stardot.org.uk

Thank you both. I assumed it had to be possible to find such things for less than 10p per pin. (-8

Anyone know of a cheap source of those strips of pins that are compatible with DIL sockets? The things you use when making a modern circuit board which inserts in place of a classical IC?

The places I've found seem to be quite pricey!

Agreed. I wasn't saying it was OO. FILE * encapsulates data, but doesn't encapsulate operations.

The encapsulated data hiding behind a FILE * under Unix includes:
* The file descriptor
* A buffer
* Various pointers and status flags relating to management of the buffer

No. I'm not talking about dynamic dispatch. I've told you what the essence of object-orientation is. I've pointed you at the Wikipedia article which confirms I'm right. I think I'm done, here.

The important point is that the operation is associated with the data. Writing f.seek(offset, whence) instead of fseek(f, offset, whence) may look like syntactic sugar, but it's quite important syntactic sugar. In particular, it means that the seek you can call on f is intrinsically different from t...

Hmm. It's obvious why the actual speech synthesis chip would need -5V as well as +5V. I've only just noticed that the PHROMs also required a negative supply. I wonder why?

Aha, thanks! It looks as though in the US keyboard PCB the +5V line is commoned between the keyboard and speech halves of the board, where normally the two circuits are entirely separate? Or do my eyes deceive me? The fitting instructions do explain everything... except why the capacitors aren't fit...

The key point about the object-oriented paradigm is that it compartmentalises data and the code which manipulates it.... That may be part of the paradigm but it does not require an object-oriented language to make it happen. For anyone familiar with C, the stdio calls which all refer to a FILE obje...

That's not really "a documented API". And it's pretty clunky: I'm pretty sure that on at least some DFSes it will physically read the disk once per letter of the alphabet! Also, it will overlook directory " " on disks from the Acorn System and similar horrors. (-8

Hiya! I've been away for ages, because real life got in the way. But I popped back to ask a question I realise has been bugging me for literally decades! On the left of the BBC Micro keyboard PCB there are those two lines of pads below the "ashtray" where connectors would be soldered in fo...

Hmm. Unfortunately all the links in that page have gone stale in the fifteen(!) years since the project was last touched.

You don't happen to have copies of any useful code or documentation, do you?

Hi all - been away for a while, but thought I'd just dip my toes back in. (-8 Is it possible to write custom interface drivers for the RISC OS IP stack, i.e. to write a relocatable module that provides an interface foo0 which can be used just like an Ethernet interface? If so, does anyone know of an...

Say you intercepted BYTEV that way. Then an EVENTV claimant calls OSBYTE in the middle of a foreground OSBYTE call. /-8

Ok, here's a first attempt. It appropriates INDV3 for use by the daisy-chaining. My main misgiving about that approach is that it's not re-entrant. If something uses that mechanism in an interrupt handler while another thing is trying to use it in the foreground, there will be fireworks. A more min...

One example where it would obviously go seriously wrong is if you trapped BRKV that way. Surely not. The OS selects the current language before dispatching via BRKV. Indeed, so there's a risk this could happen: BRK OS selects current language then does JMP (BRKV) BRKV calls the XBRKV extended vecto...

One example where it would obviously go seriously wrong is if you trapped BRKV that way. Fortunately, you can just handle paged ROM service call 6 instead. On reflection, looking through the other vectors I can see: Filing system vectors - OK Vectors that might be called under interrupt - OK Vectors...

Then you just finish by jumping to the address previously in the non-extended vector. The problem, as I mentioned, is that this means the previous claimant is called with your ROM selected, not the one that was selected when the vector was invoked. (The previous ROM is restored correctly when the f...

If one was designing a mechanism from scratch, I imagine the sensible solution would be something like: Allow a page for extended vector chains. Divide it up into 64 entries, each of which is ROM number, address in ROM, address of next entry. That would allow the space to be used as linked lists of ...

Almost a year later, I'm revisiting this issue. It seems to me you can get a considerable distance by having a primitive for "JMP to code in different ROM". On reflection, I'm kinda surprised that primitive was never made public in the way OSRDRM/OSRDSC was. Rummaging in JGH's collection o...

Hmm. Those parts are £10.52+VAT at Mouser in quantities of 100. Is that eBay price cheap, or too cheap? If it's a legitimate price, I imagine the ROHM part can be got more cheaply, too. More of an issue, although that Cypress device is 5V-tolerant, its Voh1 is only 2.4V. While fine for TTL, that's c...

(Resurrecting an old thread, despite not having been around much recently - hi, folks!) Mmm. Until now, SRAM and EEPROM/Flash have been the main options for such modules, but F-RAM chips are getting larger and cheaper, so I suspect in a few years' time they'll be the natural choice. The only questio...

The version of AMPLE in the Nucleus ROM (I get the impression the previous RAM-resident version was rather simpler) supports words coming from three places: The Nucleus The user program Modules From (25-year-old) memory , Nucleus words are represented by single bytes, whereas others are represented ...

helpful wrote: ↑Tue Jun 12, 2018 2:13 am the attendee list (actually a table list)

That's a good point. I won't need a table. But I'm still interested in the pay-for-two-days-get-three deal on access to the museum, the out-of-hours socialising, etc. (-8

Eeek! Sorry, I've been away from the forums for a bit. Many thanks to Boydie for prodding me.

Yes, I'll definitely take a place, please!

I stuck my nose through the door today. They're still being ridiculously optimistic price-wise. A lot of what's left I wouldn't buy at anything less than 80% discount, but it's only been reduced by 50% so far. Even now, they seem to have their heads in the sand about just how cheaply commodity stuff...

Finally, some melatonin:
I'm hoping this will fix my sleep disturbance and give me my life back. If it does, hopefully that in turn will mean more energy devoted to retrocomputing projects. (-8

Also, remember to translate between BBC filename characters and WinDOS characters Incidentally, it's not stated but I assume it is understood that character 96 in Acorn filenames always maps to ASCII/Unicode character 96 (i.e. backtick) regardless of whether the file is coming from 8-bit or 32-bit ...

Also, remember to translate between BBC filename characters and WinDOS characters: # <-> ? . <-> / $ <-> < ^ <-> > & <-> + @ <-> = % <-> ; And special case, as it's nonreversable: WinDOS SPC -> BBC _ As a related headache, what happens when we encounter an Acorn file called CON, LPT1 or similar...

Any alternatives must start with "what happens with existing systems". So, going back 25 years, "what happens when I use an Acorn system to copy a file from an Acorn filesystem to a DOS disk?" Which, in terms of filenames is: the filename is as close to identical as possible. So...