Best/Worst Assembly Language Instruction Set

PHX/PLX
PHY/PLY
BBRx/BBSx ZP (test bit and branch if)
SMBx/RMBx ZP (reset/set specific bits in a ZP register)
STZ <operand>
JMP [$abcd, X]
CLA/CLX/CLY (for tight code)

The BBR & SMB were not 6502 instructions. You just had BIT. Don't remember STZ, CLA,CLX or CLY either. Yes, the PHX/PLX and so on were useful but the JMP [XXXX.x) was zero-page only (unless that was C64 only).

 

STZ - implemented in the 65C02. Z is the zero register and contains fixed value of 0
JMP ($nnnn,X) (opcode $7C) - implemented on 65C02. Finally, a function table instruction.

The CMOS version added some more addressing mode opcode like ($zp) without indexing. The BIT instruction received 3 more addressing modes, with BIT #imm probably being the more important.

BBR/BBS, SMB/RMB, TRB/TSB, and BSR (branch subroutine) were implemented in the 65SC02 (sometimes labeled 65C02S). The SC02/C02S came out after the C02 - sometime around '85.

And I totally forgot that 6502 is missing DEC A and INC A.

Sorry about CLA,CLX and CLY. Those are PC-Engine opcodes. PCE has a bunch of added opcodes on top of the 65CS02 model. Sometimes I confuse them as being part of the original C02 set.

 

Thats odd, I did the 'mode 7' floor for BC racers on the 32X and unrolling the loop made it faster, if you write to memory it goes through the cache anyway, doesn't it, so only in the event of a cache write will it slow down...

 

better late then never ...

8048 (Magnavox Odyssey 2 ... 3K without bankswitching, no subtract commands, no bit-set/clear commands ...)
68000 (Commodore Amiga)
80x86 (some)

 

Best - Z80, mainly as it's the only CPU I got to grips with/

Worst - 8086, mainly as it stole all the god ideas from the Z80 added a horrible segmented memory map and IBM were stupid enough to use the 8088 in the IBM PC, they should have used the Z8000 then the world would have been a better place.

 

Wow, my kinda thread! Makes me itching to do some more hardcore asm, it's been a few years

Well...

my first: X86 (later realized how ugly it is)
most baroque: SH2
most powerful: ARM7
cute and somewhat clumsy: Z80
favourite: 32-bit MIPS, like the PSX' R3000A

Something I'd love to try once is Itanium VLIW :nod:

 

Anyone else find the 80286 bug (or others)? 80286 can read 16 bits from anywhere inside a 64K bank but if you read a word from the last byte, rather than wrapping around, it DIES!

I began with 6502 and came rather late to Z80 but it is a good (for 8 bit) instruction-set.

Anyone attempting to learn assembler language could do a lot worse than the ARM series. Now that is pretty and fun...

 

Oof ok, I have worked and played with a few...

MC 6502
MC 680x0
Intel x86 - Core Quad, with all SIMD extensions (one of the worst, latest SSE4.1 are good though)
Intel i960
MIPS R2000 - R12000
ARM 7/9 (the nicest imho)
Z80
PowerPC / Cell PPU
Cell SPU
PS2 Vector Unit
DEC Alpha
SUN Sparc 2/3/4
Microchip PIC (8bit)
ATMEL Mega8 - Mega16
NEC V60 - V70
Hitachi SH1 - SH4

Perhaps I forgot some, I have seen too many... oh well...

Jollyroger

 

How RISCy is RISC?

Are there many differences between ARM 7 & ARM 9? I wonder, did anyone like the ARM thumb-mode? I seem to remember that the guys from Shin'en wrote their GBA sound-drive almost all in thumb (only a few interupt drivers used wholesome, fulsome, full ARM).

Another related question: What is the minimum number of uniques instructions that a CPU has to have? I seem to remember a Post Graduatre student in the US designed an 8-bit RISC chip with, I think, 71 instructions.

 

There's the eponymous 3-instruction RISC chip, but I think that one cheated somehow. Hey, technically all you need is OR ;-)

Oh and jollyroger: i960? Why on earth?

 

sega model 2?

and from my computer studies class it would be nand that you need. all logic can be built from nand.

 

Well the 860/960 were used in several types of hardware, from SCSI RAID controllers to large electronic boards as an accelerator processor (SGI Reality Engine, etc...)

In the right amounts it was pretty fast, on the Reality Engine 2 there were twelve 860 which managed all the OpenGL transform and ligthing operations (and some more), this was waaay before commercial GPUs existed...

Jollyroger

 

I know, but I'm curious what you used it for... there's not that many M2 developers you know ;-)

 

Ahahah, fair enough, sorry no M2 for me... other graphics-related hardware but no M2 I am afraid... ;-)

Jollyroger

 

For a single instruction computer (OISC), the instruction is: subtract memory from memory, if zero, branch to address

 

I don't know why, but the 65816 always had an unually high amount of people who suck at programming it. Not in regards to if their code works or not, but in regards to their codes being inefficient compared to the way the 65816 was designed to be.

I find it really easy to write fast code for the 65816. All you have to do is learn to take advantage of 8-bit instructions, and only use 16-bit instructions when they allow operations to be done in less instructions; taking advantage the direct page; avoiding tight loops; and by doing things almost the complete opposite way on the 68000.

 

If only IBM had gone with a CPU with a flat address space (such as the 68000), the PC architecture likely wouldn't suck so much.

 

386 introduced the linear address range, so it's not so bad

 

Is 68000 ASM really that nice? I've seen 6502 (nes), 65816 (snes), and gameboy's custom z80 mainly. I've seen alot of people commenting that the 68000 is alot nicer than the ones I've mentioned I've seen or used. Anyone have any tutorials or documents that they think really do a good job explaining the 68000?

 

68000 has 16x 32bit registers, most instructions are very flexible, you don't even need to use a reg to move one Long from mem location 1 to mem location 2... 68000 is a really sweet CPU

There are or were some 68K tutorials on programmersheaven...
http://www.programmersheaven.com/download/3653/download.aspx
http://www.programmersheaven.com/download/3625/download.aspx