RISCOS.com

AcornUser - Customer Hotline Articles 1994

Mar 94

Disabling Relocatable Modules

In some situations, such as in a classroom, it may be considered desirable to disable some of the applications and relocatable modules which are an integral part of RISC OS.

Modules which are temporarily disabled will remain so until the machine is switched off. Modules which are "permanently" disabled (by *unplug) will remain so until the machine is reset via a Delete-Power On.

The routines for disabling relocatable modules may be inserted at the start of the !Boot or !ArmBoot file which is to be run when the machine is switched on or reset.

!Configure can be temporarily disabled using:

   *RMKill !Configure

and can be unplugged using:

   RMReinit !Configure

Put the module back if it is already unplugged

   Unplug !Configure 

With Ethernet based networks, it is recommended that the Broadcast Loader is disabled. This may be achieved using:

   SetEval BLoader$Module 1
   RMEnsure BroadcastLoader 0 SetEval BLoader$Module 0
   If BLoader$Module Then RMEnsure EconetA 0 SetEval BLoader$Module +1 
   If BLoader$Module=2 Then Unplug BroadcastLoader
   Unset BLoader$Module

The script works by setting a flag, BLoader$Module, which is then altered according to a series of tests.

Taking this sequence a line at a time:

SetEval BLoader$Module 1           
| Set the flag to 1

RMEnsure BroadcastLoader 0 SetEval BLoader$Module 0 
| Check if the Module is there. If it is NOT then  
| set the flag to 0

If BLoader$Module Then RMEnsure EconetA 0 SetEval BLoader$Module +1
|If the module is there, check if Econet is there too. If it is, increment the 
|flag.

This gives us the situation that, if the Broadcast Loader is already disabled, the flag is set to 0. If the Loader is enabled and the Econet module is enabled, the flag is set to 1. If the Loader is enabled and Econet is software unplugged, the flag is set to 2.

   If BLoader$Module=2 Then Unplug BroadcastLoader
|If the flag is set to 2, disable the Broadcast Loader

Unset BLoader$Module 
| Remove the system variable used for the flag from memory

A5000 External Floppy Drives and RISC OS 3.1

It has been found that some 5.25" floppy drives connected to A5000s have stopped working when the machines are upgraded to RISC OS 3.1.

The solution to the problem is to move link 21 on the main PCB from position 1-2 to 2-3.

An Application Note, which can be obtained from Acorn Approved Dealers and Education Centres, has been written to detail further configuration procedures for installing external floppy drives.

Apr 94

After looking after this column for almost two years the time has come to hand over to 'fresh blood' in the form of Dave Walker. Thanks to everyone who's written in over the past two years about the column.

Alan Glover

Introductions dispensed with, I'll say 'thank you' to Alan, and wish him best of luck.

Monitors

It is possible to connect VGA and SVGA monitors to Archimedes equipped with RISC OS 3.1; however, only a subset of the total number of screen modes will be available. This means that some programs which are not written to be screen mode-independent will present an unusable display. Acorn's multiscan monitors (the AKF50 and AKF52) can display all screen modes except Mode 23, which is designed for use with high resolution mono monitors.

Monitors with a 15 pin VGA style connector can be connected to an older Acorn computer's 9 pin output using a suitable adaptor available via your Acorn dealer.

After a power-on or machine reboot, your machine performs the Power-On Self Test (POST), which includes a complete memory and video test. Users with VGA and SVGA monitors, or owners of pre-Archimedes 540 machines who have fitted a VIDC Enhancer, may find that their machine fails the POST occasionally; some monitors take several seconds to synchronise, and some VIDC enhancers may start up with VIDC clocked at 36MHz when POST expects 24MHz. Errors generated by this test produce a blank red screen and a "morse code" pattern blinking out on the floppy drive light.

You can disable the VIDC check and the long RAM test by setting bit 7 of byte 188 (&BC) in CMOS RAM. This can be done with a BASIC program:

  SYS 6,161,188 TO ,,A%:       REM read the value 
  SYS 6,162,188,(A% OR 1<<7):  REM write it back with bit 7 set

If you need to perform a complete machine reset (delete-power on), you will have to run this program again to reset the relevant bit.

May 94

13/09/94Questions and Answers

Following the release of !Printers 1.22 this month's top question is:

Q. !Printers 1.22 asks for a new version of ColourTrans when I load it; I have looked in my !System.Modules directory and can't find it.

A. There is a new version of ColourTrans included with !Printers 1.22; it's in !System.310 in the !Printers suite. Use !SysMerge to update your master copy of !System, and ensure that you reset the machine before running the new !Printers.

Hints and Tips

This month, we concentrate on file transfer between the Pocket Book and Archimedes using the A-Link.

A Typical A-Link session

1. Ensure that the Pocket Book and the Archimedes are switched off
2. Connect A-LINK to Archimedes
3. Switch on Archimedes
4. Load PocketFS software
5. Connect A-Link to Pocket book
6. Switch on Pocket Book
7. On Pocket Book, set the Remote Link to On
8. On Archimedes, click on PocketFS icon

At the end of an A-Link session, remember to dismount the A-Link correctly. The procedure below should prevent any problems with the A-Link and Pocket Book.

1. Dismount A-Link via the PocketFS menu.
2. On the Pocket Book, set Remote Link to OFF
3. Quit PocketFS software
4. Switch off Pocket Book
5. Remove A-Link from Pocket Book

NOTE: When Using the A-Link it is advisable to use a mains adaptor; communications place a heavy load on the batteries and reduces their expected lifetime. The A-Link will not work if there is less than 50K free memory on the Pocket Book. More memory can be made available by quitting applications which are running in the background or by deleting files from the RAM disk.

Transferring Write, Abacus and Card files

Although the Acorn A-Link can be used to transfer any type of file between the Archimedes and Pocket Book, the most common use of the A-Link is to transfer files to and from the applications supplied with the standard Pocket Book.

As Write, Abacus and Cards formats are not understood by Archimedes applications, it is necessary for the A-Link to convert the files into an appropriate format; the following are used:

Application Name Write Abacus Cards

A-Link file format ASCII CSV CSV

CSV (Comma-Separated Variable) format means that items of data are stored sequentially as a string of ASCII, with the entry for a given field separated from the entry for the adjacent field by a comma.

Other Files, and Applications

Files from other Pocket Book applications, such as Schedule, can be transferred to and from an Archimedes without performing any conversion; this is also useful for installing new Pocket Book applications distributed on floppy disc. Choose the "Open $" option from the PocketFS icon bar menu, and use the filer displays as normal.

Errors reported by the A-Link

"Already opened by another process"

The file you wish to transfer is currently being used by an application on the Pocket Book. To make this file available for transfer, you need to quit the application using the file. An application can be quit by highlighting its icon on the desktop and pressing Acorn-Q.

"Please insert Pocket Book"

The A-Link can no longer find the Pocket Book, this may be a result of a bad connection between the machine and the Pocket Book. Check connections and start again.

Backing up files from the Pocket Book

When backing up files from the Pocket Book, it is possible that the files, when stored on an Archimedes formatted disk, will have their names truncated. This can lead to difficulty when re-installing the backed-up files.

As the structure of a PC formatted disc matches more closely that of the Pocket Book, files which are backed up to a DOS formatted disk on the Archimedes will not be truncated. For this reason, we recommend that Pocket Book files be backed up to DOS Formatted floppies.

Acorn News in Brief

For readers with Internet access, Acorn has an FTP server from which technical notes, press releases and Acorn software updates can be downloaded. Set your ftp client to binary mode, open ftp.acorn.co.uk (or 136.170.129.1) and look in directory "pub"; be sure to read the "ReadMe" file.

For technical queries, we suggest that you first contact your nearest Acorn Approved Dealer, who will have answers to most questions.

We can also be contacted directly by writing to

Customer Services Dept
Acorn Computers Ltd
Acorn House
Vision Park
Histon
Cambridge CB4 4AE

or emailing via Internet.

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June 94

Questions and answers

Q: When I try to access a CD using !PhotoView, I get the error CDFS::0.$.PHOTO_CD.OVERVIEW/PCD not found; what's the solution?

A: !PhotoView is not finding the file containing the index information for the pictures on the PhotoCD. First check that you have a PhotoCD in your drive. Corel Professional PhotoCDs do not have an Overview file on the disc; individual Image Pacs may, however, be accessed using !ChangeFSI. If your PhotoCD is not a Corel disc and the Overview file cannot be found, consult your PhotoCD's supplier.

Q. How do I delete an unformatted or non-bootable PC hard disc partition via the Desktop?

A. To delete an unformatted PC hard disc partition you need to either format then delete the partition, or go to the command line (F12 from the Desktop) and type:

*SETTYPE Text *DELETE

Q. Is there a system variable which I can access to find out what the Currently Selected Directory (CSD) is set to?

A. Yes, provided you have RISC OS 3.1. Fileswitch$ADFS$CSD contains the ADFS CSD pathname; if you use a different filing system, change the appropriate part of the variable.

More than Music

CD ROM is a wonderful medium for software which requires a large amount of resource data, and there is now PhotoCD, but you can play audio CDs too! Most CD ROM drives have an Audio Out connector, which produces a signal suitable for feeding into an amplifier. Otherwise, most CD ROM drives have a jack on the front for headphones; you can attach a pair of "active speakers" of the kind used with personal stereos to this.

CD ROM drives which are fully supported by Acorn's drivers are:

SONY CDU6111, CDU6211, CDU541, CDU561
PHILIPS CM131, CM231
TOSHIBA XM2200A, 3301
HITACHI CDR1650S, CDR1750S
CHINON CDS-431
APPLE CD300 (driver available from Acorn dealers)

PhotoCD is available using the Philips CDU541 (single-session only), the CDU561 and the Apple CD300 (multi-session).

Further drive and driver combinations are available from third party suppliers.

CD ROMs for DOS-based systems can be accessed directly using CDFS via DOSFS under RISC OS. PC Soft can access CD ROMs using MS DOS and MSCDEX. Note that MPC discs cannot currently be played on an Acorn platform, as there is no support for a SoundBlaster-compatible card.

The vast majority of CD ROMs for all platforms are written using the standard ISO9660 or earlier High Sierra standard formats; CDFS can read both of these.

Choosing SIMMs for Risc PC: A Checklist

The Risc PC marks an enhanced level of conformance to popular standards for Acorn, in that DRAM may be fitted as SIMMs (Single Inline Memory Modules). Hence you can buy DRAM for your Risc PC from many more suppliers, but make sure that the SIMMs you are considering conform to at least this outline specification:

72 contact pins, with 32 bit data
Speed of 70ns or faster
Physical size 108mm long, 36.2mm wide and 9.4mm thick
Memory must be mapped as a "square array" (same number of row and column addresses)
16 or less physical ICs on each SIMM
DRAM devices must support "fast page mode" and "CAS before RAS refresh."

Further details on suitable SIMMs are contained in an Application Note; this is available via Acorn support channels (eg dealers).

VRAM (Video memory) is installed on proprietary cards, and hence is only available via Acorn and a smaller number of third parties.

Did you know?

Some difficulties in running new software may be the result of the software requiring the latest versions of relocatable modules. Current versions of some modules for RISC OS 3.1 are:

ColourTrans 1.57 (Supplied with !Printers 1.22)
FPE400 4.03 (For users of the FPA10 Floating Point Coprocessor)
CLib 3.75
SCSIFS 1.10
CDFS 2.21

In the case of all except SCSIFS and CDFS, upgrades to these versions are available via ftp.acorn.co.uk, as well as via Acorn dealers. The latest versions of SCSIFS and CDFS are supplied as part of the PhotoView package, available from Acorn dealers as Product Code AKA35, price 34.95.

The latest versions compatible with RISC OS 2 are available as part of the RISC OS 2 Extras disc, available from the same sources.

Questions and Answers

Q. My Apps icon has disappeared from my icon bar. How do I get it back?

A. You need to go to the command line (F12) and type *UNPLUG to find out which modules are unplugged; one of them will be Resources. Re-install them using *RMREINIT .

Q. I can't fit all my PC applications onto a single 32Mb partition, and I don't want to use multiple partitions; can I make a partition larger than 32Mb?

A. Yes, you can. However, you won't be able to access the partition using DOSFS under RISC OS; partition access will only be available in the PC environment.

The Secret Life of !System

Many of your everyday programs use relocatable modules such as the Shared C Library; a lot of these are kept in !System.Modules. Your machine is informed of the location of !System by !System.!Boot, in the lines

 If "" = "" Then Set System$Dir 
 If "" = "" Then Set System$Path .

which first sets up the variable System$Dir to point to the location of !System, and then sets up System$Path, which is the variable applications should use as the start of the path they require to access modules.

The modules in !System may be supplanted or updated either by copying the modules directly into !System.Modules, or, preferably, by running !SysMerge and dragging the relevant copies of !System to facilitate copying.

A4 Battery Hints

We have recently investigated how best to maintain the performance of the A4 Nickel - Cadmium rechargeable battery. Our results suggest the following:

After every few charges, try to discharge the battery completely before recharging it. This can be done, once the A4 has prompted you to save your work and switch off, by saving your work and then leaving the A4 switched on for another two hours or so.

When the battery is recharging, it tends to get warm. The charging capability of the battery is best if it is kept cool while charging, and it makes quite a difference if an airflow can be maintained over the battery while it is charging. Even turning the A4 upside down will allow the battery to radiate some of its heat to the surroundings.

Video Support on the Risc PC

The table below gives information on the range of Acorn monitors and standard resolutions supported by Risc PC with all VRAM configurations, and examples of typical backward-compatible numbered screen modes which display these resolutions.

Although the box is ticked to indicate that 1600x1200 is possible on a machine with 2Mb VRAM, running this mode requires that the VIDC20 be clocked at a higher rate than it is specified for. Hence this display mode may not be steady on all Risc PCs.

This table applies to the Monitor Definition Files as shipped; the 1600x1200 definition file can be obtained by AKF85 owners by writing to Acorn Customer Services.

Changes to ftp.acorn.co.uk

These are now listed in /pub/changelog; the biggest change since the Comms column in the May issue is that the ",ddc" archive file endings have been replaced with ".arc". In addition to fixing the lists problem under VMS, this means that WWW browsers such as xmosaic recognise binaries as binaries.

ftp.acorn.co.uk is being mirrored by Arcade BBS (081 654 2212) and Digital Databank BBS (0707 329306), so if you have a modem but no Internet link, you can still download our files.

Sept 94

Oct 94

Questions and Answers

Q. I want to save a file from First Word Plus into another wordprocessor. How do I do it?

A. Turn WP mode off by going into the Edit menu, and click Adjust over "WP Mode". The tick by it should disappear. You can then save your file as plain ASCII text, which can then be loaded into your alternative package. You will, however, then have to re-format your headings, fonts etc.

Q. When I try to print a file, I get a "Filesystem or Path Printer: not found" error; what should I do?

A. The Parallel Device Driver module, which drives your printer port, has somehow become unplugged. Save all your work, exit from the Desktop to the command line (F12) and type

   *Unplug

to give a list of unplugged modules; this device driver should be among them. Issue

   *RMReInit ParallelDeviceDriver

to re-initialise it, follow this with a Ctrl-Break, and re-load your printer drivers.

Hints and Tips

Faster Text Printing

If you regularly use a colour printer, you may notice that printing in black takes longer than it would with a monochrome printer; this is most noticable when printing text. This is because, by default, the Printer Definition File for a colour printer is set to use the maximum number of hues available with that printer. Monochrome printing on colour printers can be speeded up by configuring another "virtual printer" to print in monochrome only; drag a second copy of the relevant Printer Definition File into the control window, so that you appear to have two identical printers. Use the "Configure" dialogue box to change the name of one or both of the printers, and de-select the "Colour" option in the "Configure" dialogue box for one of the virtual printers. You can then switch between colour and monochrome printing simply by clicking Select over the relevant "virtual printer" on your icon bar; the selected printer is shown in bright colour, while any other printers are greyed out. Alternatively, you can turn the colour option on and off within a single installed printer driver.

Ethernet III Configuration Tips

The configuration of the Ethernet card is stored in CMOS RAM, and hence may be changed using the *Configure command. This takes the form

   *Configure (driver) (option) [n]

where:

represents the driver type in use (Ether3 or EtherB)

Configuration Options:

Disable|Enable: "Enable" enables the card to be used. "Disable" prevents the card undergoing self-test, and prevents receiving and transmitting of packets.

OldInet|NewInet: Configure as "NewInet" unless you are using versions of the "Internet" or "InternetA" modules prior to 2.00. NewInet supports faster data transfer.

Strict|Ignore: If "Strict" is configured, then should the interface fail self-test, it will return an error and not activate itself for network access. If "Ignore" is configured, the card will start up whether self-test is passed or not. Normally, the card should always be configured "Strict".

NoLiveWireTest|LiveWireTest: These determine whether the network cabling is tested during the card's self-test sequence. If "LiveWireTest" is configured, both valid and erroneous packets are passed to the network, and tests verify whether these packets are correctly received. Configuring "NoLiveWireTest" prevents this test being performed.

Terse|Verbose: When configured "Terse" the driver will only report information when needed; the self-test occurs "silently," and the card interrogation commands *Ether3Info and *EtherBInfo will only report individual statistics if the count for that statistic is nonzero. If the card is configured "Verbose" then all self-test stages will have an associated message displayed, and all network statistics will be displayed on interrogation.

Default: This sets the previous five options to their default settings, which are:

   Enable OldInet Strict NoLiveWireTest Terse

Nov 94

Questions and Answers

Q. How do I change into a "RISC OS 3.1-style" screen mode on my Risc PC?

A. Click Menu over the monitor icon on your icon bar, and choose the "Mode" option. If you delete the contents of the writable icon in this dialogue box with a Ctrl-U, you can then type in the RISC OS 3.1-style mode number. Most, but not all, of the RISC OS 3.1 modes can be accessed in this way.

Q. How do I print in different fonts from !Edit?

A. !Edit will only produce hardcopy in the System font; if you wish to print text in a different font, you can save the text into !Draw, change the font via the "Style" submenu and print it from there.

Serial Ports, Printers and Modems: Part 1

There are two main classifications of serial RS232 cable; straight-through and crossover. Generally, if the cable is linking the computer to a communications device such as a modem, then a straight-through cable is used - in other words, one where the transmit line is connected to the same-signal pins at either end of the cable, as is the receive line, etc. A modem is a piece of Data Communication Equipment (DCE); hence the straight-through cable is sometimes referred to as "DTE to DCE."

If the cable is connecting the computer to a peripheral such as a printer, then the transmit line from the computer needs to be connected to the peripheral's receive line and vice versa; the two lines have to be crossed over. A printer is a piece of Data Terminal Equipment (the terminology goes back to the concept of a computer which had a number of user-interface terminals connected to it by serial lines), and so the cross-over cable is sometimes referred to as "DTE to DTE" or "null modem" cable.

In the case of the RISC PC, you should be able to use a standard serial lead with a modem and suitable communications packages; for earlier machines, the package vendor should be able to supply a lead or information on where to obtain one.

!Printers is capable of sending data to a suitable printer via a serial link; the printer usually has to be specially configured to receive serial data. Your printer manual should show you how the printer's DIP switches must be set and which formats of serial word it will accept. The figure shows a suitable cable to connect an Acorn serial port to an Apple LaserWriter; more serial communications info next month.

Palette Information on the Risc PC

Some applications, particularly those written for earlier versions of RISC OS, can be set to change the video palette information; this may cause unusual colour effects on the Risc PC Desktop.

As an alternative to resetting the machine, it is possible to restore the colours by finding a sprite which already has the default palette set; the palette information can then be extracted using !Paint, and loaded.

Rather than look for a sprite with the palette set, we suggest that you do the following before the need to reset the palette arises:

Load !Paint
Click on the !Paint icon
Create a new sprite with a 16 colour palette set
Open the menu over the "newsprite" window, and move to the "Save"
submenu followed by the "Palette" submenu
Drag the Palette file to a suitable directory.

If you find that an application corrupts your current palette, double-clicking on this saved palette file should at least make the Desktop colours usable until you can save your work and reset.

Whoops...

Ive been informed that a couple of errors slipped into the table in September's column. The Risc PC / AKF85 combination can actually support 1280x1024 in 4 colours with no VRAM, in 16 colours with 1Mb VRAM, and in 256 colours with 2Mb VRAM.

Dec 94

Questions and Answers

Q. I want to connect another IDE hard disc to my Risc PC. What links must I set?

A. Assuming you are fitting a second hard disc similar to the one already fitted (a Conner CFS series), you need to make sure that the (not)A/C link is fitted to both drives and that the M/S link is only fitted to the drive connected directly to the motherboard. (not)C/D should be left in the state it was in at shipping.

Serial Ports, Printers and Modems: Part 2

Unlike IBM PC compatibles, Acorn machines default to using the DSR line to flag readiness to transmit, and require the presence of the DCD signal. On machines fitted with the 82710 or 82711 serial controllers and the Risc PC, it is possible to change which signals are used for flagging in software, using the SWI"OS_SerialOp",0 command. Thus an IBM compatible cable may be used; the option to reprogram the serial port in this manner is currently provided by some serial communications software. If you have a suitable machine and prefer to use an over-the-counter IBM standard cable rather than resort to making your own, check with the supplier of your communications software that there is an option to reprogram the serial controller.

It is possible to transfer data between a 32-bit Acorn computer and an 8 bit BBC Model B / Master series via the Serial Port; the wiring diagram for the appropriate cable is presented below.

On the transmitting system (assumed to be the Model B / Master), issue:

   *FX8,4
   *FX3,1

The first call sets the transmission rate to 1200 baud, and the second selects the serial port as the output device.

From BASIC on the receiving machine, (assumed to be a 32 bit Acorn machine), issue:

   SYS"OS_SerialOp",1,0
   SYS"OS_SerialOp",5,4
   *FX2,1

The first command configures the parity and word size: note that the Model B defaults to one stop bit per word, whereas the 32 bit range defaults to two. The second sets the receive rate to 1200 baud, and the third sets standard input to be via the serial port.

Performing a LIST on a BASIC program stored in the BBC's RAM, or a *TYPE on a plain text file stored on disc, will cause the program or text to be loaded into whichever RISC OS application has the caret on the receiving machine.

To terminate communication, issue

   *FX3,0
   *FX2,0

on both machines; the receiving machine should terminate communication first.

Updates to the RISC OS Applications Disc

Following on from the release of !Printers 1.22, Acorn has released another disc containing improved versions of applications originally supplied with RISC OS 3.1. The disc contains:

!Alarm, version 2.61
!Calc, version 0.53
!ChangeFSI, version 0.95
!Chars, version 1.17
!PrintEdit, version 0.38
!T1ToFont, version 1.26
3Dupgrade

The applications have been changed in various ways. As well as feature enhancements, known problems with the applications have also been fixed. The applications now automatically contain the 3D icons and templates supplied as part of !NewLook, so there is no need to use the !NewLook templates.

!ChangeFSI

ChangeFSI has been updated to support further image formats, and the formats previously supported have been updated.

!PrintEdit

PrintEdit has been updated to allow support for the new options available within the Printer Definition files supplied with !Printers 1.22.

!T1ToFont

T1ToFont has been updated in various ways:

If you have a Type 1 file but no corresponding AFM file, you can produce a usable font by simply leaving the 'AFM file' field blank. The resulting font will lack kerning information, so do use the AFM file if you have it.

Most alphabetic fonts should convert successfully with the Encoding field set to "Acorn Extended Latin". Some symbol fonts have their own private encoding; for these it is recommended that you select "As specified in Type 1 file" from the Encoding menu. This causes the font's internal encoding to be used, ensuring that the glyphs are placed at the correct character codes. The encoding is also deposited in a file named "Encoding" in the font's directory, where the font manager and printer drivers can make use of it.

3DUpgrade

The directory 3DUpgrade contains two BASIC programs, one called 2D and the second called 3D. The programs can be used to set the correct bit in CMOS RAM to ensure the templates and icons are shown in 3D or 2D depending on your choice.

!Alarm, !Chars and !Calc have had minor fixes made to them.

The disc containing this upgrade suite should be available from all Acorn dealers.

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