instruction set?
come on reg - give us the instruction set and memory model, then we'll see what sort of stuff could be written for it.
A well-known British programmer, blogger and online campaigner has called for a collaborative effort to finally make a legendary steampunk mechanical computer - the Babbage Analytical "Engine", designed but never actually built - a reality. John Graham-Cumming will be well known to many Reg readers as the programmer behind …
AWTT Assemble With Tinker Toys
BOD Beat on Drum
BRO BRanch and Overheat
BWABL Bells, Whistles and Blinking Lights
BWOP BeWilder Operator
CAF Convert Ascii to Farsic
CRN Convert to Roman Numerals
DSI Do Something Interesting
DSR Detonate Status Register
DSTD Do Something Totally Different
DSUIT Do Something Utterly, Indescribably Terrible
DTC Destroy This Command
ENF Emit Noxious Fumes
ENG Enable Gravity
EOI Execute Operator Immediate [a fast version of another instruction]
EP Execute Programmer
EPI Execute Programmer Immediate
FLD FLing Disc
HCF Halt and Catch Fire
IDC Initiate Destruct Command
LTS Loop Till Smokes
LUM LUbricate Memory
RIC Rotate Illogical thru Carry
RLI Rotate Left Indefinitely
ROD ROtate Diagonally
RRC Rotate Random thru Carry
SPA Sliding Point Arithmetic
...and tetris should be possible.
There's a description of a possible mechanical display in "The Difference Engine" by Bruce Sterling and William Gibson. Fun.
A thought: now we have NC machining and much better materials than Babbage could get his hands on, there's no reason why a Difference Engine shouldn't be quite a bit smaller than the original design. This would reduce material cost and space requirements a lot and could/should still be steam powered, preferably from a bio-methane boiler: this would let it continue to run long after all fossil fuel has been used up.
Must just plug the SM's computing collection here.
Went there at the weekend with my son and my mum. He wasn't interested in the computing side so I got dragged past it at high speed.
Aside from the punched card machines that my mum worked with when she started out in programming there are some really old fashioned ways of doing stuff that were high tech at the time. Pegasus, Manchester and that financial modelling device that ran on water that I didn't get a chance to note the name of.
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The term "Bug" was coined by a Grace Murray Hopper, after locating a problem within one of the large, relay-powered mainframes of the day. A moth had become stuck in the system and was preventing a relay from working correctly. This was recorded in her log book, along with the offending moth, as the first computer bug.
So now you know.
http://www.pbs.org/wgbh/aso/databank/entries/btmurr.html
doesn't it give the original meaning to Bugs even more meaning as according to popular internet myth it was a bug in a big computer in the 50s that gave its name to the term.... it was a moth wasn't it.... *
being lazy i am not going to google the truth in this for you, do it yourself.
The article heavily implies (along with the linked article from 1999) that Ada's position as "first programmer" is based on myth. However, this is not clear from her notes on the translation of Menabrea's talk (scroll down for her notes):
http://www.fourmilab.ch/babbage/sketch.html
assuming that the transcript hasn't been favourably edited, she certainly seems competent enough. It's a little difficult to read text from ye olden days due to that fact that the style was kind of verbose and dull. However, consider this small snippet:
"In studying the action of the Analytical Engine, we find that the peculiar and independent nature of the considerations which in all mathematical analysis belong to operations, as distinguished from the objects operated upon and from the results of the operations performed upon those objects, is very strikingly defined and separated."
Sounds like OO programming to me :)
"By 'unfortunate gen[e]tic disposition' do you mean 'female'?"
Not necessarily. My mother's side of my family are all rather thin-haired, and I unfortunately picked up that gene, resulting in my inability to grow any kind of substantial beard (although I have managed to grow a halfway-decent moustache). Attempts to grow out my facial hair have resulted in pathetic little patches which make me look rather like a nuclear accident victim. So, clean-shaven but for the moustache it is.
> And what a great educational resource so that people can understand
> how computers work
<rant>
Well let's start by turning what we've already got i.e. the Difference Engine in the science museum and the reconstructed Bombe at Bletchley and the Manchester Baby at the Manchester Museum of Science & Industry into "Educational resources". At present, these are just artefacts that you can look at. If you go to the book shops of those places you can no doubt pick up a 500-page book explaining stuff, but none of those things has the 5-minute video or 1000-word booklet describing how it works. Perhaps the problem is that the geeks who make the reconstructions are incapable of explaining how they work in less than 500 pages and the museum curators are incapable of explaining them at all. I've visited each one and found myself explaining stuff to other visitors, who are definitely capable of grasping stuff at the appropriate level.
</rant>
Maybe with Lottery money - do you feel lucky, Steampunk?
It makes me wonder, though. Imagine a parallel historical track where Babbage had built it, and electronic computers hadn't happened. How would the concept have developed, and what would a 21st century analytical engine look like?
... the cyclonic hum of a trillion twisting gears, all air gone earthquake-dark in a mist of oil, in the fractioned heat of intermeshing wheels. Black seamless pavements, uncounted tributary rivulets for the frantic travels of the punched-out lace of data, the ghosts of history loosed in this hot shining necropolis. Paper-thin faces billow like sails, twisting, yawning, tumbling through the empty streets, human faces that are borrowed masks, and lenses for a peering Eye.
- The Difference Engine, William Gibson and Bruce Sterling
I would really love to see this built, but wasn't part of the problem originally that Babbage, being terrible at just sticking to one thing and getting it done, ended up coming up with loads of half-finished designs?
Also, I seem to remember that building the Difference Engine that lives in the Science Museum actually helped drive the engineering company that built it to bankruptcy.
This is all based on what I remember from the book "The Cogwheel Brain" so I might have it wrong.
I would be first in the cue to see a working AE though so I'm really hoping someone steps forward with the cash.