Future Plans: APL2 for the PC

Transcribed from the printed issue; not yet reviewed. Read it in the PDF of the issue, page 82

APL2 is IBM’s strategic interactive programming language.

The announcement and availability of a second generation APL2 system for IBM PC and Personal System/2 Machines is a significant step forward for the APL programming language. APL2/PC offers a high degree of connectivity with other PC DOS based systems and 370 APL2 systems. Functions, operators and data may be migrated via the )IN & )OUT import / export commands and the use of an upload / download capable terminal emulator program.

Deviations¶

We distribute the APL2 language reference manual from the 370 product to demonstrate our level of compatibility. In our 300 page PC-specific guide we list the deviations from that document. There currently remain just 3 major areas of difference, these are:

• Complex arithmetic
• Selective specification
• ⎕NA.

Our plan for the future is to reduce this list as further releases permit. It might be worth examining briefly the shipped alternatives to the above. Instead of ⎕NA, the AP2 auxiliary processor permits the execution of external programs in other languages.

An external program provides a subset of the Complex arithmetic function. Work is still in progress on the definition of selective specification and is planned to be addressed in the future.

APL2/PC 16 bit¶

This is the smallest second generation APL system available in the market place today. It offers excellent performance, better than many first generation APL interpreters. Due to its economy of size, it also yields a generous 400 Kilobyte workspace in a 640 Kilobyte machine giving the user extra flexibility.

The Packager¶

Packaging an APL2 written application, leaves you with a single “.EXE” file which may be freely distributed without further licensing requirements to IBM. This for the first time makes APL2 the same as any other application generating language.

Once an APL2 application is packaged then all the “APLness” is removed - it no longer has the APL2 keyboard handler, soft character set, and if the application fails then it is immediately terminated, to the PC DOS prompt line, making it no different from any other programming language. Packaging is currently only available with the 16 bit interpreter.

APL2/PC 32 bit¶

For those users owning IBM Personal System/2 Model 70 and 80 machines wishing to exploit the power of the 80386 processor installed in these machines, coupled with an 80387, then this system provides a powerful APL2 interpreter which breaks through the memory barrier providing up to 15.7 megabyte workspaces on suitable machines. This is made possible by IBM’s own extended memory manager. Coupled with an improvement in performance over its smaller 16 bit version, this interpreter is not large at just 188K bytes.

Port Time¶

APL2/PC is derived from our own high level IL language which represents the definition of an APL2 system. This facility significantly reduces port time with obvious benefits of cost and a wider variety of machine offerings to our customers.

Price Performance¶

APL2 provides excellent price performance, in the three systems discussed above, APL2/PC 16 bit, APL2/PC 32 bit, and the Packager, are offered complete with 18 device drivers, 29 workspaces (or 925 functions and operators) for £348 (plus VAT).

Conclusion¶

APL2 provides a write-once programming environment, giving second generation language power from the smallest IBM PC to the largest IBM Super Computer - the IBM 3090 with Vector Feature.