Acorn Computing

Contents

Power supply repairs

Fixing the blown diodes

Man Pages Reader

A port of an nroff clone providing a Unix 'man' page reader. (Sorry about the naming confusion, Alan and Reuben !)

A port of an make clone

Fixing the blown diodes

After a while, it seems that Acorn RISC PC power supplies blow up, usually following expansion of the machine.
I managed to blow up the supply in mine, and it turned out to be the rectifier diode in the 5 volt rail that had failed.
This diode is an MBR2045T, which is a 20 Amp 45 volt part. I found the replacement CT2045 type device in Maplins, and also a beefier CT3045 part, which is rated at 30 Amps. and which fits the holes in the PCB better !!. I have replaced it and so far so good.

In fact the application of the diode in the power supply is wrong. The MBR2045 type is a pair of diodes intended to be used in a PC supply where there is a centre tapped transformer. Then the current is shared. In the RISC PC, the two diodes are merely wired in parallel.
Whichever diode gets hottest first takes all of the current. (positive temperature coefficient of resistance). Then it gets hotter and blows. So the diode is actually only capable of carrying 50% of the current you would expect.
April 1997 : A colleague of mine had his RISC PC stop because of the same fault, with the same cure. In his case he had been scrupulously careful about not overloading the power supply !!

A port of a make clone

File :make_tar.gz (97358 bytes) tar archive, gzip compressed (Updated 03 August 1997 links with UnixLib 3.7b , compiles with gcc 2.7.2)

MAKE

Latest update : 3 August 1997
; Acorn port by M.James (Use feedback@hamble.demon.co.uk)
Suitable for gcc, and Acorn CC with UnixLib

Requires the following

1. UnixLib - My version is built with UnixLib 3.7b
   

2. I have used either
   • Acorn C v.4 cc / link
     
   • GCC 2.7.2 gcc/ ld (Drlink)
3. Gzip To UnZip
   
4. Tar to UnTar
   
5. Loads of RAM or (!virtual) for gcc - (or use Mode 0 on a 5M RISC PC)

Building Make

Sources are provided, and in fact , you build the Makefile application

1. Un-GZIP the file
   

2. tar -xvf make_tar
   
3. Ensure you have the usual .o directory present
   
4. There are three build files:
   1. BuildMakCC -- For Acorn C - Spits many warnings but none fatal.
      
   2. BuildMakGC -- For GCC - Nice & quiet
      
   3. MakeMake -- Sets up a massive WimpSlot, then runs Make to make itself
   Double-click the version that you want to compile with The first two contain commands to build a file called !runimage.
   The third actually uses make and a makefile. This only works once you have a copy.
   
5. Name the directory !pdmake

Things you must have in the !PDmake application directory:

1. !PDMake.!Sprites
   

2. !PDMake.!Runimage
   
3. !PDMake.!Boot
   
4. !PDMake.!Run

(you can delete the rest once you have built make )

The History of this Make Application:

• While hunting around info-server@ukc in 1989, I came across a set of files which claimed to be a Public Domain Make implementation. I downloaded these, and set about ANSI-fying them. I think I am about 95% of the way there.
  

• I then decided to make it RISC OS 'compatible', and discovered that there is no ?? system variable giving ' this is the path to the directory containing the file being worked on'. Before you scream, this can of course be extracted from the filename passed as parameter 0 when you double click the makefile.
  I have used &FE1 as the makefile type.

As you will see when you look in the !boot and !run files , you can either type the make command into the CLI , or double click the makefile. I have also added the -@ makefilename parameter which tells make it's running as a double-clicked application. Then it has to get the path name of everything by looking at the makefile path name.

File structure

make expects the makefile to be just above the .c and .o directories.

 
 |
 ------------------------------------
 | | | |
 makefile c o thing to make
 type FE1 | |
 sources objects
 

dont forget to settype makefile FE1 or settype makefile makefile - you can have more than one makefile with different targets in the same directory , or use it from the CLI for setting options etc.
I hope you enjoy it.. :-)
I do now I've got it going.
This has subsequently been updated by myself, for use with GCC and UnixLib, and tested by Reuben Thomas, who put up with some distinctly dodgy versions.
This version has been tested with both gcc and Acorn Cv4
It is much less stupid than AMU. In 1989 I posted a version to Acorn and they claimed AMU would be improved. Still waiting ....
Changes from earlier versions:

• I added the -v switch which makes it print what it is about to do.
  

• I made the silent -s option the default.
  
• The .SUFFIXES rule defines which Acorn pathnames get swapped as well as the usual Make meaning of this e.g.
  C:f.c gets turned into C:c.f
  a.h gets turned into h.a
  Assuming of course that somewhere in the .SUFFIXES rule there is a mention of .c and .h
  See the Makefile for an example.
  
• There is still the possibility that I will use the UnixLib __uname file name mangler in place of my own, but I will need to do some more investigations - I did this port before UnixLib had the __uname function ..

DISCLAIMER

THIS SOFWARE EXISTS ONLY THANKS TO THE GENEROSITY OF ANOTHER FAR MORE COMPETENT PROGRAMMER WHO PLACED THEIR MAKE INTO THE PUBLIC DOMAIN. NONE OF THE REALLY DIFFICULT BITS ARE MY WORK, JUST THE EVENINGS OF FRUSTRATION GETTING IT TO GO ON THE ARCHIMEDES.
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A port of an nroff clone

File :man_tar.gz (97358 bytes) tar archive, gzip compressed (Updated 03 March 1997 linked with UnixLib 3.7b)

CAWF a.k.a. NROFF

This is a quick and dirty port of 'cawf' that came from Simtel20 This implements an 'nroff' and 'man' function that runs under RISCOS.
Two invocations are possible
Once the filer has seen !man then any files in the !man.1 directory can be read by typing

 
man subject

Or by double clicking any file of type ManPages (100)

OTHER USES

The 'nroff' program itself is called 'cawf' (see the cawf ManPages file) and can be invoked independently.
Then it will also format to 1st word plus files (this prints via Acorn drivers )

 
cawf -man -dacorn manfile > printer:

Or:

 
cawf -man -dacorn manfile > FWP_file

Will produce bold and underline in a FirstWord Plus File (for e.g. Ovation) Look in cawf:lib.device/cf on how to add devices

CREDITS

For RISCOS port:
Mike James m...@hamble.demon.co.uk Thats me. Full of Pouilly-Fumé and happy for it.
For cawf:

 
/*
 *Copyright (c) 1991 Purdue University Research Foundation,
 *West Lafayette, Indiana 47907. All rights reserved.
 *
 *Written by Victor A. Abell , Purdue
 *University Computing Center. Not derived from licensed software;
 *derived from awf(1) by Henry Spencer of the University of Toronto.
 *
 *Permission is granted to anyone to use this software for any
 *purpose on any computer system, and to alter it and redistribute
 *it freely, subject to the following restrictions:
 *
 *1. The author is not responsible for any consequences of use of
 * this software, even if they arise from flaws in it.
 *
 *2. The origin of this software must not be misrepresented, either
 * by explicit claim or by omission. Credits must appear in the
 * documentation.
 *
 *3. Altered versions must be plainly marked as such, and must not
 * be misrepresented as being the original software. Credits must
 * appear in the documentation.
 *
 *4. This notice may not be removed or altered.