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More work on my Vic20 music driver

T his isn't perfect but it's getting better. I've made a way to convert my own music to a cut-down MIDI format that my driver reads and plays. The sound here is being captured from a real Vic and it doesn't sound bad. [update 21 Apr 21] I've updated the video embedded above. I did more work on my driver and ironed out some problems with the timing. As a result it sounds way more solid. I've also added a little percussion using the fourth (noise) channel of the VIC chip. As before, the sound is captured from a real Vic. This music is for my Yvonne game (still in progress).
Recent posts

Vicky Twenty - building a Vic-20 from (mostly) new parts. Part two - progress

 T his part of the board is looking very industrial: Although this board is simpler in some respects than the sixtyclone,  check out the number of components packed into this area: I had been worried about soldering those particular components neatly with many of them being stood to attention, but I'm pleased with how it's looking. Note the missing video socket. I did order the 5-pin socket, but have since decided to fit an 8-pin one (3 pins obviously won't go through the pcb and will have to be removed/bent) because I eventually plan to make the s-video mod and it'll be nice to use the same lead that I use with C64's - I'll should be able to make the extra s-video connections onto the back of the socket.

Using the Vic Rel to make a Vic-20 control some RGB LED strip

T his is early experimentation - and success - controlling some RGB LED strip using a Vic-20 with the VicRel (Vic Relay - a userport breakout).  There are 6 output relays on the Vic Rel device, and obviously three colours in the lightstrip. So the spaghetti and variable resistors is an attempt to make two switches give four possible values for each colour (including off) so 4 x 4 x 4 makes the 64 possible values = 63 colours + off using the 6 output lines. The program here is very simple, just a BASIC program to cycle through all of the possible values.

Knitwear Designer for the BBC Micro / Electron, project part 3 - Knitting begins

 F inally we arrive at this stage:  It took a while to get here because I spun the wool by hand. Sadly the stitch pattern itself isn't created by the software. It generates the patterns for the knitted pieces, and gives you "knit X in pattern" to allow you to get creative with colourwork or stitch patterns.  After an inch of ribbing (waist) the stitch pattern I've established here is something resembling the stitch pattern in the jumper I'm trying to recreate (pictured in part 1).  What the software does do is to generate a basic pattern based on the information you give it about your own  measurements and the gauge you want to knit at. (5 stitches per inch in my case here). It allows you to visually adjust things like the neckline, or even draw your pattern pieces freehand. My job now is to simply put in a lot of knitting time. (Audiobooks and podcasts at the ready.) I'm having trouble deciding where to put posts about this project, as it combines knitting an

Vic-Rel - recreation of the Vic Relay Cassette, a relay i/o interface

M y teenage self would have been very excited about this. I was very interested in electronic tinkering but a little afraid of damaging my precious Vic. I believe this is an old product, existing back when the Vic was current. (I'm not sure about this. Tell me if you know more about its origins.) It's now recreated by Tim of Shareware Plus  and it even includes a copy of the original manual. As you can see, the manual suggests that this can be used to switch (and receive input from) various things around the house - this was before the 'smart home' was really a thing, outside of Tomorrow's World and a few electronics enthusiasts. Personally I'm interested in building something robotic, such as a XYZ router or mill.  I guess that the original ones would have come in a case, like a cartridge, because the device is referred to as a 'cassette' in the manual.   I've seen a number of Vics that have been used in industrial settings ( like this one ), someti

Vicky Twenty - building a Vic-20 from (mostly) new parts. So it begins.

W ith the successful sixtyclone under my belt, I was delighted that Rob Taylor decided to work his magic with the Vic-20 . The Vic is very close to my heart; not my first computer but the one I spent years with. My board arrived on 25 Feb and it's absolutely beautiful. At first I thought this project would involve more 'pulls' than the sixtyclone, because there are fewer modern replacements for the key components. However, I was delighted to find that not only is a 6502 manufactured today, but the same goes for the 6522s. So that's three out of the four most important chips available as freshly-manufactured parts . Real chips too - not modern boards with header pins to fit the original footprint.  Here's my 65C02 in its engagement ring box!  It's the same chip that I have in my Mini Pet. It's an improvement on the 6502, adding a few new instructions, so I'm really chuffed about that. The fourth of the 'big four' chips is the VIC itself. Once ag

Games in progress for RC2014 with OLED screen.

T he OLED screen that Quazar makes for the Z80-based  RC2014 is 128 x 32 pixels, a wide and thin format. The way that you send data (bytes being vertical) makes it good for smooth sideways scrolling. I did this a while ago and as usual I'd almost finished when I moved onto something else. It's written using Forth, which I really love.  In return for a small sacrifice in performance (according to Leo Brodie's book, it can be almost as fast as assembly) you get some very helpful features. For example, numbers are 16-bit signed  (in the implementation I use), the stack makes it very easy to pass parameters in and out when calling words, and I like the way it makes me structure a program. It forces you to start with the small building blocks. So it is with some joy that I've returned to the dino game and started a new tunnel game.  Again the screen format is well-suited to this type of thing.  For the Dino game I made myself a box with two arcade buttons (he jumps and duc