator called xz81.

[ZX-80 screen capture]

I abandoned the ZX-80 fairly soon and moved on to the Commodore VIC-20 and C-64, but some time later (1985 maybe?) I bought a used ZX Spectrum for nostalgic reasons. I never used it much at the time, but in more recent years I have come to appreciate that the seemingly small improvements over the ZX-81 really made a huge difference, as shown in the screen shot below, for example. It's no wonder the Spectrum became an immensely popular home computer.

[ZX Spectrum screen capture]
(ZX Spectrum screen shot created in the Free Unix Spectrum Emulator.)

[Bild på en Sinclair ZX Spectrum]
(Sinclair ZX Spectrum, bought in the 1980s, photographed 2022.)

Commodore

During my first 9 years in school, we had no computers. It wasn't until high school that there was a room with computers. The computers in question were a number of Commodore PET, which had screens showing green text (40x25 characters) on a black background. One of the computers had 32KB of RAM, the others had 16KB of RAM. There was also a dot matrix printer and floppy drive for 5.25 inch floppy disks.

It was these Commodore PET computers that became the reason my next home computer was a VIC-20 (rather than a ZX Spectrum, for example). The VIC-20 can be seen as a home computer version of the PET. The computer was built into the keyboard and you used a regular TV as a screen. The VIC-20 had 5KB of RAM and the screeen showed 22x23 characters.

VIC-20 had colours and sound and was primarily intended for games. You could buy game cartridges and plug into the expansion port on back of the computer. But just like the PET computers there was also a built-in BASIC interpreter. In fact, it was the same BASIC interpreter as in the PET computers, i.e. there were no new commands for graphics or sound, e.g. nothing like the PLOT command on the ZX-81 and ZX Spectrum. The only way to program graphics or sound was by using the PEEK and POKE commands in BASIC, or by writing programs in machine code, which I also learned. The processor in the PET and VIC-20 was a 6502, an 8-bit processor that was used in many computers and game consoles around that time, including the first computers from Apple (Apple I and Apple II).

I also got a floppy drive for my VIC-20. It was rather expensive, but I thought it was worth it. When I programmed on the ZX-80, I saved my programs on cassette tapes, which was rather tedious.

A couple of years later, Commodore released their next home computer: the Commodore 64 (also known as C64 or VIC-64). I didn't think I was done with the VIC-20 yet, but my friends in school thought it was time to upgrade, so I did too. The Commodore 64 looked the same as the VIC-20, but it had better graphics and sound. And it had, like the name suggested, 64KB of RAM. The screen (still a regular TV) now showed 40x25 characters (the same as the PET computers in school), and there were 16 colours to choose from. In graphics mode you got 320x200 pixels, but the BASIC interpreter still had no commands for graphics and sound, you still had to use PEEK and POKE. The processor was a 6510, a variant of the 6502, and the clock frequency was still 1MHz, so the computer was not faster than the PET or VIC-20.

Historical tidbit: the BASIC interpreter that was used in many of these early but popular home computers was created by a small company called Micro-Soft. When IBM later decided to start selling personal computers and needed an operating system, they turned to Micro-Soft, who then developed PC-DOS, that was later sold under the name MS-DOS to other manufacturers of personal computers, which meant that IBM soon lost control over the personal computer market and Microsoft became one of the largest companies in the world…

Amiga

The next big step forward in the home computer evolution came when Commodore released the Amiga 1000 and it didn't take long before my friends from school and I bought one each. The Amiga 1000 had a rather compact design. The screen could be placed on top of the computer box and the slim keyboard could slide under the computer box when not in use. The mouse had two buttons.

The processor in the Amiga 1000 was a Motorola 68000, the same processor that was used in Apple's first Macintosh, which was released around the same time. But the Amiga was a lot cheaper and had, thanks to chips designed specifically for it, better graphics and sound. The operating system was also better, with support for preemptive multitasking from the start, i.e. you could have several programs running at the same time in different windows. The Macintosh could only run one program at a time.

The Amiga 1000 was sold with an accompanying analogue RGB screen, which showed a sharp image wich was 320 pixels wide (max 32 colours) or 640 pixels wide (max 16 colours). The Amiga generated a TV compatible video signal, which (in Europe) meant you got 50 frames per second with 256 lines, or 25 frames per seconds with 512 lines (with interlace). The latter caused a certain flicker, so in practise one used 640x256 pixels when working with text and 320x256 pixels for graphics and games.

In 1987 I sold my Amiga 1000 before I went to London to study for a year. When I came home I bought the successor Amiga 500, essentially an Amiga 1000 built into a keyboard (somewhat larger than a Commodore 64). Some of my friends bought an Amiga 2000, essentially an Amiga 1000 in a larger box with expansion slots.

In 1991 came a bigger upgrade to the Amiga: the Amiga 3000. Around that time I had completed my studies and started working and earning money, so I though I could afford buying an Amiga 3000 even though it cost 35000kr. But that was a one off, I have never bought a computer that expensive again.

The processor in the Amiga 3000 was a 68030 running at 25MHz, which made the computer 5-6 times faster than the earlier models, which had a 68000 running at 7MHz. But the graphics chip was running at the same clock frequency as before and was not faster, which meant it was possible to get faster graphics by installing a patch that used the main processor instead of the graphics chip, e.g. to scroll text in a terminal window.

The Amiga 3000 had a built-in flicker fixer, also known as scan doubler, which converted the TV compatible video signal to a more VGA like video signal. This meant that on the included screen you could get 640x512 pixels and 50 frames per second, without the flicker caused by interlace on previous models.

The Amiga 3000 was the first computer I bought that was disturbingly noisy. It was the fan noise that was too loud. The Amiga 1000 also had fan, but it was so quiet that you hardly ever heard it. Fortunately someone soon found a way to make the fan in the Amiga 3000 quieter: you could connect a thermistor in series with the fan to slow it down. The idea was that if the computer got hot, the resistance of the thermistor would drop and the fan would spin faster, but as far as I can remember, that never happened, the fan kept spinning slowly all the time.

The Amiga 3000 was also my first computer with a built-in harddrive, and that made some noise too.

PC

Commodore released a few more Amiga models after the Amiga 3000, e.g. the Amiga 1200 and Amiga 4000, but it seemed like Commodore was unable to keep up with the fast progress in the computer industry in the 1990s and the company went bankrupt in 1994.

So after using my Amiga 3000 for 5 years, my next home computer was a PC, which I bought in 1996. It had a Pentium processor running at 133MHz and was roughly 20 times faster than the Amiga with its 68030 processor at 25MHz. The price was also significantly lower: around 10000kr for the computer and a few thousand kr for the screen (a MAG DX1795).

The standard operating system on PCs around that time was Windows 95, but I chose to install NetBSD, a free Unix variant that a few of my colleagues at work liked. After a while I switched to FreeBSD, a somewhat more mature variant of Unix, and eventually to Linux, which by then had become very polular and thus had significantly better hardware support and software compatibility than the BSD variants.

A Pentium based PC meant that I had a home computer that was faster (and a lot cheaper) than the computers at work, and I could do things I previously could only do at work:

I upgraded my PC a few times and in the year 2000 a bought a completely new PC with a Pentium-III processor. In 2002 I got a PC with a Pentium-4 processor.

My first PC happened to be a model that was fairly quiet. Later, I deliberately chose models designed to be extra quiet. It was a company based in Gothenburg, CapTech, that had a series of models called Decibel that they made extra quiet in the following ways:

[CapTech Decibel-computer]
Just unboxed CapTech Decibel-compter with a Pentium-4 processor and the screen NEC LCD1830. Installation of Redhat Linux 7.2 in progress.

Mac

The Pentium-4-based computer I bought in 2002 became my last PC purchase. The way I saw it, there were two problems with continuing to by PCs:

For these reasons, my next home computer was a Mac mini that I bought in 2007.

At work I started using Macs too, first a MacBook Pro (15-inch, Mid 2009) and later a MacBook Pro (Retina, Late 2013). Retina meant that the screen resolution was doubled, from 1440x900 pixels to 2800x1800, which I thought was a big improvement. In particular text looked much better and I couldn't imagine going back to using a "normal" screen.

Since I used my MacBook Pro from work at home as well, I didn't feel a need to by a home computer just for personal use. So it took a while before I bough a new computer, but when it happened the new one was a Mac Mini too, which I bought in January 2016. While it had a fan and a harddisk, it was virtually silent (12dBA according to Apple's specifications), except when it was working hard, when the fan noise could be heard.

I was very happy with the different Mac computers I used, and for many years I thought "once you go Mac you never go back". But then (in 2015) Apple made the switch to butterfly keyboards, which were noisy and caused problems for many users, and then (in 2016) they replaced the function keys with the Touch Bar, which seemed rather unnecessary and just an excuse to raise the prices. After a few years without any solutions to these "problems" I sadly started thinking that my next laptop had to be something other than a Mac.

It wasn't until 2020 that Apple announced a new laptop that I found interesting: the MacBook Air with the M1 chip (Apple Silicon). I bought it in December that year, just a month or so after it was released. It was a big step forward compared to my MacBook Pro from 2013:

The only drawback was that the screen was only 13 inches, which was hard to get used to after using a laptop with a 15 inch screen for over 10 years, and I wished there was a 15-inch model of the MacBook Air. Unfortunately it wasn't until 2023 that Apple released such a model, and by that time I had already bought a 27-inch screeen with 4K resolution, which reduced the need for a laptop with a bigger screen.

[MacBook Air (M1, 2020)]
Just unboxed MacBook Air (M1, 2020)

Raspberry Pi

In recent years I have also bought a number of small Raspberry Pi computers. I thought they could be fun to experiment with, and e.g. easier to work with than a PC if you wanted to develop your own operating system.

In november 2021 I bought a Raspberry Pi Zero 2W. While it is one of the cheapest and smallest computers I have ever bought, and although it is nowhere near the fastest computer I have ever used, it is unbelievably powerful compared to the home computers of the 1980s. For example, it is powerful enough emulate the ZX Spectrum running at full speed while using only a few percent of the available CPU power.

[Raspberry Pi Zero 2 W]

My most recent purchase was a Raspberry Pi 5. It is the first Raspberry Pi with performance that feels like a "real" computer. For example, you can surf the web with Firefox and watch HD quality video (1080p) on YouTube without things feeling too sluggish. It can feed 4K60p to my 27-inch screen and provides a very fluent graphical user interface. (My Mac Mini can only deliver 4K30p). But of course the raw performance is nowhere near what I get from my MacBook Air with Apple Silicon, and there are still various little software related annoyances which means it can't quite replace a "real" computer, not even a 9 years old Mac mini, but it could definitely replace my Mac mini as a home server (for my mail and web pages, etc).

[img_2544.jpg]
Rasperry Pi 5, unboxed, plugged in and powered on

Other home computers

Here is a list of computers I have bought and used at home over the years.

When Model CPU, clock RAM HD Modem/Internet
1980 ZX-80 Z80, 3.25Mhz 1K-16K
1982? VIC-20 6502, 1MHz 5K-13K 300bps
1984? C-64 6510, 1MHz 64K 300bps
1987? Amiga 1000 68000, 7MHz 512K 1200bps
1988? Amiga 500 68000, 7MHz 1M 20MB 2400bps
1991-1996 Amiga 3000 68030, 25MHz 2MB-6MB 50MB-2GB 2400bps-16.8kbps
1996-2000 PC Pentium, 133MHz 16MB-96MB 1.2GB-3GB 16.8kbps-56kbps
2000-2001 CapTech Decibel PC Pentium III, 700MHz 128MB 20GB 56kbps, ISDN 128kbps
2001-2015 CapTech Decibel PC Pentium III, 800MHz 256MB-512MB 40GB-250GB 56kbps, ADSL 2.5/0.75Mbps, ADSL 8/1Mbps, ADSL 13/2Mbps, Cable 30/1Mbps
2002-2007 CapTech Decibel PC Pentium 4, 1.8GHz 256MB-512MB 40GB-160GB Cable 3/0.128, 1.5/0.25, 3/0.25, 6/0.384 Mbps
2007- Mac mini Core 2 Duo, 2GHz 1GB 120GB HDD, 250GB SSD ADSL 8/1Mbps, ADSL 13/2Mbps, Fiber: 100/10Mbps, 100/100Mpbs, 250/250Mbps
2016- Mac mini Core i5, 2.8GHz 8GB 2.1TB Fiber: 100/100Mbps, 250/250Mbps
2017- Raspberry Pi 3B ARMv8 (Cortex-A53) 1.2GHz 1GB 16GB-32GB
2019- Raspberry Pi 3B+ ARMv8 (Cortex-A53) 1.4GHz 1GB 32GB Fiber: 250/250Mbps
2019- Raspberry Pi 4 ARMv8 (Cortex-A72) 1.5GHz 2GB 32GB-64GB
2020- Raspberry Pi Zero ARMv6 (ARM1176) 1GHz 512MB 32GB
2020- MacBook Air Apple M1 (ARMv8) 3.19GHz 8GB 256GB
2021- Raspberry Pi Zero 2 W ARMv8 (Cortex-A53) 1GHz 512MB 64GB
2023- Raspberry Pi 5 ARMv8 (Cortex-A76) 2.4GHz 4GB 2TB SSD

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