Author Archives: Administrator

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TI-99/4A printing new key

Modern 3D printers allow us to print at tremendous quality and resolution. And some Chinese ones are quite cheap. My one of Texas Instruments TI-99/4A computers has a problem- due to a bad package and careless shipping it lost three … Continue reading

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TI-99/4A

Whenever I talk about designers of the ZX Spectrum computer I use to say that they were smoking weed. Now I acquired one computer from another family of computers, TI99, I can tell that Texas Instruments designers not only smoked … Continue reading

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ZX interface 1 and Microdrive

I collected several ZX Spectrum series computers, but I don’t have any fancy peripherals. After several attempts I managed to buy ZX Spectrum Microdrive and interface 1 for it. As always with ancient hardware it is working a bit, but … Continue reading

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PS2 keyboard for ZX Spectrum (or clone)

ZX Spectrum and other computers of that period use proprietary keyboards with direct connection to some specific chip or connected directly to computer bus. Old keyboards are damaged from elementals or time, and sometimes are not very user friendly compared … Continue reading

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Sinclair QL – modifications for EPROM

I have Sinclair QL, “issue 5″ with 3 EPROM chips. One of the chips is riding on the other chip. And yes, it is the original solution from Sinclair engineers- they were pressed by Apple computers new product and they … Continue reading

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Real easy Video fix for ZX Spectrum +2 (gray, “Toast Rack”)

I bought a ZX Spectrum +2 gray (toast rack) for my retrocomputer collection and it was the fail. The video output was bad and also there is a serious problem with RAM or ULA. But this article is about making … Continue reading

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Printer from calculator, part 2

Continued from part 1. The printer from the calculator is a neat toy, but we want a real USB printer. So, using my new STM32F103 CubeMX USB printer class for communication with the host computer and some tricky INT based … Continue reading

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Printer from calculator, part 1

In a pile of e-waste I found a printing calculator, Citizen CX-123II. It is a regular calculator (with some wicky calculations), but with a printer- all output from the screen are hard-copied to paper roll. It can print only numbers … Continue reading

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ARM:0018 STM32CubeMX hack – printer class device

This article is about printer class device for STM32F103 and STM32CubeMX. Somehow there is NO printer device class example in whole internet. There ar CDC or HID examples copied from same STM32CubeMX example with minimal explanation, few of mass storage … Continue reading

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Cutting PCB panels for new universal STM board

I’ve noticed, that Chinese made “Blue Pill” PCB has fake chips. Some chips are with smaller ROM and RAM size, some chips behaves a bit strange. Also, several mine projects are getting bigger and bigger. Recently, I acquired several bigger … Continue reading

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