Contents
WHERE DO WE GO FROM HERE?
Welcome to Issue #20 of Amigan Airwaves! Since 1988, when Issue #1 was published on a couple of sides of A4 and sent out to the 22 members of the AARUG, the intervening years have proved to be a roller coaster ride for our beloved Amiga and this past year has certainly been no exception.
The headline of Amigan Airwaves #19 was:
C=E=AT
IS THIS THE RIGHT FORMULA FOR THE FUTURE?
What a prophetic question that proved to be with Escom selling Amiga Technologies to VIScorp in the States almost exactly a year after they bought it!
VIScorp had previously taken out a licence for the use of the Amiga technology in its set-top boxes. You may recall that my comments on this deal in Airwaves #19 were: "This is a case of good news and bad news for the Amiga. It is good from the point of view of increasing demand for the technology in a huge potential market but bad because it may once again deflect resources away from the primary objective of restoring the Amiga to its rightful place as a serious mainstream computer." My views have not changed significantly but, of course, we must now accept that if the Amiga survives, it will only be as a `niche market' computer in the future.
Looking at the positive side of the present situation, some credit must go to Escom for what they achieved in the year that they owned the Amiga. They managed to restart production of the 1200 and 4000T machines and entered into a number of third party licence agreements. This at least ensured some
degree of continuity as far as existing users, dealers and software companies were concerned.
New software launches of particular note during the past year include Wordworth V5 from Digita, FinalCalc and TypeSmith V2.5 from Soft-Logic, Cinema 4D, Lightwave V5.0 and Distant Suns, the latter on CD-ROM. In addition to these and other commercial offerings, PD and shareware is still appearing both on disk and CD and Aminet is thriving. On the hardware side,
there is no shortage of accessories on offer ranging from the simplest interface to sophisticated video boards such as the CyberVision 64 and VLab Motion and a range of '040 and '060 accelerators.
On the downside, the Amiga is once more in a period of limbo and there is inevitably a continuing loss of confidence on the part of existing users and an ongoing `drift' to other platforms. It was claimed on the CompuServe Amiga
User Forum recently, that there may be as few as 20,000 people in the world who still use the Amiga as their main machine. Although no-one can dispute that the user base has been greatly reduced, I can't bring myself to believe that numbers have fallen to this level but the fact is that no-one really knows. One only has to look in the varrious `For Sale' columns to see how many Amigas are being advertised. Have you noticed that it is hard to find some Amiga magazines nowadays and that when you do find them, some are pretty thin due to lack of both advertising and general content? In a vain attempt to make up for lost advertising revenues, cover prices have been increased to an average of #4.50 or even more with a cover CD. This has proved to be counter-productive because many people now just look through the magazines at their newsagent (it doesn't take long!) instead of buying them.
While the Amiga remains surrounded by all this uncertainty about its future, the PC continues to go from strength to strength. It is staggering what is now being offered in the price range #1,000 - #1,500 and the value for money of these systems and bundled software, seems to improve all the time. It is interesting that Apple Macintosh have also been having financial problems. It is hard to understand why this should be because the Mac is a well-established platform with a healthy user base and the PowerPC versions have been in full
production for some time. What is worrying and very relevant for the future of the Amiga, is that there is some suggestion that Apple may have `backed the wrong horse' with the PowerPC. An article in a recent issue of PC Magazine said that "the company had taken too many wrong turns and ended up in a tunnel. The light it sees at the end is actually a train coming its way and the train is called the MMX Pentium". It then went on to say that the MMX Pentium "would quadruple performance, leaving Motorola with its thumb up its
PowerPC and Apple watching".
There is a further potential `fly in the ointment' which may have quite serious implications for the next generation of Amigas, whichever CPU is used. Commodore introduced the 1.76MB HD floppy disk with the original A4000 and had the drive mechanisms made for them by Chinon. When Commodore went under, it transpires that Chinon was one of their largest creditors and were owed `truckloads of money' by C=. This has, not surprisingly, left them with a rather jaundiced view of the Amiga and they have declined to manufacture any more 1.76MB floppy drives of this type. Thus, we could be stuck with the good old 880kB drive whilst PC manufacturers are considering dropping the floppy drive altogether in favour of a higher capacity media. VIScorp will have to work out a viable strategy to resolve this potential problem without delay.
With hindsight, it is clear that in spite of all their fine words and commitments to the next generation of machines, Escom never did have the resources to fund Amiga R & D at the same time as they were rapidly expanding their other businesses. Eventually, they were obliged to seek a buyer for AT, if only to provide some urgently-needed funds to cover some of the losses they had incurred in their PC retailing business. All this proved to be too little too late and even before the VIScorp deal had been completed, Escom found itself with unmanageable debts and filed for bankruptcy. Fortunately, in spite of strong rumours to the contrary, the Receivers, banks and other creditors accepted the terms of the sale and the deal was signed. VIScorp will legally own AT as from 19 Sept. There are several Amiga enthusiasts `at the helm' in VIScorp which is encouraging but the question remains, where do we go from here?
There seems to be little doubt that VIScorp will continue to focus their resources on their set-top box market. What they will do, if anything, about desk-top Amigas remains to be seen. Their senior management has made a number of encouraging statements and commitments but we have heard these before... Phase 5 is continuing to develop its PowerPC board and PIOS, a German offshoot of AT, is reported to be continuing development of the Amiga operating system independently. This is fine, provided that all the licensing agreements are tied up legally and all the various developments are properly co-ordinated. If this isn't done, there will be endless wrangling and incompatibilities between the various systems which will not only divert and dilute precious resources but also spell disaster sooner rather than later.
Where will our Amiga be in one or two years time? I think the only honest answer for most of us would be "sitting alongside a powerful PC"!
by Andy G0POY
{Part 1 of this article appeared in Airwaves #19 - Ed}
Flow control is a necessary evil. It is more obvious over a standard packet link as to why it is needed, e.g. if you have a 10K buffer in your TNC and need to send out 50K of data. The output rate from the TNC to the radio is 1200bps which for the sake of argument is about 100 characters per second. You send the data into the TNC at 9600bps, approx. 1000cps. If the TNC buffer is up to the job, you will be able to send 11000 characters before the buffer is totally full. The TNC has to do something about this situation. The first thing that happens is that an X-OFF is sent to the computer. This will stop the data, but when? This is a problem with INBAND flow control because it takes at least one character time period for anything to happen. It might also be the case that the sending computer is a little sluggish, and takes a character period to respond. If the data does not stop immediately, the integrity of the buffer in the TNC will be compromised and the data would become corrupt. In real life the TNC, or any device, will signal the sending device to stop well before the buffers are full. It is also more efficient to let the buffers become nearly empty before filling them up again. Typically 10% and 90% of buffer capacity are used.
The big problem with INBAND flow control is that you cannot send 100% binary data because some of the data might happen to equate to an X-OFF. Unfortunately the answer to this is OUT of BAND flow control, otherwise known as Hardware Flow Control. This requires the use of additional signals RTS, CTS, DSR and DTR. In some cases DCD is also used. These signals are described as follows:
RTS This is an OUTPUT signal; the connected peripheral should transmit data when an ON condition is present.
CTS This is an INPUT signal; when the ON condition is present, the peripheral can receive data.
DSR This in an INPUT signal which indicates that handshaking has been completed.
DTR This is an OUTPUT signal and indicates that the peripheral is connected to the communications channel.
These signals operate in pairs. RTS and CTS are the main pair used, with DSR/DTR as the second pair.
DCD is used to detect a `carrier'; this is normally monitored on a modem. If the carrier disappears, then the computer should `hang up the phone'. On TNCs, it is used to detect that someone has made a connection into the TNC.
DSR and DTR are normally used in a slightly different way than that stated in the specification. DTR normally means that the peripheral is switched on. DSR is hardly ever used.
In a normal communications link, the two pairs of signals get crossed over so the RTS output signal appears on the CTS input at the other end of the communications link. The DTR appears as DSR. If you ever come across a serial printer, you may get very confused with the flow control. For some strange reason, many serial printers toggle DTR when their buffer becomes full, rather than using RTS/CTS. This is a problem with most communication software packages. The cure is simple; link DSR to CTS at the computer end of the cable and this will `fool' the computer into thinking that it is using RTS/CTS flow control. Note that this works in only one direction but this is fine for printing because the direction of data flow is from the computer to the printer.
Having started talking about crossing over signals and making links, brings us nicely to the final chapter in the flow control business. The normal flow control is RTS/CTS; the other two lines may or may not be required. Communication devices are referred to as Data Communications Equipment (DCE) or Data Terminating Equipment (DTE). DTEs are commonly called Data Terminal Equipment. Although this is slightly incorrect, it does give a much better visual description of the type of equipment, i.e. a Terminal screen. The rule to remember is just like the one for magnets, like poles repel and opposites attract. You do not need to do anything `special' to connect a DTE to a DCE; quite often a `straight-through' cable is all that is required.
If you want to connect a DCE to a DCE then a `Cross-over' cable is required. It might seem strange to want to connect two DCEs together, but it is often necessary in the case of a modem, which is by far the most common DCE that you are likely to come across. For example, if you had a business with three sites connected together via modems, you might want to close one site overnight and run your business from only two sites. By joining the two modems together at the central site, all traffic will be passed on to the third site while the modems are linked.
Common cable configurations that you will come across are:
Straight-through connection e.g. Computer to Modem/TNC
Computer to Printer
Link pins 5 & 6 at the computer end
Computer to computer
Link pins 6 & 8 in each connector
Computer to Modem (`Get you going' connection without flow control)
On the Amiga RS232 interface, pins 11 and 18 are AUDIO connections NOT RS232, so don't go and connect anything to these pins!
Congratulations to former SWL members who have passed their RAE: Nick Taylor - G7VLE. John Galloway - 2M1ERB (MM1 soon!)
A CW receive program and a serial 9-25 pin interface is available from: Alan Jones G8AZT B & J Telecomms 9 Queens Walk Thornberry Bristol BS12 1SR
Sadly, Jeff Walker has decided to cease publication of his excellent JAM magazine after more than 50 issues. JAM is now part of the EM magazine (also dedicated to the Amiga) which, like Jam, is only available on subscription. The SX32 expansion unit for the CD32 (manufactured in Germany) is available from Eyetech in the UK. The SX32 provides serial, parallel and external drive ports and allows an external keyboard to be connected thus converting it to the equivalent of an A1200. For technical specifications and prices, telephone 01642 713185.
The Community Relations Office at RAF Valley near Holyhead is endeavouring to compile a history of the station but there are many gaps in the `official' records. If you were there during the period 1941-1971 (or you know someone who was) and can help in any way, please telephone Dave Keely GW0OGI, on 01407 810996 any evening or weekend.
An additional Amateur Radio and Computer Show is to be held at Picketts Lock this year on 16 November. If you can make it to this very popular show, try to be at the main RSGB stand at noon for the usual gathering of AARUG members.
Pete ON9CUK, has been off the air for several months because of a dispute with the Belgian authorities about his ON9 licence. It seems that he may have to use a lawyer to `persuade' the bureaucrats.
by Pete G3EMF
I have been the owner of a Maplin TU 1000 RTTY encoder/decoder for about twelve years now and I have to say that it still gives just as good service as it did on the day I finished building it. That's the whole point of course, you build it yourself from a kit supplied from the excellent Maplin range. Having constructed a few of their kits over the years, the quality of this one comes as no surprise to me.
The unit as a whole is designed as an interface between a computer and the audio output/mic input of your transceiver, giving AFSK Rx/Tx. On the computer side, it is RS232 compatible which presents a slight problem for those who still use the old Commodore C64 as I did for many years, as that particular computer runs at TTL levels. Conversion however is easy enough as Maplin even supply a kit for that. Very few people would find this a problem today, as the Amiga and PCs use RS232.
To my mind, the most important part of the unit is its receive side. This, it has to be said, is superbly sensitive and selective. Its input limiting is kept very low which means that the working signal level is kept constant, even for the lowest level of input. The write-up quotes a figure of 10 mV for the start of limiting, so deep fading as well as low audio are well catered for.
The proof of the pudding is in the eating of course and when I first put my TU 1000 into use, I was amazed at the signals it was decoding. With hardly any detectable signal, text was still appearing on my screen!
The unit has three preset mark/space tone shifts: 170Hz, 425Hz, and 850Hz, and a continuously variable shift from 0-1000Hz. The mark tone is detected at 1275Hz and the two tones are very tightly filtered by two filter blocks in an MF10 chip, a dual switched capacitor filter controlled by a clock generator. This provides excellent selectivity.
Signal tuning is made easy by the use of two in-built panel meters, one for mark tone signal strength and one for the space tone. Equal strength means `spot-on' tuning. For signal monitoring, there is a speaker output socket provided, but this can be muted by a front panel switch if desired which simply inserts an 8 ohm resistor in place of the speaker.
Construction is not too difficult, but care is needed. Maplin categorises construction complexity from 1 to 5, 1 being `beginner' level. This particular unit is rated at 4 on their scale, but having said that, if you are competent to the level of being able to put together a good frequency counter, then this kit should present no problems.
The TU 1000 has been on sale for a very long time now and still features in the current Maplin catalogue. This must surely speak well for its usefulness and value for money. Mine certainly operates very well alongside the Amiga, and gives excellent results and I can heartily recommend it.
In the last Airwaves, the possibiliity of using the Internet to improve communications between AARUG members was mooted. Thanks to stirling work on the part of Steve, G6LPF and Paul, G4DCV, we now have both our own Listserver and Web Page!
AARUG Listserver
Steve's Listserver works in conjunction with his AmigaBee BBS. All you have to do to circulate information of interest to AARUG members, is to send it as E- mail to: aarug-L@amigabee.org.uk and it will be 'posted' for all subscribers to the Listserver to read and/or comment on.
There isn't sufficient space here to describe all the features and facilities of the Listserver system. If you have a modem and can access the Internet, send an E- mail requesting all the information to: steve.turner@amigabee.org.uk
To date, the Listserver has proved to be both popular and successful with 26 subscribers from all over the world at the last count. There has been a 'hiccup' in recent weeks because Steve has had to transfer the system to another service provider but it will be up and running again by the time that you read this.
AARUG Web Page
Paul's Web Page has really taken off with about 500 log-ons at the last count. It is now possible to join the AARUG via the Web Page and to register electronically the personal details normally submitted on a paper slip. To date, about 35 new members have joined in this way from all over the world.
The AARUG logo is on the Web Page (see enc. screen-shot), together with information from Disk #0, the text of Amigan Airwaves and, as they say, "much, much more!" The Web Page is linked from and to several other www Amiga-related web sites and Aminet. Paul has ideas for further expansion and additions in the future and your suggestions are also welcome! The URL for the AARUG Web Page is:
http://homepages.enterprise.net/pwhatton
If you aren't yet on the Internet, why not? 14.4kBit/s modems are cheap, local call rates are 1p/min. in the evenings and at weekends and some service providers now charge less than #10 per month. No more excuses, go for it !
by Bob G0LBQ
Greetings to all. Due to a serious injury to my hand as a result of an accident at work earlier this year and the resulting stay in hospital, I have not been able to do very much with the library in recent months but I have added five new disks:
#8 Utilities, mainly circuit design tools, an 8K screen blanker, a 1.7K `Menu Stay on the Screen' program and an 800 byte disk drive click stopper.
#84 Icom Scanner control program (Not tested with Icom HF rig)
#85 Yet another CW tutor, but this one will run under WB 1.3
#86 Comms Utils. A `Guide to Comms' for beginners, UUxT for sending binary files via a modem, PKUnzip for unpacking PC archives and Dialling Codes to find codes by entering the town or towns by entering the dialling code. It also does International codes/countries.
#87 The Big Dummies Guide to the Internet.
Disk #0 was last updated in August 1996, except, of course, for the database of the membership. We are still looking for a volunteer to do this... Any offers?
Some library disks have not been requested for over 5 years and many are out of date. The list will be slimmed down and re-issued on 1st Jan. 1998 so if you might want anything, order it now!
We are having some packet modem PCBs made up for use with Amicom. If you are interested in buying one of these at the bargain price of #15, let me know. Bob Tel. 0121 624 1095
Commodore A2620 accelerator, 68020 with FPU and MMU. 2Mb of 32 bit ZIP RAM. Makes an Amiga 2000 go 3 - 4 times faster for just #60.00 Spirit Zorro II RAM expansion card. Fitted with 4Mb, expandable to 8Mb. #50.00 GVP Type 64 pin 4Mb SIMM. # 50.00 Commodore 286 Bridgeboard. Might work? For spares or repair. #15.00 All plus p&p. Del. possible S. London/Kent/Surrey. Tel. Paul G4DCV 01304 368790 E-mail: pwhatton@surrart.ac.uk
Complete A1200 set-up with 2MB 32 bit RAM, FPU, clock, 80MB HD, ext. 880K drive and 1084S monitor Hi-Q Desk-Top Tower with PSU, quad CD-ROM, Squirrel Interface, cables & software. Pair of matched 80W speakers with amp. & PSU. PK 232MBX, Pakratt & misc. decoding software Pen Pal, DOpus 5, flight sim., and other software Various books Bargain at #650 for the complete package (no split). Tel. Tony G3SSQ 01727 851518 (St Albans)
Kenwood MC-60 desk mic. #25.00 inc. postage OS 2.00 Kickstart ROM, free to good home! Wanted - working Baycom modem (Amiga version) Tel. Steve G6LPF 0181 698 0313
by Ralf DL9KCG
With a few years of experience in home computers we all have come to know about `sensational offers'.... Just recently, someone was trying to sell us a package which would allow us to write to CDs in read-only CD ROM drives. On closer inspection, it turned out that this latest `miracle' would just s imulate this by occupying an ever-increasing amount of precious hard disk space. Nice try but, no thanks, I'd rather not.
Then there were the first rumours about ShapeShifter, software written by a 20 year old German student, which would emulate a Macintosh on an Amiga, without any additional hardware - and all this for 45DM (#20). Now hold it mate, not again! We all know that a decent Mac emulator includes a plug-in board and won't cost less than #300 - or do we?
Well, for once all my suspicions have been proven entirely wrong and, yes, it is the real thing. It doesn't require any additional hardware and, best of all, it does work! It's shareware, so you'll even have the possibility to try it out for yourself free, if you don't believe me!
So, let's have a closer look at what it is, what it does and what you'll need to be able to use it. As far as the hardware goes, it really depends on whether you'll just want to have a look at what a Mac feels like or whether you're intending to use your `Amigatosh' for serious work. If it's just for the fun of it, any Amiga with a 68020/30/40, 4MB of RAM and Amiga OS 2.1 or higher will do; in other words an Amiga 1200/3000/4000 or an A500/2000 with an accelerator board. Although SS will work with such a basic configuration, you won't be shifting mountains with it. Particularly on the RAM side, a Mac can be quite demanding. Programs like PhotoShop easily gobble up 10MB. I'd recommend a minimum of 8MB if you are contemplating any serious use of the system and also a graphics board. Using normal Amiga video, one is limited to two colours, which doesn't do justice to the heavily graphics-oriented Mac OS and also, video output is a bit on the slow side.
There is only one real snag - the Mac ROMs - which you'll have to provide yourself. The only legal way would be to buy them from an Apple dealer and Apple dealers are reputed to be a bit reluctant to sell spares or components. Rather like a Rolls dealer who wouldn't expect you to buy a set of brake linings, take them home and fit them yourself! Do insist and you'll get what you need. Then, you'll need to have these ROMs read out as ShapeShifter requires them as a data file on either a floppy disk or your hard disk. Someone owning a real Mac can be quite helpful, here. All this may sound a bit complicated but it can be done and you certainly wouldn't want to spend the rest of your days in a prison cell for having used a pirated ROM image file, i.e. one of those which circulate all over the place, would you?!
After this hurdle has been overcome, you're ready to go. The only limitation of the non-registered version is that it will not support your hard drives for the Mac files. You may install the emulator software on your hard drive but not the actual Mac software or data files, so you'll have to do a bit of disk swapping. Once you have registered the software with the author, you'll receive a key file which then lets you create a Mac partition on your hard drive.
The software runs as a task, so you'll be able to switch back and forth between the Mac and Amiga screens while both are running at the same time. How far does the emulation go? According to a recent comparison done by the German magazine Amiga Special, ShapeShifter is at least as compatible as its two main competitors which both involve additional hardware and won't run on a A500 or A1200; they are also much more expensive. All interfaces are supported, as are floppy drives, hard disks, a CD ROM and sound output through the normal Amiga sound device as well as sound input using a normal Amiga sound digitizer connected to the parallel port.
The sound features are quite useful, as all recent Mac models have built-in sound inputs and outputs. If ever there has been a real multimedia machine, it certainly is the Mac. Even a basic text editor will allow you to write a letter containing a picture of yourself as well as your voice saying `Hello Granny'! You can then save this to disk as a single file and have your Grandmother play it back on her own Mac, hi.
Software compatibility is amazing, to say the least. With the exception of the odd game and some programs using Mac-specific interface hardware which cannot be emulated, everything works. This includes the prestigious PhotoShop, without doubt the best picture processing software available on any platform, as well as all kinds of application software including Mac versions of Microsoft Word, Excel and the like.
There's a good selection of Mac magazines around, some of them with attached CD ROMs containing lots of public domain software. The Mac PD and shareware scene is really buzzing and you will be able to use your Mac emulator for a lot of things without having to spend a fortune on software.
Mac software is, admittedly, usually quite expensive, although the higher prices do buy you a level of quality which is sadly missing from many Amiga products.
Data exchange between the Amiga and the Mac emulation is via a special driver which lets you access the Mac hard drive partition from the Amiga side. The speed of the emulation is about the same as that of an original Mac with a comparable processor/clock rate. Thus Shapeshifter running on an A3000 is just as fast as a Mac Performa with the same type of processor. The fact that until quite recently, Macs used the same processors as our Amigas must help a lot, as the emulation does not have to `fake' an entirely different processor as is the case with PC emulators running on an Amiga.
So, does the promise of a real Mac at #20 hold true and where are the problems and drawbacks? Let's deal with the price, first. It costs #20 to register the shareware and a set of original Mac ROMs will set you back another 60 quid. That's a total of #80 but this is still way below any of its competitors, which aren't any better, as already mentioned. The rest depends on your Amiga. You can't reasonably expect a 1200 with 4MB of RAM to perform like a top-of-the-line Mac Quadra with a 68040 and 16MB but it will work, although somewhat slower and you won't want to use some of the really sophisticated filter functions in PhotoShop. An A2000 with a 68030 accelerator board, a graphics board and, say, 8MB does a really nice job. A graphics board, if you don't already have one, will also be a very useful addition to the Amiga side. If you're seriously considering a Mac emulator, I'd certainly recommend going for ShapeShifter rather than the more expensive hardware- based emulators and then, if necessary, spending part of the difference in price on upgrading your Amiga, thus killing two birds with one stone.
Shapeshifter can be obtained from a number of Amiga BBS systems, Aminet CDs, or downloaded from the Internet and it will also be available from the AARUG disk library, by the time you read this.
We are still plagued by abysmal, long-skip conditions on 40M and with very few exceptions, the 40M Amiga Net on Sundays has been a non-event for more than a year. This is due to the sunspot cycle but now that we are past the sunspot minimum, conditions should slowly but surely improve. Keep listening but it may be at least another year before we can all hear each other again at S9+ as we used to in `the good old days'!