The ZX81 was under 100 quid as well when it came out

Built in that famous silicon valley area known as Dundee

I bought one last week and think it is brilliant. It has superb I/O capabilities – the only problem is that I am trying to learn Python – in itself not a problem but I am having to unlearn and forget all my previous programming knowledge. Whilst it is true that you can use most languages with it, Python is now the most universally used language – so to me it makes sense to try and become fluent with it.

I am quite surprised how quick and easy it was to set it up on my network and use my PC to access and control it remotely. Value-wise it is superb.

I am currently using it to replace my underfloor heating control system so I can remotely access it from anywhere and change the program and set temperatures at will and use the data logging capabilities.

Edited By Steve Skelton 1 on 02/11/2020 11:39:06

I'm a big fan of the Micromite family (and Micromite BASIC – MMB which is a very well developed language for embedded control purposes).

I can build a 'Mite' with just two components (a 28pin DIL chip and a capacitor) for less than a fiver. The Micromite 'family' originally began however with Geoff Graham's original Maximite, a 'single' chip computer first released in 2011 that used a monochrome TV as it's console device. This was followed by the Colour Maximite shortly afterwards.

This year the Colour Maximite 2 (CMM2) has been released and it is basically a very well integrated single board computer (based on a very fast ARM one). The general details can be found here…

Colour Maximite 2 – Details

For a quick review of some of it's capabilities look here CMM2 – The 8 Bit Guy

Now I will admit that I don't yet own a CMM2 – although I certainly do have a number of 'Mites' in various guises.

But I do own both Arduino and RPi systems, so have some experience of the alternatives.

My RPi is a 3B and is very fast but frankly, almost as unfriendly. I need simplicity and "enough" speed and in my experience the RPi may be good for folk needing a full 'System' (with its Linux Operating System) but if you need something that actually works out-of-the-box (and which doesn't need continual software updates) then the CMM2 may be much better option for you.

Plug a monitor into a CMM2 (turn it on) and away you go. You will be immediately into MMB, with direct access to all the graphics and I/O facilites that are built-into the CMM2.

If I compare that to my efforts with the Pi, then I know which one I would be choosing if I needed a desktop graphical display that was easy to programme and that could connect easily to the outside world. It's an alternative approach that might suit some here much better than the Pi (especially if they are like me – technically & time limited)

Regards,

IanT

Reliability issues aside, the ZX81 was more than adequate for controlling something like a central heating system, with just 1k of memory and machine code I could understand. I was in the process of adapting one for an automated cattle feeder just before I gave up keeping cattle a few years ago, and the program used nowhere near 1k of memory.

The Pi sounds rather like a sledgehammer to crack a nut in such circumstances. It has as much RAM as around two million ZX81s and the processor runs about a thousand times faster

But, if there was enough free time in my life, I would love to play around with a Raspberry Pi . . .

£100 was worth a LOT more in 1981, about £340 in 2020.

While I have a couple of Pi's, a a hardware type I don't like that there is virtually no data available for the Broadcom chip they ae based on.

The Micromite is interesting and a bit lower level. Being microchip PIC based there is lots of data. Personally I use "bare" PCs and a basic compiler running on a PC to generate code rather than a interpreter on the chip. I us PicBasicPro PBP3. As I use it for work and hobby I have the full version, but they do a perfectly functional free "student" version for non commercial applications.

It's great for simple, and not so simple, control aplications It won't replace a PC of course.

Robert G8RPI.

A friend of mine used a ZX81 to operate his heating system back in the eighties. He hit the pipes with it whenever there was an airlock.

George B.

Hi Robert,

My 'Mites' are all PIC32 based (including the 28-pin DIL ones) but there are also versions based on STM Nucleo ARM boards too. The CMM2 uses a 32-bit ARM Cortex-M7 at 400MHz (or 480MHz) with 2MB of flash and 1MB of on-chip RAM. There is another 8Mb of RAM memory on the board itself.

I think back in the day (e.g. late 70's, early 80's) when folk were trying to squeeze the last bit of performance from 8-bit processors – there may have been good reasons to prefer a compiler over an interpreter.

However, these days I value my time more than the CPUs and most of my small programmes spend much of their time just sitting in loops, waiting for something to happen. However, when I'm sat there trying to get something to work, the fact that the system is interactive is a real bonus that saves me a lot of time and patience. Even my little 28-pinners run an order of magnitude faster than an 8-bit 'console' did from back in the day. 'Speed' is rarely an issue for me.

Of course, if I were a games programmer, performance might well be an issue. But with a modern CPU (such as the ARM Cortex-M7) this is much less so today. The CMM2 can currently run over 300K BASIC lines per second and clever people (clever than me for sure) are writing 'retro' games like Wolfenstein on it, that are running at 30 frames per second. That's using just an interpreted (on-board) BASIC like many here may remember from their distant past.

Regards,

IanT

Edited By IanT on 02/11/2020 15:36:02

Hi,

By lower level I meant closer to the hardware, not lower performance.
For any given processor a compiler will always give better perfomance and I'm not tied to one supplier for my chips. I'm a bit biasied as I started with the BasicStamp intepreter pic modules nearly 30 years ago and with those early 8bit 4MHz chips with little memory PBP was a big improvement.

I try not to say too much but I really don't like Arduinos. It sarted with the realisation that they had offset the two expansion connetors so you could not use standard prototypying board but had to use Shields. This drives the modular culture where an electronics "design" is a bunch of pre-built modules and often not even solder. This does have advantages in getting people interested, but is limiting in the long term. Very similar to the "maker" robots. Rant off.

Robert G8RPI.

I'm another Micromite fan. You just switch it on and start programming. Micromite BASIC is powerful, easy and elegant. A programmer friend despises BASIC: he worked extensively in Java, on serious applications. I've seen some of his code, for simple applications – it's pages long and has to load several libraries, just to do what a few lines of 'primitive' BASIC can do. Not elegant. The Pi boots up relatively slowly, loading masses of arcane stuff, most of which won't be used, and then you need to find a suitable programming language. OK, in some ways it's more versatile, but it's like having a Ferrari to pull a donkey cart. If I were building an electronic leadscrew, for instance, I'd base it on a Micromite. Horses (including donkeys) for courses.

I think the actual Broadcom chip used for the display can actually output the the old analogue video as the Pi-compute board brought out more of the pins and could do so – it’s an annoyance as I too have several old monitors which could be used as single use machines

I bought a ZX81 as a kit for £49.95 and the most entertaining part was assembling it, I played with it for a couple of hours and lost interest, motorbikes seemed much more exciting. My Raspberry Pi went the same way, mildly entertaining for a while and then forgotten about, the Arduino suffered the same fate. Not being interested in games it is a job to find a task for these gadgets to be useful for.

Mike