You Make Robots Blog

Keeping Retro Computers Alive!


Considering buying an SD tape emulator for your retro computer? Well here is a nice checklist to help you choose:

  1. Make sure the device has an AMP circuit to boost the volume. Time and time again low powered devices have proven to fail while loading games. You might get away with loading some games but essentially you need an AMP.
  2. In one scenario an AMP by itself might not be enough if you have a deaf computer. Deaf computers need more than volume on the characteristics of the audio. The Deaf computer issue is not limited to ZX Spectrum. You could experience this with other computers. Make sure the device can accommodate this issue.
  3. If you are planning to use a device as a wave player running Arduitape or Digiwavuino make sure the audio circuit contains a low-pass filter.
  4. If you need the device for MSX, Dragon, Acorn/BBC, or Oric make sure the sd device has a remote socket. Without it, it is useless. A lot of games on these computers like to control how the games are loaded by pausing the tape from the game automatically.
  5. If you need a device for multiple computers at the same time be careful on buying a device based on an Arduino Nano. The Arduino Nano is limited on memory. This is ok when you have a few retro computers. Check out the Maxduino Ultimate which is based on the Atmega 4808 chip and has double the memory and can support 2-3 times computers in one device.
  6. Check to see if the vendor offers an easy way to update the device. Most of these devices are programmed using the Arduino IDE. If you don’t know what you are doing it can be a bit daunting. That is why we developed an easy flash tool called TZX_Tools which runs on Windows that allows you to flash TZXduino, CASduino, Arduitape, Digiwavuino, and Maxduino without knowing how to code.
  7. Some TZX player apps claim to be multi-load compatible. Multi-load is where the game loads in stages and if you were loading it from cassette you’d be expected to manually pause the tape. Now the only software that truly supports Multiload TZX files is Maxduino. Maxduino monitors for a “stop tape” block and automatically stops the game load. Nothing on the market can do this in the same way.

I hope you found these tips useful..

The Mattel Aquarius seems to have a very small community of users and I was trying to work out whether a Maxduino type device would sell in that community. I asked Rafael Molina Chasserot the developer of Maxduino to add the caq file format to maxduino. I helped by retrieving the caq2wav source code. As an interim solution between me and Rafael, we have developed CAQ2WAV2TZX a tool allowing you to convert caq files in bulk to either wav format compatible with Arduino wav players like ArduiTape and DigiWavuino or convert to tzx format making it compatible with any TZX type player like Maxduino. I don’t see a mass market for such a specific device but here you can buy a Maxduino especially for the Aquarius machine. Click >HERE<

This is a nice video of TJ demonstrating the ZX-Frankenstein . Early mode and still work in progress because in the next iteration I’m moving the joystick port to the top. For those who just cannot wait to get one I now include an angle adapter so the joystick cable is pointing upwards and doesn’t trail across the keyboard. Nice video nonetheless.

Nice unboxes video by TJ Ferreira with lots of goodies from You Make Robots. We like to support retro channels. Below are a few of the other Retro Channels we have supports:

  • Phil Kruman
  • Retro Robbins
  • Chris’s Retro Corner
  • The Retro Shack

But back to TJ… Thomas makes me laugh and he is a true Speccy fan so here goes:

TJ also recorded a 2nd video using the Maxduino Ultimate to load up a game on a Timex 1000 machine:

A nice but honest review from the Retro Shack of the 48K+ ZXuitape which is an SD solution for a ZX Spectrum. If you need a solution that lets you load games into your ZX Spectrum 48K+ from an SD card this is the one. It screws into the speccy case to make it look like part of the speccy. ZXuitape comes in different models. This is the model for the ZX Spectrum 48K+. You can use it to load up games in tzx, p, o, or tap file format.

When I first started developing my own TZXduino PCB boards I was struggling to get it working with my Sharp MZ700 computer. Sometimes it worked and others not. I couldn’t put my finger on it, but then I put a scope on the output of the TZXduino device I purchased from the original guy who made them. I noticed a difference while playing around. I thought about this for a while and had read that LM386 needs to operate at 5v-18v and but really needs to operate higher than 6v to minimize drain. Most of the TZXDuino that were in the wild were driving the LM386 ( or AMP module) from the 5v pin on the Arduino thus allowing it to operate from the Arduino USB power. I noticed that with the drain of other components that only 3-4v was coming out of that pin and it occurred to me maybe that is the issue. So I factored that into the design of the PCB. Sometime later I found myself in a similar situation with certain ZX Spectrums. After digging about I found out some older models of the ULA chip can go a little deaf. In my own systems, I was fixing this issue by replacing the ULA. Fast forward and I decided to architect in the fix I had included for my Sharp MZ700 into my main PCB I use for all the other Retro Computers.. I’m calling it the Deaf Computer option. Now I cannot guarantee it will fix all your problems but Wayne over at Retro Robbins offered to test this theory out for me since he had a deaf Spectrum 128K+. Watch the first part of the video and decide for yourself.

Deaf Computer Test.

Someone gave me an idea to document the firmware feature differences that the TZX_Tools firmware tool supports. TBH It is a good idea so we can dispel the myths and views on the different firmware as they all do something a little different. From this table, you can see why I prefer MaxDuino. Even more than my own firmware Digiwavuino. I’m sure over time I’ll have to update it and I’m sure there will be 1 or 2 incorrect entries but this is my view on the features.

FYI TZX_Tools is a tool that allows for simple updating of devices running the below firmware.


Disclaimer in the DigiWAVuino record feture: Whilst the program logic is in the firmware there is an issue with the audio driver which is an opensource library. I’m exploring other options.

I realized very early on, that people wanting to update their TZXduino, MaxDuino, CASduino, or ArduiTape would struggle if they had no experience with the Arduino programming tool. So I built a FREE tool to do that for you in a way to give back to the Retro Community. Watch the video below and CLICK HERE if you want to download the tool.

Nice video from Wayne Robbins who is a big-time ZX Spectrum vlogger in which he shows off multiple ZXuitape models which allow you to load games on ZX Spectrums from SD card. He had an issue with one which I later identified as a problem with the SD card Wayne was using. Also Wayne referred to them as a TZXduino which is not technically true. ZXuitape uses the MaxDuino firmware which is far superior. Wayne is awesome in the community so I’ll let him off this once 😉 If you want to buy one for yourself CLICK HERE