Learn vintage electronic / computer engineering at 2019.

[Muttley Black]

If you build your own design, there will be absolutely no ready made software for it. So you will need to write some software yourself. The Z80 only understands 8 bit binary numbers (bytes) [called machine code]. So to program at this low level in a manner that is a bit friendly to humans, there is assembly language. The mnemonics translate directly into machine code.

If you build a design which is the same as, or compatible with an existing design, then there will be at least some software that you can run on it.

In both cases, you have to give the CPU the start-up code somehow. In the designs that I talked about earlier, this is code that is programmed into a ‘ROM’ chip.

If you have a RS232 serial communications port, it may be possible to transfer program code from another computer (say a PC) into the RAM of your home build computer, and then run that software.

If you have a reasonable fast PC, you can download various emulators for most of the popular 1980s computers. Using cross compilers, you can write and edit source code using a editor on the PC. Then instruct the cross compiler which file you want assembled, and it will produce a file containing the machine code. Load this into the emulator and you can see if it works. Then you can adapt the code to run on your home built computer. [Warning, this sounds easy, but it eats time and can be frustrating at times].

There are many ways to learn. It does not have to be do 1, 2, 3 etc... in a strict order.

If you don’t have any experience building circuits, then I strongly recommend you start with some simple electronic projects first. Learn about the various components. These days, it is easy to find all kinds of interesting stuff via internet searches.

If you can wait for a bit of a delay, buy some bits from China, such as a breadboard, a selection of resistors, capacitors, diodes (1N4148, 1N4001), transistors (2N2222), and some simple logic chips (74LS00, 74LS02, 74LS04), a couple of NE555 timers have a play.

I’ll add some links later...

Mark

I totally understand! Thank you very much for the time you spend to explain all this stuff with simple words! I just order the components you suggest me to buy. I started watching some videos about electronics for beginners and of course reading also about them on the net. When the components arrive and feel ready and comfortable to deal with them, i am gonna search for small project's inside the philosophy of computers to do.

For dabbling with logic gates, microprocessors, etc., I highly recommend Ben Eater’s video series on how to build an 8-bit computer. It’s very detailed and quite easy to follow.

Very nice and helpful videos! Thanks for sharing!

[1024MAK]

This supplier on eBay is what I have used recently for breadboards. Mine came in about ten days.

One thing that I forgot to include in my suggested list of bits, was LEDs. You don’t need fancy white or blue ones. Red, green and maybe yellow will be fine. For use on a breadboard, 3mm types will be fine. Always (unless shown differently) connect a resistor (typical value 330 ohms to 1K ohms for use on a 5V supply) in series with each LED.

Again, packs of LEDs can be obtained from China for not much money these days.

It will be handy to have a suitable DC power supply. The easiest type to get these days is a USB PSU. Then cut the end of a cheap USB lead. Alternatively an old mobile telephone PSU may be suitable. But post up details first, as some are unregulated.

Alternatively you can use a battery. For circuits designed to run on 5V DC, you will need either three fresh 1.5V alkaline cells, or four 1.2V NiMH cells. And of course a suitable battery holder for them.

Mark

[dfzx]

For learning the basics it might be quicker and easier to use one of the many circuit designer and simulator websites. They're not as much fun as soldering real things together, but they make experimentation a lot quicker (and less expensive when you get to the point of blowing things up).

For Arduino stuff I like https://www.circuito.io/ because it simulates the Arduino hardware and software, plus all the devices you're likely to want to lash up to an Arduino. There's lots of others which are less Arduino specific.

[djnzx48]

Thanks for posting those links, there's a lot of useful information in there.

Do you guys often get PCBs etched for circuits after you've got the initial design working? I've done a few boards myself and it was a pretty simple process, but I know the materials can get expensive, especially if you make a mistake.

[Ast A. Moore]

PCB etching is quite simple indeed. For more complicated designs and larger quantities, though, it’s better to outsource it. There’s no shortage of places that will happily make you a bunch of PCBs of virtually any complexity. Even through-hole plating doesn’t cost a lot (if anything) nowadays. The slight downside is that you’ll also have to learn how to properly prepare layout files for them.

[Muttley Black]

This supplier on eBay is what I have used recently for breadboards. Mine came in about ten days.

One thing that I forgot to include in my suggested list of bits, was LEDs. You don’t need fancy white or blue ones. Red, green and maybe yellow will be fine. For use on a breadboard, 3mm types will be fine. Always (unless shown differently) connect a resistor (typical value 330 ohms to 1K ohms for use on a 5V supply) in series with each LED.

Again, packs of LEDs can be obtained from China for not much money these days.

It will be handy to have a suitable DC power supply. The easiest type to get these days is a USB PSU. Then cut the end of a cheap USB lead. Alternatively an old mobile telephone PSU may be suitable. But post up details first, as some are unregulated.

Alternatively you can use a battery. For circuits designed to run on 5V DC, you will need either three fresh 1.5V alkaline cells, or four 1.2V NiMH cells. And of course a suitable battery holder for them.

Mark

Hi Mark.

I have plenty of green, red and yellow Led's. I had purchased them for my arduino dram tester's back then. About breadboards i also order some yesterday, but i forgot to mention it. Also to be able to give power to breadboard i order two from this. Apart all above mentioned, i got also some cheap 5W 9V 12V 24V To 5V DC 7805 module's to play with them. By the way, have you (or anyone else) ever tried this module's to replace the old 7805 on ZX Spectrum? Are they any good? In a long term of use...

Thank you!

For learning the basics it might be quicker and easier to use one of the many circuit designer and simulator websites. They're not as much fun as soldering real things together, but they make experimentation a lot quicker (and less expensive when you get to the point of blowing things up).

For Arduino stuff I like https://www.circuito.io/ because it simulates the Arduino hardware and software, plus all the devices you're likely to want to lash up to an Arduino. There's lots of others which are less Arduino specific.

I got that in mind and of-course i give it a try. Why not! As you say you can do a lot quicker test's. But all the fun is the real soldering way with real components!

Thank you!

[1024MAK]

I have not used that particular DC/DC converter, but have fitted RECOM DC/DC converters to ZX81, ZX Spectrum 48k computers and to a recreated Jupiter Ace computer.

ZX81 fitted with a RECOM over on Sinclair ZX World

A recreated Jupiter Ace fitted with a RECOM over on Sinclair ZX World

Mark

[Muttley Black]

Yes, I know about Recom, MuRata and Traco. Traco is what I used to replace the 7805 in my issue two tester board. I just wondering about that cheap fellas, if are good idea to be a part of Zx spectrum dc circuit. Anyway, when they come I do a stretch test in one of them and I post the results.

Thank you.

[Muttley Black]

Anyway, when they come I do a stretch test in one of them and I post the results.

That cheap as chips Chinese regulators work nice. I did some stretch tests with no problems. They give perfect 5 Volts and they cooperate nice with the DC spectrum circuit. More than 20 days is fitted on my testing board, with every day of use, with stretched input voltage from regulated power supply.

In case you want to give them a try, you need to replace the angle type pins that are soldered on them and put new straight ones, upside down.

[1024MAK]

Thanks for that

They also are available from other places, for example eBay. Search for “5v 7805 lm2596 dc converter”.

Some time ago I was asked about books to learn more about electronics. One book I found very useful, but is not really a beginners book, rather an intermediate level book, is “Instrumentation and Test Gear Circuits Manual” by R.M.Marston. ISBN 0 7506 0758 0. The same author also has various other books, but I don’t have those. I have no idea if it is still in print. Note this book and the books, magazines, and links below are all general electronics, not specific to 8 bit computing.

For learning, EPE (Everyday Practical Electronics) which has recently changed name to PE (Practical Electronics) has “teach-in” series. Some of which are available separately. See their web site https://www.epemag3.com/. Teach-in CD-ROMs (these are not cheap if money is an issue). They also do two electronic “manuals” on CD-ROM. I have older paper versions, they do go into a fair level of detail, but are a bit “dry” (meaning, not exciting, more formal education type material than fun).

There is a good book that I used to borrow from my local library, but I can’t remember the name of it

These You Tube channels may also be of interest:
Big Clive Dot Com and he also has a web site
Julian Ilett
DiodeGoneWild and he also has a web site!

Mark

[Muttley Black]

Thank you for the treasure!

You have an opinion about the “Electronic Principles” book, by Albert Malvino?

[1024MAK]

in terms of general computing, which includes how home computers work, there is also the part work magazine “The Home Computer Course” which was followed by the “The Home Computer Advanced Course”. They covered the mainstream U.K. home computers, which of course included the ZX Spectrum

Mark

[1024MAK]

Thank you for the treasure!

You have an opinion about the “Electronic Principles” book, by Albert Malvino?

Yes, as I understand it, it is a very good book. I don’t have a copy myself. But I think I did see a copy in my local library back in the 1980s.

You don’t need to spend money on the latest edition though, not for understanding a 1982 computer

Mark

[Muttley Black]

in terms of general computing, which includes how home computers work, there is also the part work magazine “The Home Computer Course” which was followed by the “The Home Computer Advanced Course”. They covered the mainstream U.K. home computers, which of course included the ZX Spectrum

Mark

I just read that post! This is magic found for me, thank you!

[Hyuma]

I use this interesting topic to ask, as a novice that I am, if you know some video tutorials to learn how to use the oscilloscope applied to these vintage computers (zx spectrum, commodre 64, etc.). I would like to buy one, but I would also like to learn how to use it well.