Oolite Bulletins

EDIT: This might sound stupid, but on the log in / create new account page on the wiki, I can't see a create new account link.... If you went straight to the oolite section you may have missed the notice on the front page - new account creation is disabled because the spamming was reaching unmanaga...

I'm also developing an ethernet card for the Spectrum (complete with shadow ROM to hold the socket library and a few programs, and some extra memory). Hopefully have the first few prototypes going by the Speccy's 26th anniversary! Then onto making a version for the BBC Micro (which hopefully may be ...

The GNUstep tools (well, at least for the Base stuff) isn't all that hard to use, as long as you don't require a GUI. I'd argue having it work at all is a required step before making it point-and-click compatible. Not much point having an easy to use cross platform development kit if it doesn't actu...

I’ve also played around a little with the GNUstep developer tools, which are like a horrible, horrible parody of the OS X ones. Why do you think I have a nightly build that's fully automatic? So I don't have to fiddle with these things all the time :-) To be fair, GNUstep is entirely a volunteer ef...

It is double sided. Here's the website:

http://www.alioth.net/Projects/Spectrum-Diag/

Hrm. The bad news is that my assumption that USB joysticks would always give some reasonable values, and the bad old days of joystick calibration were gone - were obviously wrong. That means don't expect your joystick to work tomorrow because it now needs code to be written (and I've been suffering ...

In which case, you can use your computer's sound card input and write a software frequency counter without spending any more money :-) Connect the 555's output to the sound card's input (making sure you're running it on a voltage that won't kill your sound card), and it should be pretty easy in soft...

With a 555, you'd wire it as an astable multivibrator (i.e oscillator), and feed its output to a frequency counter. For measuring normal components (i.e. you don't need stunning accuracy!) a frequency counter can be made with a couple of BCD counters and 7 segment decoders, and a 7 segment display. ...

Hmm. That's interesting. SDL returns a signed 16 bit number for joystick axes. With my Freedom 2.4 wireless stick, I get -32768 to 32767 as the stop-to-stop values for all axes. If yours is only returning an unsigned 8 bit number I can see why that might be a problem, it's like wiggling my joystick ...

The joystick control is abstracted via SDL - do you have any other joystick-using programs that use SDL that you can check it out with? My memory is a bit hazy on how I made it recognise the analogue axes, I'll have to look at the code - IIRC, it looks for a near full deflection to recognise which a...

There are calculators on the web now, so you don't have to do the sums :-) Just so you understand the principles of why you're making the calculation, of course! There's a web calculator for 555 timers which will accept frequency, R1 and R2 values, and return the capacitance. Just round the capacita...

Don't have any acid lying around though, and currently don't have access to a lab. I use ferric chloride to etch. It's the least nasty of a nasty lot, and any electronics place sells it (I get it from Bowood Electronics - http://www.bowood-electronics.co.uk - since they stock the easier-to-mix pell...

The chips in the cash registers are all common parts, 74HC* logic (which is still made in vast quantities, the NXP website has datasheets for all of them - http://www.standardics.nxp.com/ ). For all the other stuff (ADCs, DACs, PIO etc), Datasheetarchive.com has them all (most is still in production...

I have the guts of about 20-odd Z80 based cash registers that we were getting rid of at work. More 74* series logic than you can shake a stick at, lots of 128K static RAM etc. The best tool for disassembly is my B&Q paint stripping gun. Clamp the PCB you want to strip, start up the heat gun at h...

Fair enough. (Note in the case of Oolite doing the listening, you can bind to 127.0.0.1 then you don't expose anything to the intertubes.)