Bad AY emulation. Bad AY emulation. BAD AY EMULATION! Have you tried some of the demos? Even those which require precise timing and are designed for the stock 128K have problems. The saddest thing is the bad hardware envelopes emulation of the AY sound chip. Take your time and have a comparison between the real thing (even Fuse emulator sounds better!) and this. I'm disappointed and I would never use this instead of the real one or a "proper" clone for presenting the ZX Spectrum stuff.

Here some more info: -> 110V output: your transformer probably has isolation outlets. This are 1-1 transformers where you have the same windings in primary and secondary. They are very handy when you work on something where you don’t really know if electrical isolation is done properly. The transformer will isolate the device from your mains and create a floating voltage. That means that if you touch something that carries current, you pull the floating voltage to 0. effectively you don’t get electrocuted. BUT be very careful. If you short BETWEEN the 0 and phase if you isolated outlet you still die.

But the fact still stands, the amiga was what it was and its a thing of the past and so upgrading the ability of the system leads nowhere as more demanding games etc were not made for hardware that didnt exist. The performance is wasted unless youre an avid Amiga Quake player.

Is it still good 3 years on? O here they go yellow again within months.

OOOONSHAPE!!!!

Your expertise really shine through-great work! 👏⚡

can you have the switch coming out of the trapdoor on an amiga 600/1200 so it's not untidy?

What kind of 40pin dip chip are they actually then?

Just about anything Germany is going to be high quality. Flush cutting tools are a big plus.

Why not wire your entire station with an isolation transformer? That is the smarter and safer solution. Then you can use an OLFA cutting mat. This is what professionals do. An isolation transformer will save your life in many circumstances, so why not just completely remove ground?

Thanks for the review - I immediately ordered one. Actually a ZX Spectrum was my second computer in 1983 (after the ZX81) and did a lot of (assembler) programming on it. It was the major reasons why I studied computer science - my life would have been completly different without it... 🥰

Everything Retro learned from their earlier projects paid dividends here.

My theory is that they have tons of fake chips with the same dip packaging. They post it as dozens of retro chips, and as orders come in, they laser whatever markings match the one that was ordered.

Most lovable video i was waiting since childhood. I m made for electronic 😊

They may not have sponsored you but they should have! I just went out & got one on the strength of this great video. I'm afraid to admit it was the blue & yellow bars that got me! brings back so many fond memories and as a software & product engineer, I can respect what an awesome job they've done on this repro.

Lord Alan Sugar says: "Inviting" like a "pregnant calculator" 🤣 Nice presentation, thank you! I like the Speccy, have a few myself.

where did you get the brand new dragon 64 from ?? thanks

I need to get brave here sometime soon and clean my CRT before it dies. Also I should stop inhaling computer dust. I wonder what kind of fun cancer I'm going to get when I get older. 🤔

its a lovely looking machine

This computer was my first and it started my journey. My history of computers: TI-99/4a --> Vic 20 --> C64 --> Atari 1040Stfm --> Amiga 500 --> Amiga 1200 --> Amiga 4000/040 --> Gave up and went PC

I played a lot on my ZX Spectrum 48K but also learned how to program. I followed an IT career. I still own it and it still works. Some years ago I coverted game images to wav and connected the audio to my computer to upload the game. The Spectrum looks like a great alternative.

One thing to remember about oscilloscope sampling rates is that you aren't always going to be looking for signals when repairing equipment - sometimes you will want to see transient bugs that can be several/many times the rate of the signal. Especially if you are dealing with devices that have a lot of power supplies on the board. I would argue something like 5x the signal rate is a better rule of thumb than the Nyquist rate. This will depend a lot on what exactly you work on and what you use your scope for, so definitely take your own use case into consideration. Cheers!

Thanx for the heads up! I just ordered one.

Question - is OUTI/INI are ever used in practice? While LDIR/ LDDR are highly useful and used all the time, have there been peripherals fast enough to handle? Memory disks?

Thank you very much for this tutorial, just repaired my fdd by rotation this motor!

Just curious, are there an options to expand the memory? As indicated, the board as 512k static ram, but eZ0f90 Architecture has an 24 bit address bus for a max of 16mb. Are the address lines available for an external memory option?

Thanks you for this video. I learned so much and got the courage to try to repair my other SVI-728. I had opened it and was put off by the hot glue mess and what a pain it would be to get to the pcb. I also found the service manual that pinpointed the issue with my machine. My issue was that neither of the joystick ports worked. There was a flowchart that pointed to 74LS157's so I desoldered and replaced them and it fixed the issue.

Most problems with CPCs are RAM chip related ones. Should be the thing you check first.

Thanks a lot, i fix my floppy drive just now after find your video.❤

Can you type the hidden code 6031769 to enable shortcuts to jump to another label in Manic Miner. Hmm I wonder why still remember this, and what these number means for the inventor of Manic Miner

Scalpers have gobbled up all stock and are selling it for between £30 and £100 more on Amazon and ebay.

As a kid I cut my teeth on assembly code for Zilog family processors and the mos6502. Software and hardware were hardly any different when you code on metal trying to make the things do what you want. This was delightful! The Dandanator solution is so clever!

I had a Spectrum +2, and later a +3 (which I still have).

It's sold out now in the UK. The power of nostalgia!

I'm loving that the price is about the same as it was when I bought mine in '83. Very happy to see it has The Hobbit but a little upset they didn't include Psion Flight Simulator or Spectres (also by Psion), one of the best Pacman clones on the market at the time. In fact it was Spectres that got me into assembly language programming (and my career in IT) as I needed very badly to know how it went so fast, with such fluid sprite movements and animation!

excellent. what about exhaust system to suck all that solder smoke ?

Thanks. It was also in Denmark although I only knew one guy who had one. I started out with my father's Speccy, but when I had to get my own micro, the C64 just ruled the day.

lol what tools do you need? yes, all of them!!

Awesome video! Please advise me what power supply to buy for it

"The Microdrive" made me cry. I've had the real thing (and the ingenious ZX Printer with my magnificent Spectrum+).

Correction: the ZX Spectrum actually has a much more extensive BASIC than the Commodore 64, which was only rudimentary. The keys producing keywords instead of typing them must have been a way to compensate the awful keyboard quality. I'm surprised they replicated it instead of giving a decent one. The fact it's emulated is a little sad, as it lags more than an FPGA.

Could you please design a simple I/O device? I wish I could have a simple device with 8 bit output and 8 bit input on two different addresses one for input and one for output, for example it should use basic instructions in and out: A=IN(&F8E0) Where A is a variable B=(0...255) OUT(&F8E1), B

Amstrad CPC use A10 to select F8xx, F9xx, FAxx, FBxx so the lower address busmust be decoded while A10 is low, the manual say it is possible use F8E0 as first available user I/O address

In terms of processing power the Commodore 64 wasn't more powerful at all than the ZX Spectrum. Yes, the C64 had better keyboard, better sound, but the Spectrum had a faster CPU and MUCH better BASIC interpreter.

The RAS/CAS switching not being done explains it. I was not aware of that addressing scheme, but you explained it brilliantly! I'm glad I've found your channel.

This is NOT ZX Spectrum. This is cheap chinese console in disguise.

Never have seen a badly de-laminated PCB. Definitely, it suffered a bad case of excessive hot air, and vintage FR4 PCBs de-laminate more easily than the new material. Anyway, great video!

Two things about the video system. First, external terminals with microcomputers were a thing. In the bad old days, you might have had an ADM3A or even a VT100 that did all the graphical processing, such as it was. Second, the fast microcontroller could be thought of as replacing custom chips like VICII.

Fun fact. Matthew Smith programmed Manic Miner in a special way to increase graphics performance because of the memory contention. The screen was animated in high RAM, and then moved to the screen buffer with the ldir command to update the screen itself.