New answers tagged apple-macintosh
15
TL;DR:
They simply picked an off the shelf connector readily available and fitting their specs (like size, reliability, stability, etc.).
Almost all of the mainstream classic desktop computers that had internal slots relied on the card-edge type of connector.
Not really. At least not when it came to (more) professional systems. I guess your benchmark would ...
29
I’m not sure the Macintosh II designers chose the connector as such, but rather the bus, NuBus, developed at MIT and documented by Texas Instruments (Document No. TI-2242825-0001, published in 1983). NuBus specified the use of three-row, 96-pin 603-2-IEC-C096-M connectors (see page 7-1 in the linked document).
This bus had a number of features which make it ...
4
Early computer mice worked by sending a series of pulses
At one level, it sounds easy: just run a loop, counting pulses. I did find a description of how this worked in a simpler system, the Apple II with its paddles [...]
The Apple paddles and joystick don't work by sending pulses (it's just variable resistors, no additional logic), and you cannot connect ...
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If you want to look into early computers handling mice, you really need to take a peek at the Xerox Alto, developed in the early 1970s. It was the first computer designed with a mouse from the very beginning, and the first system to be built around the GUI. The mouse, as a device, had been invented earlier, and added onto existing equipment as a ...
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Here's a concrete example of Amiga low-level mouse reading from a programmer's perspective:
As mentioned in other answers, the Amiga board handles counting X/Y mouse movement on its two joystick/mouse ports in hardware, not software. A cumulative 8-bit X and Y position is stored for each port and is updated as the quadrature pairs change for each axis due to ...
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On MS-DOS, the system would be configured to generate an interrupt request (IRQ) whenever the mouse port had any input to report. In the case of a serial, rather than a bus, mouse, the bits of input would be combined into bytes by the serial port’s UART. The exact format would vary from mouse to mouse, but many used the same protocol as the Microsoft mouse ...
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How exactly did early computers like the Amiga, Atari ST and Macintosh handle the mouse while also carrying out demanding tasks?
This was achieved by simply not low level handling the mouse.
The Atari ST for example had a 6301 based keyboard controller handling keyboard and mouse (or joystick). The mouse is a simple bus mouse type sending a pair of phase ...
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It's rather simple, the earliest mice were just outputting digital pulses from a quadrature encoder, and these pulses were not counted in software but hardware. How it basically works is that for each of the X and Y axes, there are two wires, which are basically digital sine and cosine waves of movement.
So nothing like the paddle interfaces, which did not ...
2
I'd look to an electronic parts distributor to source a replacement. If the battery is the same as the one in @user23333's comment (Lithium-ion rechargeable 3032 3.7 V with solder tabs) then what you're looking for is something like the RJD3032ST1 which Mouser, Digikey, and Newark/Element 14 stock. In case it's not the same here's links to some parametric ...
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