HINTS AND TIPS Compiled by Tim Strachan & Steve Bolton )*( 37 )*( 37 )*( 37 )*( 37 )*( 37 )*( 37 )*( 37 )*( WB 2.05 ROM and A600s Some A600s were released without hard drives and with KS 2.04 - if you were unlucky enough to get one of these, you'll find that you can't add an IDE drive such as other A600s (released with KS 2.05 and hard drives) have. You need KS 2.05 ROM and they are as rare as the proverbial chicken molar. - = - = - = - = - = - = - = - = - = -  Set Echo On command If you have ever encountered problems during your startup-sequence such as error messages suddenly being displayed in the CLI or your startup-sequence stopping half way through, then you'll know that it can be a nuisance tracking down the problem. The fastest way is to edit the startup-sequence and put the following line at the start: set echo on  You then reboot and you should now see everything in the startup-sequence appear on the screen as it is executed. You can then watch where the startup-sequence fails and thus narrow done the root of your problem! - = - = - = - = - = - = - = - = - = -  DTP and Large Workbenchs If use Pagestream you can get it to load up on the workbench rather than its own screen. With the use of large workbench sizes you can end up with a large page on screen which you can easily scroll around without the program having to readraw the entire screen since it is already there. Of course this can also depend on your chip memory availability. - = - = - = - = - = - = - = - = - = -  Using more fonts If you are running on a small hard drive or just a floppy based Amiga and use a lot of fonts here is a handy little tip. Store you fonts onto floppy disks and rename the floppy disks "Fonts". Then when you go to change fonts just insert a Fonts disk and AmigaDOS will look on the floppy rather than the assigned Fonts: directory on your boot disk. This means that you don't need to have fonts cluttering up your boot drive. - = - = - = - = - = - = - = - = - = -  Commenting When you installing new software it is always a good idea to keep track of the files it places into your system and then adding a comment to those files saying what program they belong to. For example, have a look at your fonts: drawer and you may find a whole lot of fonts which you aren't 100% certain belong to a particular piece of software. If you comment the files then find later on that you have found a better piece of software or are just deleting the old software it is easy to find the extra files such as fonts or config files which belong to it and delete them. This will help to free up vital space on your system. - = - = - = - = - = - = - = - = - = -  Make your own Stereograms/Holusions On Fish 763 you'll find a program called SIRDS which lets you roll your own - why pay $45 for a poster-sized full-colour one from Megadisc when you can get a small measly one in black and white for nothing from the PD? Heh, heh. We have a couple of Holusions available too, if you're really keen - full colour, poster size. Check out the Art-Gallery this issue for a home-made stereogram by Graeme Whittle using his own process. And see next issue for an article on how he did it, and indeed, why... - = - = - = - = - = - = - = - = - = -  Changing SCSI IDs on hard drives On hard drives and indeed any internal SCSI device (CDROM, Syquests etc) there are a set of jumpers on there underside or at the rear end of the unit which are used to set various parameters for the drive. Jumpers are little black "plugs" which sit astride a pair of pins sticking out of the board. You will usually see a row of these pairs of pins and a few may have jumpers on them already. The required pins for changing the SCSI ID number of the device are usually the 3 pairs at one or other of the ends of the row of pin. Next to the pins may be numbers and/or letters. The ID number pins can usually be recognised by the numbers 0, 1 and 2 next to them somewhere with 0 being the outer pair. Some drives have these three labeled X0, X1 & X2 or ID0, ID1 and ID2 or some such combination involving 0, 1 & 2. To change the SCSI ID numbers involving a binary arrangement. The following table shows how the get a particular SCSI ID number setting, a Y means that there should be a jumper across the pair of pins and a N means that there shouldn't be. Pin Pairs: X0 X1 X2 ------------------------------------- SCSI ID 0 N N N SCSI ID 1 Y N N SCSI ID 2 N Y N SCSI ID 3 Y Y N SCSI ID 4 N N Y SCSI ID 5 Y N Y SCSI ID 6 N Y Y SCSI ID 7 Y Y Y So when you are adding a new SCSI device to your system always make sure to check the ID numbers so that you drives all work smoothly together. - = - = - = - = - = - = - = - = - = -  Video Formats RGB (Red, Green, Blue) - This is the Amiga's internal format video signal and gives the purest output. By connecting directly to and RGB monitor you get the best picture quality possible. RF (Radio Frequency) - This is a compressed format containing both the Video signal and the Audio signal. It is the quickest and easiest to transmit (this is what you TV antenna picks up) because of it's compression. It also gives the lowest quality picture and as such is only suitable for video recording/display but can't be genlocked. Composite Video - This is better quality than RF because it only contains the Video signal in a less compressed format. It is a very popular format to used since it doesn't require expensive equipment to use. YC (Y=Brightness, C=Colour Information) - This is far better to use since the Y and C components of the signal are kept separate and the resultant picture is of a very high quality. This is used in S-VHS and Video8 systems. - = - = - = - = - = - = - = - = - = -  Seeing Stereograms Darken the room and dim the picture, according to Richard Swinoga, and the image jumps right out at you. Check out the Stereograms this issue and last. - = - = - = - = - = - = - = - = - = -  Learning C Nic Wilson recommends as the best book for learning C programming: Programming in ANSI C by Stephen G Kochan ISBN No. 0-672-48-408-0 Available from Hotline books and other places. - = - = - = - = - = - = - = - = - = -  WHAT ARE NEURAL NETWORKS ? A neural network is a processing device, either an algorithm, or actual hardware, whose design was motivated by the design and functioning of the building blocks of the human brain, such as neurons and connections (axons, dendrits). It is realized as a network of many simple processing units that are regularly interconnected. The connections carry a numerical information, they are "weighted". What makes neural networks very attractive is their ability to "learn" from examples. Most neural networks have some sort of "learning law" which describes how the weights of connections are to be adjusted on the basis of presented patterns. Probably the most popular neural networks are the feedforward networks, with the backpropagation technique/generalized delta rule being the learning law. WHAT CAN NEURAL NETWORKS DO ? In principle, NNs can compute any computable function, i.e. they can do everything a normal digital computer can do. Especially can anything that can be represented as a mapping between vector spaces be approximated to arbitrary precision by feedforward NNs (which is the most often used type). In practice, NNs are especially useful for mapping problems which are tolerant of a high error rate, have lots of example data available, but to which hard and fast rules can not easily be applied. BOOKS ON NEURAL NETWORKS (No completeness intended) Hecht-Nielsen, R. (1990). Neurocomputing. Addison Wesley. Aleksander, I. and Morton, H. (1990). An Introduction to Neural Computing. Chapman and Hall Beale, R. and Jackson, T. (1990). Neural Computing, an Introduction. Adam Hilger, IOP Publishing Ltd. Rumelhart, D. E. and McClelland, J. L. (1986). Parallel Distributed Processing: Explorations in the Microstructure of Cognition (volumes 1 & 2). MIT Press. and lots more ... [From Aminet] - = - = - = - = - = - = - = - = - = -  Subject: Re: A3000 FFS and High Density Floppy Questions In article <1993Oct25.140740.12954@sparky.sterling.com>, jeff@ITD.Sterling.COM (Jeff Mosher) writes: > Questions about my new A3000 FFS and High Density Floppy > > 1) What is the "correct" FFS Filesystem Mask for an A3000 with 2.05 ROMS and > 2.1 WorkBench? My 2000HD with 2.04 and 2.1 WB is 0xffffffe and my new > A3000 says 0xffffffc (according to HDToolBox for both systems). > Whats the difference and which is correct? > The mask is not really related to the filing system - what it does is tell the driver where in memory and with what alignment disk transfers can occur. The filing system is allowed to ask the device driver to supply data only to addresses which have a zero everywhere there is a zero in the mask, i.e. Address == Mask & Address So 0xfffffffe means "only at word-aligned addresses" and 0xfffffffc means "only at longword-aligned addresses". The reason for the difference is that the 2000 is a 16-bit machine but the 3000 is 32-bit, so in the latter case the address must be 32-bit (longword) aligned. So both are correct for their respective systems. The other way in which the mask is useful is to prevent access to memory which isn't DMA-able, e.g. if you have a 68030 accelerator in a 2000, with some 32-bit RAM located at 0x20000000 - the Zorro II HD controller cannot access addresses outside the 24-bit address range of the 68000, and in any case the 32-bit RAM would not be DMA-able since it is not on the main bus, so the correct mask is 0x00fffffe (addressses below 0x01000000, 16-bit aligned) > > 2) How can I tell if my new A3000 has a high density floppy drive? > How do format and use it as a high density floppy if it is? The answer to the second question also answers the first: (e.g.) format drive df0: name Fred noicons ffs The OS (2.04 upwards) will automatically recognize the HD disk and format it accordingly. CrossDOS should similarly format 1.44Mb PC disks (2.1 and up). > > > Any info would be appreciated. > > Thanks in advance! > > Jeff > -- David Crooke, Department of Computer Science, University of Edinburgh Janet dcc@ed.dcs : Internet dcc@dcs.ed.ac.uk : IP talk dcc@129.215.160.2 Work: JCMB Rm 1408, King's Bldgs, W Mains Rd., Edinburgh EH9 3JZ. 031 650 5164 Home: 12 (GFR) West Savile Tr, Edinburgh, SCOTLAND EH9 3DZ. 031 667 4854 )*( 37 )*( 37 )*( 37 )*( 37 )*( 37 )*( 37 )*( 37 )*(