Listing contents with tag DIY:
A long time ago I acquired a microcomputer-grade tape recorder produced by Polish factory: MK-450. The problem with this device and a few other tape drives (like Mera one for large cassettes) and even consumer-grade decks (MK-250) was a poor quality of its gears prone to breakage. Usually, during seeking or playback, a loud crack is heard and tape is pulled into recorder or forward seeking stops working while motor is still heard. Recently I got a possibility to print something with 3D printer, so I decided to experiment with it. In this post I'll show how to re-produce the existing, physical gear into computer model. To quickly show things, the result is nice:
The plastic used to make these two specific gears (in MK450) is different than polymer used in other gears. It degrades into white, crumbling powder with atmospheric contact and probably...
... Read More
Sometimes old computers come with broken plastic parts. When only cracks are present, it's easy - we can fix them with glue or staples melted into plastic using soldering iron. Even totally broken casing can be fixed this way. The bigger problem is when the casing lacks some part which cracked off. Recently I purchased an old computer with broken front panel. From photos it can be seen that damages aren't so big and two parts can be glued together, but if you look closer you will notice that a whole bottom-left corner of panel is missing. How to fix it?
I decided to try with hot-melt glue applied from pistol-type hot glue applicator. First, I found that front panel is made of porous, well-glueable plastic, so I glued broken parts together using cyanoacrylic glue. I found that this panel is painted with something similar to white acrylic paint. Next, I started to apply hot-melt glue to form a patch. The key factor here is temperature. The glue comes from the gun very hot. When hot, the glue is liquid...
... Read More
After replacing laser I needed a Modchip for my 20-year-old PS1 console. Following the "DIY" principle I downloaded an archive from Eurasia.nu with dumps of MultiMode 3 mod chip for PIC12F629. It contains even source code! I obtained a blank PIC chip and tried to program it in Willem programmer PCB v. 3. Of course Willem has no support for them. But it is still possible to write to the chip.
The first rule when programming PICs in Willem is to avoid Willem software. It is not well prepared for programming PICs. First of all, PICs have not only configuration bits (like AVR's Fusebits), but also factory-configured last 16-bit word called OSCCAL word. This word is used to calibrate internal RC oscillator and is set separately for each chip in factory, where RC characteristics are verified against real timing. So to program a PIC, you have to read it first, get OSCCAL value and program a new dump with old value good for the particular chip you have in programmer. It's really easy to erase OSCCAL with Willem...
... Read More
Again I got an old computer with a sticker missing. This is quite frequent, especially in machines which were used in schools - everyone wanted to have a piece of computer and stickers were stolen in the beginning. If the sticker was molded using non-flat form, then there is a problem as they are not easily made at home (but still possible using e.g. silicone forms and polymer resins). But if the problem is a flat sticker, it can be made very simple way. You need:
1. 1:1 scale print-out of the sticker.
2. Transparent sticky tape
3. Two-sided sticky tape. Do not use foam tapes, use flat ones. You can find it in home improvement stores as tape for fixing carpets or doormats.
So first of all, print the sticker proper way. Use a good vector graphics program like Inkscape to make your sticker, as it allows to get the true scale of the image, lossless rescaling of vector graphics and its CMYK has black. If you put a black-background bitmap on black-background vector, you will get two black colors: From...
... Read More