EN: Flashing Verb 99


TL;DR – From February 15th to 19th 2021 I had a privilege to represent Poland, my country and Bielsko – Biała, my „City in the mountains” in IBSF Skeleton Europe Cup on Innsbruck Igls track. This was my first international skeleton competition and a milestone in my, so called, sliding career. I was the last slider in the overall ranking but as for the first time it was really good 🙂 For sure it was great experience and even better adventure :). If You want to know more jump on board and hold the saddle firmly 🙂

This article is an English variant of the original "Świry do przodu, próchno za drzwi", which tells the same story about the IBSF Innsbruck competition in 2021. It is flavored by polish punk rock and new wave, even the title is a slogan spoken by the leader of punk band "Siekiera" (Axe) during the gig from 1986 performed in "Riviera Remont" music club in Warsaw (the place similar to Erick's Club or the Cavern in Liverpool). The story would be hard to catch if translated 1:1, so I've rewritten the same in another way. 

This way floats somewhere around Lunar orbit ;)


This article is a third in the series describing my Skeleton career (haha, 'career' very brave word). Events and adventures described here are a direct consequence of the Skeleton School in St Moritz and what’s more important in this scope, a training camp in Sigulda in December 2020. I strongly recommend reading previous parts first to fully understand the story. Both From Sigulda With Love (first part) and It’s normal thing to capsize (second part) are embedded below.

The first one
And the second one

Let’s start from the real beginning

I’ve started my 'real' sliding in the similar way than almost every polish slider does, in Sigulda. This was December 2018 when I arrived there for the first time and had an occasion to see how the real sliding looks like. My first sliding ever was the luge in Krynica Zdrój on very old, very bumpy wooden track, of course without artificial refrigeration. This was an unique place where not things like speed or centrifugal force, but bended wooden planks and sticking nails made sliding challenging. You can thing about this track like

The Pain Maze

Sixth map of „The Elder World”, Fourth episode in Quake 1

I was introduced into the sliding world by Przemek Pochłód, one of the main driving force of Polish luge. I clearly remember him looking at my poker-face before my first run ever an explaining me: „Don’t get wrong impression, this isn’t how real luge looks like”.

My road to real skeleton started with the real shovel, the Showelrace. I clearly remember this cold and cloudy morning when I walked from Kaķu Māja to see the track for the first time in person. My legs started to shake when I saw the men luge start elevated to the 7th floor of track building and monstrous 15th curve, few meters in height.

The original logo of the Showelrace competition from: https://www.facebook.com/showelrace
Apollo Lunar Mission was the first one in human space exploration history where digital navigation systems had so big impact and role in the mission success. Both Command Module (CM) and Lunar Module (LM) had been equipped with AGC - Apollo Guidance Computer. AGC is a masterpiece and a milestone in digital electronics and computers development. AGC was a first case where Integrated Circuits was used do build entire logic of the machine.

Even then I had completely no idea about the direction all these crazy stuff will lean towards. By that time I’ve already know that luge probably will be out of my range. I was feeling an anxiety that sliding will be completely unavailable and I will be left with this awareness how awesome it is and what I miss. The Showelrace supposed to be a cure for this disease.

I started skeleton somehow incidentally. This didn’t happened because showelrace was too slow or things like that. I just got know that Olympia Bob Run in St Moritz organizes the skeleton school open for everybody. I thought „Why not” ? Worth mentioning is that this „great discovery” happened during train trip from Bielsko to Warsaw where my plane to Riga departured from. Of course this was a trip for Showelrace 😉

The team

I have successfully made six runs in Olympia Bob Run in St Moritz. Three from Montis Bolt (an equivalent of the top in Innsbruck Igls) and next three from the top. What happened next is described in „From Sigulda with Love”. I not only bought my own equipment like sled, helmet, speedsuit etc. but I signed a contract between me and Polish Bob & Skeleton federation.

As You may already guess exact statements in my contract are confidential. The important thing to be aware about is that even when I’m a de-facto member of the Polish national team I’m not fully professional, government funded athlete who trains thanks to money being in possession of the national federation.

I need to pay for all my sliding. Equipment, accommodation, runs, transport, just everything. Unfortunately as You might imagine sliding is not a cheap thing to do. In year 2020 I have spent about 4000 to 5000 Euro for this sport. My (used!) skeleton sled alone costed me 1500 euro.

So now You can imagine how big love to sliding has to be to overcome all these difficulties.

The first point of my track development with the National Team was a training camp in Sigulda. The story of that has been already described, but at the end of the camp our coach made a decision. Europe Cup in Igls will be my skeleton debut in International Competitions.

Apollo Guidance Computer has been designed by MIT Instrumentation Lab in early 1960s. AGC is 15-bit word machine with 16th bit used as a hardware parity control for memory errors detection. AGC predates the concept of 8-bit byte. In those times computers worked on words of data with length specify chosen to the main task of the machine. 

Main computer logic was made of 2800 integrated circuits, each consists two NOR gates with three inputs. ICs was designed and manufactured by Fairchild in weird in today standards Resistor-Transistor Logic operating at 4V. AGC consist of course other kinds of ICs or discrete electronics but mostly in power supply, clock generator and interfaces to memory and peripherals.

The computer is clocked at about 1MHz. Its performance in integer arithmetic, logic operations, memory access and program control (like branching, comparing) is on about the same level as in Commodore 64. In the other hand it overcomes C64 in fixed point decimal arithmetic, multiplication and division, which are an order of magnitude faster in AGC.

Pure driving skills are not the only success factor in Skeleton, not even the most important one. In my case the main issue is not to teach me how to steer the skeleton sled through the track, but rather fill huge gap in physical and athletic training. Even one third of the final result is 'generated' during the launch. If an athlete isn’t strong and doesn’t push the sled fast enough his potentially superb driving makes no big effect, especially on so easy track like Igls

During the training camp in Sigulda and between it and EC in Igls a great emphasis on the physical preparation has been taken. Me and national team coach had to fill as much of my weaknesses as it was possible. The goal was and still is to echance my speed in short distance sprint, correct my motor coordination etc.

What might sounds weird is that I’m not an athlete with great experince. I’m not coming to skeleton from another sport with a solid foundation in overall performance. I fly paraglider for 10 years, but aviation doesn’t really require any pysical preparation at all. To be honest during most of my life I wasn’t only doing any sports.I had an opinion that sport is something stupid and why anybody wants to became tired for fun.

What makes the skeleton sport so awesome and cool for me is the lauch itself. That dynamics of running and then jumping on the sled in head first position 🙂 This really rocks and makes the athlete looking at least like Navy Seals. Of course You can also say that I’m talking this only because skeleton is much easier than luge and I’m too old to train luge. Generally this will be truth to same extend but it doesn’t change the awesomnes of Skeleton 🙂

The track

Innsbruck Igls is well known across the sliding world as the easiest track. It is widely recommended as a good place to learn how to slide and to start in first competitions. Because of that and its location it is heavily used by athletes from all the Europe. Innsbruck is almost in the middle of central/west Europe, not more than 800 – 1000km from almost every place in Germany, Italy, France and of course Czech Republic, Slovakia, Hungary and southern Poland.

During the track walk. Curve 6th in the foreground and Kreizel (curve 7th) in the background

The IBSF competition always starts from the official training and the official training always starts from the track walk. Everybody, even athletes with great experience always do the track walk if they don’t slide on the track very frequently. As You may assume while sliding at speed 90km/h and more there is a little time to think what to do where. The slide on skeleton is a little bit like executing software with preprecessed data.

Apollo Guidance Computer has two kinds of memory. 2 kilowords of Erasable Core Memory which was used as RAM (Random Access Memory) and 36 kilowords of Permanent Rope Memory used as a ROM, the memory where software is stored. Converting to modern units we can say that AGC has 4 KB of RAM and 72 KB of Flash/ROM.

Because in early 1960s there were no Solid State memory (except low density and expensive R-S latches used as registers) RAM was done using Core Memory. This type holds data as a magnetization direction of tiny ferrite cores. If the core is magnetized in one direction (like clockwise) it holds one, otherwise it holds zero.

Erasable Core Memory holds data even if it is not powered up, but has a destructive read. The read is done by sensing the current coming from so called 'sense wires' when the core is reseted. If the core is set to 1 a faint current pulse will be induced in the sense wire. Because the read is in fact an erase operation the data word has to be written back every memory cycle.

Igls track can be divided into four parts:

  1. Omegas
  2. Upper labirynth
  3. Kreizel
  4. Lower labirynth

Generally in most cases Igls guarantees than with no steering at all, or some minor mistakes an athlete will be able to cross the finish line in the same state as on the start line 😉

This doesn’t mean that such run will be a good one. In fact this will be very crappy with a lot of skiding, bouncing from track bands etc. This makes the Igls very easy, but very hard in the same moment. Because almost everybody would be able to start from the top and cross the finish and admittedly learn the track very quickly, every slight mistake will ruin the runtime. If You lose even tiny little amount of speed You won’t be able to recover it later.

To have good slide some steering needs to be applies in certain places. Almost all curves needs to be entered in the middle or late. The most cticital parts are Kreizel (7th curve) and 9th curve. Everything is marked on my 'backup note' I made after watching almost all on-board footage in Youtube with some corrections made after the track run.

Please DO NOT treat this description as any form of how-to or „Igls Ice track User Manual for Skeleton sliders”. As I’m a new slider at this point, my steering is much different from the line used by the top of EC or World Cup athletes on this track. I don’t reach the top speed (which is almost 120km/h in good ice condition) so some parts of the run are a little bit different. My launch is not very good and of course I make a lot of different kind of mistakes.

This explanation is only to give overall view on how the run looks like, to satisfy Your curiosity and give some entertainment.

My hand notes done after reviewing almost all skeleton on-board footage on Youtube

The Kreizel (7th curve – left) is somewhat similar to 15th in Sigulda but of course much longer. It has two, so called 'pressure points' which are marked by two, small blue dots on my notes. At entry where the first pressure point is, the slider shall steer down using right shoulder to prevent going too high. Then sled shall be kept on the straight level by left shoulder. At the second pressure point at the end of the curve the sled should be pressed by right shoulder to exit the kreizel gently.

An athlete at about secod pressure point of Kreisel. Or I think that the second pressure point is here 😉
View on Kreisel curve from it’s entrance. Yes, the photo is out of focus.

9th and 10th are the only two consecutive curves with the same direction. Both are towards left, but the rest of the track are somewhat 'rhythmic' with sequence left – right – left – right etc.

8th is a short curve with only one steering point somewhere in the middle. The 9th was a more trickier for me 🙂 Normally it should be driven through similarly to Kreizel but of course it is much shorter. So right shoulder at entrance, then left shoulder to stay high enough and right shoulder at the exit. In my case I was too slow here so the steering at the beginning of the curve wasn’t essentially needed. The 10th is almost similar that 9th.

The best curve on the track is the last 14th. Just lie and do nothing 🙂

Apollo Guidance Computer is very weird also from modern programming and software standards. First at all it uses ones complement to encode negative integers. It means that AGC has actually two zeros in it's arithmetic. The positive one, represented by all bits set to zero and negative one represented by all bits set to one (0x7FFF hexadecimal or 077777 octal)

AGC has also very different set of registers located in first 60 addresses of memory space, which is weird on it's own that CPU registers are mapped into memory (such design simplified electronics design)

Accumulator [ A ] at address 0 - used to do most of operations on data (add, subtract, decrement, compare etc)
Lower Accumulator [ L ] at address 1 - used for general data storage and for multiplication and division
Link Register [ Q ] at address 2 - stores an return address from the subroutine.
Program Counter [ Z ] at address 5 - point to the instruction to be executed next (99.9% of today's CPUs uses PC to point to current instruction)

There are much more registers like three used to switch memory banks (EB, FB, BB) or even an edit registers. AGC doesn't have an bit-shift operation directly on the opcodes list. Instead there are certain registers which do this job automatically after the data is loaded into them.

One of things which is missing in AGC is SP, the Stack Pointer. This is because there are no concept of hardware stack here, which is almost unbelievable in today's standard. AGC has something called shadow registers, located at addresses 10 octal to 17 octal (0x8 do 0xF hexadecimal) which are used to backup values of 'base registers' during handling interrupts (some are copied automatically some needs to be copied by software). If a programmer want's to have more than one level of subroutine calls they must construct the stack fully in software using load/store instructions with an indirect memory access.

The Athlete

So now something about me 🙂 Let’s be clear. A participation in the IBSF Europe Cup was a big load for my psyche. When my coach had announced this decision I was very excited about the privilege I received, but very short after I have started to feel some pressure. I knew from very beginning that maybe the Europe Cup is an entry level of the competition, but still this is serious thing. Everybody who compete there here only one common goal

The Olympics

Of course with 99% certainty I will never reach that level of my skill. Nobody from Polish skeleton have gone to Olympics so far. If people who were taking this as full time effort wasn’t able to did this I won’t either. Before we will go further let’s talk about my personal motivation and shortly why and when I have started sliding sports.

Everything started very accidentally, in very similar circumstances as I had started paragliding. I’ve just watched some Youtube video about the skeleton and a switch made the click in my head. „That is really cool”.

Ignoring the rest of the in-between story, we may just ask why I’m doing this? Maybe because I want to beat myself and push my limits further. Definitely because it is very interesting to be a participant of the continuous process of training and preparation. I’ve changed a lot because of skeleton sport. I’ve lost about 20 kg of weight, my speed, motor coordination, strength etc improved a lot. Of course those things are still poor in comparison with the typical, full-time skeleton slider but this is only because I’ve started from almost nothing.

At the end maybe my knowledge and experience would be useful to somebody in the future. Sliding in head first position is definitely an idea worth wide spreading 🙂

As You can see I don’t fit in a definition of typical competitive skeleton slider. Thankfully in this sport (in contrast to luge) it is maybe not very common for people like me to start with it at ~30, but it happens from time to time. This is mainly because skeleton is way, way, way easier than luge. To master luge to the point when the athlete is proficient enough to try the men start even in Igls a lot of runs and whole seasons is required. I came to Igls with only 18 runs in the logbook and I was able to lauch from the top and cross the finish line.

As I told the first appearance in real competition was very stressful. To be honest before first training run I was more scared that during the skeleton school in St Moritz. Skeleton school is from definition a basic training, so it is obvious that an experience of participant is none and runs will be garbage. During the track walk I was trying to remember exact curve sequence with an information what to do where, but to be honest when we went back to the start I have a big memory hole in my head 🙂

Bob/skeleton start at the top of the track before second training day.

You may ask why I even bother with such sport if it stress me so hard. The exact reasons why each athlete train and compete in sliding sport is very individual, but these reasons are located around the one common foundation. An adrenaline 🙂

I think everybody who slide either on shovel, on skeleton, or on luge sled do this to feel emotions. Everybody dropped sliding if it wouldn’t give 'a strong feeling of being alive'.

The time had ran out and my turn in start order has approached. Thankfully due to unknown reasons my stress changed from being a source of mental paralysis to being a source of motivation. After the epic sentence spoken by dispatcher

The track is clear.

I started to run not so fast and after few seconds I jumped onto my sled and started my fight with the easiest track in the world

AGC has very minimalist user interface. Of course it doesn't have any king of graphic or even a text display. Instead of that the AGC has something called DSKY, which is an abbreviation of "display and keyboard". An assembly consist "calculator like" display made of eight-segment electroluminescent displays grouped in three rows of five digits and three two digit ones. 

Data is entered using numerical keyboard. Beside standard 0-9 keys it has plus, minus keys, Enter (ENTR), Clear (CLR), Proceed (PRO), Reset (RSET) and few more.

DSKY has a set of status lights which signalize the internal state of the computer, mostly alarming an user in case of any fault or error. Separate COMP ACTY lamp on the electrolumienscent screen is controlled by the idle task of the Operating System (called just Apollo System Software) and it shows when CPU is executing any application thread.

The another quirk of the AGC and a DSKY is that it is not able to display the decimal point. Astronauts had to remember where the decimal point is or check it each time in checklist or user manual.
Apollo DSKY used to interact with Apollo Guidance Computer

The Training

My fight with the Igls track has started with score 0:1 just during the first run. I was awarded by DNF in score list, after I capsized after the 9th curve 🙂 I would passed the finish line If I had a little bit faster 🙂

The capsize wasn’t a big issue. If You have read my articles about the training camp in Sigulda You already know that I have some experience with them 🙂 Official IBSF training is a little bit different in that manner that an internal policy requires a medical check after each crash. After I get out of the track with my skeleton the doctor was waiting for me to perform basic diagnostic routines. Of course even that I’ve stopped after four curves of sliding on my back I was perfectly fine.

Worth mentioning is that this crash was the only one during both training and competition.

Consecutive runs was better one after the another. Of course in overall I made a whole set of problems:

  1. Steering too hard, especially on the kreizel. I was very surprised how hard such curve could be. Igls is very often described as 'the zen karma track', the place where an athlete shall apply as little steering as they are able to. During some of my runs I was going up and down slightly due to too intense steering applied to my sled. During another run I almost bounced from the roof of the kreizel. Another time I was going slightly sideways (skidding) because of the same root cause.
  2. Keeping head to high when sliding. This might sound ridiculous. From one reason You might think that due to sliding position an athlete has a great view towards the run direction. From another one You definitely would want to keep Your head high to have as good view as it might be possible. Both things are bullshit.
An athlete at the exit from the Kreizel – with definitely good sliding position.

In practice, during the skeleton ride You should keep your head as low as it is possible. This is because two factors: sled balance and aerodynamic drag. I did a simple experiment to check how the balance could change because of head position and I was a little bit surprised. I placed my sled on the wooden stick perpendicular to runners. I have found a position where the sled was almost in balance and only by moving head few centimeters up and down the balance shifted towards front or back of the sled.

What this change in practice? In great simplification this is the same principle as how skis work. You should keep the balance towards front to have any steering. If a head will be kept to high during the run, the balance will move backwards and the sled will become very difficult to control. This is very important especially on upper section of track where the speed is not so high and centrifugal force isn’t helping You to keep Your head as it should be 🙂 .

The competition

So lets move to the key point of the party, the competition itself. Of course after only five training run on the new (for me) track I wasn’t able to expect much and this was a result 🙂 Of course I was the last person in the overall ranking but as I said before the result wasn’t the most important reason to be here.

Before the launch in competition

The first reason is to learn the somewhat complicated IBSF competition protocol which consist a lot of different rules. All of those may kick You out of the party if not taken carefully enough. First at all the institution of Parc Fernee and locking all sleds 45 minutes before the first run. During that period jury checks each sled according to technical requirements. Things like the IBSF stamp on runners, runners temperature, and geometry are checked.

An athlete is not even allowed to bring it’s own sled before the run. This is a task for it’s coach (like on the photo above where Gints Dzerve holds the sled for Netlaus Krists. Sometimes a jury can request for something called ice box. If the parc ferne is located in the place exposed to the sun, sled runners can warm up very easily which of course will speed up the athlete. To balance everybody (some sleds can became warmer than another one) the sled is put on the ice for one or two minutes before the run to cool down runners.

The user interface of the AGC was constructed around the numeric list of Verbs and Nouns. Shortly the Verb was a command for the computer to execute and the Noun was a specifier which clarify what the computer shall exactly do with this command (like witch program should be started). 

Verbs varies from very general like displaying a value from the memory (verbs from 01 do 05) or storing the value in the memory (verbs from 21 to 25), through starting an application (verb 37) or performing software reset (verb 69) ending at very specific like controlling the landing radar or the IMU - Inertial Measurement Unit.

If the AGC is waiting for an user action like typing parameters using DSKY or performing an action from the checklist both VERB and NOUN display starts to blink.

Another part of the competition protocol is weighting. After each run each athlete must go to the designated place where firstly the sled itself will be check and and then the total launch weight will be measured. If the weight will exceed allowed 120kg the athlete will be immediately disqualified.

This was the most stressful part of my participation. I have 195cm in height and about 87-88 kg, but my weight can vary slightly +/- 1kg from morning to evening which makes very tight margin to the limit. Thankfully after my first and the last run I have 117.5kg so everything was fine.

An athlete itself 🙂 Everybody need to take a selfie from time to time 🙂

The training and competition changed also my attitude to the sliding. Before my first time in Igls I was really scared. Each run gives me a little bit of confidence (even this DNF 🙂 ) so I was very relaxed before the competition. I was sure that I will be the last so this was just a honorable run to present myself in front of not-so-many spectators in the official, PL branded speed suit 🙂

Of course it doesn’t automatically mean that I wasn’t a little bit stressed. Of course I was but this is why I was there. To feel that thrilling emotions 🙂 I think that waiting for the green light on the semaphore was similar like descending towards the moon surface while being on board of Apollo 11 mission 🙂 This was like the last verb on AGC list. Verb 99 which was used by Program 63 – ENTRY INITIALIZATION the first in row of few, automatically sequenced moon landing routines.

Flashing Verb 99 was displayed just few seconds before firing descend engines. This was a final question: „Do You really want to land”

The athlete after successful landing after the finish line. Please look at the way the sled is transported by the coach (or judge) from the runway to the place where the scale is located. Runners shall not be cleaned or even touched before the mandatory weighting.

The future

Ok, so the emotions have cooled down. The question is what next? The summer sliding season brake will be a time to take care about overall physic preparation. The team has scheduled a series of training camps which I will attend in. I have also some plans for 2021/22 sliding season. Of course everything bases on an assumption that the shitty Coronaparty will have it’s end before. Not only because I am an anarchist and punk with very distinct opinion about that, but:

Because I pay for all my sliding I must plan every Euro spent on sport. Corona test in Poland costs now about 80…100 EUR. This is an equivalent of up to three runs.

In 'normal circumstances', in sliding clubs in Germany, Austria or Latvia an athlete usually does not less than 100 runs in the preparation period before first competition.

As for now I’m sure that this is far above my financial capabilities. 100 runs equals 4K EUR with standard price of 40 EUR per run in Germany. More than 16K PLN. If we will include travel & accommodation this make a horrendous amount of money. I don’t have any exact plans specified but I want to do about 50 runs, as usually mostly in Sigulda which is our home track.

It is worth mentioning that I can effort sliding mostly because the job I actually do for living. I have always work as a software or electronics engineer. To adjust my life to Skeleton I dropped working for the corporation and started my own business. Now I’m a freelancer and admittedly I earn about two to three times more than average salary in PL, but this is still much less than I’d have in Germany, Austria or Norway. Skeleton is the biggest separate slice of my budget.

Somebody may instantly catch a dead-lock here. I don’t spent enough money for my development so I don’t make a great progress. I make poor progress so I don’t have an official government financing. You may also ask if this is worth bothering to spent such money to be only a poor slider at the bottom of results.

I am not able to answer such question and to be honest I do not want to do so. I had no plans or clues about skeleton, even after my first Showelrace competition. Everything happened 'accidentialy'. Maybe next time it also will.

The only thing I know is that the next season will be even more intense that the previous. I will have to face more difficult task like maybe the ladies start in Sigulda or very difficult tracks like Koenigsee or Altenberg – The Honecker Revenge. For sure this will be a little bit unpleasant and painful :).

Because of the space hype the AGC is very well documented and to some extends it is still used today. All related documentation like electronics and logic diagrams, hardware manuals, assembly drawings are available in digital form in the internet. 

Almost all software used during Apollo Project is available both as a source code and compiled, binary form. There are modern, working reconstructions of original compiler (assembler) used for compiling the software. There are few emulators and even a complete modern toolchain including compiler, linker, debugger and emulator which can be used to write own software for Apollo Guidance Computer.

Some guys, like Mike Steward even designed the modern replica of the AGC hardware. You can build Your own AGC either using a FPGA and configuration files provided on Github or if this looks too mainstream there is modern equivalent done using 3.3V/5V CMOS logic ICs :)

Mike’s Github with all things related to the AGC


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