Mac GUI

This is not the Mac 128K Blog. But today, it is. The Mac 512K Blog has had a few articles over the years which center more on the Mac 128K. Most recently we had Mac 128K: What Really Limited It?. Prior to that, it was Faking a Mac 128K and How to Use the Hard Disk 20 with Mac 128K

Well, I am happy to show that I don't have to fake it anymore, or conduct thought experiments, or even live vicariously. I am now in the Mac 128K owner's club, and this article will give readers some sense of the experience of unboxing and setting up a Mac 128K in 1984.


The Adventure Begins Here.

This phrase, which is on the inner leaf of the 1984 Macintosh brochure, was intended to convey the Macintosh experience as Steve Jobs envisioned it. Macintosh was not just another PC-DOS or Unix clone; it was an entirely new comput...

Let's review some common knowledge that everyone knows is true: the Apple Lisa and Macintosh both use the same Motorola 68000 microprocessor, but the Lisa allowed for multitasking. It was possible on Lisa to have more than one application on screen at the same time, and copy data between LisaWrite and LisaDraw, for example. Macintosh, however, was a single-tasking machine. Only one application could run on screen at a time, but small desk accessories like the NotePad allowed for a small degree of multitasking.

Everyone knows this much is true, but do you want to blow people's minds?

Tell them that the Macintosh in 1984 had multithreaded applications!

No, I am not referring to desk accessories! The first multithreaded Macintosh application was MacTerminal in 1984. Furthermore, multiple threads of execution were not only built in to the ROM-based operating system, but were essential to the functioning of Macintosh.

In today's Mac 512K Blog article, we will first see how th...

Interrupts are essential to the Macintosh; without interrupts, the arrow cursor would not move on screen. This Mac 512K Blog article will first explain how the Mac's CPU handles interrupts, then will show the source code and dispatch tables for the two main interrupting devices on the Macintosh 512K and 128K motherboard with 64K ROM.

The information in this article will enable advanced programmers to understand how interrupts are signaled and serviced so as to write their own interrupt handling code on the Macintosh. References for required further reading are given at the end of this article.


How Interrupts Work on the MC68000

When some peripheral device requests the attention of the CPU, it does so by signaling an interrupt. On the

In today's Mac 512K Blog article, we will take a look at the SystemTask procedure to see how it works and how we developers can make it work for us. The information in this article will be of particular interest to developers who want to write operating system drivers which need background processing time. According to Inside Macintosh, volume 1, SystemTask is a procedure in the Desk Manager, which is a unit of the Macintosh User Interface Toolbox. The Toolbox is that part of the Mac's ROM which developers use so that their applications all have a consistent user interface.

Desk Accessories such as the