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by neilf
Tue Oct 01, 2013 10:28 pm
Forum: Raspbian
Topic: RISC OS User Slowly learning to like Raspbian.
Replies: 114
Views: 12277

Re: User Slowly learning to like Raspbian.

Ok I do not see a way to get microseconds using ANSI C99, next up I will take a look at the RISC OS SWIs, see if there is something there that I have forgotten about. Under Risc OS you can time in microseconds using the TimerMod module from the Arm Club's website http://www.armclub.org.uk/free/ Obv...
by neilf
Tue Oct 01, 2013 11:07 am
Forum: RISCOS
Topic: PDF Files
Replies: 15
Views: 4812

Re: PDF Files

If you need to run older programs that are not compatable with the RPi you will probably want to use !A310,
What's !A310?
by neilf
Tue Oct 01, 2013 11:02 am
Forum: RISCOS
Topic: Assembly,Wimp
Replies: 4
Views: 1595

Re: Assembly,Wimp

Not sure what you're reading the Nutshell CD on, but the links are OK when viewing it on a Risc PC. You have to click on the black !Nutshell logo when the CD opens, to access the magazines via the 'official' route. If you click instead direct on the mags directory the links won't work. I tried copyi...
by neilf
Mon Sep 30, 2013 12:46 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Interfacing with Old buffer boxes
Replies: 6
Views: 1505

Re: Interfacing with Old buffer boxes

USB to printer port adapters do not allow the kind of bit bashing you'd need for the individual buffer box lines. They are only designed to work with printers - most won't even work with a scanner as that requires bi-directional control.
by neilf
Mon Sep 30, 2013 12:42 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: Interfacing with Old buffer boxes
Replies: 6
Views: 1505

Re: Interfacing with Old buffer boxes

BBC buffer boxes used the computer's userport for inputs and the parallel port for outputs, so you'd need to write a little software to switch GPIO lines between the two I/O modes. Either way, you'd need an eight-way voltage converter board to read and write the buffer boxes' 5v lines and interface ...
by neilf
Mon Sep 09, 2013 7:49 pm
Forum: General discussion
Topic: Very, very impressed with NOOBS
Replies: 4
Views: 988

Re: Very, very impressed with NOOBS

Works great here for RISC OS too - many thanks Rob.
by neilf
Thu Aug 22, 2013 6:27 pm
Forum: Beginners
Topic: On/Off Switch for Pi
Replies: 3
Views: 585

Re: On/Off Switch for Pi

TECHMAN1298 wrote:Does anyone know where to get a on/off switch, I don't care if it's digital or physical but I just don't feel comfortable just yanking out the power cord when i'm done.
If all you need is a plain power switch, see bottom post here:
http://www.raspberrypi.org/phpBB3/viewt ... 40&t=48757
by neilf
Sun Aug 11, 2013 8:08 pm
Forum: Other projects
Topic: on off switch
Replies: 65
Views: 142869

Re: on off switch

I added an onboard miniature on/off switch to all my boards as soon as I got them a year ago. There was no need for a cutout in the case as I mount my Pis in wafer cases so that I can get at all the GPIOs. I couldn't imagine using a Pi without an on/off switch now - it's so convenient. Mind you, I m...
by neilf
Sun Mar 17, 2013 10:38 pm
Forum: HATs and other add-ons
Topic: Gertboard Connection to Pi (cable twist)
Replies: 17
Views: 7822

Re: Gertboard Connection to Pi (cable twist)

The P5 holes are too close to P1 to be able to fit a header on top. That's why the Foundation recommends they are fitted underneath.
by neilf
Sun Mar 03, 2013 4:39 pm
Forum: Automation, sensing and robotics
Topic: Model railroading
Replies: 3
Views: 852

Re: Model railroading

Search the forum using 'model railway'. You'll find plenty of threads covering this topic already.
by neilf
Sun Feb 24, 2013 11:12 pm
Forum: Other projects
Topic: 26way female socket
Replies: 30
Views: 3721

Re: 26way female socket

You're not trying hard enough ;-)

How about 26p each?

http://www.ebay.co.uk/itm/20pc-Pin-Fema ... 1e75fb74bf
by neilf
Tue Feb 05, 2013 11:24 pm
Forum: For sale
Topic: Raspberry Pi Case @ £2.98 DELIVERED. design by Adafruit
Replies: 17
Views: 5734

Re: Raspberry Pi Case @ £2.98 DELIVERED. design by Adafruit

Be warned, those springy clips that are used to 'snap' the ends in place are prone to snap right off. If any of the four clips breaks, the case is dead, so be very gentle with them - especially when dismantling for any reason.
by neilf
Wed Jan 30, 2013 3:12 pm
Forum: RISCOS
Topic: RISC OS; Pros and Cons
Replies: 145
Views: 32245

Re: RISC OS; Pros and Cons

[quote="DavidS"]Problem I have run the ackermann test in BBC BASIC and I am getting 1.82 seconds consistently.

Probably because you're using integers instead of floating point.
by neilf
Tue Jan 29, 2013 11:54 pm
Forum: RISCOS
Topic: RISC OS; Pros and Cons
Replies: 145
Views: 32245

Re: RISC OS; Pros and Cons

I disagree - some crude benchmarking is better than none - try converting this to Python: PRINT "The Ackermann test. Expect this to run in about" PRINT "0.5 seconds on a 2GHz Intel CPU." PRINT PRINT "Start" rec=0 start = TIME FOR y = 0 TO 3 FOR x = 0 TO 7 z = FNackermann(y,x) PRINT z; " "; NEXT PRI...
by neilf
Mon Jan 28, 2013 9:10 am
Forum: RISCOS
Topic: RISC OS; Pros and Cons
Replies: 145
Views: 32245

Re: RISC OS; Pros and Cons

BBC BASIC V can run blisteringly quick on the R-Pi because its entire interpreter fits in the ARM's primary cache. That's the advantage of a small footprint OS with much of it hand coded for speed and efficiency - remember BBC BASIC is effectively built in to the OS. In certain applications, other B...
by neilf
Thu Jan 24, 2013 4:58 pm
Forum: HATs and other add-ons
Topic: Farnell assembled Gertboard
Replies: 47
Views: 9533

Re: Farnell assembled board

ianajo wrote:Pictures of boxed male header ribbon
Zoom in to see DNC pins are removed
Where did you source the boxed header from?
by neilf
Thu Jan 24, 2013 10:19 am
Forum: Troubleshooting
Topic: Fried my Pi by using 5V from GPIO header :(
Replies: 16
Views: 1946

Re: Fried my Pi by using GPIO :(

Put the Pi away for a day or two. You might find it works after that. There are two ways you might have broken it: either you blew the fuse due to pulling too much current, or you blew the chips by putting a highly inductive load on their power lines. Since the fan did not move, I doubt the latter....
by neilf
Wed Jan 23, 2013 11:54 am
Forum: RISCOS
Topic: What does RISCOS bring to the RPi party
Replies: 63
Views: 19262

Re: What does RISCOS bring to the RPi party

There are very very few situations where single tasking is an adantage On the contrary, if you're into robotics or physical computing in general, there are many, many situations where single tasking is not just an advantage, it's often vital. RISC OS makes an excellent OS for such purposes because ...
by neilf
Wed Jan 23, 2013 10:43 am
Forum: HATs and other add-ons
Topic: Farnell assembled Gertboard
Replies: 47
Views: 9533

Re: Farnell assembled board

malakai wrote:If they used headers similar to these https://www.adafruit.com/products/1112 they could have used a ribbon
You can use just the male pins from that header on their own to allow a ribbon cable to be connected to the gert. Then you'd have the best of both worlds.
by neilf
Tue Jan 22, 2013 9:53 am
Forum: Other programming languages
Topic: ARM Assembly; Easy for begginers.
Replies: 2
Views: 2617

Re: ARM Assembly; Easy for begginers.

With the ARM CPU there are not a huge number of instructions to emember, the syntax of the instuctions in the standard assemblers for RISC OS (including the BBC BASIC ARM assembler) is very simple, and the usage of registers (and naming of registors) is very consistant. Thus it does not take long t...
by neilf
Thu Jan 17, 2013 12:00 pm
Forum: Other programming languages
Topic: BBC Basic
Replies: 2
Views: 924

Re: BBC Basic

Always place these lines at the start of your code: MODE MODE ON ERROR REPORT: PRINT " at line "; ERL: END MODE MODE will make your program run in full screen, so you can see the output of graphics, etc. If you don't want this then leave the MODE MODE off. The ON ERROR line will print a comment like...
by neilf
Tue Jan 15, 2013 11:44 pm
Forum: RISCOS
Topic: RISC OS SOUND
Replies: 14
Views: 4344

Re: RISC OS SOUND

VGA doesn't have any capability for sound, unless someone has used the I2C and RES pins as a sound connection.
Well yes, I know that.
The question remains. Why does use of a VGA adapter kill sound output on the headphone socket? It does this under RISC OS, but not apparently under linux.
by neilf
Tue Jan 15, 2013 10:24 pm
Forum: RISCOS
Topic: RISC OS SOUND
Replies: 14
Views: 4344

Re: RISC OS SOUND

The good old fashion VDU 7 beep command does not seem to work anymore! Freddie, I’ve now solved my sound problem and it just might be relevant to your setup too (as well as other people's). I my case I tried substituting a number of R-Pi boards, SD card images and headphone/speaker setups, but they...
by neilf
Tue Jan 15, 2013 8:52 pm
Forum: RISCOS
Topic: RISC OS SOUND
Replies: 14
Views: 4344

Re: RISC OS SOUND

The good old fashion VDU 7 beep command does not seem to work anymore! Did you ever get your sound working again? My two R-Pis seem to have developed the same problem. The system beep was loud and clear a couple of weeks ago but now they are both mute. Fiddling with the Configure sound app makes no...

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