I distinguish the following types for 80-column punched card codes:

- 3 Zone Hollerith
- 4 Zone Hollerith
- 4 Zone Hollerith plus extensions
- BCD Hollerith
- BCD Hollerith plus extensions
- EBCD Hollerith
- EBCD Hollerith plus extensions
- Non-Hollerith
- Binary Zone
- Tiered Code

The most limited of all, 7 letters are missing they are defined as alternate meanings of other symbols:

symbol alternate meaning 0 O 1 I 2 Z 6 G 8 S K X U V

A little bit less limiting, V, X and Z have now their own punch, but O, I, G and S are still alternate meanings for 0, 1, 6 and 8.

The limits are the same as with the previous code, the only difference is the actual coding.

Curious in this code is the reverse meaning of the digit punches

Here we have a curious placement of the letters alphabetic along the columns rather than the rows.

The codes for 10 and 11 are of course typical British.

Here digit punch

Here

The first BCD code. Only a single

The standardized BCD code. Here the zone

The later development where zone

CDC's own variant of the BCD code.

A BCD Hollerith based code from NCR. The

One of the original definitions of Extended BCD card codes by IBM. I have no idea why they called this code EBCD because it is missing quite a lot from the EBCDIC code. (Actually I know it but will explain it in the section on these pages devoted to the Standard EBCDIC code.)

The version for the Dutch Electrologica computers.

Another version, now for BCL computers.

This one was used by General Electric.

For the British ICT (later merged into ICL) 1900.

The CDC Scientific character set on card.

Philco 2000 computers used this one. I have no idea why the lower case letters e and n are present.

An EBCD Hollerith based code from USS. The

The original Bull code. The digits 0 and 1 serve a dual purpose as the letters O and I.

The Bull code was extended by the addition of the

The code was changed later to accomodate computer programming. Many symbols were changed, but also four more punch combinations were added. It is strange that these were incompatible with the other punches (and so are shown in a separate subtable) rather than with a

The zone punches

A curious code, I do not know whether it has been used in full much. Apart from the standard zone punches also

first bits card punches used 00 Y-0-9-8-1 Y-9-1/8 Y-9-8-1/7 01 Y-X-9-8-1 X-9-1/8 X-9-8-1/7 02 X-0-9-8-1 0-9-1/8 0-9-8-1/7 03 Y-X-0-9-8-1 9-1/8 9-8-1/7 04 Y-0 Y-0-9-1/8 Y-8-1/7 05 Y-X Y-X-9-1/8 X-8-1/7 06 X-0 X-0-9-1/8 0-8-1/7 07 Y-X-0 Y-X-0-9-1/8 8-1/7 10 Y-0-8-1 Y-0-1/9 Y-0-8-2/7 11 Y-X-8-1 Y-X-1/9 Y-X-8-2/7 12 X-0-8-1 X-0-1/9 X-0-8-2/7 13 Y-X-0-8-1 Y-X-0-1/9 Y-X-0-8-2/7 14 Y Y-1/9 Y-0-9-8-2/7 15 X X-1/9 Y-X-9-8-2/7 16 0 0-1/9 X-0-9-8-2/7 17 - 1/9 Y-X-0-9-8-2/7Note that except for the first column the remainder is done in four blocks, but the separation is staggered, punch

EBCDIC coding expected 100 - Y-0 120 Y Y-X 140 X Y-0 141 0-1 X-0-9-1 152 Y-X 0-8-2 300 Y-0 Y 320 X-0 X 340 0-8-2 0 341 X-0-9-1 0-1 360 0 -The exceptions are however less numerous than for the 96-column card code, but the basic translation is a bit more problematical. There were deep reasons behind this all. And again 0-8-2 is a victim, one of the most problematical punches in the history of IBM. There is a tale behind this: when the 029 card punch was designed at IBM it could punch in a single step all combinations of an

This card code has been used on the IBM clones (the EC series) produced in the Soviet Union. It is based on the EBCDIC internal code defined in standard GOST 19768/74. The translation to card code is based on what IBM used for its translation, however only a limited number of symbols is actually used in the card codes. Those used are shown. But even there, those with a green border in the chart are replaced by the codes for the appropriate, similar, latin script symbols, so they were also not used. It appears that the hard sign (a 'b' with a bar to the left) may have been coded as the 'B' in the chart above. But there is no documentation about that. Thanks to Uwe for a pointer to this code. The chart is based on the EBCDIC codes, but with omissions and some replacements. The code is called KPK-12 (Kod dlya PerfoKart).

This code is a bit strange compared to the others, it precedes the GOST code I just gave earlier. In the chart above the digit 0 is given with a red border, this is because the actual punch for this symbol is not "no punch", but the single punch