First: thanks for thinking about this discontinued device.
Then: I originally did not want to discuss, whether a continuous clock makes sense or not. I am simply asking whether there is someone, who would modify this app for me (I would not mind to pay for it). Even better if this change would be helpful for others.
And finally - if we want to discuss the reasonability - then there are three reasons why the clock should be running:
1.) Theory: MIDI clock slaves do not use the MIDI-clock itself in a “hardware” sense (like for example the 16th-clock in a CD4017 based analogue sequencer), but they have to adapt their own internal tempo to the external tempo. The slave “gets used” to the tempo. If you stop the clock at 72 bpm, then change the tempo to 120 bpm, then the slave will be at the first ticks in the wrong tempo, because the adaption to the new tempo has to happen after the start command.
In fact: for many devices we don’t talk only about a few ticks, but for several beats or even bars. For example my electrix repeater needs two or three quarters to adopt the new tempo. The electro harmonix 2880 takes even longer and will fail in 50% to adopt to the new tempo at all. I never tried with ableton or reaper, but I assume that all appliances, which have to handle audio (especially with timestretching) will have this problem.
2.) Necessity: Some devices require clock. This affects mainly DIN-Sync and/or “analog” step-clock which is derived from midi-clock.
Setups for problem reproduction:
a) MIDI-Pal with clock app --MIDI–> Doepfer MSY2 --DIN-Sync–> TR-808 in external clock mode.
If the MIDI-Pal stops, then the TR-808 is frozen. You cannot change patterns, you cannot change to write mode, nothing…
b) MIDI-Pal with clock app --MIDI–> MIDI-to-ClockTrigger Interface --16th trigger and start / stop triggers --> sequencer like Doepfer A-155 or A-157 or Make Noise Brains/Pressurepoints. The stop-trigger is connected to the reset input of the sequencer.
The stop/reset enables the reset, and the next clock tick will make the sequencer jump to the last step. So the first clock tick after the start would advance to the first step of the sequence. But with the clock missing in stop mode, this jump to the last step won’t happen while stop mode, but instead the sequencer will jump to the last step with the first clock tick after start. So the sequence always will hang one step behind.
If I remember right the same happens with the Intellijel Metropolis (but I don’t have it here at the moment, to test it).
3.) Rules: There is no detailled regulation that the clock MUST run while stop mode, but the MIDI Spec 1.0 is aware, that this may be required, due to the reasons I mentioned in #1.
Quote from page 36 of the MIDI spec, Version from February 1990: “…If Timing Clocks (F8H) are sent during idle time they should be sent at thecurrent tempo setting of the transmitter even while it is not playing. Receivers which are slaved to incoming Real Time messages (MIDI Sync mode) can thus phase lock their internal clocks while waiting for Start (FAH) or Continue (FBH) command. […]”
So once again: I don’t call the stopped clock as a bug, it is a change request