Dyalog Ltd.

Dyalog Ltd. (originally Dyadic Systems Ltd.) is a British firm which specialises in APl products, especially Dyalog APL.

Early history

Dyadic Systems was formed in 1976 by a breakaway group of APL consultants from Atkins Computing (a time-sharing bureau) that had been working on their Sigma APL processor. They provided independent design and development services unaffiliated with any specific vendor. The steadily growing group of analysts gained a broad collective experience over numerous flavours of APL. While the emphasis remained with SHARP APL, APL*PLUS and Sigma APL, they also worked with APLs from IBM, DEC, Honeywell, Burroughs and others. There was also work in other languages. IBM was promoting VSAPL as its primary personal and departmental computing platform; this was a potential source of further demand for consulting. However, there was the nascent market for personal computers.

In principle, Dyadic, with no time-sharing business to manage, could simply switch horses and write APL programs for PCs. But there were few PCs with APL about. One was the rather quirky MCM micro, whose APL interpreter was in firmware. It had an idiosyncratic reverse implementation of the scan operator and limited the size of arrays to 255 elements along each axis. It provided the facilities to generate a GUI interface, at least in providing form-based input and output, but was slow. More substantial APLs had been implemented for the IBM 5110 and for the Motorola 68000 chip, available as Wicat computers. Even Bill Gates of Microsoft contemplated writing one, and talk to Ian Sharp of [[I.P. Sharp Associates]] about a reduced APL – how little one could get away with, but the project was cancelled before a product was released.

Zilog UK wanted an APL for the Z8000, since the Swedish Ministry of Defence, in a call for tenders from Unix suppliers, had listed APL as a software requirement. They provided Dyadic a dedicated Z8000 minicomputer and generous development facilities.

Dyalog (Europe) Ltd. was registered for this purpose in 1981. The new company blended both names, as mentioned in the press release:

This company is DYALOG (EUROPE) LIMITED, the name Dyalog being a hybrid derived from Dyadic and Zilog.

The “Marketing Strategy” paper read:

Our plan is to develop a low-price:

• Industry-standard APL interpreter (Sharp look-alike but more comprehensive)
• Running on an industry-standard 16-bit chip (Z8000)
• Under an industry-standard operating system (UNIX)