HDTenEightyP/NetNews huggingface dataset:
From: D.S.Walker@bradford.ac.uk (Simeon Walker)
Newsgroups: comp.sys.acorn.tech
Subject: Re: Hi res modes
Date: 15 Sep 92 14:03:49 GMT
Distribution: comp
Organization: University of Bradford, UK
Originator: 91909178@ccw405

In article <6578@armltd.uucp> astevens@armltd.co.uk (Ashley Stevens) writes:
>In article <1992Sep11.193305.20265@rhrk.uni-kl.de> m_sattle@tangram.informatik.uni-kl.de (Matthias Sattler) writes:
>
>
>>
>>I just replaced the 36 MHz quarz on the board of my A5000 by a 60 MHz one. This
>>had several results on my A5000.
>>1.) The VIDC is clocked faster so I could do 1024x768 60Hz (if your vidc
>>can do this)
>>2.) Mode 31 is 93 Hz (if your monitor can do this...)
>>3.) 800x600 256 Colours isn't possible any more
>>4.) There are problems with very low-res modes like mode 0, but I don't
>>know why
>>5.) The computer gets remarkably faster... >22000 Dhrystones in mode 21, 28 
>>    (with CPU 30 MHz) and I don't know why as well.
>
>The 36MHz clock also clocks the memory system. It's divided by 3 inside MEMC
>(effectively). So using a 60MHz clock means you are now running your memory
>system at 20MHz. Obviously this has a beneficial effect on your machine
>speed...if it continues to work.
>
I assume this is why the A3/4xx series have an 8 Mhz bus with a 24 Mhz
VIDC clock. What happens when a VIDC enhancer is used with these machines?
Does the MEMC now divide the higher clock by a higer number? If so then is
this division programmable?

Sorry to ask so many questions but I didn't realise that the memory
speed was related to the VIDC clock and would really like to know
how it all works.

Perhaps it is different on the older machines?

>
>___________________________________________________________________________
>Ashley Stevens, Design Engineer, Acorn Computer       astevens@acorn.co.uk      
>Temporarily encamped at ARM Ltd...                    astevens@armltd.co.uk


-- 
Sim. ----------------------------------------------------------- Simeon Walker,
----------------------------------------- Department of Electrical Engineering,
D.S.Walker@bradford.ac.uk -------------------- University of Bradford, England.
Newsgroups: comp.sys.acorn.tech
From: goodwin@edieng.enet.dec.com (Pete Goodwin)
Subject: ADFSbuffers in RISC OS 3.1
Organization: Digital Equipment Corporation
Date: Mon, 14 Sep 1992 07:53:26 GMT


Is there a problem with ADFSbuffers being non-zero in 3.1 or has that been
fixed? My system defaults to 16, I've set it to 0 (better safe than sorry!). I
couldn't find any mention of it in the release notes.

I know it was a problem with 3.0 (on A5000) is it a problem with 3.1?

Pete Goodwin
goodwin@system.enet.dec.com
From: psyhsmb@unicorn.nott.ac.uk (Simon Burrows)
Newsgroups: comp.sys.acorn.tech
Subject: A4000 Keyboard
Date: 9 Sep 92 15:09:19 GMT
Organization: Cripps Computing Centre, University of Nottingham
Originator: psyhsmb@unicorn.nott.ac.uk

I am somewhat confused over the keyboards supplied with the A4000.
Since their launch, I have seen some A4000s fitted with Acorn 'PC'
keyboard (with LEDs above the numeric keypad), and also A4000s fitted
with standard Acorn keyboards. Both types of keyboard carried the A4000
logo. Which would be supplied if I purchased one (not that that is likely)?

Simon.
Newsgroups: comp.sys.acorn.tech
From: kortink@cs.utwente.nl (John Kortink)
Subject: Basic -quit bug
Organization: University of Twente, Dept. of Computer Science
Date: Wed, 9 Sep 1992 12:09:14 GMT

merlin@maths.tcd.ie (Merlin Hughes) writes :

>If the RISC OS 3.10 basic is unimproved, I'll be incredibly
>annoyed. How many people have come across the problem where
>*Basic -quit <filename> (ie double-click on a basic program)
>doesn't in fact clear the variable space. This has the
>delightful result that you can write code that accesses
>variables that don't exist. Basic can find them somewhere
>(with of course, totally screwy values), and your code will
>run with garbage variables, and quite possibly crash (machine
>code).

Aha ! And I thought I was crazy. I have come across this so many
times that I thought I was slipping away from reality. All those
silly crashes on unknown variables that magically got some erratic
value anyway... And Roger denied that it could exist ! (Sorry Rog,
you did, several times !)

>Blee.

Bleargh. Fix it ! It has cost me hours and hours of useless hair-
tearing (while I could have been nail-biting !).


John Kortink

Student of Informatics at the University of Twente, The Netherlands
NETMAIL : kortink@cs.utwente.nl              DISCLAIMER : the usual

'The sun is blinding, dizzy golden, dancing green
 Through the park in the afternoon, wondering where the hell
 I have been'                            - Suzanne Vega, 'Cracking'
Newsgroups: comp.sys.acorn.tech
From: Gavin.Flower@comp.vuw.ac.nz (Gavin Flower)
Subject: Re: RISC OS 3.10
Organization: Dept. of Comp. Sci., Victoria Uni. of Wellington, New Zealand.
Date: Mon, 7 Sep 1992 00:12:47 GMT


Any changes to the version of BASIC that comes with Risc-OS 3.1 over
Risc-OS 2.0?  I don't recall any recent mention of this, though I'm
sure that there are changes, if my memory serves me correctly.


-- 
Tomorrow's Society                              | flower_g@kosmos.wcc.govt.nz
    Depends on                                   ----------------------------
Today's Children  - help us raise them properly! 
*******  These comments have no known correlation with dept. policy!  *******
Newsgroups: comp.sys.acorn.tech
From: m_sattle@tangram.informatik.uni-kl.de (Matthias Sattler)
Subject: Re: Hi res modes
Reply-To: m_sattle@tangram.informatik.uni-kl.de (Matthias Sattler)
Organization: University of Kaiserslautern (Germany)
Date: Mon, 14 Sep 1992 14:34:11 GMT

Here are some nice 50 Mhz. screenmodes, as i promised.
Mode 125 is 1024X640 16 colours 57 Hz (with 50 Mhz VIDC)
Mode 126 is 1280X512 16 colours 60 Hz (with 50 Mhz VIDC)(good for big monitors)



begin 644 Md125_41Hz
M````````````````F````!P````D````0````$UO9&4Q,C4`36]D93$R-0D)
M,2XP,"`H,3$@4V5P(#$Y.3(I`$UO9&4Q,C4`````````````````7```````
M``!-;V1E(#$R-2!P<F]V:61E<R`Q,#(T>#8T,"!G<F%P:&EC<R!A="`T(&)I
M=',@<&5R('!I>&5L+@T*``!0`%'C#O"@$0$`4^,!`',3#O"@$7T`4N,`$*`#
M"#"/`DQ`CP(.\*`!#O"@X0$````;`````,"?@`#`!H0`0!V(`,`<C`#`G)``
MP)V4`,"IH`"``*0```BH`(`(K`"`J+```*FT"P``X/____^@C```_____P``
M```;```````````````!````?P````(```!/````!`````$````%`````0``
E``8``````@``!P``````!0`+````_P,```P```!_`@``_____P`%
`
end
 


begin 644 Md126_43HZ
M````````````````F````!P````D````0````$UO9&4Q,C8`36]D93$R-@D)
M,2XP,"`H,3$@4V5P(#$Y.3(I`$UO9&4Q,C8`````````````````7```````
M``!-;V1E(#$R-B!P<F]V:61E<R`Q,C@P>#4Q,B!G<F%P:&EC<R!A="`T(&)I
M=',@<&5R('!I>&5L+@T*``!0`%'C#O"@$0$`4^,!`',3#O"@$7X`4N,`$*`#
M"#"/`DQ`CP(.\*`!#O"@X0$````;`````$#`@`#`!H0`@!>(```7C```MY``
M`+B4`("%H`"``*0`0`2H`(`$K`"`A+``P(2T"P``X/____^@C```_____P``
M```;```````````````!````GP````(````_````!`````$````%`````@``
E``8```"``@``!P``````!0`+````_P0```P```#_`0``_____P`%
`
end



Matthias Sattler
Newsgroups: comp.sys.acorn.tech
From: amell@nyx.cs.du.edu (Andrew P.Mell)
Subject: Re: RISC OS 3.10
Organization: Nyx, Public Access Unix at U. of Denver Math/CS dept.
Date: Wed, 9 Sep 92 02:02:21 GMT

In article <Bu6LxC.HC7@comp.vuw.ac.nz> Gavin.Flower@comp.vuw.ac.nz (Gavin Flower) writes:
>
>Any changes to the version of BASIC that comes with Risc-OS 3.1 over
>Risc-OS 2.0?  I don't recall any recent mention of this, though I'm
>sure that there are changes, if my memory serves me correctly.
>

Changes I can remember offhand are...
@% follows the ANSI C printf format, you can set it partially too
Faster array statements
TRACE TO <filename> and TRACE CLOSE, TRACE is also a boolean variable.
TEXTLOAD and TEXTSAVE
CRUNCH for compacting your programs

And a few other things.

Andy
From: smb@cs.nott.ac.uk (Simon Burrows)
Newsgroups: comp.sys.acorn.tech
Subject: More on displaying the RISC OS 3 Credits
Date: 8 Sep 92 19:53:45 GMT
Organization: Nottingham University

Following much investigation, disassembly etc, here is a summary of the
RISC OS 3 Credits which work on my machines:

RISC OS 3.00
============

When the RISC OS 3.00 title screen is displayed, quickly type the letters
'r-m-t-m-d', and if you get the timing right, photographs of the RISC OS 3
Development team will be displayed on screen.

Go to the RISC OS 3.00 Info Window (from the switcher icon). Click on the
letters 'r-m-t-m-d' from the words 'Acorn Computers Ltd' using the MENU
button, and a long list of credits will be flashed up.


RISC OS 3.10
============

The photograph facility appears to have been removed.

To access the info window credits, click on the letters 't-e-a-m' from
'Acorn Computers Ltd' using the MENU button, and a (different) long list
of credits will be displayed. (If you click in the wrong places, the
machine *may* crash).


Have fun!


Simon.

****************************************************************
I went to the Watford Electronics Open Day a couple of days ago,
and was showing the RISC OS 3.10 feature to a friend when a certain
Acorn chap came up and said 'Oh, you know about that - there's
another hidden feature to display some photos, but I'm not going
to tell you how to get it!'. I proceeded to tell him that the
keys are 'r-m-t-m-d', and it doesn't work with 3.10, and he
promptly disappeared!

If I hadn't known this, I would have been rather annoyed by
his attitude.
****************************************************************
Date: Fri, 11 Sep 92 11:50:53 +0100
From: gunnar@fasel.hotb.sub.org (Gunnar Zoetl)
Newsgroups: comp.sys.acorn.tech
Subject: Which bit switches the VIDC clock speed?
Organization: El Gunthor Pasa

Hiya,

now that Risc OS 3 is coming around, I would like to make my homebrew VIDC
enhancer software switchable. However, I don't know which bit switches the
clock speeds. Does anyone know this and is willing to tell me?

rgds
Gunnar
-- 
Oh my god!     __  ______   ____  __  __        ______ __  __ ____   ____ || 
Something  _  (( \ | || |  //  \\ ||\ ||   /\   | || | ||  || || \\ ||    || 
following (_L  \\    ||   ((  ___ ||\\||  //\\    ||   ||  || ||_// ||==     
me - it's     \_)) |_||_|  \\__|| || \|| //--\\   ||   \\__// || \\ ||___ []
Newsgroups: comp.sys.acorn.tech
Subject: Escape and the Sound System.
From: banksie@khantazi.welly.gen.nz (Philip R. Banks)
Date: Mon, 14 Sep 1992 17:13:02 +1200
Reply-To: banks_p@kosmos.wcc.govt.nz
Organization: My Arc.

   Another question for the Acorn bods out there. When Escape is enabled
under RO2 and pressed all sound synthesis stops (well on channel 1 anyway.).
But how does this get signaled to the voice synthesis code? Usual behavior
would, I would have thought, be to send the voice synthesis code a 'GateOff'
call indicating synthesis was to halt immediately (and allowing 'smart'
code to do a nice quick fade out to avoid clicks.). But from my studies it
appears this is not happening...

   Now this is rather annoying as my sound code maintains a current address
pointer to indicate how far through a sample it is. Defined behavior is that
when the sample finishes this resets to zero to indicate that. However with
my voice code being unaware that synthesis has halted the pointer gets left
at the last address filled and consequently doesn't do as it should.

   Anyway I can fix this?

    Philip

--
Philip R. Banks  Syntax: mail < banks_p@kosmos.wcc.govt.nz >            @@@@@/|
                                                                        @@@@/#|
                                                                        @@@/##|
And who are we to criticize or scorn the the things that they do?       @@/---|
For we shall seek and we shall find Ammonia Avenue. ---A.P.P.           @/    |
Newsgroups: comp.sys.acorn.tech
From: nas20@cl.cam.ac.uk (Nick Smith)
Subject: Re: RISC OS 3.10
Reply-To: nas20@cl.cam.ac.uk (Nick Smith)
Organization: U of Cambridge Comp Lab, UK
Date: Mon, 7 Sep 1992 11:38:58 GMT

In article <1992Sep6.230410.4489@cs.nott.ac.uk> smb@cs.nott.ac.uk (Simon Burrows) writes:
>In article <1992Sep6.095131.3855@cl.cam.ac.uk> nbvs@cl.cam.ac.uk (Nicko van Someren) writes:
>>In article <1992Sep5.185031.23487@cs.nott.ac.uk> smb@cs.nott.ac.uk (Simon Burrows) writes:
>>>
>>>Two observations from using RISC OS 3.10 on my A440/1:
>>>
>>>1) When I switch on, a huge blue floppy disc is displayed on screen, with
>>>what looks like a !System folder icon on it. Also the bottom few pixels
>>>of the picture look to be corrupted. What is this for?
>>
>>I think you will find it is wanting a disc containing the text to all the
>>messages etc. in some language other than english.  Take a good look at
>>your country configuration.
>
>Thanks for your answers to both of my questions. I have checked the
>country configuration, and it is set to UK. No modules are unplugged,
>and furthermore, the computer does not appear to look for any files
>once a key has been pressed.
>
>SimonB.

It is not your *country* configuration - it is your *territories* configuration
Look in your welcome/user guide. Your Territory should be set to 1 for UK I
think.
(I did try and email you about this on Saturday Simon - but have had lots of
failure messages from your site ... )

Nick.
--
Nick Smith, Churchill College, Cambridge, UK.  %$%  Email: nas20@uk.ac.cam.phx
sig quote wanted - must be under guarantee.   $%$  --- Usual disclaimer. ---
From: mybg@huji.ac.il (Michael Ben-Gershon)
Newsgroups: comp.sys.acorn.tech
Subject: Taxan 875 Plus Monitor as a HRM
Date: 6 Sep 92 10:22:12 GMT
Reply-To: mybg@shum.huji.ac.il (Michael Ben-Gershon)
Organization: The Hebrew University of Jerusalem

The Taxan 875+ Monitor should be able to work as a High Res Monitor with 400
and 540 series Acorn RISC computers (Archimedes), as it has an H scan
frequency up to 75 kHz.

Does anyone know how to connect it?  On its rear, it has  R  G/S  B  H/C  V
sockets, but these are not well documented in the manual.  I presume that R,G,B
are obvious, but what is G/S and what is H/C?  Could it be that the composite
video output from the Archimedes needs to be split into 3, each going to
one of the 3 R,G,B sockets on the monitor (a sort of opposite version of
cable type MF on page 87 of the 540 series Installation Guide) ?

Michael Ben-Gershon
mybg@shum.huji.ac.il   OR  mybg@doc.ic.ac.uk
Newsgroups: comp.sys.acorn.tech
Subject: Re: RISC OS 3.10
From: julian@bridge.welly.gen.nz (Julian Wright)
Date: Thu, 10 Sep 1992 18:56:37 +1200
Reply-To: wright_j@kosmos.wcc.govt.nz
Organization: USS Enterprise, NCC 1701a

jwil1@cs.aukuni.ac.nz (TMOTA) writes:

> There are also some new instructions I think...

Yeah, CRUNCH, TEXTLOAD, and TEXTSAVE spring to mind:

{Cranks up a taskwindow}

>HELP CRUNCH
This command removes specified spaces from the current program.
CRUNCH <expression>. The bits in the number mean:
0: spaces before statements
1: spaces in statements
2: REM statements (except first)
3: empty statements
4: empty lines
>
>HELP TEXTLOAD
This command loads a new program, converting from text form if rqd.
>
>HELP TEXTSAVE
This command saves the current program as text [with a LISTO option].
TEXTSAVE[O <expression>,] <string>
>

I also believe that Basic 1.05 will CRUNCH 31 any program that was started
up with a *Basic -quit command.

    Cheers, Julian.
From: andrewa@harlqn.co.uk (Andrew Armstrong)
Newsgroups: comp.sys.acorn.tech
Subject: Re: How *does* one write a good text editor?
Date: 10 Sep 92 17:57:31 GMT
Organization: Harlequin Limited, Cambridge, England


I've written a couple of editors that do this sort of thing, and I've
always stored the text as a doubly linked list of lines, where each
line is a structure containing the text for that line, color/font
information, class information (what type of line - e.g. comment,
function header), etc. This is very flexible, and makes the code very
simple, but at least doubles the memory usage for an average file (for
my most ambitious editor, I was quadrupling the memory usage!)

I hope that's of some help - if you want to chat about it, feel free
to e-mail me.


Andy
From: sproven@cs.strath.ac.uk (Simon B Proven IE91)
Newsgroups: comp.sys.acorn.tech
Subject: Re: RISC OS 3.10
Date: 7 Sep 92 12:47:10 GMT
Organization: Comp. Sci. Dept., Strathclyde Univ., Glasgow, Scotland.

In article <1992Sep5.185031.23487@cs.nott.ac.uk> smb@cs.nott.ac.uk (Simon Burrows) writes:
>
>Two observations from using RISC OS 3.10 on my A440/1:
>
>2) Occasionally (3 times so far) I have been going about my business in
>the desktop, when I have got the error "!!! CAM Map Corrupt!!!" (note
>the exclamation marks), which promptly kills the task manager. Any
>clues to what causes these would be much appreciated.

The CAM is the memory in the MEMC chip which is used to look up logical->
physical memory mappings.  Either RISC OS 3.1 is very buggy or you have
a faulty MEMC.  The CAM being corrupt means that the machine is unusable
when that part of memory has been accessed since the memory access will
be mapped to the wrong place.

Is the error happening only when you have a lot of tasks running?

>
>Simon.

mad@bike
Newsgroups: comp.sys.acorn.tech
From: cudat@warwick.ac.uk (J M Hicks)
Subject: Filecore in use bug (summary)
Organization: Computing Services, Warwick University, UK
Date: Wed, 9 Sep 1992 16:56:04 GMT

A few days ago I asked about the "Filecore in use" bug.
Two people replied and their replies are below.  Many thanks to both.

However, I couldn't reproduce this bug on my A310, however hard I tried.
Perhaps I should be pleased. :-)



From: Kjetil Torgrim Homme <kjetilho@ifi.uio.no>
Date: Thu, 3 Sep 1992 01:59:59 +0200

If you insert ten floppies without dismounting any of them, you will
get the error message "Filecore in use", and the only way to get out
of it is to switch off the machine. To avoid thiss bug, configure
ADFSbuffers to 0. (The dircache works ok.)

Kjetil T.



From: tomc%siesoft.co.uk@shark.uucp (Tom Crossland)
Date: Thu, 3 Sep 92 9:23:55 BST

: A recent item of news in comp.sys.acorn.advocacy mentioned a bug
: in RISC OS 2.00 called the "Filecore in use" bug.
: What is this bug and how does one recover from it?

If you used more than 12 (I think) diskettes without dismounting any after use,
it would generate a "Filecore in use" error. It's something to do with
filecore remembering disc names and things like that. I think it was more an
oversight than a bug.

Tom.


--
Jim Hicks, Computing Services, Warwick University, Coventry, England. CV4 7AL
cudat@csv.warwick.ac.uk
JANET: cudat@UK.AC.WARWICK.CSV
EARN, BITNET or NetNorth: cudat%CSV.WARWICK.AC.UK@UKACRL
Internet: cudat%csv.warwick.ac.uk@nsfnet-relay.ac.uk
cudat@warwick.uucp
From: smb@cs.nott.ac.uk (Simon Burrows)
Newsgroups: comp.sys.acorn.tech
Subject: Where's my mouse gone?
Date: 12 Sep 92 17:50:07 GMT
Organization: Nottingham University

Where's the bottom half of the mouse sprite disappeared to when you use the
SWI "OS_Confirm" with RISC OS 3.10 ???

Simon.
-----------------------------------------------------------------------------
Simon Burrows   smb@cs.nott.ac.uk  psyhsmb@unicorn.nott.ac.uk +44 533 712030
-----------------------------------------------------------------------------
Newsgroups: comp.sys.acorn.tech
From: smb@cs.nott.ac.uk (Simon Burrows)
Subject: Re: RISC OS 3.10
Organization: Nottingham University
Date: Sun, 6 Sep 92 23:04:10 GMT

In article <1992Sep6.095131.3855@cl.cam.ac.uk> nbvs@cl.cam.ac.uk (Nicko van Someren) writes:
>In article <1992Sep5.185031.23487@cs.nott.ac.uk> smb@cs.nott.ac.uk (Simon Burrows) writes:
>>
>>Two observations from using RISC OS 3.10 on my A440/1:
>>
>>1) When I switch on, a huge blue floppy disc is displayed on screen, with
>>what looks like a !System folder icon on it. Also the bottom few pixels
>>of the picture look to be corrupted. What is this for?
>
>I think you will find it is wanting a disc containing the text to all the
>messages etc. in some language other than english.  Take a good look at
>your country configuration.

Thanks for your answers to both of my questions. I have checked the
country configuration, and it is set to UK. No modules are unplugged,
and furthermore, the computer does not appear to look for any files
once a key has been pressed.

SimonB.
Newsgroups: comp.sys.acorn.tech
From: merlin@maths.tcd.ie (Merlin Hughes)
Subject: Re: RISC OS 3.10
Organization: Dept. of Maths, Trinity College, Dublin, Ireland.
Date: Tue, 8 Sep 1992 15:08:47 GMT

jwil1@cs.aukuni.ac.nz (TMOTA) writes:

>I don't know if there has been an update since v1.05, but this had several
>improvements over the 1.04 in RISC OS 2.00. [...]

If the RISC OS 3.10 basic is unimproved, I'll be incredibly
annoyed. How many people have come across the problem where
*Basic -quit <filename> (ie double-click on a basic program)
doesn't in fact clear the variable space. This has the
delightful result that you can write code that accesses
variables that don't exist. Basic can find them somewhere
(with of course, totally screwy values), and your code will
run with garbage variables, and quite possibly crash (machine
code).

The only way to avoid this is to load and run the program
directly from basic, or to (as we have) set up Alt-click
on basic programs to *Basic -chain <filename>.

Blee.

Merlin.
From: smb@cs.nott.ac.uk (Simon Burrows)
Newsgroups: comp.sys.acorn.tech
Subject: PostMortems from RISC OS 3.10
Date: 14 Sep 92 22:37:07 GMT
Organization: Nottingham University

Since upgrading to RISC OS 3.10, I have been presented with several
postmortems, generally when copying a file between filing systems
in the desktop.

Can anyone shed any light on this?  Full postmortem details can be
posted if they are of any use or interest.. No unusual module or
application tasks were running, or had been loaded since the last reset.

Simon.
----------------------------------------------------------------------------
Simon Burrows  smb@cs.nott.ac.uk  psyhsmb@unicorn.nott.ac.uk  +44 533 712030
----------------------------------------------------------------------------
Newsgroups: comp.sys.acorn.tech
From: bhotvedt@usit.uio.no (Tor Houghton)
Subject: Bug in FontManager 2.85?
Followup-To: comp.sys.acorn.tech
Organization: My Archimedes
Date: Mon, 14 Sep 1992 14:02:38 GMT

Apart from being quicker than 2.66 (my previous version), is there a bug in
version 2.85 of the FontManager?

After assembling some code to print out some vector fonts (using 2.85) I
got them allright, but after a cold reset I did not get any fonts at all.
Or were they just black? I tried colouring them, but to no avail.

Right now I'm using version 2.66 for the above program, but I could use
some more drawing speed.

Hope I'm the one who is doing it wrong.

Cheers,


Tor Houghton

PS: For those registered : Scanner is now in version 1.47
From: astevens@armltd.co.uk (Ashley Stevens)
Newsgroups: comp.sys.acorn.tech
Subject: Re: Hi res modes
Date: 14 Sep 92 17:19:17 GMT
Distribution: comp
Organization: Advanced RISC Machines Ltd, Cambridge, England

In article <1992Sep11.193305.20265@rhrk.uni-kl.de> m_sattle@tangram.informatik.uni-kl.de (Matthias Sattler) writes:


>
>I just replaced the 36 MHz quarz on the board of my A5000 by a 60 MHz one. This
>had several results on my A5000.
>1.) The VIDC is clocked faster so I could do 1024x768 60Hz (if your vidc
>can do this)
>2.) Mode 31 is 93 Hz (if your monitor can do this...)
>3.) 800x600 256 Colours isn't possible any more
>4.) There are problems with very low-res modes like mode 0, but I don't
>know why
>5.) The computer gets remarkably faster... >22000 Dhrystones in mode 21, 28 
>    (with CPU 30 MHz) and I don't know why as well.

The 36MHz clock also clocks the memory system. It's divided by 3 inside MEMC
(effectively). So using a 60MHz clock means you are now running your memory
system at 20MHz. Obviously this has a beneficial effect on your machine
speed...if it continues to work.


___________________________________________________________________________
Ashley Stevens, Design Engineer, Acorn Computer       astevens@acorn.co.uk      
Temporarily encamped at ARM Ltd...                    astevens@armltd.co.uk
Newsgroups: comp.sys.acorn.tech