1002: CREO L'USCITA VIDEO SUL MITICO ZX80 SINCLAIR

🎁 Get a FREE $25 coupon: https://jlcpcb.com/events/pier-coupon 🎁 Z80 Minicomputer Board: https://www.pieraisa.it/eshop/pay.php... 📜 Z80 Minicomputer Board Datasheet: https://www.pieraisa.it/php/forumshar... 🔥 Kit Catalog for Sale: https://www.pieraisa.it/kit/kit.php ✴️ Patreon Subscription:   / pieraisa   🎁 Recommended Products: https://www.pieraisa.it/amazon 🅿️ Paypal Donation: https://www.paypal.com/donate/?hosted... 📣 Forum: https://www.pieraisa.it/forum/ 🎬 Full list of videos: https://www.pieraisa.it/videolist 📌 Free Download Area: https://www.pieraisa.it/download 📺 Website: https://www.pieraisa.it/ ✉ Email: [email protected] 📌 NFC Tag: https://www.pieraisa.it/nfc In this video, I analyze an ORION 7506 portable TV that has been out of service for 40 years. Initially, the TV won't turn on, but after some investigation, I discover a peculiar connection regarding the power supply. I then analyze a Sinclair ZX80 PC, received as a donation from one of my Patreon members. I power it with a benchtop power supply and can see the modulated RF signal on the ORION TV. I decide to make a modification to directly extract the composite signal from the ZX80 and drive a monitor on the AV input, but I realize that the signal is too weak, so I set up a small amplifier circuit to drive the monitor. Everything works, and out of curiosity, I replace the Z80 with a more recent Z80 processor, produced a few years ago and originally by Zilog. The interesting thing is that the video signal is constructed in software directly by the Z80 CPU, using HALT mode and sweeping the ROM to construct the raster video signal. Consequently, when you press a key on the ZX80, the video flashes to handle keyboard input. Greetings to my friends Marco from MVVblog and Carlo Santagostino from RETROCAMPUS ⏰ Index: 0:00 Prologue and Theme 1:09 Introduction 2:35 Analysis of the ORION 7056 portable mini TV 3:40 Power supply with 12V DC, the TV remains off 4:20 Opening and analyzing the TV circuits 6:30 Power supply with 12V DC, the TV turns on 8:20 Power supply with 230V AC 8:52 Analysis of the Synclair ZX80 11:20 Opening and analyzing the ZX80 circuits 12:30 Power supply of the ZX80 with 9V DC 13:15 Searching for the ZX80 channel on the TV 14:05 Analysis of the ZX80 circuit diagram 15:18 Testing with a monitor 16:05 Waveforms with an oscilloscope 17:10 Diagram of the video signal amplifier 18:20 Modification of the diagram ZX80 7:30 PM Back porch TV signal 9:00 PM Contrast and brightness adjustment 9:50 PM Z80 modification 12:00 AM Test with recent Zilog Z80 10:35 PM Video signal modification test #repairs #electronics #amplifiers #lab #tools #oscilloscopes #tutorials #projects #tv #audio #pieraisa #electronics #electronics #technicians