Usenet 1994 January

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Path: senator-bedfellow.mit.edu!bloom-beacon.mit.edu!gatech!europa.eng.gtefsd.com!uunet!olivea!hal.com!decwrl!waikato!comp.vuw.ac.nz!actrix.gen.nz!khantazi!banksie Date: Wed, 15 Dec 1993 00:00:12 +1300 From: banksie@khantazi.actrix.gen.nz (Philip R. Banks) Newsgroups: comp.sys.acorn.announce,comp.sys.acorn,comp.answers,news.answers Subject: Comp.Sys.Acorn FAQ List Posting (Automatic) Keywords: Frequent Questions Answers Message-ID: <65XPb6j029n@khantazi.actrix.gen.nz> Reply-To: banks_p@kosmos.wcc.govt.nz Followup-To: comp.sys.acorn Organization: My Arc. Approved: announce@acorn.co.uk Lines: 810 Xref: senator-bedfellow.mit.edu comp.sys.acorn.announce:248 comp.sys.acorn:21129 comp.answers:3001 news.answers:15790 Archive-name: acorn/faq Comp.Sys.Acorn FAQ List. Last alterations 11/Dec/1993 ----------------------------------------------------- ------------------------------------------------------------------------------- Recent alterations :- Q8 amended slightly. Q13 ammended for the A30x0 series. Q16 spelling and slight semantics correction. ------------------------------------------------------------------------------- Contained below is a list of the most commonly asked questions about Acorn machines in comp.sys.acorn. Before posting to comp.sys.acorn, if you are new to the group, check to see if your question(s) are already answered below. Corrections and/or additions to the list can be emailed to :- banks_p@kosmos.wcc.govt.nz And I'll try to add them as soon as possible.... When reading this FAQ List it is reccomended that you use a text editor if you are not interested in reading every question's answer. Each answer is seperated by a line of '-' characters. To find the answer you are interested in try searching for (in !Edit) "--\x0AQ##)" using Magic characters where ## is the question number you are interested in the answer to. This will leap directly to the answer. The posted sections of the FAQ is available from an email server at MIT. To request the FAQ from this server send an email to mail-server@rtfm.mit.edu. No subject is needed and the body should be :- send /pub/usenet/news.answers/acorn/faq Also stored there is Gerben Vos's Acorn Archive list. This can be obtained in a similar manner to the faq with the email body being :- send /pub/usenet/news.answers/acorn/archives Finally sections of this FAQ are stored in another email server to reduce bandwidth when posting it due to these sections being commonly asked but not quite often enough to warrant the continual posting. To obtain these sections from the email server send mail to the address 'banks_p@kosmos.wcc.govt.nz' with the subject (case and spelling important ignore the quotes.) "ServerMail". The body of the message should be of the form :- Start: [line-limit: <x lines per message>] Section: FAQData Send: <filename> End: All commands in the body of the message are case insensitive. The line-limit command is completely optional and multiple send commands are possible if you to request more than one file at a time. Please remember that this server is a) in Beta test. I only coded it recently and there may be some lurking bugs in it yet. & b) at the other end of a 2400 baud modem. Thus frivoulous requests for large files will not be appreciated. Also if you get the Subject lines case or spelling wrong that email will be sent to me instead of the server. Not unsurprisingly I probably won't be terribly appreciative to receive email server requests in my personal email section... Index of Questions ------------------ Q1) I have obtained [PD] program X but find it needs [version Y.YY of] module Z, which I don't have. Where can I get it? Q2) What version of module X can I assume that all users have? Q3) What's the minimum version of module X that my program needs? What features were introduced/what bugs were fixed in which versions? Q4) I have had problems with my printer. It's a dot matrix printer, when printing graphics or a document, it sometimes mangles a line of output, usually printing a $ sign, too. Q5) Why have there been no postings to comp.{binaries,sources}.acorn recently? Q6) What archives/FTP sites are available? Q7) How can I protect against viruses? Q8) Where can I obtain !Killer? Q9) What is a VIDC enhancer? Will I need one for my new multisync monitor? Q10) What are the main new features of RISC OS 3? Q11) How do I enable solid drags in Risc OS 3? Q12) What kind of Acorn machines are there? Q13) What are the memory limits of the Acorn machines? Q14) What is a second processor and what second processors are there? Q15) Are there any cards for IBM PC or compatable machines that Acorn have produced? Q16) What configuration of serial cable should I use on my Arc for modem work? Q17) Can PC VGA Monitors be added to an Archimedes? Q18) What is ADFSBuffers and what is the best setting for it? Q19) What is the current File-type allocation ranges and why won't Acorn provide a full file-type list? Q20) My disc gives me a 'Broken Directory' or my Free Space Map is corrupt, what can I do? Q21) My hard drive gives me disc errors when I use, what do the error numbers mean? Q22) What does the power on self-test check and how does it signal errors back to you? Q23) Is there a Modula 2 compiler for the Arc? Q24) Is Virtual Memory possible under RiscOS? Q25) How compatible with other systems is an Archimedes? ---------------------------------------------------------------------------- Q1) I have obtained [PD] program X but find it needs [version Y.YY of] module Z, which I don't have. Where can I get it? All patch modules and current versions of Clib and its ilk are sited on the NZ info-server and can be obtained from there if you are sited in NZ. Ideally your dealer will also have copies of them too and you should be able to obtain them from them. (If they don't you may like to pass on the ones from the info-server if you request them, so that they are up to-date.) ---------------------------------------------------------------------------- Q2) What version of module X can I assume that all users have? Currently the version numbers are :- Clib v3.75 Colours v0.52 FPEmulator v2.80 IRQUtils v0.12 Hourglass v2.02 Sound v1.13 WimpUtils v0.04 All of these modules are only needed if you intend running your applications on Risc OS 2 machines. The functionality of all these module versions have been incorporated into ROM under Risc OS 3. ---------------------------------------------------------------------------- Q3) What's the minimum version of module X that my program needs? What features were introduced/what bugs were fixed in which versions? These details will come with the release notes accompanying the module and the particular program, if properly done, will inform you of which versions of the module you need as required. ---------------------------------------------------------------------------- Q4) I have had problems with my printer. It's a dot matrix printer, when printing graphics or a document, it sometimes mangles a line of output, usually printing a $ sign, too. Get your dealer to carry out Field Change Order XXX (which corrects the problem). Or if you are competant enough do it yourself like this :- 1) Remove the circuit board from the computer. 2) Locate and identify resistor R24. Cut the leg of R24 closest to IC9, and carefully move the free end of R24 away from the adjacent resistor. Secure R24 to the PCB with adhesive (for example Loctite TAC PAC), leaving the free end of R24 available for soldering. 3) Prepare new IC (74HC14) by: Removing pins 5,6,8,9,10,11,12 and 13 Lift pins 1 and 4 ready to solder leads Lift pins 2 and 3, and solder them together 4) Position new IC onto IC15 piggyback fashion so that pin 1 of the new IC is directly above pin 1 of IC15. Solder pins 7 and 14 of the new IC to pins 7 and 14 of IC15. 5) Solder thin insulated lead from pin 1 of the new IC to the free end of R24. Solder a second insulated lead from pin 4 of the new IC to the vacated pad of R24. Keep these leads as short as possible, and secure them to the PCB with adhesive. 6) Reassemble the computer and check operation of the printer port. The 74HC14 IC is widely available.........(Acorns part No).... Please note that it is particularly important that a profile of this modification is kept as low as possible, to ensure that there is no fouling of the modification on any podules that may be fitted to the computer. Be warned that modifying your Archimedes invalidates the warranty on it and should preferrably be carried out by an Acorn sanctioned technician. ---------------------------------------------------------------------------- Q5) Why have there been no postings to comp.{binaries,sources}.acorn recently? The moderators run c.b.a and c.s.a in their spare time. They may not have any at the moment - they're studying hard at University. Please be aware the submissions address for the binaries and sources groups is cba@acorn.co.nz and *not* the moderators 'home' addresses - the distinction is important as they have to pay for incoming email at these addresses. ---------------------------------------------------------------------------- Q6) What archives/FTP sites are available? See the regular (fortnightly) posting by Gerben Vos. ---------------------------------------------------------------------------- Q7) How can I protect against viruses? Pineapple Software have produced a program called !Killer, which is the definitive means of checking for or killing viruses. See the next question. There are also a few PD programs around, but these tend to detect only a small subset of the viruses in circulation. !VKiller used to be OK, but it is no longer maintained, is now seriously out of date and fails to work under Risc OS 3. Out of the PD virus utilities the current best is Tor Houghton's Scanner. This detects most known virues and removes quite a few as well and serves as a good secondary defense if Killer is unavailable to you. Scanner should be available on various FTP/Email servers. ---------------------------------------------------------------------------- Q8) Where can I obtain !Killer? It is now a commercial product and will be distributed by Pineapple Software. Who can be reached at:- 39 Brownlea Gardens, Seven Kings, Ilford, ESSEX IG3 9NL Tel. +44 (81) 599 1476 Fax +44 (81) 598 2343 via email :- sales@pinesoft.demon.co.uk support@pinesoft.demon.co.uk Early versions (up to 1.26) are PD, but should not be used now as they are ineffective against the new crop of virus that have subsequently appeared since it's release. ---------------------------------------------------------------------------- Q9) What is a VIDC enhancer? Will I need one for my new multisync monitor? A VIDC enhancer is basically a clock change for your VIDC. Most Arcs (bar the A540 and newer machines) have 24 MHz VIDC chips installed in them. A VIDC enhancer increases this to 36 MHz allowing much higher resolution screen modes to be displayed on your Arc. (800x600x16 or SVGA standard becomes available.) You do *not* need one to use a Multisync monitor - the standard VIDC handles that just fine. However having a VIDC enhancer is only really useful if you do have a Multi-sync monitor. ---------------------------------------------------------------------------- Q10) What are the main new features of RISC OS 3? This information is now contained in my email server. If you wish to know the 'new' features of RO3 over RO2 then send a request to my email server, as detailed at the start of the FAQ, for the filename 'RO3diffs'. ---------------------------------------------------------------------------- Q11) How do I enable solid drags in Risc OS 3? Solid drags are controlled by bit 1 in byte 28 of the CMOS RAM. Setting this bit enables solid drags on all solid drag 'aware' applications. However setting this bit using a *FX command from the command line is a foolish way to do it, as this will unset/set the other 7 bits in that byte which have meaning to FileSwitch and the Wimp. Accordingly the reccomended way to set this bit is using a program like this basic one enclosed below :- REM Toggle state of DragASprite bit in CMOS REM Read byte SYS "OS_Byte",161,&1C TO ,,byte% REM EOR byte with mask for bit 1 byte% = byte% EOR 1<<1 REM Write byte back again SYS "OS_Byte",162,&1C,byte% END Which safely sets bit 1 while preserving the settings of the other bits. (thanks go to Micheal J Hardy for this one.) ---------------------------------------------------------------------------- Q12) What kind of Acorn machines are there, and what are their specifications? The full list of Acorn made machines is somewhat lengthy now and are mostly no longer in manufacture. Accordingly this list distributed in the FAQ includes only Archimedes/ARM based machines, which are the currently manufactured by Acorn. A full list is maintained in my email server under the filename 'MachineLst'. This is, as far as I am aware, a complete list of all Acorn machines made with the possible exception of the latest machines for which I have yet to get the detailed specifications. A5000 - the A5000 is the first machine to feature high density (quad - 1.6 Meg formated) drives by default as well as the latest (at the time) version of Risc OS - version 3. It also features an inbuilt IDE hard drive (40 Meg) on it's higher end model. With the re-release of the series the basic hard drive size has been upgraded to 80 Meg. Released late 1991. 1024k Memory Advanced Disc Filing System by default with High Density drives. IDE interface by default. ARM 3 processor. (25 MHz) 12 MHz RAM. 2048k OS in ROM. ~13.5 MIPS. A4 - Acorns first portable machine. The A4 is functionally an A5000 in portable form. Featuring power save modes, an LCD screen and software configuration of the power saving features it was released July 1992. It is called the A4 because it's footprint on a desk is apparently that of an A4 piece of paper. It is interesting to note that the A4 is *not* an A5000 squeezed into portable form but rather the A5000 is the A4 in desktop form, whereby the A5000 design was largely a spin off from the design of the A4. 2048k Memory Advanced Disc Filing System by default with High Density drives. ARM 3 processor. (24 MHz normally, 6 MHz in power save mode.) 12 MHz RAM. (3 MHz in power save mode.) 2048k OS in ROM. ~13.25 MIPS. A30x0 - Two models of this machine exist the A3010 and the A3020. Both are designed as low end 'family solution' machines. They are also among the first machines to feature the ARM250 processor offering improved performance over an ARM2 (but less than an ARM3) and are designed to supplement the A3000 machine as a low cost entry machine into the Acorn world. Its other main claim to fame is it is the first Archimedes series machine that features joystick ports (only in 3010 model, the 3020 has a network connector instead.). Launched August 27th 1992. 1024k Memory Advanced Disc Filing System by default with High Density drives. IDE 60 Mb Hard Drive (only in A3020 with HD option). ARM 250 processor 12 MHz RAM. 2048k OS in ROM. ~7.2 MIPS A4000 - This is a higher end more expandable version of the A30x0 series machines and is in a three box format similar to the A5000. It also is driven by an ARM 250 processor however it features over the A30x0 machines optional Ethernet & Econet ports, a high density floppy drive and an 80Mb IDE drive by default. The aim of this machine is strongly towards the home office and more 'serious' applications than the A300x0 series. Launched August 27th 1992. 2048k Memory Advanced Disc Filing System by default with High Density drives. IDE 80 Mb Hard Drive by default. ARM 250 processor 12 MHz RAM. 2048k OS in ROM. ~7.2 MIPS A5000 (alpha variant) - This is an improved variant on the A5000 featuring a considerably faster processor, 33 MHz, with the ability to have a similarly clocked FPA unit installed. It also features a considerably larger base hard drive size of 160 Mb on the 4 Mb model, the lower 2 Mb model still as an 80 Mb drive. Finally it has improved alterations to it allowing easy expansion of the machine to 8 Mb of memory by default. (IE without having to use third party solutions.) Released 10th September 1993. 2048k Memory Advanced Disc Filing System by default with High Density drives. IDE interface by default. ARM 3 processor. (33 MHz) 12 MHz RAM. 2048k OS in ROM. ~16.96 MIPS. ---------------------------------------------------------------------------- Q13) What are the memory limits of the Acorn machines? For the most part the 8 bit machines were limited to a maximum of around 256k of memory. Although various expansion systems including second processors effectively meant the upper limit was about 1 Meg. For the 32 bit machines *the* upper limit currently is 16 Meg of memory. Not all of the range of machines are capable of this however and the list looks something like this :- A3xx - 8 Megs maximum through third party, 1 Meg official limit. A4xx & A4xx/I - 8 Megs maximum through third party, 4 Megs official limit. A3000 - 4 Megs maximum through third party, 2 Megs official limit. A540 - 16 Megs maximum. A5000 - 8 Megs maximum through third party, 4 Megs official limit. A4 - 4 Megs official limit. A30x0 - 4 Megs official limit. A4000 - 4 Megs official limit. A5000 (alpha variant) - 8 Megs official limit. ---------------------------------------------------------------------------- Q14) What is a second processor and what second processors are there? A second processor was the generic name for a range of parasite processors that could be linked to Acorn's 8 bit machines via what was called the `Tube` interface. Basically the host machine became dedicated to handling the Input and Output while the second processor would do the higher level functions (like running your programs). The second processor ran asyncronously to the host processor allowing incredible increases in execution speed for programs. A wide range of processors were supported this way allowing Acorn's eight bit range of machines to remain viable and useful for much longer than their technology would suggest. The Second Processors that existed are :- Z80 second processor. 6 MHz RAM. 64k Memory. CP/M OS. External second processor for all eight bit machines. 6502 second processor. 3 MHz RAM. 64k Memory. Extended version of the BBC MOS. External processor for all eight bit machines. 32016 second processor. Unknown. 256k-4096k Memory. Unknown. (Panos at a guess) External processor for all eight bit machines. ARM 2 second processor. 8 MHz RAM. (Guess...) 4096k Memory. Brazil OS. External processor for all eight bit machines. 6502 co-processor. (internal second processor). 4 MHz RAM. 64k Memory. Extended version of BBC MOS. Internal processor for Master 128 machines but could be fitted external to the other eight bit machines. 80186 co-processor. 10 MHz RAM. 512k Memory. DR-DOS+ with GEM. Internal processor for Master 128 machines but could be fitted external to the other eight bit machines. ---------------------------------------------------------------------------- Q15) Are there any cards for IBM PC or compatable machines that Acorn have produced? Yes. Three cards in total :- Springboard. ARM 2 processor. 4096k Memory. 8 MHz RAM. Brazil OS. PC ARM development system. Precursor to Springboard. Hardware functionally identical. Ecolink. An econet link card for the PC. ---------------------------------------------------------------------------- Q16) What configuration of serial cable should I use on my Arc for modem work? Here follows a diagram of the necessary connections for common terminal programs to work properly. They are as far as I know the informal standard agreed upon by commercial comms software developers for the Arc. Pins 1, 4, and 8 must be connected together inside the 9 pin plug. This is to avoid the well known serial port chip bugs. The modem's DCD (Data Carrier Detect) signal has been rerouted to the Arc's RI (Ring Indicator) most modems broadcast a software RING signal anyway, and even then it's not really necessary to detect it for the modem to answer the call. Arc (9 pin) Modem (25 pin) ----------- -------------- +---1---DCD | | 2---RxD------------------------RxD----3 | | 3---TxD------------------------TxD----2 | +---4---DTR------------------------DTR---20 | | 5---0v-------------------------SG-----7 | | 6---DSR------------------------CTS----5 | | 7---RTS------------------------RTS----4 | +---8---CTS 9---RI-------------------------DCD----8 Of course you can connect the Modem pin 20 to any one of pins 1, 4, or 8 on the Archimedes plug, as they are all connected together anyway. Chocks Away Extra Missions (the flight simulator from 4th Dimension) suggests that the serial cable be wired as above except that pins 1-4-6 are connected together and the modem's CTS (pin 5) be connected to the Arc's pin 8 (ie the connections at pins 6 and 8 be swapped over at the Arc's end). This has been and it also seems to work fine. However newer Arc's like the A5000 have come out (and indeed the occasional A310) with a `corrected` serial port. This newer serial port operates as it should and is directly compatible with standard PC cables. Most comms software about at the moment does not take this in account and assumes that you have a cable patched in the manner described above. If you do not use such a patched cable on these `fixed` serial ports the software will generally fail to work. ---------------------------------------------------------------------------- Q17) Can PC VGA Monitors be added to an Archimedes? It depends on what monitor you have, and what Archimedes you have. There are two main types of PC VGA monitors out there... 1) Fixed Frequency These monitors will only display video signals with certain line and refresh rates. They will typically only display CGA / EGA / VGA modes. 2) Multi Frequency These monitors will display any video signal within a certain range, typically 30-50Khz line rate and 50-80Hz refresh rate. Type 1 almost always require seperate syncs as the monitor uses the polarity of the syncs (mainly positive going negative or mainly negative going positive) to determine what the line and refresh rate should be. Type 2 vary. Some require seperate syncs (vertical and horizontal) and others will work with composite syncs (vertical and horizontal EOR together). As PC monitors typically start at a line rate of 30Khz compared to the TV broadcast modes (mode 12 etc.) that have a line rate of 15Khz, VIDC has to do more work to obtain a 30Khz line rate. This means that you computer will slow down silghtly if you use a 30Khz+ line rate monitor. If you have an ARM 3 fitted such slow downs will probably be negligable. Now, depending on what type of Archimedes you have depends on what type of monitor you can use. A540 / A5000 / A4 / A3010 / A3020 /A4000 Has software control over the polarity of the syncs and what frequency VIDC is clocked at. The A540 with RiscOS 2 can only use modes 26-28 (640x480) [I can't rember if an A540 has a mode 31, help?]. However, by changing links and a *configure option, you can get the computer to generate seperate syncs with no problem. The other machines with RiscOS 3 can do even better. If you tell the computer that you have a VGA monitor it will re-map all of the 15Khz line rate modes up to 30KHz line rate. This means that you can play your games that require mode 12 / 13. However, as a PC monitor is designed to display 320 lines minimum then you will get a 'letterbox' effect as mode 12 has only 256 lines. All these machines have 24Mhz, 25.175Mhz and 36Mhz crystals to drive VIDC with. The 25.175Mhz crystal is needed to obtain the correct video rates for PC monitors displaying 640x480 screens. The 36Mhz crystal is used to obtain higher resolution modes, like 800x600x16 colours. A3000 This can generate seperate syncs but requires links to be set to determine the polarity. It has only a 24Mhz crystal and can therefore only drive 'forgiving' monitors correctly that don't mind the 640x480 video mode timings being slightly incorect. In order to obtain proper timings, and software control of the sync polarity, you will need a VGA VIDC Enhancer for the A3000. A400 series. The situation gets more complex. Due to an 'error' in the PCB / circuit diagram, the A400 series cannot generate seperate syncs satisfactorly. The video signal loses the green component when seperate syncs is selected. As standard, there is no polarity control over the syncs. In common with the A3000, there is only a 24Mhz crystal. If the PC monitor can handle composite syncs then the monitor can be used in 640x480 mode only. A300 series. Most, if not all, of the A300 series had the circuit board hardwired into composite mode continously. There is only a 24Mhz crystal, and only composite PC VGA monitors can be used. Conclusion: Apart from the A5000 and newer machines, no computer as standard can drive either a fixed frequency or multi-frequency PC monitor in all of the Archimedes modes satisfactorily. However VIDC enhancer boards can be bought to upgrade an Archimedes to handle the needed timing and signals. ---------------------------------------------------------------------------- Q18) What is ADFSBuffers and what is the best setting for it? ADFSBuffers are Read Ahead and Write Behind buffers for ADFS on your Archimedes. These are designed to improve the speed of filing operations by doing work at optimum times. There are some side effects of using them though. When active under Risc OS v2.00 and v2.01 discs *must* be dismounted before being removed from the floppy drive. Failure to do so results in the dreaded 'FileCore in use.' error. However if you are prepared to sacrifice the speed improvment they give configuring the buffers to 0 does remove this problem. (Or so I am informed.) Under Risc OS v3.00, as supplied with the early A5000 machines, these buffers generate a different problem and must *always* be configured off. Failure to do so results in spurious errors when using the Hard Drive on an early A5000. Symptoms include reformating of crucial sectors of the disc, disc address errors and general failure to save files to the drive. So when using an A5000 with Risc OS 3.00 remember to configure them to off! With Risc OS v3.10 all of the old problems have been cured with a new one introduced. Namely that if you have only a few ADFSBuffers configured and are accessing the floppy drive then your machine can occasionally lock up completely for you. It appears that any value of ADFSBuffers above 8 causes that problem to be largely alleviated (read it only occurs rarely at these settings). So under Risc OS 3.1 it is reccomended that you set your ADFSBuffers to 8+. There is a patch module available, called ADFSUtils, that does fix this problem - contact your local dealer for a copy of it. As for the optimum settings for ADFSBuffers, as far as I am aware no one has done any speed tests to see what is the best setting. Presumably though Acorn will have arranged for the system to start up (Well except for RO3.00...) in the optimum state for most uses. I would be interested in anyone who has done speed tests sending me the results of their investigations.... ---------------------------------------------------------------------------- Q19) What is the current File-type allocation ranges and why won't Acorn provide a full file-type list? Acorn have reallocated the File-type ranges for applications. The new ranges are :- Non-user area &E00-&FFF Acorn &B00-&DFF Commercial software &A00-&AFF Acornsoft, and other commercial software &400-&9FF Commercial Software User area &100-&3FF Non-commercial distributed software (ie PD) &000-&0FF User's personal usage (ie non-distributed) 75% of the user area is for PD/Shareware, with allocations co-ordinated by Acorn. If your software is going to be distributed, you should have an allocated filetype to avoid clashes. Acorn cannot publish it's master list of filetypes because, at any given time, it will contain allocations made for products which have not yet been announced. Therefore, Acorn would be in breach of confidence by doing so - and the editing overhead for producing a sanitised list is too great. ---------------------------------------------------------------------------- Q20) My disc gives me a 'Broken Directory' or my Free Space Map is corrupt, what can I do? Unfortunately due to the highly complicated nature of the filing system data there is little that can be done easily. Your simplest and best way of correcting the problem is to backup as much software as you can and reformat your drive, restoring everything from those backups you make regularly... (What you don't back up your discs? :-) ) To do anything else requires a good knowledge of how the underlying structures work and is beyond the scope of this FAQ, although this detail is covered in the Risc OS 3 PRMs. ---------------------------------------------------------------------------- Q21) My hard drive gives me disc errors when I use, what do the error numbers mean? The error numbers returned indicate the type of error encountered. Exactly why slightly more meaningful messages are not returned I am unsure. The error codes meanings are as follows :- 06 unit select signal has not been returned by drive 07 write fault signal from drive 08 drive not ready 09 seek complete has not been returned 10 data error has been detected by ECC (Error Correction Code) 13 a fatal ECC error has occurred in DATA area 16 sector ID has not been found 17 an ID area that begins with an improper address mark has been detected 18 the address mark in DATA has not been detected ---------------------------------------------------------------------------- Q22) What does the power on self-test check and how does it signal errors back to you? The purple screen at power on indicates that the self-test has begun. A brief ROM, RAM, VIDC and IOC test is performed and then the screen colour changes to blue and a full memory test is performed, along with a second test of the VIDC and IOC. When the screen returns to purple, the machine is testing for an ARM3. At the end of this sequence the screen colour is set to green (for pass) or red (for fail). If the tests have all passed then the machine starts to boot and the RISC OS 3 welcome screen is displayed. If any test fails, the screen will remain red and the disc drive light will blink a fault code. A short flash is used to indicate a binary '0' and a long flash indicates a binary '1'. The bits are grouped into eight nybbles (blocks of four bits) with the most significant bit first. The lowest seven bits are a status word. The meaning of each bit is given below in hex :- 00000001 Self-test due to power on 00000002 Self-test due to interface hardware 00000004 Self-test due to test link 00000008 Long memory test performed 00000010 ARM 3 fitted 00000020 Long memory test disabled 00000040 PC-style IO world detected Bits 8-31 indicate the fault code and are described below. Not all the bits are used. 00000200 ROM failed checksum test 00000400 MEMC CAM mapping failed 00000800 MEMC protection failed 00004000 VIDC Virq (video interrupt) timing failed 00008000 VIDC Sirq (sound interrupt) timing failed 00020000 RAM control line failure 00040000 Long RAM test failure ---------------------------------------------------------------------------- Q23) Is there a Modula 2 compiler for the Arc? Currently, no. Acorn did have, in the early days of the experimental ARM work, an in house compiler. However this compiler was sufficiently unstable and buggy to be unreleasable as commercial product and was only used because in house support was available immediately to the users of the compiler. When Olivetti invested in Acorn this technology went to them so that Acorn no longer have even an in house Modula 2 compiler. However some companies have stated intentions to produce Modula 2 compilers for the Arc. Whether these intentions become reality has yet to be seen. ---------------------------------------------------------------------------- Q24) Is Virtual Memory possible under RiscOS? Short answer, full VM is *not* possible under the current versions of RiscOS. The problem is that most of RiscOS works in SVC mode, if a DataFetch abort occurs then R14_svc *is* corrupted. This makes returning from the SWI somewhat problematic. This is a hardware limitation with the ARM2 and ARM3 cell chips. Future hardware using ARM6 or better processor cells have special memory abort modes that alleviate this problem so future machines and incarnations of RiscOS may well have VM available. However limited solutions are available now. !Virtual is one such solution allowing VM for a user process using a limited subset of SWI's that are carefully 'protected' against R14_svc being corrupted. Such solutions suffer from the restricted set of SWI's they support and are mostly useful for batch style processing jobs like compilation or memory intensive processing jobs. ---------------------------------------------------------------------------- Q25) How compatible with other systems is an Archimedes? PC :- The Archimedes can handle DOS discs (720k; the A5000 and later models can also handle 1.44M floppies). In RO3, this is built in, under RO2 you have to use one of the (PD) utilities. There are two PC (software) emulators that can handle most PC software, three if you count the fact that Acorn's offering is split into two emulator programs. There are also PC cards, containing an 80x86 processor and other PC hardware, which uses the Archimedes' disc and video. All emulators are multitasking (and not PD). Unix :- Unix software can be ported (and in fact many packages already have been) with the help of UnixLib, which is PD. Memory-hungry ports, such as gcc, can be run with the aid of !Virtual (also PD). Of course if your really desperate to run Unix software it might be advisable to buy RiscIx, the Acorn flavour of Unix. Mac :- Due to the pecularities of the double density Mac disc format it is difficult to read the Mac disc directly. However a company is releasing a filing system and drive combination to read Mac high density discs allowing transfers. Also Macs often can read PC format discs allowing transfers to occur using that medium. There is no Mac emulator available. Atari ST :- Like PC floppies, the Archimedes can read, write and format ST-format floppies. No emulator for the ST is known. Amiga :- The amiga uses an unusual disc format that is not easily read by other machines. Accordingly there is currently no Amiga format disc reader available. But Amiga's can read PC discs, so again transfers can occur via that medium. There is no Amiga emulator. Spectrum :- There seem to be a couple of Spectrum emulators around, but (according to rumour) they can't be distributed legally because they require the contents of the ROMs, and Sinclair still holds the copyright. ---------------------------------------------------------------------------- Thanks go to all the people who have contributed corrections and additions to the list. Without this help this list would be a hell of alot buggier (spot the programmer... :-) ) than it is... ---------------------------------------------------------------------------- All additions, corrections & suggestions for the FAQ List should be sent to -=> banks_p@kosmos.wcc.govt.nz <=- Being the maintainer of this FAQ I reserve the right to be wrong, incorrect, slow, out of date and generally how I please with the FAQ List.