Risc PC Mother board.

Risc PC Mother board.

Post by Malcolm Riple » Wed, 29 Sep 1999 04:00:00



Out of curiosity.  If the following, quoted from the FAQ is true :

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 six* possible speed settings. This table
summarises those speed settings :-

   Setting  Switch  Speed (MHz)
   ----------------------------
      0      uuuu       88.3
      1      uuuD       95.6
      2      uuDu       99.4
      3      uuDD      106.7
      4      uDuu      143.5
      5      uDuD      150.9
      6      uDDu      161.9
      7      uDDD      169.3
      8      Duuu      191.3
      9      DuuD      202.4
     10      DuDu      213.4
     11      DuDD      228.1
     12      DDuu      242.8
     13      DDuD      257.6
     14      DDDu      276.0
     15      DDDD      287.0

   u = up, D = down, MSB to the left.

How do you get a 233Mhx machine ?  Mine was set to DDUU.


> I wonder if someone could help with RPC mother board version numbers.

> I have an early issue RPC600 +SA.

> The main PCB silk screen print has: 0197 000 ISS D
>                   Copper print has: 0297 000/51 ISS 1.

> Is this then a version 1 mother board?

> The reason I'm asking is I'm thinking of upgrading from a 202MHz Rev K, to
> the faster 233 Rev T StrongArm.

> Are there likely to be timing problems with this mother board.

> Regards

> Colin McDonagh

> --
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> |__||__)/ __/  \|\ ||_   |   /
> |  ||  \\__/\__/| \||__  |  /...Internet access for all Acorn RISC machines


 
 
 

Risc PC Mother board.

Post by Fred Bambroug » Wed, 29 Sep 1999 04:00:00




Quote:> Out of curiosity.  If the following, quoted from the FAQ is true :

> 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 six* possible speed settings. This table
> summarises those speed settings :-

>    Setting  Switch  Speed (MHz)
>    ----------------------------
>       0      uuuu       88.3
>       1      uuuD       95.6
>       2      uuDu       99.4
>       3      uuDD      106.7
>       4      uDuu      143.5
>       5      uDuD      150.9
>       6      uDDu      161.9
>       7      uDDD      169.3
>       8      Duuu      191.3
>       9      DuuD      202.4
>      10      DuDu      213.4
>      11      DuDD      228.1
>      12      DDuu      242.8
>      13      DDuD      257.6
>      14      DDDu      276.0
>      15      DDDD      287.0

>    u = up, D = down, MSB to the left.

> How do you get a 233Mhx machine ?  Mine was set to DDUU.

[snip]

Later processors ran at a different clock speed. The 233Mhz would be the
equivalent of 202Mhz on the older ARMs with the same switch settings.

--
Fred
PGP key available

 
 
 

Risc PC Mother board.

Post by Malcolm Riple » Thu, 30 Sep 1999 04:00:00





> > Out of curiosity.  If the following, quoted from the FAQ is true :

<snip>
> > How do you get a 233Mhx machine ?  Mine was set to DDUU.
> [snip]

> Later processors ran at a different clock speed. The 233Mhz would be the
> equivalent of 202Mhz on the older ARMs with the same switch settings.

> --
> Fred

Do you mean switch settings of DUUD which was 202 on the older strongarm
is 233 on the new one. In which case the maximum clock speed for the
newer strongarm would be around 330Mhz ie all speeds are up by 15%

or

Do you mean the factory switch settings of DDUU sets it to 233mHz which
means the maximum for the newer arms is 276Mhz ie all speeds are down by
4% ?

 
 
 

Risc PC Mother board.

Post by Fred Bambroug » Thu, 30 Sep 1999 04:00:00







> > > Out of curiosity.  If the following, quoted from the FAQ is true :

> <snip>
> > > How do you get a 233Mhx machine ?  Mine was set to DDUU.
> > [snip]

> > Later processors ran at a different clock speed. The 233Mhz would be the
> > equivalent of 202Mhz on the older ARMs with the same switch settings.

> > --
> > Fred

> Do you mean switch settings of DUUD which was 202 on the older strongarm
> is 233 on the new one. In which case the maximum clock speed for the
> newer strongarm would be around 330Mhz ie all speeds are up by 15%

> or

> Do you mean the factory switch settings of DDUU sets it to 233mHz which
> means the maximum for the newer arms is 276Mhz ie all speeds are down by
> 4% ?

The former, though I should qualify this with AFAICR. Not sure about the
330Mhz setting though. Not sure if the increments are parallel.

I'm going by my recall of postings around the time it was released (233)
so Deja wotsit might be of help. ISTR postings containing comparative
tables.

--
Fred
PGP key available

 
 
 

Risc PC Mother board.

Post by Marc Warn » Fri, 01 Oct 1999 04:00:00






> > Do you mean switch settings of DUUD which was 202 on the older strongarm
> > is 233 on the new one. In which case the maximum clock speed for the
> > newer strongarm would be around 330Mhz ie all speeds are up by 15%

> The former, though I should qualify this with AFAICR. Not sure about the
> 330Mhz setting though. Not sure if the increments are parallel.

The Rev-S and above (233MHz) all use a different crystal oscillator.
My processor is currently at uuud which only brings me 268MHz - the
highest setting on a 233MHz processor is lower than the highest on a
200MHz one.

Not sure of the exact values for how fast the switches make it...Someone
once posted a table on a csa group but I can't find it any more.

All the best,

        Marc Warne
--
   _________________,__________________________________.
  / /\/\           / Cracking RC5-64 with a RiscPC700 /_________________
 / /   /arc Warne /   http://www.acornusers.org/rc5/      Team #4266  ,/
/________________/__________________________________/~~~~~~~~~~/_/~/_/

 
 
 

1. Was: Risc PC Mother board.

Sent the SA card off to Simtec on tuesday morning and received the mod'ed
card this morning! How's that for service.

Machine appears to work O.K. except !Director had to quit while using the
file tree function. It hung-up once when I was using Black Holes file
finder routine. Had to use the reset button.

Not had any problems apart from that.  Can I now remove ROMPatch from my
predesk directory?

Colin.

--
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|__||__)/ __/  \|\ ||_   |   /
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