New Stuff For Old Stuff :: Blog

T his weekend I've tried a different approach to writing and recording a song and it's worked out so well I thought I'd make some notes here about the process. First of all, here's the finished music. I only spent an hour or two actually writing it. That was in itself an exercise in composing but I wanted to try this new method of recording and just got something down to work with. I like it a lot and will definitely expand it. All sounds here are produced by the C64, albeit one fitted with an ARMSID (set to 6581). Only because my working C64 with a real SID chip is playing up. Rather than try to write for 3 or 6 voices and then import that information to end up with a .prg that will run and play the music (aka a "sid") I've written any number of parts, with up to 3 voices in each, and used the C64 as a MIDI instrument, sending each part as MIDI to the computer and recording the audio that comes out of the computer. I think that Logic and other...

I'm typing this blog post on the Plus/4 itself. I'll have to transfer to something more up-to-date before posting because Commodore didn't include a web browser alongside the word-processing, spreadsheet, graphics and database packages that they built into this machine. The first word-processor and spreadsheet I used were on the Amiga. When I saw that the Plus/4 had even earlier examples of such packages on-board, I was curious. There was a non-working one in my collection, bought sometime in the 90s at a car boot sale. The 1984 Plus/4 has a lot in common with the Commodore 16. In fact they share the same key chips. The Plus/4 just has additional RAM and the office software on ROM. On opening up a 'spare' working C16 and the Plus/4, I found the important chips socketed and identical, down to revision numbers. Chip-puller came into play and chips were exchanged one at a time, starting with the most likely suspects until the Plus/4 worked. In this case the ...

A  ZX81's keyboard is frustrating to use. Especially for games. One too many times, you find your finger isn't quite over the pad when you have to make that crucial jump... It's easy to use an emulator, but personally I don't get the same buzz. My first computer, probably in '82 was a secondhand ZX81 which had been screwed to a board along with some kind of aftermarket keyboard (which really wasn't very good). So for that reason I feel perfectly OK about sorting myself out with something similar now. After looking at many options (including the ZX-Key, which looks excellent  and the Minstrel keyboard which has tactile switches ) I noticed while recapping a Spectrum +2 that the keyboard connections are very similar to the 81's: There are more lines because the later spectrums have many more keys. But some study of the matrix diagrams made me think that they were compatible* if you take the first five and the first eight lines from those ribbons. ...

T he ZX81 was my first computer. Mine was screwed to a board with a terrible external keyboard, and I was proud of the fact that someone had fitted 2k of RAM. It was my introduction to BASIC and machine language. Let's not forget that the humble zeddy is a vehicle for a Z80 (which has 16-bit features) running at >3Mz. (Of course you can only harness that amazing power in fast mode, ie without display output, because much of the CPU time is usually used to generate the display.) Other than buying some kind of box that will convert the TV signal (with which I had limited success), it's possible to perform surgery to convert the output to composite, which modern displays may be more likely to display (but still maybe not in the case of the ZX81s with the older ULA). Here are three methods - rewiring (cost zero), using some simple components (cost pence) and a purchased modification (still less than a tenner.) With the newer issue 81 it's possible to simply tap the...

M y 'bionic' C64 has reached another milestone. I wrote about it after I'd installed a PLAnkton , ARMSID and TOLB , and in the process resurrected a 'black-screen' computer. Although I have an external SD2IEC which is good for plugging into any C64, Vic20 or C16 that I am using, I'd always intended to put an internal SD card drive inside this machine, I had envisaged simply leaving the drive inside the machine, opening it up whenever I wanted to copy anything to the card. But I found that Gaz Marshall has designed a replacement side panel for the C64 which has an SD card slot and houses the SD2IEC. It's available as a model for 3D printing , or ready-printed direct from his Shapeways shop . I hadn't found the shop for ordering the printed version, so I asked a friend to print one for me. Here's the result. Note that there's an all-in-one version, and a 'modular' version where you have to screw the tray to the side panel. ...

I 've set up a YouTube channel for posting my music, mostly to give myself an incentive to keep writing and hopefully improve those skills. I recently posted a version of this eastern-sounding piece rendered by the notation software. An exercise in using the pentatonic minor for that eastern flavour. I've now made recordings of the C64 playing the piece. First of all I made a 3-voice version (not yet posted) and then an 8-voice version using multi-tracking. That's the first version you hear in this video, played on my 'bionic 64' which is fitted with an ARMSID. Curious about how this would compare with the same music played by a real 6581 SID, I did the same recording using an all-original 64 and made a video with one recording after the other. My observations are below but judge for yourself. In the 'pure' tones it's hard to hear a difference. But there is definitely a difference when there are many voices playing together and using pulse-w...

P rogress has been slow, I've been caught up in ironing out a few problems. Debugging those was tiresome, which meant that I found it easy to do other things instead. But now we have smooth scrolling background, music, enemies that scroll in from the left at an angle (hopefully soon multiple enemies / collectibles) multiplexing sprites (the sheep are each made of two sprites, a multicolour and a hi-res outline overlaid. The clouds are also sprites).