Help building a computer

[Sheepner]

Before I even start (building),

Hello,

These are my questions.

How does a shift register work and why should we use one?

Is adding a multiplication specific unit to your CPU worth it?

How does a hard drive work in MC and how should I integrate it?

I think that's all 

BTW I'll start 4 bit 

Thank you in advance,

Yours Sincerely,

Sheepner

[Koyarno]

1. a shift register isn't widely used these days anymore, however it is still used in combination with an ALU for...
2. sequential multiplication or division. But a dedicated unit is quicker in the end. If its too hard to picture a program that uses multiplication (besides using your cpu as calculator), dont bother about it yet.
3. a hard drive holds data and a single register holds data. But i guess characteristics are important. Registers near your ALU are quick but they dont hold alot of data. Making data sequential or compressing it to hex allows for some dense data setups but it is ofcourse slow to use. IF you can make a cpu that has memory with pointer capability and the program is big enough to even use a "hard drive", then by all means go ahead! My advise is to keep to a standard size packet like 16 or 32 bytes and have your memory accept these packets by the same amount.

[Sheepner]

1. a shift register isn't widely used these days anymore, however it is still used in combination with an ALU for...
2. sequential multiplication or division. But a dedicated unit is quicker in the end. If its too hard to picture a program that uses multiplication (besides using your cpu as calculator), dont bother about it yet.
3. a hard drive holds data and a single register holds data. But i guess characteristics are important. Registers near your ALU are quick but they dont hold alot of data. Making data sequential or compressing it to hex allows for some dense data setups but it is ofcourse slow to use. IF you can make a cpu that has memory with pointer capability and the program is big enough to even use a "hard drive", then by all means go ahead! My advise is to keep to a standard size packet like 16 or 32 bytes and have your memory accept these packets by the same amount.

Ok thank you    
I just realized I meant right shift program memory or something like that :/

I guess I'm holding off hardrives and compressing to hex since I'm not that advanced yet.

And about the packets you mean to make my ram able to accept them or the ALU's registers? And I would store them in ROM right?

Yet again thank you (coffee machine) and sorry for asking so many questions I'm a big noob...

Yours Sincerely,
Sheepner