[Oberon] [Off topic] MPW-Pascal

Tomas Kral thomas.kral at email.cz
Thu Sep 24 10:29:53 CEST 2020


Just discovered classic old Macintosh platform can be emulated.
(BasiliskII, mini vMac).

Installed MPW and MPW-Pascal. There are some common ideas with Oberon
systems, perhaps worth mentioning here.

MPW Apple's development environment, supporting flavour of languages,
Pascal, C, C++, Fortran, .., there is also Oberon variant for it.
Perhaps worth exploring further.

A piece of selected texts [commands] can be executed in MPW shell.

MPW-Pascal has object extension, allowing for single inheritance.

SET type can be defined on integer range 0..2039 [max], e.g.

VAR bits: SET OF 0..1024

In Oberon notation that would be {0..1024}!
Wow, that seems a lot.

My explanation is the `QuickDraw', which is underlying graphics
manager, with rich functionality, can handle not only monocolour, but
also 256,1024,1024*1024 colours. Such big sets are perhaps well
justified for screen bits manipulation.

Must really be complex, part of each Mac ROM, typically 1MB in size, all
written Pascal some portions in assembly. Cannot tell how big QuickDraw
really is.

Out of curiosity, reading some old docs, and programmes.
Pascal still reads better to C, not only in tutorial texts, in my

Interesting is also Mac runtime memory design. Applications are
segmented in code and resources. Loaded / unloded on demand.

There is no module concept analogy, closest idea is that resources and
code can be shared.

Tomas Kral <thomas.kral at email.cz>

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