Radio Shack Rambles

 The Marconi 2955 Receiver & Transmitter Test Set This is my story repairing one of these endlessly useful pieces of test equipment from the 1980's. Like the one in the photo, mine is an early example, with no letter suffix in the model number.  And not as clean and tidy looking either - in fact it was pretty grubby outside and very grubby inside. Some of the buttons have been used so often, that the lettering has rubbed off. So a well used example for sure. At switch on, the cooling fan would run, but nothing else - cold and dark as they say. These units have a 10MHz reference oscillator, oven controlled, and, as well as providing an RF reference, is used to derive the clock signal for the microprocessor. For some weird reason it is fitted to the EHT Supply board for the CRT - but anyhow, checking the output signal on this board showed no activity. The Reference Oscillator Removing the EHT Board is not too difficult and then the oscillator module, housed in a small greay ...

Retro Chip Tester - Firmware Upgrade with Raspberry Pi https://8bit-museum.de/sonstiges/hardware-projekte/hardware-projekte-chip-tester-english/ As a certified addict of vintage test equipment, I have been a big fan of Stephan's chip tester for some time now. I use it a lot to check TTL logic chips as good or bad. Also SRAM from the classic Tektronix TDS 'scope series. It is quick and easy to use.  I have had mine for a while now, and have been aware that a number of new firmware releases exist since mine arrived. From a quick read of the instructions, however, it was clear that a bit of learning and some kit would be needed, so never got around to doing it. Until now. Over the years I have developed a keen dislike for MS Windows, so am predominantly a Mac and Linux user. This does have a downside, in that a lot of tech nerdy stuff revolves around Windows. Another reason to delay launching in to the firmware upgrade. However, I have now successfully done it using a Raspberry Pi...