1% complete...
now I'm just waiting for the remaining 99% of the pipeline to be laid to my house.
2773 publicly visible posts • joined 1 Mar 2007
"They don't measure continuously, fitness machines only measure when you have a firm grip on the electrical contacts and that's not possible during vigorous movement"
It can be worse than that - There have been occasions in the gym where the HRM on my treadmill was still displaying after I let go of the handles - it turned out that the person on the next treadmill had a radio linked HRM and my treadmill was picking up their signal - it did make me look rather fitter than usual for a while!
Real 6502s were dynamic. The CMOS 65C02 (at least the WDC version) was (and still is) static. The WDC 65C02 also has extra addressing modes on some instructions and a few extra instructions. I can't remember whether they fixed the indirect jump wraparound bug from the original 6502, or left it as-is.
If I remember correctly, X and Y were used differently for indirect addressing thus
LDA (aa,X) added X to the operand aa, and the contents of memory at (aa+X) and (aa+1+x) were used as the address from which A was loaded.
LDA (aa),Y took the data from (aa) and (aa+1) as an address and then added Y to that. A was then loaded from that total address.
The first was useful if you had a list of pointers to objects, the second was useful if you had one pointer to an object, but wanted to access data from a particular offset into that object.
Well, the 6100 was based on the PDP8, so you could copy the PDP8s design (that one used discrete transistors).
The next step would be to recreate your discrete version of the 6100 as a FPGA. Then you'd have an integrated version of a discrete version of an integrated version of a discrete transistor CPU.
I was wondering this first when I realised that the original AT motherboard ran at 5MHz and was not much smaller (13.8" x 12").
I think the PCB size itself does not necessary limit the speed so much. However, if the CPU is simply a transistor for transistor substitution from the die to the PCB without any redesign, simply scaling things up might well scale up parasitic capacitances and time constants. Also, the 6502 used some dynamic registers (essentially single byte DRAMs) to reduce transistor count - scaling up the storage capacitor might also limit the clock speed by increasing the charge/discharge time constant.
I presume the 1960s transistor based computers running in the MHz range were designed on the macro-scale to control these capacitances in the first place.
"Trust me, Microsoft reads these forums."
I think you forgot to write that post in The Colour Of Irony.
"Atom was single board with keyboard on one side and all chips hanging from sockets underneath and could slowly work loose as you typed."
The second generation of their colour encoder that turned the signals from the 6847 into PAL relied on you removing the 6847 from the mother board, plugging it into the colour encoder, and then plugging the colour encoder board (with the weight of the PCB itself, a 40pin dip package, various 16pin packages, all socketed, and discrete components) so it was hanging upside down and held in by the friction of a 40 pin dip socket - not sure how that was ever supposed to not fall out!
Probably the biggest advance Acorn made between the Atom and the BBC was moving all the chips to the top of the PCB!
" I don't think many people are reliant on connectivity. They like it and expect it, but when its not there, then meh."
Not just connectivity, but continuation of specific services. Imagine you have an internet connected home controller system (the Revolv, for example), and the company controlling those services goes tits-up or to discontinue services for what they consider an obsolete device.
http://www.theregister.co.uk/2016/04/06/nests_bricking_of_revolv_a_wakeup_call/
Every time Netflix or BBC iPlayer buffers or drops out, it might be a meh moment, but it's a little hammer to the brain to remind you never to trust the internet to be permanently available.
"Why keep the submarines in Scotland some aggrieved Scot Nat will surely ask, because Faslane is the cloudiest place in the UK which made (makes?) it harder for foreign satellites to count the number of submarines alongside."
And I thought security through obscurity was supposed to be a bad thing!
"Duvel is 8.6%, as I learned the hard way. But I think Chimay Bleu is over 10. Hic! Which I think is the strongest beer I've had that was actually drinkable. Delicious in fact."
Both very good choices, as I discovered in the north of Belgium last week. Brugse Zot is another nice one (as are all the HalveMaan brewery beers) with a lighter taste at only 6%.
"because you got "snow" on the screen if you tried to write to the buffer while the image was being displayed"
I remember that being an significant Atom problem, but I don't remember having snow problems updating the screen on the BBC.
Probably a pre-production Atom - it should have the Acorn Atom logo to the right of the spacebar - unless it's just the way the light is falling there doesn't appear to be one here. It could possibly be a mockup using an Acorn System 2/System 3 keyboard - this used the same case moulding as the Atom.
Technically it is the same amount of RAM, but on the BBC Micro that RAM had to hold application code, the screen buffer (up to 10K on the model A) and working variables, stack, etc. - this could leave, depending on graphics requirements only about 5K for code. On the Bit, I assume application code will go into flash, and there is no screen buffer to speak of, so the 16K is only necessary for working variables, stack, etc., and code can be much larger.
BTW - I think you might have meant 256KB and 16KB rather than 256Kb and 16Kb.