[old] Hullo World

[Sevis]

Thanks, everyone.

RichardGv, yep, I'm designing my own instruction set, plus writing a program to run the machine code (mostly to test whether the instruction set is sane), plus writing an assembler, plus either making a circuit in TkGate or programming a FPGA. I'm currently leaning towards the TkGate option, designing some basic peripherals seems easier than making the thing interact with real hardware (and besides, I doubt it'll be something that will be used in PCs).

To answer your questions one by one:

1. CISC
   
2. 32-bit data bus, address bus, and largest register (although still subject to change, it started out as 4-bit...)
   
3. 32-bit words for pretty much everything.
   
4. 8-bit opcode, can be expanded to 9-bit later (instruction has one free bit)
   
5. Microcode control unit
   
6. No cache planned for now.
   
7. 128 addresses, half of them user addressable, about evenly split between 8-bit, 16-bit and 32-bit. Actually comes out as less, as many are parts of others (for example, 8-bit register B0 is the least significant byte in 32-bit register W0).
   

I have the feeling that by the time I finish this processor, I'll be horrified by how awful it is, and will remake large parts: most notably the registers and 32-bit multiplication (shifting instead of looped adding). On the other hand, things have been developing steadily, although I've had the feeling I couldn't possibly manage to do anything more in the time I have available: this is a school project, and is due in December.

I've got a Google Code page set up for this architecture, http://code.google.com/p/sevarch/, if you're interested. Once I've got an assembler and emulator/simulator (machine code interpreter) going, I'll write a C compiler and kernel for this thing.

I'm a Gentoo user as well, but have an LFS machine I play around with occasionally.