Nomenclature

All primitive models 12 and 16 with the letter “e” have an electric motor
All models with the letter “L” are semi-automatic machines (no automatic multiplication)
All models with the letter “A” are fully-automatic machines
All models with the letter “B” have technical improvements compared to the corresponding “A” model
All models with the letter “T” have a cumulative Register (Register IV or Triplex)
All models with the letter “Z” have a complete capacity carry-over in the Result Register
All models with the letter “S” have a tabulator of 10 keys for controlling the left carriage stop
All models with the letter “V” have a dividend set-up key, provided that they have no “T” nor “S” letter
All models with the letter “G” have the following modernizations (mid-1950s):

A new bottom plate
A device for inverting the revolution Register
A new modernized keyboard
Always grey color

Letters are presented above in the order of priority with which the naming of machines is built.

Gradually, various models evolved and the old ones were replaced.

Basis model	Replaced by
16L	16LG
16LV	16LS
20L	20LVG
20LV	20LS
20LZV	20LZS
20AV	20AS
20AZV	20AZS
20AT	20ATG
20ATZ	20ATZG

Known codenames

Model	Codename
12e	POSS
16e	PONA
16LG	PONADELGE
16LS	ESPONA
20LS	ESPOLO
20LZS	ESPOZET
20LVG	POLDIVGE
20AS	ESTROLO
20AZS	ESTROZET
20ATZ	TRIPLOZET
20AG	TOPOGE
20ATG	TRIPOGE
20ATZG	TRIZEGE

The semi-automatic machines

Identification of models 12 and 16

	12/12e	12eN	16/16e	16eN	16L	16LV	16LG	16LVG	16LZG	16LZVG	16LS
Keyboard - #columns	8	8	8	8	8	8	8	8	8	8	8
Register I - #digits	12	12	16	16	16	16	16	16	16	16	16
Register II - #digits	6	6	8	8	8	8	8	8	8	8	8
Register III - #digits	8	N/A	8	N/A	8	8	8	8	8	8	8
Dividend Set-up key						yes		yes		yes	yes
Tabulator stops											yes
Keyboard clearing key	circular	circular	circular	circular	circular	circular	square	square	square	square	square
Full-capacity carry-over									yes (#)	yes (#)
Repeat-key, marked "REP" or plain	marked	marked	marked	marked	plain	plain	plain	plain	plain	plain	plain
Usual colour	black	grey	black	grey	black	black	grey	grey	grey	grey	grey
Carriage shift keys	N/A	R-L	N/A	R-L	both	both	both	both	both	both	both
Corr key	yes	yes	yes	yes

Identification of models 20

	20/20e	20L	20LT	20LZ	20LV	20LZV	20LG	20LVG	20LZS	20LZVG	20LS
Keyboard - #columns	10	10	10	10	10	10	10	10	10	10	10
Register I - #digits	20	20	20	20	20	20	20	20	20	20	20
Register II - #digits	10	10	10 x 2	10	10	10	10	10	10	10	10
Register III - #digits	10	10	10	10	10	10	10	10	10	10	10
Register IV			yes
Dividend Set-up key			yes		yes	yes		yes	yes	yes	yes
Tabulator stops									yes		yes
Keyboard clearing key	circular	circular	circular	circular	circular	circular	square	square	square	square	square
Full-capacity carry-over				yes(#)		yes(#)			yes (#)	yes (#)
Repeat-key, marked "REP" or plain	marked	plain	plain	plain	plain	plain	plain	plain	plain	plain	plain
Usual colour	black / grey	black	black	black	black	black	grey	grey	grey	grey	grey
Split-lever for partial clearing	yes	yes		yes	yes	yes	yes	yes	yes	yes	yes
Carriage shift keys	N/A	both	both	both	both	both	both	both	both	both	both
Corr key	yes

# Test the feature by subtracting 1 after clearing all the registers. If the result in Register I is set to all “9”, the machine is a “Z” model.

The fully-automatic machines

Identification of "Type A" models

	20A	20AT	20ATZ	20AV	20AZV	20AG	20ATG	20ATZG	20AS	20AZS
Keyboard - #columns	10	10	10	10	10	10	10	10	10	10
Register I - #digits	20	20	20	20	20	20	20	20	20	20
Register II - #digits	10	10 x 2	10	10	10	10	10 x 2	10	10	10
Register III - #digits	10	10	10	10	10	10	10	10	10	10
Register IV		yes	yes				yes	yes
Register V	yes	yes	yes	yes	yes	yes	yes	yes	yes	yes
Dividend Set-up key		yes*	yes	yes	yes		yes	yes	yes	yes
Tabulator stops									yes	yes
Keyboard clearing key	circular	circular	circular	circular	circular	square	square	square	square	square
Full-capacity carry-over			yes (#)		yes (#)			yes (#)		yes (#)
Usual colour	black	black	black	black	black / grey	grey	grey	grey	grey	grey
Split-lever for partial clearing	yes			yes	yes	yes			yes	yes
Negative multiplier bar	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A

* A variant, mamed “AT Tripolo” has no Dividend Set-up key.

Identification of "Type B" models

	20BG	20BVG	20BZVG	20BTG	20BTZG	20BS	20BZS
Keyboard - #columns	10	10	10	10	10	10	10
Register I - #digits	20	20	20	20	20	20	20
Register II - #digits	10	10	10	10 x 2	10	10	10
Register III - #digits	10	10	10	10	10	10	10
Register IV				yes	yes
Register V	yes	yes	yes	yes	yes	yes	yes
Dividend Set-up key		yes	yes	yes	yes	yes	yes
Tabulator stops						yes	yes
Keyboard clearing key	square	square	square	square	square	square	square
Full-capacity carry-over			yes (#)		yes( #)		yes (#)
Usual colour	grey	grey	grey	grey	grey	grey	grey
Split-lever for partial clearing	yes	yes				yes	yes
Negative multiplier bar	yes	yes*	yes	yes	yes	yes	yes

* A variant has a “+/-” lever, right nearby the keyboard clearing key, instead of the negative multiplier bar, as for the model 20ATG.
# Test the feature by subtracting 1 after clearing all the registers. If the result in Register I is set to all “9”, the machine is a “Z” model.

A special adaptation of the 20BTG (named 20BTR) and of the 20BTZG (named 20BTZR) allows transfer between Register IV and Register I, or vice versa.

Model creation date

Year	Models
1931	12, 12e, 16, 16e
1932	20, 20e, 16eD
1933	20AZ
1934 /35	20LZ, 20A, 20AV
1936	20AT, 20L, 20LV, 20LT
1937	20LZV
1939	20ATZ
1950	16LV, 20AS
1951	16LG, 16LS, 20LVG, 20LS, 20AZS, 20ATG, 20ATZG
1953	16LVG
1954	20AG
1955	20LG
1958	20BG, 20BVG, 20BZS, 20BTZG, 20LZVG, 20LZS
1959	20BS, 20BTG, 16LZG, 16LZVG
1961	20BZVG