Archive Magazine CD 1995/Archive Magazine CD 1995.iso/text/hints/volume_04/issue_03

Text File | 1995-02-16 | 11.5 KB | 282 lines

• Basic Text File Type − Acorn have specified field type &FD1 for BASIC
ASCII text.  This is very useful for BASIC programs which are kept in
!Edit format as it allows the user to define a RunType for them.  For
example, the following command will cause a BASIC text file to be run
just like a normal BASIC file:
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   *Set Alias$@RunType_FD1 Basic-quit |“%0|” %*1
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Jim Markland, Cirencester.
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• Converting old Arthur programs to RISC OS − Before the days of RISC-
OS, programs running under the old Arthur used a form of reconfigure
system to adjust the CMOS RAM settings.  Now that RISC-OS is available,
those programs are out of date, and are a pain, as in most cases they
don’t “Boot-Up” from the desktop.
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RISC-OS uses a different form of reconfiguring.  Two in fact − one is
the WimpSlot command, which tells the computer the minimum and maximum
amount of memory the program is going to need and the other uses the
module MemAlloc, found in the !Lander directory on Application disc 2.
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These two things are quite easy to use.  The only problem is how to find
out how much room the program is going to use.  This can be discovered
fairly easily.
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Load up the !Boot file and examine it using the BASIC Editor.  What you
are looking for are a set of commands/variables, which tell the computer
the amount of SpriteSize/Screensize, etc it is going to need to run.  To
convert this, all you need is the MemAlloc module, and in a run file,
use MemAlloc to allocate the memory needed for the application.
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Here are some examples:
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Holed Out
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1. Format a fresh new disc
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2. Create a new directory called !HoledOut
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3. Copy all the files on the original Holed Out disc, except the !Boot
file into the new directory.
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4. Copy MemAlloc into the !HoledOut directory.
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5. Use !Edit to create the following Obey file:
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   program segment missing
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6. Load HoledOut 2 into the BASIC Editor and, where the program loads a
particular file, change it to
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   (LoadCommand) <HoledOut$Dir>. (File to be loaded)
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for example
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   70 *RMLOAD BELL
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change to
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   70 *RMLOAD <HoledOut$Dir>.Bell
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and
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   610 CHAIN “HOLEDOUT3”
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change to
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   610 CHAIN  “<HoledOut$Dir>.HOLEDOUT3”
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etc, etc.
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7. Do the same as above to the file HOLEDOUT3, wherever the program
loads a particular file, put the command<HoledOut$Dir>. in front of the
filename.
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8. Create a !Sprite file for the application icon and away you go!
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Then HoledOut should run as a RISC-OS application, and will also run off
a Hard Drive (N.B. I used Holed Out Extra Courses 1)
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Explanation of !Run File:
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Line 1:  Tells the computer to set a directory, and to enter it without
changing the root directory whenever the <HoledOut$Dir> command is used.
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Line 2:  Allocates the minimum and maximum amount of memory needed to
run the application.
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Line 3:  Tells the computer to look for the module MemAlloc in memory,
if it isn’t found then it tells the computer where to find it and loads
it.
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Lines 4-9:  Tell the computer the memory settings the program needs.
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Line 10:  Kills the module MemAlloc for more memory.
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Line 11:  Runs the actual program.
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Pacmania:
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In this case, things are a little different.  So do the following:
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1.  Format a new disc.
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2.  Create a new directory called !PacMania.
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3.  Copy all the files except !Boot into the new directory.
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4.  Use !Edit to create an Obey file containing the following...
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   Set PacMania$Dir <Obey$Dir>
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   Run <PacMania$Dir>.!RunLoad
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5.  Use the BASIC Editor to create a file called !RunLoad...
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   10 *Load <PacMania$Dir>.PacMania 10000
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   20 CALL &100000
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6.  Create an application !Sprite file.
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PacMania should then run as a RISC-OS application.
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So there we are, I’ve also used another command to help with the loading
process.  <Obey$Dir> and <(Application name)$Dir>.  These two commands
tell the computer where to find certain files, no matter where they are.
(Hidden in directories on a hard drive for example.)  Duncan Burbidge.
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• Getting Taxan 795 to work with Archimedes.  The Taxan 795 is an
excellent multi-sync colour monitor, but it was a bit unnerving, on
unpacking and assembling my new A440 with VIDC Enhancer and 795 monitor,
to be confronted with a screen which just would not synchronize!  But,
with help from Paul and from Atomwide, and with a lot of exploration, I
think that I now know what screen modes it will support and how to get
them.
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Initially, the trick is to set *CONFIGURE MONITORTYPE 1 and *CONFIGURE
WIMPMODE20.  Then the machine wakes up in the desktop in mode 20 whether
or not the VIDC enhancer software (VIDCmodes for the 795) is installed,
provided that (if it is not installed) the VIDC switch is ‘off’.
However, if VIDCmodes is not installed, loading an application which
changes the mode to one of the basic Archimedes modes (0-17) plunges you
back into an unsynchronized screen.  Therefore, my initial explorations
were done with an ordinary monchrome monitor connected to the sync BNC
socket, after changing two links on the circuit board − as explained on
page 434 of the RISC-OS user guide.  Options for all Acorn and Atomwide
modes (except the high-resolution mono mode 23) are listed in the
accompanying table.  (See opposite.)  Bill Mapleson.
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• Keywords in BASIC − I have found that PRINT ‘SHIFT F1’ showed a lower
case underline ‘a’.  From BASIC on pressing return to ‘PRINT’ the result
I found a number that looked just like TIME.  It was.  SHIFT F2 gives
HIMEM and SHIFT F3 = LOWMEM.  No other Fkey gives a number, but they all
act as quick entry keys for use in BASIC program writing within ARMB
edit.  They must be programmed with BASIC keyword token values.
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I expect this is widely known but here is the list for completeness.
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   program segment missing
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Simon Anthony, Nottingham.
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• Locating screen coordinates − When writing wimp programs (out of
desktop) it’s often hard to plot things because you’re not sure what the
coordinates of the screen are.  Using the program below, it is possible
to do this.
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   program segment missing
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I hope the program is of some use to wimp programmers.  Duncan Burbidge.
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• MSDOS installation on hard disc − Here is a summary of the steps for
getting an MSDOS partition installed onto a hard disc.
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1. (This step applies only if you have an old PCEmulator, e.g. V1.20,
and a V1.33 upgrade disc)
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(a) Read ‘ReadMe2’ on the V1.33 disc.
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(b) Run ‘MakePC’ on the V1.33 disc.  (This copies the file !PC.Rom from
the 1.20 disc to the 1.33 disc.  Although the desktop displays this as a
‘text’ file, I reckon that in fact it is the emulator itself and that
all the other files are concerned with preparing the Archimedes to run
the Emulator.)
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2.  Read ‘ReadMe’ on V1.33 but don’t take too much notice of it − it
confused me a lot!
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3.  Examine the files !PC.GenBoot.! Config and !PC.GenBoot.!Modules.  If
you have more than 1M of RAM, it may be worth changing some of the ‘Y’s
to ’N’s in !Config.  When I first tried it, without any changes, my
screen went blank because my Taxan 795 monitor requires the VIDC
Enhancer and the VIDCmodes software installed in order to synchronize
when not in modes 18-21.  With a 4M machines, I decided to make all the
response ‘N’ and everything seemed OK.
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4.  If you have a SCSI hard disc (as I have), run !SCSIDisk.  This
renames !PC.SCSIRun2 to !PC.!Run2 and !PC.!Run2 to !PC.!ADSF[sic]Run2.
That is, it makes !Run2 the file that defines where the MSDOS partition
is to be placed − on a SCSI hard disc not on an ADFS one.  !SCSIDisk
then creates a file ‘PC.Drive_C’ on the SCSI disc of the size you
request (1 to 32M).  This file can be *TYPEd from the Archimedes command
line − but don’t do it until everything is complete because its contents
misled me!  The screen then displays information for running two MSDOS
commands:  FDISK and HDINSTAL.  It also displays the injunction ‘Press
ESC’ to stop:  Press RETURN to continue‘.
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5.  If you press <return>, the instructions are cleared from the screen;
the PC Emulator is loaded, and you are invited to put the MSDOS boot
disk into ‘DriveA’ (Drive0).  Doing so, and pressing <return>, loads
MSDOS which asks for date and time − but pressing <return> in response
to each request supplies the information from the system clock.  When
the ‘A>’ prompt appears, you need to carry out the instructions that
were recently wiped off the screen:  Type ‘FDISK’, then ‘1’ to create a
DOS partition, then ‘Y’ to assign all of file Drive_C to DOS: then
‘HDINSTAL’ which formats the hard disc and transfers the MSDOS system
files from the floppy MSDOS boot disc to the hard disc.
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6.  If you press ESC (at the ‘ESC to stop, <return> to continue’
injunction) and need to run !SCSIDisk again, beware that this will re-
rename the !Run2 files.  I avoided this by ‘Remming’ the *rename
statements in !SCSIDisk.!RunImage.  (This is a BASIC program from which
it would appear that the procedure for installing MSDOS on an ADFS hard
disc would be the same without the complication of renaming the !Run2
files.)
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7.  Once MSDOS is safely on the hard disc, the !PC application can be
transferred from the V1.33 disk to the PC directory on the hard disk.
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8.  One last complication fo me was that when I type ‘HDINSTAL’ I go the
quaint message ‘insert new diskette in drive C’ and, on pressing
<return>, ‘drive not read − format failure’.  Eventually, after many
hours and several phone calls, the explanation turned out to be that I
have two external 5.1/4“ drives and MSDOS was seeing the second of these
as Drive C and the SCSI hard disc as Drive D.  To avoid amending
HDINSTAL (which is a simple batch file) I told RISC-OS that it had only
two floppy drives (*CONFIGURE FLOPPIES 2, followed by <ctrl-break>) and
all went smoothly.  Subsequently I reconfigured to three floppies and
now MSDOS wakes up with a ‘D>’ prompt ready to run from the hard disc.
The most useful tool for finding out what MSDOS thinks it has is to type
CHKDSKA:.CHKDSKB: etc,
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9.  Finally, in RISC-OS, lock the ‘Drive_C’ file.  I’m astonished that
this is not done by the PCEmulator programs.  Without it, a careless
click in RISC-OS might destroy all your MSDOS files!  Bill Mapleson.
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• Saving your configuration settings − I recently needed to change the
batteries in my Archimedes but this meant that I would lose the
configuration settings stored in the CMOS RAM.  I managed to solve the
problem by writing two small programs that saved and then restored the
CMOS RAM settings to and from a file.
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   program segment missing
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Sham Gardner, Karlsruhe (Germany).
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(The other way of doing it is to open the computer, switch the computer
on, change the batteries, switch off and then put the computer back
together again − but I dare not suggest that you should do that because
someone might stick a screwdriver into the heavily protected p.s.u. and
I’d get blames − so I didn’t suggest it, OK? Ed.)
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• Wimpslotting warning.  Always give the maximum amount of memory your
program is going to use.  Otherwise, the computer will eat up all the
available memory and use it for the program and you can’t get the memory
back unless you quit the application!  This happens in FormEd (All
versions, I would assume).  The FormEd !Run file contains the line:
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   WimpSlot -min 288k
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Using !Edit, change this line to...
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   WimpSlot -min 288k -max 288k
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The program will then run, using up less memory, meaning that both
!FormEd and !Paint can run at the same time on a 1M machine.  You have
been warned.  Duncan Burbidge.
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