Made by Perrenoud et Fils S.A.-2520 LaNeuveville in Switzerland the Sixis range of high-precision universal milling machines was based on three models: the 101, 102 and 103 - as well as some hydraulic-drive examples of the 102 and 103 and variants with customised controls for individual customers. Although most example found today are marked "Sixis", others (presumably older) can be marked "Perrenoud & Fils," - though when the change was made is not known. The layout of all three versions followed the same Deckel-like pattern: the main body of the miller had a machined surface on the top of the main column on which slid a head able to accept both horizontal and vertical heads - and with a self-contained motor and V-belt drive system mounted at the rear. The standard "table" was arranged with just a vertical surface, but with a choice of tables and accessories able to be bolted to it. As the tables included both fixed and "swivelling-and-tilting" types the operator could be guaranteed to be able to present work at almost any angle to the cutter. The vertical "table" could be moved sideways and up and down, but not in and out, that function being left to the head assembly. 
Sixis 101
Designed for the precision machining of small components used in the instrument, watch, jewellery and similar industries, the Sixis 101 was a superbly made miniature universal miller capable, in the right hands, of the finest quality work. Like the better known and very similar (but rather lighter and smaller) Aciera F1 it is not as big as photograph might suggest and, even allowing for the full extent of the table's travel and the length of the operating handles, it is possible to mount and work one within a space equal to a square with a side length of little more than 24 inches (580 mm). With its cast-iron base plate the (58 kg/127 lbs) machine could be either bench mounted or fitted to the maker's heavy 60 kg (130 lbs) cabinet stand that was neatly arranged inside to hold a range of accessories.
Consisting of a motor, a smooth-running 3-step flat pulley and a 2-speed gearbox, the drive system was arranged as a neat, integral unit and able to power the spindle in either a horizontally or vertical position (although in the latter case a support casting  part number 211 was necessary) with a total of six speeds that spanned 125 to 4000 rpm. However, these speeds were not fixed, the factory being able to vary the speed range according to a customer's requirements by fitting different pulleys - although the gearbox speed range always remained unchanged. The options available were:
Geared speeds: 125, 250, 500, 1000, 2000 and 4000 rpm
Direct (belt) drive: 1000, 2000 and 4000 rpm
2000, 4000 and 6000 rpm
6000, 8000 and 10000 rpm
9000, 12000 and 15000 rpm
Two T-slotted tables were offered: a plain right-angle type and a useful swivelling, tilting and inclinable version both of identical size at 200 mm x 600 mm. The table feed screws were hardened and ground and (on the example used by the writer) ran through backlash-adjustable bronze nuts; each axis was also fitted with a lever feed, the very sensitive feel obtained through the long (adjustable) activating arms being considered an advantage when machining delicate jobs. The length of both the longitudinal and vertical feeds was just under 6 inches (150 mm) and the traverse a little less than 4 inches (100 mm). Large and clearly engraved micrometer dials were fitted, graduated in intervals of 0.001" on the longitudinal and traverse feeds and at intervals of 0.0005" on the vertical. All feeds were by hand, there being no provision for a power fitting, though rumors persist of one offered by a third-part supplier and not included in the main catalogue.
Unfortunately, and a surprising omission on a machine developed for ultra fine work of a complex nature, the vertical head had no quill movement, either fine or quick-feed. Consequently,  all vertical travel had to originate from the knee - a serious inconvenience when the need arose to drill or machine downwards along an inclined axis. The direct competitor to the Sixis 101, the Aciera F1 did offer such a fitting (part 01-87-1504-01) and it is just possible that Sixis did too, but no details have come to light. The collet fitting was the popular and easily-obtained Schaublin type W12..

Sixis 101 shown, left,  as a vertical miller with the motor-drive system held in the adapter unit No. 211. A plain table was fitted as standard while the much more useful tilt-and-swivel version was an expensive optional-extra.  On the right is the Sixis set to work as a horizontal machine

Sixis 101 fitted with a very rare indexing attachment. This unit was originally indexed by an external gear wheel but the owner has added a 40 : 1 worm-and-wheel gearing together with suitable degree and minute dials. The work took a not inconsiderable ten hours to complete.