CALIFORNIA - Apple dikabarkan akan merilis Smart Cover untuk perangkat iPad. Cover pintar tersebut dapat menampilkan notifikasi LED ketika iPad mendapatkan pemberitahuan.

Ide ini ditemukan oleh AppleInsider dan telah dipatenkan. Gagasan ini menjelaskan variasi pada Smart Cover yang memungkinkan penutup iPad (cover) menampilkan pemberitahuan melalui peringatan visual.
Dengan menggunakan panel electroluminescent, Smart Cover yang tergabung dengan lampu LED dapat difungsikan.

Apa itu Cisco Packet Tracer ??

Saat ini banyak sekali cabang untuk Ilmu komputer, antara lain adalah Rekayasa Perangkat Lunak (software engineering), System bisnis cerdas, Sistem Informasi, serta tak lupa ilmu mengenai jaringan komputer. Diantara cabang ilmu diatas, yang paling sering terdengar belakangan ini adalah mengenai jaringan komputer.

Dalam jaringan komputer banyak sekali yang harus dipelajari, antara lain mengenai internet, TCP/IP, HTTP, pengamanan jaringan, jaringan multimedia, simulasi jaringan dan masih banyak sub-sub ilmu yang harus dipelajari. Namun yang menjadi dasar adalah bagaimana kita paham tentang dasar jaringan komputer itu sendiri, untuk itu kita tidak hanya membaca teori semata, kita juga harus praktek di lapangan agar mengerti.

Remapping the PICs

Remapping the PICs is quite easy. It is done in the initialization of the PICs. We must initialize the PICs *before* using them, and this is done by sending some ICW (Initialization Commands Words) to the PICs controller. The procedure is as follow:

• send ICW1 to PIC1 (20h) and PIC2 (A0h)
• send ICW2 to 21h for the first PIC and 0A1h for the second PIC
• send ICW3 to 21h for the first PIC and 0A1h for the second PIC
• finally, send ICW4 to 21h for the first PIC and 0A1h for the second PIC

ICW1 is used to tell the PICs if a ICW4 is following and if the PIC is working in a cascaded PIC environment (that means, if they communicate with each other).
ICW2 is the thing that is important for us. It tells the PICs where to map IRQ0 and IRQ8.
ICW3 is used for telling the PICs which IRQ to use for the communication between each other
ICW4 is used for telling that we are working in a 80x86 architecture and if the interruption is handled
automatically or if it needs help from software.

Programming the PIC

What is the PIC?

The PIC is a controller in the PC hardware that handles hardware interrupts (IRQ0, IRQ1, etc.). When there wasn't a PIC, we would have to poll the hardware devices regularly, this would be time expensive. So instead of that, when a hardware interrupt occurs, the PIC gets the signal and sends it to the CPU. The CPU stops execution and processes the interrupt handler. We actually we have two PICs. The first one is for IRQ0-IRQ7, and the second for IRQ8-IRQ15. We must have a connection between PIC1 and PIC2.