I'm Richard Gregory AKA Greg AKA Richie, I've completed a Computer Science degree at Liverpool University, a Phd and now in an RA postion continuing the work of the PhD. One of the exercises in the first year of the degree was to write a web page, so here it is. It has been updated each year to keep it reasonably up to date, though some of it hasn't been touched since I first wrote it all those years ago. This page hasn't been updated since 2001, which shows its age. Have instead focused on some various projects.
In those few spare minutes available between doing Phd related things, I enjoy (or did enjoy as this site has now developed a history):
I also try to maintain and build on a large collection of useful(honestly!) fortune cookies. There are approx. 60000 fortune cookies available for grabs. They range from famous quotes (computer science, English literature, applied maths, pure maths, physics, psychology, The Simpsons) to jokes and sayings to political slogans. All in all, a very mixed bag which nobody has ever dared organise.
A faded black and patchy light brown tabby that knows what he wants and how to get it. This picture was taken about a year before he died, it was one of the few chances I had to frame grab him. He was enjoying himself in the summer sun.
Sadly Tibby's liver gave up and he spent some time in pain. He was put down in late October 1998 aged 19 years, smiling to the end. He continues to be missed.
The next best thing to Tibby is another cat, so I now have Charley. He was bought at local cattery who had rescued him from his previous owner, who kept him outside in a coal bunker.
Charley is about 4 years old and the entirely black expect for a patch of 50%-50% black/white hairs on his chest. So far he doesn't speak to me much, he is just to timid and shy. I have seen his playful side every now and again, he should turn out to be a very nice cat when he recovers.
Obviously music is a personal choice, so in the company of others something like Euphoria Chilled fits in well. I would describe it as unobtrusive.
The project on the go (before going to Liverpool University) was a texture mapped polygon 3D engine that aimed to be real time. It was the sort of thing that Descent and Quake became. Unfortunately it was held back by the lack of power my Amiga could supply and my inability to optimise the biggest slowdown of the algorithm - the use of a divide per pixel.
The divide per pixel problem could have been sorted out, using some approximating algorithm or calculating every now and then but the speed of my Amiga still held it back.
Since then other people with the time and money have taken the idea of a 3D engine far beyond what I could have done. So this project is now more of a curiosity than anything else, I could never have envisioned the explosion in 3D hardware...
During Uni I've had time to do some small projects of various sizes, some of which are on the latter end of this page.
PIC Programmer - Hardware/software project the programs the PIC series micro controller
PIC simulator - Software project that aims to simulate the internal workings of the PIC micro controller.
One Cookie - Something to remove duplicate fortune cookies. Uses CRC checks and indexes to speed up the otherwise lengthy and memory intensive process.
Snake - An investigation into the movements involved in simulating walking. In this case it was a snake (okay so it doesn`t actually walk...). Other ideas tested have been on quad and many legged cyber creatures. That this project needs is a little more design now some of the problems have been highlighted.
During the first year of uni I was an enthusiastic poster on
Fidonet; a amateur electronic mail network that spreads one way or
another around the world. In practice the actual coverage is variable
since the service provided is free, mail transfer is paid for by the
kind efforts of the owners of each BBS the mail is passed between.
A
BBS can be called by anyone with a modem, computer and terminal. With
the right software you can then select mail areas to join and
read/send messages into those areas without being on the phone.
Area
topics are diverse, the system I call has approximately 1200 areas.
Obviously most are for computers of different platforms but a large
number are for just about any general topic or hobby that is vaguely
popular.
So what are the problems? Unlike Usenet, mail is
transferred between BBS's at night in clumps and so message can take
a few days to cross the country (yet they sometimes take the same
time to deliver across to east Europe).
Another problem is
reliability, sometimes a BBS will disappear because of hardware
problems or the operator has suddenly had enough. This can then make
messages disappear altogether or take weeks to appear. A related
problem is the overall reliability of message transfer, messages have
been known to disappear and old messages that should have been
removed can appear again. All this is caused by bugs in the mailer
software used by various platforms to transfer the mail; although
some of these bugs are fixed there is always new software coming out
that will have new bugs.
All in all it`s a bit rough around
the edges at times but the characters can be friendlier than Usenet
since the audience is smaller.
During the second year of Uni, I left Fidonet because of the decreasing traffic level, decreasing number of interesting people and the increasing number of idiots that came with the arrival of the 'web surfing' fad.
I reckon the whole scene was dying with the arrival of easy access to the internet and Usenet which gave generally much better performance for those people who just can't wait (most people).
When I started Uni I had just built a model boat and was trying to learn to fly a model helicopter. The boat was more of an electronics project than anything else, all the control electronics was home brew (diagrams below). Once the boat was completed it lost it's appeal as there is only so much you can do with it; though I suppose you could say that with most things.
The helicopter was put to one side when I had a near miss with a rotor blade. Having just taken off, hovered and then landed (it is not as easy as it sounds); I was revving it up to take off again when one of the main rotors flew off at incredible speed and the helicopter shook itself apart. Its things like that that make you notice just how fragile things (you, it) are.
The bottom line is that a helicopter needs more effort to maintain
than I am prepared to expend, all those moving parts need to be kept
freely moving. Currently the helicopter has been rebuilt and is ready
to try again using my newfound experience of fixed wing flying
machines, but I'm in no rush as the maintenance problem will still be
there and so will the inevitable engine failure leading to certain
doom.
Some of these problems could be because of the model, it is
a Sport 500; an early example of model chopper. It isn't very well
designed or built and the modern chopper is much better in every way,
except the price...
At some point I got involved in flying and building a model plane,
which led to other planes.
I started to fly a Super Sixty, which
is a basic training model of 60" wing span used by novices to
get the basics of flying; such as hand-eye coordination, model
orientation (model's left/right opposed to the pilot's left/right).
In my opinion the Super Sixty is a reasonable model for the beginner,
it is stable and forgiving but is easily broken having a fuselage
constructed like a high tension power line made of 1/4" balsa
wood. It also requires calm conditions as it's slow speed and
lightness make it easily blown around useless you are experienced
enough to control it.
Since then (progress was quite quick) I've moved to flying a
Mascot, this is a 56" wing span fast trainer made of plywood
with veneer covered foam wings. It was bought second hand (cheapest
way of doing things) and was distressed before I had it, since then
it has had countless flights and 5 crashes of varying severity.
At
some point point the Mascot was retired; to be eventually sold to a
beginner. In its place was a Baby Boss, a small very fast highly
agile model. Apart from teaching and test flying other models, this
has been the plane of choice for months now (possibly a year).
There are also plenty of other models in the collection which my Dad owns but doesn't necessarily fly (it seems some people find flying more difficult than others), they are:
Sopwith Pup, the classic British Biplane (51 four stroke
O.S.)
Though it looks nice this plane feels under powered and so
flying it is a potential risk. Also, through experience it has shown
to be difficult to land accurately in even the slightest gust
because the the wings lift varies with even the slightest change in
airspeed.
Piper Cub, the 1930's general workhorse (60 two stroke
Thunder Tiger, 72" wing span)
Another scale model, this one
has seen better days though. When it first had the above engine
installed it was a great flyer. It was fast, stable and had the
power to nearly manage a sustained vertical climb. Somewhere along
the line it must have been crashed and since then something is badly
wrong with the airframe. Picking up speed above say half throttle
will make the plane roll slowly to the right and not respond to
ailerons or rudder. The only course of action is to use the elevator
to slow it down and then at that point every thing works.
Needless
to say this problem is a hindrance, but as the airframe seems to be
without fault there is not a lot that can be done without stripping
the covering off.
P51 Mustang, the American version of the less powerful
Spitfire (91 Thunder tiger four stroke O.S., 60 something span)
Since installing the 91 four stroke this model clearly has the
power. Unfortunately the engine has turned out to be unreliable,
aside from important bolts dropping out (some of the others were
loose too), the idle mixture needle has somehow moving making the
engine very rich. Trouble is, when installed in the model you can't
get at the idle mixture screw and so I am currently waiting for that
combination of being home during the daylight hours and good
weather; so that I can set it up on a test stand.
Ezee Pzee, a large limited circulation non-scale model (70
four stroke O.S., 84")
Though an easy flyer and well suited
to the job of towing the glider, the pilot at the time somehow
managed to stall it on the final approach. All but the radio
equipment was smashed to pieces.
Gangster, a standard sized general low wing model. (61 Super
Tiger, 54" span)
This was bought second hand and after a
lot of time ignoring it, I pulled it from the loft and fitted the
above engine. Bear in mind that a 46 was probably the targeted
engine. I found it a tight fit in the fuse, the engine sides pushed
the fuse sides apart slightly. But anyway. I tried it and smashed it
up.
On takeoff everything was fine, but at the point that I came
to turn around (as it was now some way away) I noticed the elevator
wasn't responding, the other controls were fine but the plane
continued to dive and dive. In total it did a perfect arc, from
level to vertical ; at which point it hit the ground (with full
power on at all times).
This little accident smashed the model,
the engine and damaged the radio receiver. All because the elevator
push rod (fitted by the previous owner) couldn't take the strain on
the elevator. Instead of pushing it just bent to one side. I know
this because is was one of the few parts of the model that remained
intact.
Kestral (54" 52 four stroke Super Custom)
A standard
sized vintage look alike, similar to the Gangster but has older
styling. Though it has been mostly built for a year now, that is as
far as its got.
Hawk
A scale jet - the same thing the Red Arrows fly.
Still boxed, it is loft bound and I expect it to be for a long time
yet.
Baby Boss, a extremely acrobatic model. (25 Irvine two
stroke, 34", 2.7 lb)
Designed for the sole purpose of
performing every possible acrobatic maneuver by using the brute
force of agility. I am still flying this after what must be a year
of use. The only crashes have been loops to low to the ground and
rough landings caused by the Babys inability to glide. The only
thing any of this has ever done is bend the under carriage.
Super Sixty, beginners trainer. (40 four stroke O.S., 60")
Designed to be slow and self leveling. A good trainer if you are
prepared to built it. Beware though, wings can warp in the sun (all
built up wings do, but these seem to do so more than most).
Mascot, fast beginners trainer. (40 two stroke Irvine, 60")
Designed to be tough and be reasonably fast. Is partially self
leveling and will do most maneuvers, if not very tidily. This model
has since been sold to another beginner in the club. Although he got
the hang of flying it within maybe 8 lessons (8 tanks of fuel), he
crashed it and after the repair it has developed scary tendency to
do a sharp right roll when initiating a left roll (as part of a
banked turn). By sharp I mean it will roll from say -10 degrees
(left bank) to +45 degrees in the blink of an eye. Still trying to
track this problem down.
Diamount Glider (74" 12oz)
As the name suggests a
glider. This is based on the classic glider design unlike modern
model gliders which don't look like the real thing. Being a glider
it has no power of its own and must be towed or piggy-backed to a
usable height, when it is released and the object is then to find
some thermals to 'keep it up'.
Being of traditional design this
is made of balsa and doped tissue, unlike most nowadays which are
made of plastic covered foam or possibly fiber glass.
Learjet (46 two stroke Irvine, retractable under-carriage)
Exact scale model of the real thing. This has now been built,
but after spending well over a year making it (on and off) no one
has the balls to try it, besides the trouble of landing it a 20x20
yard grass landing strip.
Extreme (61 two stroke, 58" ish span)
A plane for
the same niche as the Baby Boss, but larger, much better looking.
Have still to get used to this one, as the colour scheme makes its
difficult to see which way up it is; unlike the Boss which has an
orange underside and white top.
All in all, it flies straighter
than the Boss and looks better.
Turbulent (160 twin four stroke Super Custom, 80" ish
span)
Third scale of the full size vintage. Has flown a few times
but the cost of the model and the time spent building it make it
a model for ideal conditions.
Aireonica Champ (120 Irvine two stroke, 110" ish span)
Bought second hand, this model is still being done up to the
point that it will fly again. Apparently it used to be used as a
trainer, though with a 108 two stroke engine.
Bi-Fly 25 (25 Enya two stroke, 36" ish span, biplane)
Not bad looking but difficult to fly (because orientation is
difficult), stalls badly when upside down. Hence its been pending
major repairs for months now.
Limbo Dancer (40 OS two stroke, 52" ish span, funfly)
A bigger but lighter version of the Baby Boss, a very popular
model because of its agility and resilience.
Magnetilla (semi-scale vintage)
Currently being covered.
Alongside the description are some details of the models wingspan, the size of the engine that powers it (in 1/100th of cubic inch) and the make of engine.
Lately there has also been some electric powered planes, and a new helicopter. Details will follow...
I also like the occasional bit of electronics, usually either
gizmos for use on the phone, something in one of the models or something
for the computer.
I
plan to put the circuit diagrams of a few select circuits here when I
can make the space to put them in.
They include:
| 3.3V(A) | 5V(A) | 12V(A) | 5VSB(A) | -5V(A) | -12V(A) | W | Machine/state |
| .36 | 4.73-4.75 | 0.19 | 30 uA | 0 | 30 mA | 28 | P166 - full load |
| - | 3.48-3.52 | 0.19 | 30 uA | 0 | 30 mA | 21 | P166 - playing MP3 |
| .33 | 2.76-2.77 | 0.19 | 30 uA | 0 | 30 mA | 18 | P166 - idle |
| 4.1 | 4.8 | 0.2 | 0 | 0.2 | 0.04 | 41 | C 1G - full load |
| 3.7 | 4.3 | 0.2 | 0.09 | 0 | 0.04 | 37 | C 1G - idle |
| 1.1 | 2.6 | 0.1 | 0.01 | 0 | 0.01 | 18 | C 400 - in BIOS |
| 0.9 | 2.6 | 0.1 | 0.01 | 0 | 0.01 | 17 | C 400 - Fail boot |
| 0.7 | 2.5 | 0.1 | 0.01 | 0 | 0.01 | 16 | C 400 - Fail boot, no gfx card |
| 1.6 | 2.0 | 0.2 | 0.09 | 0 | 0.01 | 18.3 | C3 533 - in BIOS |
| 1.4 | 1.3 | 0.2 | 0.09 | 0 | 0.01 | 13.9 | C3 266 - in BIOS |
If you are interested in power requirements for a UPS, then some figures on power usage as measured from the mains side are:
0.02A Monitor Off, Computer Off
0.04A Monitor on standby, Computer Off
0.27A Monitor Off, Linux in Console and Idle
0.42A Monitor On, Linux in Console, find / > /dev/null
0.42A Monitor On, Linux in Console, both HDs sleeping
0.45A Monitor On, Linux in Console, dd if=/dev/hdc of=/dev/null bs=1k
0.47A Monitor On, Linux in Console, Idle
0.485A Monitor On, Linux in Console, gzip < /dev/urandom > /dev/null
0.525A Monitor On, Windows 98, running Unreal Tournement
0.53A Monitor On, Windows 98, Idle
0.54A Monitor On, Linux, xdm login idle
This was for a Celeron 400 in a complete system. TNT2 gfx, sound card, network card, cdrom, 5400 rpm hd and 256 meg of PC100. The monitor was a 17" low end of the market (1280x1024 at 60 Hz, rather than at 85 Hz).
The 12V to ATX power supply is now complete and tested. The board layout is available here (eps), which implements the schematic found at the above link (which themselves came from datasheets) and also includes a full ATX style ON/OFF from this(eps) schematic. In making the board I spotted some problems with this layout. The ground wires are too hard to get to, the -5V bits should have been moved further right to make more room. Forget the Power Good signal, turns out there was enough room on the bottom left of the board to add the capacitor and resister that the reference used. Would have be better to use the bottom right. While the power supply is on, powering the Celeron 400, the 5V regulator gets really hot and needs a large heatsink. By itself it is too hot to touch in 20 seconds. For the Celeron 400, all other parts ran cool - even the 3.3V regulator. Suggests there is a cut off point above which the regs will need a good heatsink - even though the worst case showed the 3.3/5V regs would give off around 7 W each. So, the layout of the regs I used isn't the most ideal for easy heatsinking. The heavy diodes all ran cold and so are fine as they are. In the BIOS the whole system was drawing 2.5A from the 12V supply. Testing on the Cyrix 3 533, running at 266 Mhz, the 5V reg didn't get quite as hot, and the 3.3V reg was hotter than before. At around 2A on the 12V supply this generally drew less current so it was to be expected. Putting the system into sleep mode it draws 1A, but as the CPU fan was still running, I suspect it can go lower.
I`ve also got some notes on various frequencies, timing and
p.d./current aspects of the digital exchanges as well as various test
numbers and other interesting bits. I`ll put these on when they`ve
been edited into some sort of order.
Some of the above was in the past, nowadays I put my skills learnt doing the above to some real world problems. These particular problems are the sort that should not be advertised here in case it reduces my freedom.
Back to home page.
Greg's home page version 2.3 greg@csc.liv.ac.uk last updated on March 2001