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Comp.Sys.Acorn.FAQ part 1 of 3

( Part1 - Part2 - Part3 - Part4 - Part5 )
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WELCOME TO THE COMP.SYS.ACORN FAQ MONTHLY UPDATE.

See reader questions & answers on this topic! - Help others by sharing your knowledge
This update is automatically generated by my machine, so please email me at
csa-faq [at] riscos.org if any parts are missing or corrupted.
--------------------------------- part 1 of 3 ------------------------------

WELCOME TO THE COMP.SYS.ACORN.* FAQ MONTHLY UPDATE.

This database comprises answers to the most Frequently Asked Questions on the popular Acorn Usenet newsgroup hierarchy, and is maintained by Paul Vigay.

A text based version of this web site is posted to comp.sys.acorn.announce and comp.sys.news.answers on a monthly basis.
This text version consists of three parts of up to 50K each, broken down into the following segments;

Part 1 - Index, sections 1 & 2 (45K)
Part 2 - sections 3, 4 & 5 40K)
Part 3 - sections 6, 7, 8 & 9 (30K)


If you have any queries, or would like to suggest a new question, please contact me by emailing csa-faq-09 [at] riscos.org


Last alterations
----------------
 * 1st Feb 2009 - Split FAQ into three sections again, for ease of distribution to news servers
   with size limited articles.

Contained below is a list of the most commonly asked questions about Acorn machines in the comp.sys.acorn hierarchy. Before posting to comp.sys.acorn.*, if you are new to the groups, check to see if your question(s) are already answered below. Corrections and/or additions to the list should be sent to csa-faq-09 [at] riscos.org and I'll try to update the main FAQ as soon as possible....

This FAQ is posted monthly to comp.sys.acorn.misc, comp.sys.acorn.announce, comp.answers and news.answers.

For Web browsers out there, the FAQ home page is http://www.riscos.org/csafaq/. This will always contain the latest version of the FAQ.

Lastly this FAQ is maintained by Paul Vigay. Credit is given to Philip R. Banks who created it and maintained it until I took over from him on 1st Dec 1998. The aim of this FAQ is to share information and help newcomers to the RISC OS scene, therefore permission is granted for free distribution of the entire list or quoted segments of it.

If you wish to include segments of the list into other documents then proper attribution must be performed and if you wish to include a part of the list, or the list in full, in any commercial product then express permission must be obtained from myself.


Index of Questions
------------------
The questions have been categorised loosely into related sections, in an effort to make finding the desired information simpler and quicker.

Section 1 - Hardware and Operating Systems

   Q1.1) What is an Acorn machine?
   Q1.2) What kind of Acorn/RISC OS machines are there?
   Q1.3) What versions of the ARM processors are there?
   Q1.4) What are the differences between different RISC OS versions?
   Q1.5) What is RISC OS 3.8/Ursula?
   Q1.6) What are the graphics capabilities of RISC OS machines?
   Q1.7) Is Virtual Memory possible under RISC OS?
   Q1.8) What 'Easter Eggs' are present in RISC OS?
   Q1.9) What is the current status of Linux for Acorn machines?
   Q1.10) What is the current status of NetBSD for Acorn machines?
   Q1.11) What is 'Lazy Task Swapping'?
   
Section 2 - Upgrades and Expansion

   Q2.1) What's the memory limit on current machines?
   Q2.2) What is a second processor and what second processors are there?
   Q2.3) Can PC VGA & Multisync Monitors be added to an Acorn machine?
   Q2.4) Can I connect a SCART monitor to my Acorn machine?
   Q2.5) What was a VIDC enhancer?
   Q2.6) Are there any Acorn cards for IBM PC or compatible machines?
   Q2.7) What configuration of serial cable should I use for modem work?
   Q2.8) How do I make a Null modem cable?
   Q2.9) How can I get unfiltered sound from an Acorn machine?
   Q2.10) What are StrongARM dipswitch settings?
   Q2.11) Are there any PIC programmers available for RISC OS?
   Q2.12) Can you add a TV card to a RISC OS machine?
   
Section 3 - Hardware Issues and Compatibility

   Q3.1) What do the hard drive error numbers mean?
   Q3.2) What can I do with a 'Broken Directory' or a corrupt Free Space Map?
   Q3.3) What does the power on self-test check?
   Q3.4) My Real Time Clock has paused, how do I restart it?
   Q3.5) Why doesn't *Speaker work on my machine?
   Q3.6) What can I do about my fan making excessive noise starting up?
   Q3.7) After fitting the RISC OS 4 upgrade my CD Rom reports 'Drive Empty'.
   Q3.8) Occasionally a fairly early model Risc PC will completely hang for no apparent reason, usually when filer windows are redrawn.
   Q3.9) What IDE drives work on Acorn machines?
   Q3.10) What are the Master/Slave link settings for my IDE drive?
   Q3.11) Why won't my Western Digital IDE drive work after a cold boot?
   Q3.12) What peripherals work with RISC OS?
   Q3.13) What specification memory can I use with my RISC OS machine?
   Q3.14) What's the biggest hard drive I can fit?
   Q3.15) To what size should I partition my Hard Drive?
   Q3.16) What is the maximum size for a file under Risc OS?
   
Section 4 - RISC OS Configuration

   Q4.1) What is ADFSBuffers and what is the best setting for it?
   Q4.2) How do I enable solid drags in RISC OS 3?

Section 5 - Software Issues

   Q5.1) Why does DOSFS corrupt my files occasionally?
   Q5.2) Where can I obtain the latest version of module X?
   Q5.3) What are the current File-type allocation ranges?
   Q5.4) Is there a Modula 2 compiler for the Arc?
   Q5.5) What Programming Languages are available for Acorn machines?
   Q5.6) Why does the RO3.5 desktop sometimes revert to the system font?
   Q5.7) Why does ChangeFSI display a blank white window, not an image?
   Q5.8) What causes the 'nager:Sprites22' error?
   Q5.9) Is there a Real Audio or Real Video player for Acorns?
   Q5.10) Is there any 'streaming audio' player software available for RISC OS machines?
   Q5.11) How do I get a faster interrupt timer than the centisecond ones?
   Q5.12) How can I create Interlaced GIFs on Acorn machines?
   Q5.13) Is the PC Card software still available?
   Q5.14) How do I obtain an allocated filetype or SWI chunk for my software?
   
Section 6 - Viruses and Security

   Q6.1) What RISC OS virus killers are available?
   Q6.2) I have received some information about a virus from a reputable source, it apparently affects Windows, Mac and/or Linux systems, is it perhaps dangerous for RISC OS users too?
   
Section 7 - Online Resources & Support

   Q7.1) What archives/FTP sites are available?
   Q7.2) What Acorn related companies are available on the net via email?
   Q7.3) What are the submission addresses for comp.{binaries.sources}.acorn groups?
   Q7.4) What WWW pages are out there for Acorn topics?
   Q7.5) What Acorn BBS's are there?
   Q7.6) Where can I advertise second hand Acorn kit?
   Q7.7) Where can I find a user group local to me?
   Q7.8) How do I kill-file people using NewsHound?
   
Section 8 - Compatibility with other Machines

   Q8.1) How compatible with other systems is an Acorn machine?
   Q8.2) Is there a BBC BASIC for other machines?
   Q8.3) Can I run 65Host on the Risc PC?
   Q8.4) Can I read Acorn format discs on a PC?
   Q8.5) What software handles files with this extension?
   Q8.6) Is there a version of Draw for Windows?
   Q8.7) Can I run Windows software on a RISC OS machine?   

Section 9 - Common Questions about the FAQ

   Q9.1) Why do I get the FAQ twice?
   Q9.2) Why does the full FAQ have to be posted?
   Q9.3) Isn't the FAQ overly long?
   Q9.4) If I find something wrong or am unhappy with the FAQ, what do I do?
   Q9.5) How to retrieve the FAQ from the source...
   Q9.6) Is there a more detailed Network FAQ available?
   Q9.6) Is there a comp.sys.acorn.games (csa.games) FAQ available?


----------------------------------------------------------------------------

Section 1: Hardware and Operating Systems 

----------------------------------------------------------------------------
Q1.1) What is an Acorn machine?

Acorn computers were a British built line of computers that started with 6502 based machines and later became based upon ARM (Acorn Risc Machine) processors. Acorn computers were made by the Acorn Computer Group, originally founded in 1978 by Cambridge business men Chris Curry and Herman Hauser.

In January 1999 Acorn Computers Ltd., was renamed Element-14, focussing more on their Digital TV technology. Element-14 were later purchased by Broadcom Corporation on November 24 2000. More information can be found on their web site at http://www.broadcom.com

The remaining part of Acorn was later sold to Pace Micros, including the remains of their set-top box division. Thus Acorn the company, is technically no more - other than a brand name. Pace subsequently agreed to licence RISC OS, Acorn's powerful wimp-based operating system to a newly formed company called RISCOS Ltd.

Castle Technology took over the original manufacture of the Acorn Risc PC and A7000 range, and now produce the Iyonix which is currently the fastest RISC OS computer available. In 2003 Castle Technology bought the rights to RISC OS from Pace, and in 2006 a new company, RISC OS Open (ROOL) was created in order to manage the open source release of RISC OS. More details can be found on the RISC OS Open website at http://www.riscosopen.com/

Section 1.2 details those RISC OS machines currently in manufacture and how to fetch a full list of all machines known to have been made by Acorn. Acorn machines are known for their innovation, flexibility and reliability of hardware/software.

----------------------------------------------------------------------------

Q1.2) What kind of Acorn/RISC OS machines are there?

The full list of Acorn made machines is now getting somewhat lengthy as many variants and new machines have been launched amd discontinued in the last few years.

As of June 2002, only current machines are listed in this FAQ, as there are numerous online resources available which give details of the history of Acorn & RISC OS computers. The following sites may be useful to find out about past machines. However, I've included some information on various diverse machines (below).

* http://www.khantazi.org/Archives/MachineLst.html - Philip Banks comprehensive list of Acorn machines.

* http://www.mcmordie.co.uk/acornhistory/acornhistory.shtml - A technical history of Acorn Computers, compiled by Robert McMordie.

* http://atterer.net/acorn.html#hard - Richard Atterer's Information about Acorn Computers.

* http://homepage.tinet.ie/~lrtc/computers/acorn_ro/acorn/ - Richard Butler's History of Acorn & RISC OS

What follows is an up to date list of machines currently in production and available to purchase.

The Iyonix
~~~~~~~~~~
The Iyonix is currently the most powerful RISC OS based, ARM powered computer. Manufactured by Castle Technology, it is available in a variety of models.

It is also the only current machine running a full 32-bit version of RISC OS.

Detailed specification for the base model comprises;
Intel XScale 80321 Processor running at 600MHz.
32-bit RISC OS 5
128Mb 200MHz DDR RAM
40, 80 or 120Gb Hard Drive
UDMA 100 support
16-bit Sound system
nVidia GeForce 2MX graphics giving resolutions of up to 2048x1536 pixels in 16 million colours.
Virtually silent operation (quieter than even the latest iMac range of Apple computers)
USB Keyboard & Mouse.
USB expansion
Full PCI DMA for expansion cards

More information is available on the Iyonix Ltd website at http://www.iyonix.com

The A9 Home
~~~~~~~~~~~
The A9 Home is a miniature RISC OS based machine, manufactured by Advantage Six (www.advantagesix.com). Based on the ARM9 processor, it's technically not quite as fast as an Iyonix, but none the less is an extremely capable machine, even more useful because its very small form factor.
Weighing in at only 6.6" x 4.1" x 2.1" in size, it has the following specification:-
Samsung ARM 9 Processor running at 400MHz
Graphics co-processor and Power control processor
128MB SDRAM
8MB VRAM supporting graphics up to 16.7 million colours at resolutions of 1600x1200
40GB internal 2.5" hard disc
RISC OS Adjust32 operating system
2 x USB (1.1 standard)
2 x PS/2
3.5mm Microphone in and headphone out sockets
10/100 BaseT integral network
RS232 serial out
5V, 20W PSU, although in operation the A9 Home consumes only around 3W of power.
More information can be obtained at www.thea9.info


Acorn RiscPC series
~~~~~~~~~~~~~~~~~~~
In 2003 Castle technology announced that they were ceasing production of the Risc PC range, which has now been supeceded by the Iyonix PC (see above).

The Risc PC was the last generation of Acorn badged machines, superseding the original Acorn Archimedes computers. All of them were based on a highly configurable and modular system that made a bewildering variety of options available. All were founded on the 'second generation' chipset featuring VIDC20, IOMD and the latest StrongARM processor. The 'RPC' range was launched on the 15th of April 1994 with the RiscPC 600 series of machines. The last 'Kinetic' RPC was some ten times faster than the original 19
94 model.

A list of older, legacy machines is now archived at http://www.riscos.org/legacy/

----------------------------------------------------------------------------

Q1.3) What versions of the ARM processor are there?

The details of various ARM chips and their capabilities are described on Philip Banks web site at http://www.khantazi.org/Archives/ARMChips.html
Current developments can be found on ARM Ltd's web site at http://www.arm.com

----------------------------------------------------------------------------

Q1.4)  What are the differences between different RISC OS versions?

Between RISC OS 2 and RISC OS 3?
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
A good article on the differences between RISC OS 3 and various versions of RISC OS 3 is available on Richard Goodwins website at http://www.houseofmabel.com/puters/RISCOS3/

Between RISC OS 3.5 and RISC OS 3.6?
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Quite a few, although nothing particularly drastic OS wise, mostly improvements although the lifting of the FileCore partition limit and the incorporation of JPEG handling into the OS are quite substantial improvements. Here is the list :- 

 * Now stored on 2x2Mb ROMs, or an increase ot a potential 4096Kb of OS.
 * FileCore improvements allowing at least 4Gb partitions.
 * Support for ATAPI style CD-ROM drives.
 * JFIF handling incorporated into the OS.
 * Standard applications have been moved back into ROM.
 * Toolbox modules, the Cv5 support modules, moved into ROM.
 * CDFS modules moved into ROM.
 * Access modules moved into ROM.

Between RISC OS 3.6 and RISC OS 3.7?
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Like RISC OS 3.6, RISC OS 3.7 was primarily changed behind the scenes and was an incremental improvement of the OS. The changes were mostly geared towards rendering the OS StrongARM compatible. Here is the list :-

 * Autodetection of processor type enhanced to detect and cater for ARM6 and better processors up to the StrongARM
 * Memory handling has been moved into the kernel, away from the Window manager. This not only speeds up task switching but now means the kernel is now aware of multiple applications.
 * FileSwitch supports 2048 byte buffers, useful for CDFS.
 * The Font Manager is now capable of blending anti-aliased fonts to a variable colour background. Improving the readability of fonts displayed over colour images. (Like Web pages, say. :) )
 * An improved Internet module is supplied in ROM.
 * A StrongARM compatible Econet module is supplied in ROM.

Between RISC OS 3.7 and RISC OS 3.8/4?
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
RISC OS 3.8 was a developmental version of RISC OS 4 released to developers just before the closure of Acorn's Workstation division and cancellation of the Phoebe project. It was code-named Ursula (see Q1.9).

It was finally completed by RISCOS Ltd and RISC OS 4 was the first new version of RISC OS to be released by a company other than Acorn, A comprehensive list of features was released onto their own web site during April 1999. This is available online from http://www.riscos.com/risc_os_4/Features.htm

In a nutshell some of the major new features were:-
 * Performance Enhancements
 * New Disc format brings new features, improved performance and more disc space.
 * Redesigned icon set
 * Faster/Easier configuration and !Boot
 * New screen saver system
 * 'Lazy Task Swapping'
 * Improved applications including a new !Writer appliction for simple word processing and !Taborca - an Adobe PDF creator.

Between RISC OS 4 and RISC OS 5?
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
RISC OS 5 was exclusively written by Castle Technology for the Iyonix PC. It was essentially a completely re-written and fully 32-bit version of RISC OS 4.02
A list of features is available online at http://www.iyonix.com/iyonix/features/osfeatures.shtml
RISCOS Ltd maintain a RISC OS 4 FAQ at http://www.riscos.com/faqs/ro4_qanda.htm

----------------------------------------------------------------------------

Q1.5) What was RISC OS 3.8/Ursula?

Before Acorn decided to abandon Workstations and focus on Digital TV, work was at an advanced stage on an updated version of the operating system (codenamed Ursula) to live in their new machine (Phoebe). Developers had access the RISC OS 3.8 (as Ursula declared itself to be) for evaluation and beta testing purposes. Versions of RISC OS 3.8 were primarily available for ARM710 machines, although some StrongARM compatible versions are known to exist.

For those who don't know, Phoebe is a character from the hit US sit-com Friends, and Ursula is the name of Phoebe's twin sister.

----------------------------------------------------------------------------

Q1.6) What are the graphics capabilities of RISC OS machines?

I've now decided to restrict this section of the FAQ to detailing currently available models. For the graphics capabilities of older machines, please visit my legacy systems page at http://www.riscos.org/legacy/

Each type of monitor generally requires a mode definition file (MDF) set up for it, to allow you to take advantage of the specific monitor capabilities. A library of common MDFs can be found at http://www.riscos.org/resources/ although you'll generally find that with most modern monitors you can find one that works by trying other available MDFs via trial and error.

Iyonix machines
~~~~~~~~~~~~~~~
The most notable difference in the graphics capability of the Iyonix is that it now incorporates a 'standard' graphics card, namely the nVidia GeForce 2MX. This gives much higher resolutions and colour depths than previous 'Acorn' machines, but also sacrifices 2 & 4 bit colour depths (ie. 4 and 16 colour screen modes).
Rather than give an exhaustive list of all 'modes' available, it will suffice to say that the Iyonix display resolutions from 320x200 up to 2048x1536 pixels, each in either 256, 32 thousand or 16 million colours (8, 16 or 24 bit). However the latest nVidia graphics cards do not support 32K colour modes due to the Red and Green components being swapped around.

The A9 Home
~~~~~~~~~~~
The A9 Home has the Samsung ARM9 integreated graphics processor which can drive up to 1600 x 1200 in 16 million colours or 2048 x 1536 in 32 thousand colours.

----------------------------------------------------------------------------

Q1.7) Is Virtual Memory possible under RISC OS?

The short answer is that full VM is not possible under the current versions of RISC OS. The problem is that most of RISC OS 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. Hardware using ARM6 or better processor cells have special memory abort modes that alleviate this problem so future machines and incarnations of RISC OS may well have VM available. Indeed the 
RiscPC machines make prime candidates for having virtual memory, however there are still re-entrancy issues that make this problematic for RISC OS. (Consider loading data from a file into paged out virtual memory...)

A number of limited solutions were devised over the years but are no longer under development. One such utility was !Virtual by Nick Smith and Ferdinand Oeinck, which allowed VM for a user process using a limited subset of SWI's that are carefully 'protected' against R14_svc being corrupted. This solution suffered from the restricted set of SWI's supported and was mostly useful for batch style processing jobs like compilation or memory intensive processing jobs.
!Virtual v0.37 (and its source) can be downloaded from http://downloads.orpheusweb.co.uk/pub/RISCOS/StuttgartFTP/riscos/util/memory/

Virtualise was developed by Alexander Thoukydides for the Risc PC machines. It was originally sold by Clares Micro Supplies, who's range of products were taken over by APSL in December 2002. Alex's web page giving more information is at http://homepage.ntlworld.com/thouky/software/virtualise/

----------------------------------------------------------------------------

Q1.8) What 'Easter Eggs' are present in RISC OS?

It has been a long tradition with Acorn OSes to have hidden sections that give credit to the people involved in the creation of that OS. The BBC Model B ROMs had the names of the people involved hidden in the memory space occupied by Fred, Jim and Shelia. With the release of the ARM powered machines this tradition has continued on.

RISC OS 2.00
------------
 * tucked away in the ROMs is a list of the names of involved people.

RISC OS 3.00
------------
 * If you type 'rmtmd' when the desktop welcome screen is displayed a slide show of the key RISC OS team members is displayed on the screen.
 
 * In the info box of the task manager if you clicked menu over the letters 'rmtmd', in that order, contained within the author icon a full list of the people involved with the OS's development is displayed in that icon.

RISC OS 3.10 & 3.11
-------------------
 * In the info box of the task manager if you clicked menu over the letters 'team', in that order, contained within the author icon a full list of the people involved with the OS's development is displayed in that icon.
 
 * Using a template editor examine the task managers templates file from the Resources filing system. (Resources:$.Resources.Switcher.Templates)
 
 * Inside the 'power' dialogue is a message.

RISC OS 3.50
------------
 * In the info box of the task manager if you clicked menu over the author icon four times a full list of the people involved with the OS's development is displayed in that icon. (This can take a while to watch, be warned...)
 
 * Using a template editor examine the task managers templates file from the Resources filing system. (Resources:$.Resources.Switcher.Template3D) Inside the 'power' dialogue is a message, in 3D. This message also appeared in the replacement templates supplied with NewLook for RISC OS 3.1.

REM Extract Names and Pictures from RISC OS 3.50, 3.60 and 3.70 ROMs
REM
REM Based on an original program (for RISC OS 3.50) by Nick Craig-Wood.
REM Updated by Matt Rix <BigRISC@CyberJunkie.Com>
SYS "OS_Byte",129,0,255 TO ,version%
CASE version% OF
  WHEN &A5: S=&1F47AC :REM RISC OS 3.50
  WHEN &A6: S=&358F18 :REM RISC OS 3.60 - Thanks to Terry Adams for finding this
  WHEN &A7: S=&3A0868 :REM RISC OS 3.70
  OTHERWISE: ERROR 0,"Cannot run on this ROM version.":END
ENDCASE
S+=&3800000
E=S+&3130
O=65536

SYS "Squash_Decompress",%1000,-1 TO Q
DIM R Q,P O
SYS "Squash_Decompress",%0100,R,S,E-S,P,O TO,,,,,U

path$="Pipe:$."
piccy$=path$+"Pictures"
names$=path$+"Names"
run$="Filer_Run "

SYS "OS_File",10,piccy$,&FF9,,P+8,P+P!4+8
SYS "OS_File",10,names$,&FFF,,P+P!4+8,P+O-U

OSCLI "SetType "+piccy$+" Sprite"
OSCLI "SetType "+names$+" Text"

OSCLI run$+piccy$
OSCLI run$+names$
END
        
RISC OS 3.60
------------
 * In the info box of the task manager if you clicked menu over the author icon four times a full list of the people involved with the OS's development is displayed in that icon. (This can take a while to watch, be warned...)
 
 * Using a template editor examine the task managers templates file from the Resources filing system. (Resources:$.Resources.Switcher.Template3D) Inside the 'power' dialogue is a message, in 3D. This message also appeared in the replacement templates supplied with NewLook for RISC OS 3.1.
 
 * Run the program listed in the RISC OS 3.50 section to be given a list, and pictures, of the primary developers of RISC OS 3.60.
 

RISC OS 3.70
------------
 * In the info box of the task manager if you clicked menu over the author icon four times a full list of the people involved with the OS's development is displayed in that icon, including a 'special' acknowledgment to Peter Bondar. (This can take a while to watch, be warned...) This only works if the menu was opened from the Task Manager window, not the icon.
 
 * Using a template editor examine the task managers templates file from the Resources filing system. (Resources:$.Resources.Switcher.Template3D) Inside the 'power' dialogue is a message, in 3D. This message also appeared in the replacement templates supplied with NewLook for RISC OS 3.1.
 
 * Run the program listed in the RISC OS 3.50 section to be given a list, and pictures, of the primary developers of RISC OS 3.70.

RISC OS 3.71
------------
 * In the info box of the task manager if you clicked menu over the author icon four times a full list of the people involved with the OS's development is displayed in that icon, including a 'special' acknowledgment to Peter Bondar. (This can take a while to watch, be warned...) This only works if the menu was opened from the Task Manager window, not the icon.

RISC OS 4.02
------------
 * From BASIC, issue the command SYS "OS_Module",2,"IRQUtils" and RISC OS will launch an invaders game.
 
 * Click MENU over the RISC OS 4 icon on the far right of the iconbar. Move the pointer over to 'Info' and then across to open the RISC OS 4 information box. Click MENU four times over the icon containg ' 1999, RISCOS Ltd'. Sit back and watch a list of RISCOS Ltd. developers scroll by.
 
 * Using a template editor examine the switcher module's file in the Resources filing system. (Resources:$.Resources.Switcher.Templates) Inside the 'power' dialogue is the message "Help! We've been released from the software factory, and don't know what to do!". There is another one inside the 'Confirm' template. :-)

----------------------------------------------------------------------------

Q1.9) What is the current status of Linux for Acorn machines?

Due to the rapid development of Linux exact details about the latest incarnation of Linux are not kept in this FAQ. However for the latest information you might like to consult these web pages, or email the people involved with the port :- 

Native Linux page :- 
http://www.arm.linux.org.uk/ (rmk@arm.linux.org.uk)

The Iyonix machine has a near complete Linux port available for me. Further information can be found at http://www.iyonix.com/linux.html

Peter Naulls has some very useful ARM Linux resources available on his website at http://www.chocky.org/linux/

----------------------------------------------------------------------------

Q1.10) What is the current status of NetBSD for Acorn machines?

N.B. The RiscBSD name has been dropped entirely in favour of NetBSD/arm32.

Due to the rapid development of NetBSD exact details about the latest incarnation of it are not kept in this FAQ. This is a port of NetBSD, a Unix variant, to the RiscPC. However for the latest information you might like to consult these web pages, listen to the NetBSD email list or email the people involved with development of it:-

NetBSD/arm32 - For RiscPC and later machines - http://www.netbsd.org/Ports/arm32/

NetBSD/arm26 - For Archimedes and other pre arm600 boxes - http://www.netbsd.org/Ports/acorn26/

----------------------------------------------------------------------------

Q1.11) What is Lazy Task Swapping ?

On RISC OS 3.5 and 3.6 machines there were seen to be serious delays in the desktop when running applications with large wimpslots, mostly indicated by the lack of reponsiveness. The problem was identified as being that of having to page in the entire application which, with a 4k page size was quite slow. In RISC OS 3.7 this situation was improved by changing the way in which the application is paged in.

RISC OS 4 can support a new method of paging tasks in - Lazy Task Swapping. This can also be called 'demand paging', because instead of paging the entire space in, individual pages are only given 'on demand'. This means that in a large application only sections of the application space may be physically present although the application itself will be unaware of this.

There is a problem, however, with some versions of the StrongARM processor which will (under certain circumstances) cause Lazy Task Swapping to fail. StrongARMs prior to revision T exhibit this failing and Lazy Task Swapping is consequently be disabled. You may also want to disable Lazy Task swapping if you encounter problems when using DMA.



----------------------------------------------------------------------------

Section 2: Upgrades and Expansion

----------------------------------------------------------------------------

Q2.1) What's the memory limit on current machines?

The Iyonix computer can have a maximum of 1GB RAM added to it, in the form of two 512MB RAM modules. The Iyonix RAM is 200MHz DDR RAM. The most common configuration of Iyonix machines is 128MB or 512MB.

The A9 Home cannot be upgraded, as it's a sealed unit. It contains 128MB SDRAM and 8MB VRAM.

Information on Risc PC and earlier systems can be found at http://www.riscos.org/legacy/

----------------------------------------------------------------------------

Q2.2) What was a second processor and what second processors were there?

A second processor was the generic name for a range of parasite processors that could be linked to Acorn's original 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 asynchronously 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.

For more information on legacy second processor systems, see http://www.riscos.org/legacy/2ndprocessors.html

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Q2.3) Can standard PC video monitors/projectors be added to a RISC OS machine?

All current RISC OS machines and older Risc PCs, come fitted with standard 15 pin 'D-type' VGA connectors for video out, so should work on pretty much all standard monitors, both CRT and LCD flat panel types.

If you have an older legacy machine, additional information and wiring diagrams for connecting VGA monitors is available online at http://www.riscos.org/legacy/monitors.html

N.B. The Risc PC can sometimes get confused when set to 'auto' monitortype, resulting in a blank screen and no display on the monitor. If this happens, try re-configuring the CMOS ram settings to the following and then reseting the machine.

*Configure Monitortype 4
*Configure Sync 0
*Configure Mode 40

These settings should prevent the monitor confusing the auto setting of the Risc PC.


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Q2.4) Can I connect a SCART monitor to my Acorn machine?

If you have an older Acorn machine with a nine pin video socket, then yes and here is the wiring diagram :-

    .------------------------.    Arc 9-pin plug
    \    1   2   3   4   5   /
     \                      /
      \    6   7   8   9   / Case
       '------------------'
        _____________________
       |19                  1|    SCART 21-pin plug
       | | | | | | | | | | | |
      /                      |
     / |  | | | | | | | | |  |
    /___20_________________2_| 21 (metal casing)


A SCART connector is also known as a Euroconnector or a Peri-Television connector. 

                Arc             SCART
Case            | ------------- 21              Case
Red             1 ------------- 15              Red
Green           2 ------------- 11              Green
Blue            3 ------------- 7               Blue
CSYNC           4 ------------- 20              Composite video input
Ground (0V)     6 -+---------+- 13              Red ground
Ground (0V)     7 -+         +- 9               Green ground
Ground (0V)     8 -+         +- 5               Blue ground
Ground (0V)     9 -+         +- 13              CVBS video ground

Ideally each ground wire should be linked to a separate Arc pin. Also, depending on your SCART monitor, pin 16 may need a +5V input to it. Unfortunately the Arc 9 pin socket does not provide a +5V output so this will have to be sourced from somewhere else.

If you have a newer Acorn machine, with the 15 pin high density video socket then you need this kind of wiring :-

       .--------------------.   15-pin VGA style plug
       \    1  2  3  4  5   /
        \ 6  7  8  9  10   /
         \ 11 12 13 14 15 /
          '--------------'

Connections:

Arc                               SCART

1 red ---------------------------- 15
2 green--------------------------- 11
3 blue---------------------------- 7
4 ID[2] nc
5 0V (test)
6 red rtn------------------------- 13
7 green rtn----------------------- 9
8 blue rtn------------------------ 5
                  75 ohms
9 +5V-------------/\/\/\/--------- 16
10 0V----------------------------- 17,18
12 ID[1]-------------------------- 8
11 ID[0] &lt;--13 |
13 HSync --&gt;11 |
                    120 ohms
14 CSync------------/\/\/\/------- 20
15 ID[3] nc

Notice the two resistors. Also notice that the HSync output (pin 13) of the 15-way plug has to be connected to the ID[0] input (pin 11) of the same plug. (Be aware I have no direct confirmation that this wiring works.)

As is usual care must be taken when doing this procedure. Older Acorn machine did not have their VIDC chips fully buffered and unplugging/plugging cables from the video socket while the machine is turned on can cause damage to the video circuitry.

If you want to connect a BBC B computer to a Scart monitor, there are some online wiring diagrams at http://www.riscos.org/legacy/monitor.html (previously at www.astro.livjm.ac.uk/~bbc/monitor/monitor.html)

----------------------------------------------------------------------------

Q2.5) What was a VIDC enhancer?

A VIDC enhancer is basically a clock change for your VIDC. Most Acorns (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.

Details on a 'build-it-yourself' VIDC enhancer are available online at http://www.riscos.org/legacy/vidc.html

Note a VIDC enhancer is unnecessary and incompatible with the Risc PC (and newer) range of machines.

----------------------------------------------------------------------------

Q2.6) Are there any Acorn cards for IBM PC or compatible machines?

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. 

However, to the best of my knowledge none of these cards are commercially available.

----------------------------------------------------------------------------

Q2.7) What configuration of serial cable should I use for modem work?

All current machines, along with all machines since the A5000 have come fitted with a 'corrected' serial port as standard. This newer serial port operates as it should and is directly compatible with standard PC cables.
Some older communications software may not take this in account and assume that you have a cable patched in the manner described at http://www.riscos.org/legacy/serial.html
If you do not use such a patched cable on these 'fixed' serial ports this software will generally fail to work completely. (Usually hardware flow control fails.)

With the advent of the Risc PC and all current machines, a standard PC cable is advised. For details on how to wire up a cable for older machines, visit http://www.riscos.org/legacy/serial.html

If you want to wire a console cable to a Sun Netra/Sunfire server, detailed wiring diagrams are available online at http://www.sunhelp.co.uk/sun/serialcable.html

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Q2.8) How do I make a Null modem cable?

For starters you will need soldering skills and the necessary components.
Namely cable, connectors (9 pin female D-type), a soldering iron, solder and the will to use them. All of these items, bar the will, can be found down at the local electronic components store. Assuming you have them all then you will need to decide what kind of machines you are hooking together.

There are three cases and I need to define a few terms.

'Archimedes' is defined to be A300 series, A400 series (including the /I machines), R140, A540, A3000 (but not the A30x0 machines) and R260 machines.
'RiscPC' is defined to be both the RiscPC series but also the A5000, A4000, A30x0 & A4 machines. All of these machines have a 'PC Style' serial port that conforms closely to RS232 specifications.

This means that if you are connecting your Acorn machine to a non Acorn machine then generally treating the foreign machine as a RiscPC, in terms of serial handling, will work. There are exceptions, Macintoshes in particular have had non-standard serial ports and may require further research before you can create a cable for them.

The cases are :- 

Archimedes to Archimedes

 Arc (9 pin)                      Arc (9 pin)
 -----------                      -----------

 +---1---DCD                        DCD----1---+
 |                                             |
 |   2---RxD------------------------TxD----3   |
 |                                             |
 |   3---TxD------------------------RxD----2   |
 |                                             |
 +---4---DTR------------------------DTR----4---+
 |                                             |
 |   5---0v-------------------------0v-----5   |
 |                                             |
 |   6---DSR------------------------RTS----7   |
 |                                             |
 |   7---RTS------------------------DSR----6   |
 |                                             |
 +---8---CTS                        CTS----8---+
 |                                             |
 +---9---RI                         RI-----9---+


Archimedes to RiscPC

 Arc (9 pin)                      RiscPC (9 pin)
 -----------                      --------------

 +---1---DCD                        RI-----9---+
 |                                             |
 |   2---RxD------------------------TxD----3   |
 |                                             |
 |   3---TxD------------------------RxD----2   |
 |                                             |
 +---4---DTR------------------------DTR----4   |
 |                                             |
 |   5---0v-------------------------0v-----5   |
 |                                             |
 |   6---DSR------------------------RTS----7   |
 |                                             |
 |   7---RTS------------------------CTS----8   |
 |                                             |
 +---8---CTS                        DSR----6---+
                                               |
     9---RI-------------------------DCD----1---+


RiscPC to RiscPC

  RiscPC (9 pin)                   RiscPC (9 pin)
  --------------                   --------------

     2---RxD------------------------TxD----3
 
     3---TxD------------------------RxD----2
 
     4---DTR---------------------+--DSR----6
                                 |
     6---DSR--+                  +--RI-----9
              |                  |
     9---RI---+                  +--DCD----1
              |
     1---DCD--+---------------------DTR----4
 
     5---0v-------------------------0v-----5
                                
     8---CTS------------------------RTS----7
 
     7---RTS------------------------CTS----8


Note that most PC compatible machines have 25 pin D type male ports for their second COM port. You have two options in this case - either re-wire the cable for the 25 pin port or you can buy a 9 to 25 pin converter plug.
Either solution works well. Here are the relevant pins for the 25 pin port :-

  Pin No.  Function
  -------  --------
     8       DCD
     3       RX
     2       TX
     20      DTR
     7     GND (0v)
     4       RTS
     5       CTS

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Q2.9) How can I get unfiltered sound from an Acorn machine?

All Acorn machines are equipped with a sound filter designed to remove high frequency harmonics from the sound output. However this does cause a muffled feel to the sound as on some machines the filter is a little too excessive and it filters out valid frequencies. Also the filter is optimised for 20.833 kHz output and has less desirable results when the output rate is changed. Accordingly people who do audio work often want to bypass the filter.

On all machines bar the A3000 there is the Internal Auxiliary Audio Connector (usually called link LK3), which can be easily plugged into to provide the unfiltered output. This connector has 10 pins on it and is usually found near the headphone socket on the motherboard. The pins are :-

1 Unfiltered Left
2 Ground
3 Filtered Left
4 Ground
5 Auxiliary Input
6 Ground
7 Filtered Right
8 Ground
9 Unfiltered Right
10 Ground

Simply hook into the Unfiltered outputs.

On an A3000 you need two 10uF 16V ALEC capacitors. Look for chip LM324 (IC39) and hook the capacitors like this:-

Pin 1 --> --|+ |--- Unfiltered Left
Pin 2 --> --|+ |--- Unfiltered Right

The Risc PC & A400 machines have a connector similar to the A5000. 

There are several caveats to this procedure. Opening your machine may void your warranty and most definitely should not be attempted if you are unsure of the procedure. Do not unplug/plug the unfiltered audio output while the machine is turned on, by bypassing the filter you also bypass the normal protective circuitry for the audio output.

Finally you will hear higher harmonics present in the audio signal so you will need to connect the signal to a filter of some kind to reduce this extra noise.

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Q2.10) What are StrongARM dipswitch settings?

The StrongARM card has a set of dipswitches on it that control the clock speed of the processor.

These can be altered but there are some important caveats to mention first :- 

This information is for the original 202MHz StrongARM. The newer 233MHz ones can't be clocked as high, as the base crystal speed is different.

Don't change the links while the card has power. This can result in damage to your processor, always turn your machine off before changing settings.

By default two tracks on the back of the card constrain the card to never go faster than 202 MHz. Cutting these tracks invalidates your warranty, so only do this if you are prepared to replace the card.

The chip is officially rated for 202 MHz, running it faster than this speed can result in hardware damage to the processor and will shorten the chip's lifespan. Again, only do this if you are prepared to replace the card.

If you do cut the tracks remember that the card is a multi-layer one, cutting deeper may sever more tracks than you intended and render the card non-functional.

Without cutting the tracks, the dip switches can be used to slow the processor down from 202MHz to 88MHz if required. Each switch sets one bit making sixteen possible speed settings. This table summarises those speed settings :- 

     Switches      |              SA frequency
----+----+----+----+------------------+---------------------
 1  | 2  | 3  | 4  | Revision J and K | Revision R, S and T
----+----+----+----+------------------+---------------------
 on | on | on | on |    88.473600 MHz |       85.909080 MHz
 on | on | on | off|    95.846400 MHz |       93.068170 MHz
 on | on | off| on |    99.532800 MHz |       96.647715 MHz
 on | on | off| off|   106.905600 MHz |      103.806805 MHz
 on | off| on | on |   143.769600 MHz |      139.602255 MHz
 on | off| on | off|   151.142400 MHz |      146.761345 MHz
 on | off| off| on |   162.201600 MHz |      157.499980 MHz
 on | off| off| off|   169.574400 MHz |      164.659070 MHz
 off| on | on | on |   191.692800 MHz |      186.136340 MHz
 off| on | on | off| * 202.752000 MHz |      196.874975 MHz
 off| on | off| on |   213.811200 MHz |      207.613610 MHz
 off| on | off| off|   228.556800 MHz |      221.931790 MHz
 off| off| on | on |   243.302400 MHz |    * 236.249970 MHz
 off| off| on | off|   258.048000 MHz |      250.568150 MHz
 off| off| off| on |   276.480000 MHz |      268.465875 MHz
 off| off| off| off|   287.539200 MHz |      279.204510 MHz

The default speeds are indicated with *'s.
(Thanks go to Matthias Seifert for this information.)

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Q2.11) Are there any PIC programmers available for RISC OS?

Robert Sprowson has produced an application called !PICsuite which caters for PIC programming under RISC OS. There is also a free PIC assembler to download, which has BBC Basic style assembly conventions. Visit http://www.sprow.co.uk/pics/ for more information.

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Q2.12) Can you add a TV card to a RISC OS machine?

The Iyonix machine supports standard PCI expansion cards and Robin Hounsome has written drivers for the Pinnacle Rave PCI TV card using the SAA7134 chip from Philips.
More information and his driver can be downloaded from http://www.hounsome.org.uk/


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- Comp.Sys.Acorn FAQ ---------------------------------- End of part 1 of 3 -

This FAQ is maintained by Paul Vigay (csa-faq [at] riscos.org)
Please email me with any queries/amendments or problems.
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Last Update March 27 2014 @ 02:11 PM