by bruce » Fri May 23, 2008 9:13 pm
Ice Cream Jonsey wrote:AArdvark wrote:Those carts work in the old Apples, do they not? I remember they worked in the C64 cart slot.
The 2600 joysticks worked for the C64, the Sega Genesis (although not all the buttons were there, of course), the Atari 400/800 computers and.... I.... think? they al... no! They did not work for the Apple II, according to my memory.
Is that correct, bruce? The 2600 joysticks weren't compatible with the Apple?
Correct, although both use a DB9 connector.
The Atari joystick is what we call "digital", these days: a leaf switch (well, in the fancy sticks like the Wico; the classic 2600 is, I think, basically plastic and tinfoil) at each cardinal direction (so you could close two at once) and a switch under the fire button.
The Apple II joystick is what we'd call "analog", although, really, it's just two potentiometers and an 8-bit A-D converter. So each axis would give a reading of 0-255. You could exploit this to use the joystick port for sampling, well, anything that would give you a TTL-range voltage: give it 0-5 volts, and you could read the voltage in increments of (5/255) volts. I used this once to build a sensor to determine how fast a coilgun projectile was going, with a photocell and a laser.
There were also two buttons on the Apple joystick. These were not present on the II+ keyboard, but they became Open-Apple and Solid (usually called "Closed")-Apple on the //e keyboard. Open-apple became the Command (propeller) key on Macs, although Closed-apple went the way of the Dodo.
Bruce
[quote="Ice Cream Jonsey"][quote="AArdvark"]Those carts work in the old Apples, do they not? I remember they worked in the C64 cart slot. [/quote]
The 2600 joysticks worked for the C64, the Sega Genesis (although not all the buttons were there, of course), the Atari 400/800 computers and.... I.... think? they al... no! They did not work for the Apple II, according to my memory.
Is that correct, bruce? The 2600 joysticks weren't compatible with the Apple?[/quote]
Correct, although both use a DB9 connector.
The Atari joystick is what we call "digital", these days: a leaf switch (well, in the fancy sticks like the Wico; the classic 2600 is, I think, basically plastic and tinfoil) at each cardinal direction (so you could close two at once) and a switch under the fire button.
The Apple II joystick is what we'd call "analog", although, really, it's just two potentiometers and an 8-bit A-D converter. So each axis would give a reading of 0-255. You could exploit this to use the joystick port for sampling, well, anything that would give you a TTL-range voltage: give it 0-5 volts, and you could read the voltage in increments of (5/255) volts. I used this once to build a sensor to determine how fast a coilgun projectile was going, with a photocell and a laser.
There were also two buttons on the Apple joystick. These were not present on the II+ keyboard, but they became Open-Apple and Solid (usually called "Closed")-Apple on the //e keyboard. Open-apple became the Command (propeller) key on Macs, although Closed-apple went the way of the Dodo.
Bruce