Eu e o ShutterSpeed temos um carinho por estas máquinas e acabamos de descobrir hoje que as versões limitadas, que são mais caras mas não têm a função Silent Mode... PODEM SER UPGRADED PARA TAL!
Esta função foi tirada pela Konica depois da marca ter sido processada, mas ao que parece é tudo uma questão de programar o firmware porque todo o hardware continua na máquina.

Eu consegui implementar na minha e existe imenso feedback no photo.net, Rangefinder Forum, Fred Miranda, youtube, etc.
Em pesquisa, descobri ainda que dá para programar mais algumas funções que não vêm no manual, aqui ficam as que consegui compilar.
Multi-exposure:Switch from Off to P-mode while pressing SELF
The display will show 0 left of number of shot, e.g. 0[03]
With each exposure, the left number increases, e.g. 1[03], 2[03] etc..
Switch to Off, and the film is transported to the next frame.
More than 9 exposures are possible, but not indicated!
Manual selection of flash guide number:Switch from Off to P-mode while pressing SELECT.
Keep pressing SELECT and use UP/DOWN for GN selection.
When releasing SELECT, camera displays [PFl].
Switch to Off, and the selection is deleted.
When required GN number is not available, select nearest lower number, e,g. GN24 not available, then select GN23.
Infrared auto focus:Load film, and switch camera on (P, A, or M mode).
IR film is non DX, so requires pressing the shutter release button to advance to frame 1.
Switch to A mode, then press SELECT until ISO values are displayed.
Within 3 secs, press DOWN untill [---] is shown.
Press MF once to display [750] (corresponding to Konica IR750 film) press MF twice to display [850] (corresponding to Kodak's 850 film) (the numbers correspond to the wavelength the films are sensitive for)
After 3 secs, the display will show [iso 100], acknowledging successful setting of IR value.
For correct exposure, consult the data sheet of the film.
Fast exposure setting (fast related to setting, not exposure!)Select aperture in M-mode.
Partially press shutter release button.
Display shows proper shutter time.
Press UP or DOWN, and that time is selected. This allows for a very quick spotmetering. When now the composition is changed, including DOF, the measured time still is used.
Auto-bracketing:Switch to M-mode and press SELECT until [+/- 0.0] is shown.
use UP/DOWN to select increment, from 1/3 to 2 stops.
when pressing shutter release, three exposures are taken.
Important:
though engaged in M-mode, switching to A or P is possible before pressing shutter release.
bracketing varies shutter release time. When in P-mode this is outside of the range 1/250 - camera shake critical speed, the aperture is changed.
autofocus is activated before the first exposure and maintained for second and third.
shutter release time indication shown in A or P mode is only calculated for the first exposure. Under low light conditions, the shutter time may end up under the camera shake critical speed. When in doubt use a tripod.
when the aperture/shutter time combination falls entirely out of the range of the Hexar, the exposure is not made. This results in only 1 or 2 exposures.
when the film is full, the bracketing is stopped, and the film gets rewinded.
when using bracketing together with EV-compensation in A or P mode, the entire bracket moves up or down the amount of the compensation.
no bracketing is possible with flash or T(time) exposures.
bracketing has to be cancelled by setting the EV to [+/-0.0] again.
Como é óbvio, este post é informativo pelo que não me vou responsabilizar se ocorrer algo de mal na implementação do mod!