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21st November 2001 |
KEN ABOUT ... FEEL THE BURN |
Ken Ross |
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FIRING THE BOILERS One of the differences between a battleship and a cruiser of the same tonnage is speed. To get a ship's velocity increased requires more horsepower. However, this is not just a matter of doubling things to get twice the speed. To get twice as much speed requires the squaring of engine power, which requires more bunkers etc. Naval people will no doubt inform me that I'm not quite right in my sums, but it's the nearest analogy. A very good illustration of this is the JPG format. Even a slight reduction in quality can have dramatic effects in file sizes! When using Graphic Converter for domestic duties I reset the saving quality to 100% and then forgot this fact, (Ed: When creating the piccies for Captain Commodore 4). (Me and Homer Simpson both still use 8 track cartridges!) A few days later I had to put my dunces cap on. Pictures that had taken up 44K in transmission at 100% quality reduced down to 20K when the slider was set to just 90% quality, which is quite a dramatic saving to say the least and a lesson to be learnt. Another related point is that when resaving JPGs the picture quality degrades, because JPG compression loses bits of the image every time a save is made. This has to be taken into account when doing graphics work. It is always best to edit using a 'non-lossy' compression format, such as TIF. You can then save as many times as you like. When you have the final image to perfection is the time to save as a JPG for e-mail attachment or the Internet. ALL SORTS OF BREAD Recently, we got a new family member, in the shape of a Yamaha 2100 CD burner living on the end of my SCSI chain. The specs said SCSI-3 interface and I found out that all it meant, (in my case), was more pins on the back of the beastie. Thus, an adaptor cable, (SCSI-3 / SCSI-1), was needed to link it into my existing Mac SCSI chain. When the box turned up, the specs printed on the outside quoted 'for use with G3 PPC / OS 8.6', but it worked anyway with my 603e PPC / OS 8.6 so I was content. It came supplied with a cut down version of Toast, (lacking the ability to create ISO 9660 disks), that stated the minimum machine needed was a 68040. As an experiment I put an OS 7.5.5 system onto my external HD and restarted using that, instead of OS 8.6 on the internal HD. Everything worked very well indeed and I ran off a few testers. After finishing the experiment I trashed the OS 7.5.5 and went back to OS 8.6 without any problems. While the version of Toast that came bundled with the CD Burner, (and also with the Zip USB burner it seems), can't create IS0 9660 disks for PCs without an 'upgrade', (you've got to go and buy the full version), there's a work around. You create a CD extra format disk, (sometimes called CD plus), by burning a music track as the first session, (or partition), and then re-inserting the disk and burning the data as the 2nd session. When this is done the CD defaults to a dual format which can be read by most modern CD drives -
The main cause of 'coasters', as duff burnt CDs are termed, is the data buffer running out of data while writing. Hence, Buffer Under RuN - proof drives is a selling point. (Unfortunately my drive does not have this). Checking the speed at which your beastie can supply data to the burner will give you the maximum burning speed at which you can operate . In my case, when copying from the Mac internal CD drive, 4X is the fastest possible. I get 8X when copying from the internal HD. Theory says 12X is possible from the HD, but allowing for a safety factor ensures a good result each time. To 'personalise' Mac CDs with their own icons, (any graphics format can be used), see the article, 'Changing Icons on the Mac' . SUPERQUICK CINEMA ADVERT Toast, as bundled, can create Mac HFS CDs; Music CDs; or just copy CDs, (ISO/Mac HFS/music). So, it's natural to want to transfer your 8 tracks & vinyls etc. to gleaming CDs. Macs are usually fitted with a sound-in facility. (A few aren't). This may be just a mono microphone socket, in the case of the LCII, or full stereo capability. A jumper cable from the tape-out socket on the back of my hi-fi to the back of my Mac was the only hardware I needed (and was already in place). I'd been using the freeware 'MPEG audio recorder' to create MP2s in real time prior to the burner, but Toast didn't like them. A bit of looking around found 'Quick Recorder 1.0.1' which did AIFF in real time that Toast would use without worry. Toast will reject anything that's not sampled at 44.1Khz /16 bit. I tried a few MP3 programs out, but they didn't quite work out that useful, (or demanded registration fees). A minute of CD quality sound takes up around 10MB on your HD in AIFF format so make sure you have plenty of space. The full version of Toast will come with a program that can remove the odd bit of noise that some records are prone to, but it doesn't like the virtual memory that the PPC uses. (The vinyls I've got have been well looked after so it wasn't a major consideration). Switching off virtual memory to run the program means you've got to have lots of RAM to work in, assuming the 10MB/min applies to it as well. On a historic note, I'm using a pre-amp to go directly from record deck to Mac. A Sinclair Stereo 60, which came with an instruction booklet with prices in shillings & pence, that has had a lot longer life than some of Clive's other creations(?). WHAT TO GET UNCLE NORRIS At this time of year the shops are full of toys and novelties that will be forgotten by the time the decorations come down. Many years ago, when Airfix was still in the future, there was a range of models that came printed on sets of postcard sized cards. These were Micromodels and they covered a range of subjects, railway engines, ships, planes and buildings. Plastic injection moulding swept them away into the odd corners of history. But we have the technology. The average colour printer nowadays can produce printout that would have required lots of effort in those days. Modern glues can be as hard or as fast as you want. So, with that in mind why not pay a visit to: http://www.peterjvisser.demon .nl/links.html http://www.scalemodels.net http://www.homestead.com/_ksi0701961587376893/paperforge/files/xl5_web.pdf |
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