Ferranti RTL integrated circuits

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Ferranti module I have a number of strange Ferranti devices as shown in the composite image on the right of one marked FF1201. These use a bizarre 13-pin DIL module that appears to be built from two encapsulated multi-lead TO-18 cans (seen on the underside) which are flip-chip connected to a glass substrate (superstrate?) on top that bears metallised interconnects.

The glass top plate on this example is printed FERRANTI FF1201, and I have others marked GG1210, GA1207, BB1210, ST1214 and GG1204. All have the same construction, but each type has a different pattern of wires emerging from the TO-18 cans, and a different pattern on the top glass plate. All the devices have numbers printed on the end which, if interpreted as a standard IC date code, gives a year of manufacture of 1966 or 1967. I have not been able to find any data on these devices.

I even have two strips of them held in special plastic carriers like modern ICs, one of the carriers having Ferranti-branded end caps. One strip is hand-inscribed "TESTED 21-2-68"
Intellux module I also have this remarkably similar device made by the American company Intellux Inc. of Santa Barbara California (no longer in existence). It too comprises the same two TO-18 cans, the same glass top plate, the same 13 leads, and it has the same overall dimensions. In the example in my image, the body is thinner than the Ferranti types, and the leads are correspondingly longer to compensate, but I have obtained another type with exactly the same dimensions as the Ferranti devices. The one shown appears to be dated 1969, later than my Ferranti types. Its part number GG2524B is suspiciously similar to some of the Ferranti devices.

Surprisingly, I have been able to find data on this device. It is listed, together with a number of other Intellux types, on the datasheetarchive site (specsheets at the bottom of the page, change the GG2 in the link to GG1 or FF3 or DM3 to see more - however datasheetarchive.com don't seem to offer a search for all devices made by Intellux). I have also located a fascinating document (6 Megabyte pdf !) in the NASA archive, which lists many of the US ICs being manufactured in 1968, and includes some of these Intellux modules (but sadly no European types). Both sources indicate that they are built from RTL (resistor-transistor logic), the oldest type of logic IC technology. The Intellux part numbers are all greater than the Ferranti ones.

I have no data at all on these strange Ferranti devices, but the use of RTL suggests that they are very early ICs, as does the use of TO-18 cans. Several early 1960's NASA documents refer to ICs in TO-18 cans, but I had not come across any until I found these. Fairchild preferred the larger TO-5 (later designated TO-99 and TO-100), and TI invented the flatpack. The dates of manufacture of my examples are not exceptionally early, co-inciding roughly with Ferranti releasing Micronor II in TO-99 cans (and later in plastic DIL) but tif these devices were used by the UK military then production would have to be maintained for a number of years.

The connection with Intellux is intriguing. The part number order suggests that Intellux followed Ferranti. Did they second-source the technology? In any case it was not a success in the USA, where Fairchild and TI had already secured the lucrative military market.

Those are, of course, just educated guesses. If you can provide any concrete information, please