Chronos Manual

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Chronos clock
Chronos clock

My Chronos clock is several years old, and I think at least one newer model has come out since then. I hope somebody with a newer clock will edit this information if it is obsolete. --Matt Noonan

I just bought a chronos (11-2006) for use playing over the board in Tokyo. It is great. I don't find much wrong with Matt's instructions below except that some of the best modes for Go are outside of the selection presented. See my comments below. -- Dave

Table of contents

General Information

To get to the main menu for clock modes, start with the clock off. Holding in both black buttons at once, press the red button. Pressing the red button now cycles through modes. To select a mode, press the corresponding black button. You may then begin to play with the default settings for this mode, or hold in the red button to edit the settings. When editing values, the red button moves to the next item, and the black button adjusts the value. To finish editing and start playing, hold in the red button again. When you are playing a game, hold in the red button to add or remove time from the clocks. Press the red button a bunch of times in a row to reset the time controls.

The final menu for each mode says Copy to 0. To make it easy to use these options at a later time, change 0 to a number from 1 to 4 and then finish editing. This will save your time controls into one of the 4 slots which appear when you turn on the clock by pressing the red button.

Dave: The number of user modes is now up to 12. It is very important to understand and use the user modes provided on the chronos. These save your prefered settings for either 12 different modes or more than one setting for fewer modes. Once you choice is copied to a user mode, it is saved when you power off the clock, otherwise you have to start over again in the main menu. Since the current main menu holds about 80 different modes, you really don't want to go there more often than necessary. For example my current settings are:

  1. 30 minute absolute timing, mose SD-1
  2. 40 minute absolute timing, mode SD-1
  3. 20 second byo-yomi with a 10 minute non-spilling byo-yomi period, mode AN-1A
  4. 9 second byo-yomi with a 15 minute non-spilling byo-yomi period, mode CH-A1
  5. 10/10 Fischer timing (10 minute initial time with 10 second increment), mode CH-P5
  6. 15/15 Fischer timing (15 minute initial time with 15 second increment), mode CH-P5
  7. 5/12 Fischer timing (5 minute initial time with 12 second increment), mode GO-P2
  8. 10/10 Capped Fischer timing (10 minute initial time that is capped at 10 minutes with 10 second increment), mode CH-P4
  9. 2 minute hourglass timing, mode CH-H1
  10. 5 minute hourglass timing, mode CH-H2
  11. 10/15 Bronstein timing (10 minute initial time with 15 second spilling increment, mode AD-1
  12. 15 second byo-yomi with a 10 minute non-spilling byo-yomi period, mode GO-A2

Note that setting time or number of moves to zero is equivalent to setting it to the highest value: setting a timer with the format x:yz to 0:00 will give 10 minutes. Similarly, setting a 2-digit move counter to 00 will be interpreted as 100 moves. Therefore, in most modes you cannot turn off a timer or a move counter: try setting them to 1 second or 1 move instead.

Japanese ByoYomi

Choose the mode go - J1. The first screen is the main time allotted to each player. The next screen is the total amount of byoyomi. In this mode, each byoyomi period is one minute long, so if you move within the minute, you get it back, otherwise it is gone. The next screen is the beep and LED options, followed by beep at end. Next comes beep at tc (time control) -- turn this on if you want the clock to beep when byoyomi time begins. The following menu is the halt at end option. After this is the byo beeps menu. The clock will beep when you are in the last seconds of a byoyomi block. The byo beeps option lets you set how many seconds the clock should beep. The next option is dbl beeps. Turn this on if you want the beeps ending each period to be double, to set them apart from normal time control beeps.


go - J2 is similar to go - J1 but with finer byoyomi control: after setting the main time, you will see a display like 05 - 0:30. The first number sets the number of byoyomi periods, the second number sets the length of each byoyomi period. The rest of the options are the same as go - J1. The cost of this extra control over byoyomi is the main time in go - J2 can go 'only' to 9:59:59, while go - J1 can go to 99:59:59, for people who like to do too much thinking.

Example: KGS default byoyomi:

  • Mode: go - J2
  • Main time: 0:30:00
  • Byoyomi: 05 - 0:30
  • Beep: 0
  • LED: 1
  • Beep at End: 1
  • Beep at tc: 0
  • Halt at End: 1
  • Byo Beeps: 5
  • Dbl Beeps: 1

Dave: You can see my views on timing systems on timing systems - redux. I think it is close to a crime to use a chronos to play Japanese byo-yomi :-) There are some quite interesting alternatives that should be considered instead. The most basic change is to switch from a fixed number of spilling byo-yomi periods (for example 10 periods of 30 seconds each) to a single non-spilling byo-yomi period of X minutes. In the chronos manual this is called "Andante", "Adagio", or "delay" depending on how time is displayed. The Adagio method is Bronstein timing where an increment is added to your main time. The AD-1 mode is best here because it is the only mode outside of the GO-J* modes that has full byo-yomi "beeps" as your clock runs down. Nevertheless, in my experience people enjoy the Andate display better than the Adagio. In Andate modes (e.g. GO-A1, GO-A2, AN-1, AN-1A, AN-2, AN-3, and CH-A1 through CH-A8) the byo-yomi seconds count down on the left side of each player's diplay while the remaining byo-yomi period time shows on the right side. People find this easy to grasp and easy to follow during play.

Canadian Overtime

Starting with the clock off, hold in both black buttons and press the red button. Press the red button until the mode go - C1 appears and choose this mode. The first screen is the main time allotted to each player. The next screen will say something like "25_0:15:00". Here 25 is the number of moves which must be made in each 15 minute period after the main time is used up. After this screen is the beep/LED setup, followed by the beep at end option, then beep at tc (see the section about the go - J1 mode), and finally halt at end.


go - C2 appears to be the same as go - C1 but there is no main time, both players begin in overtime.

go - C3 is like go - C1 but after each time control screen you can also set a delay (default is 5 seconds). If you move within this delay period, no time is deducted from your clock.

go - C4 is the same as go - C3 except the clock does not flash "Forfeit" when the time runs out. This is something like the manual chess clocks, where the winner must call flag.

Example:1/5 game, IGS style:

  • Mode: go - C1
  • Main Time: 0:01:00
  • Overtime: 25_0:05:00
  • Beep: 0
  • LED: 1
  • Beep at End: 1
  • Beep at tc: 0
  • Halt at End: 1


From the main menu, choose go - P1. The first menu is the main time for each player. The second menu is the first overtime setting, and looks something like 25 - 0:15:00. This means that once the main time is up, you must play 25 moves in the 15 minute first overtime period. The next menu is the setting for the second overtime period, and looks like 10 ^ 0:05:00. This means that after the first overtime period is up, you will have 5 minutes added to your clock for each 10 moves you make. The next menu has the usual beep/LED options, then beep at end, beep at tc, and finally halt at end.

Example: To play a game like 1/5 Canadian where the remainder of each overtime period stays on the clock:

  • Mode: go - P1
  • Main time: 0:01:00
  • First overtime: 25 - 0:05:00
  • Second overtime: 25 ^ 0:05:00

Fischer Timing

From the main menu, choose go - P2. The first menu is the main time, which acts like a normal clock (no added time each move). The next menu is the amount of time to put on the clock once the main time is up. The third menu is the amount of time to add to the clock after each move (once the main time is up). The usual menus beep through halt and end follow.

Example: To play Fischer time controls of 5 minutes plus 15 seconds per move:

  • Mode: go - P2
  • Main time: 0:00:01
  • Added time: 0:05:00
  • +time per move: 0:15

Dave: As noted above the GO-P2 mode is a main time + Fischer overtime mode. I think that people would seldom use this for Go (hence Matt's example of main time = 1 second). The chess progressive mode V (CH-P5) is a pure Fischer mode with only an initital Fischer time plus increment. I recommend this for Fischer timing.

Dave There is a very interesting Fischer hybrid mode, CH-P4. It appears to be an accident. The mode was designed as a "blitz Fischer" mode. Like the blitz 5-minute chess modes (e.g. CH-F1), it only dispays 3 digits. As a result, the largest time that will display is 9:59. The clock continues to function properly when it hits this value, however, it stops accumulating additional time. In other words your ability to accumulate time is capped at 10 minutes. If you think for a 5 minutes on one play and run the clock down to 5:00, you can rebuild your accumulated time back to 9:59 with quicker subsequent plays, but you can never reach 10:00. Unfortunately since it was an accident, you can not set the cap to other values. It is potentially interesting for those who want to try out larger increments in Fischer but do not want the time accumulation to get out of hand.

Absolute Timing

From the main menu, choose Sd - 1. The first menu is the time per player, followed by beep, LED, beep at end and halt at end options.


From the main menu, choose Ch - H1. The first menu is the starting time for each player, followed by beep, LED, beep at end and halt at end options. Every time a second ticks off of one clock, a second is added to the other clock.

Dave: I live in Japan and have been using my chronos in a Saturday study group at the Nihon Ki-in for a couple of months now. As a result, I have shown it to a number of professional players. They are quite interested in it. But the big hit with the pros has been hourglass timing. This is the favorite mode especially when we go drinking after the study group! Highly recommended for (very) casual Go :-)


user manuals, for as long as this link will last...
dealer info

Chronos Manual last edited by velobici on March 2, 2012 - 13:59
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