Music interface for the famous czechoslovak home computer TESLA Ondra SPO186
You can read the OndraMELODIK story in this article (Czech language)
OndraMELODIK music interface - introduced in 2022
Czechoslovak home computer Tesla Ondra SPO186 - introduced in 1985
- Opensource hardware
- Based on SN76489 chip
- Compatible with OndraSD interface, OndraMELODIK is through out interface
- It can play 3 channels square wave, 1 channel noise simultaneously
- Minimum CPU usage - two byte transfer, in some cases even one byte transfer, this is essential for such a slow computer
- External interface - no changes on the computer
- Designed with 80´ technology - all parts was available in 1985
- DB25 Centronics printer port (formerly known as LPT from PC) in one case
- 3D printed case STL files included
- Turn off your belowed Ondra
- Plug OndraMELODIK to Ondra X1 connector
- Optionally plug the OndraSD or whatever interface to the OndraMELODIK
- Switch the switch to the MELODIK position
- Plug the 3.5mm audio jack of your favorite audio system
- Turn on Ondra
- If you hear some noise or tone, just push once the RESET button
- Load the software meltest.bin from this repository and test the device and listen the music
Notice: If you perform just Ondra reset and some tone or noise is coming out, just push the RESET button once
- Switch the switch to the PRINTER position
- Be sure you dont have plugged in the audio jack or the audio system is turned off
- Plug your printer using standard PC printer cable
- Turn on Ondra
- Print using Ondra's monitor, BASIC or TEDIT (if you forget to unplug the audio jack and strange noises are coming out, it is normal)
How it sounds
https://www.youtube.com/watch?v=u5RyUs0VGdg
How it prints
https://www.youtube.com/watch?v=VYsxnQOKPeM
MIT license