Blast from the past... Z80!

PDP-11

ADD a, b

where a, b are memory or registers.

John

but it probably takes just as long, same operations are needed, two loads an add and.... you just have to type less.

its small and simple vs. smart and big.

anyway for most cpus with a sane architecture theres little reason now to program in assembler exept for the stuff like getting the processor configured, getting in and out of interrupts,a highly optimized calculation or something very timing critical C will just just fine

-Lasse

I really liked the 6809. OTOH it's just a real shame that IBM chose the 8086 for the PC and not the Z8000 (or 68000).

--
Dirk

http://www.transcendence.me.uk/ - Transcendence UK
http://www.theconsensus.org/ - A UK political party
http://www.onetribe.me.uk/wordpress/?cat=5 - Our podcasts on weird stuff

I expect he means LDDR, LDIR etc.

I liked having plenty of registers,

I find it intersting that he has nothing bad to say about it.

bye.

closer to 40%

some 16 bit math (register add,sub,cmp) can be done on HL

(INC and DEC

is a 16 bit CPU, and not a fair comparison.

Z80 has that, not with two index registers though, and not in 16 bit width.

add al, ( ix + 6 )

19 clock cycles on the Z80.

yeah, it has nice simple timers.

Your nym should then be NooseFart.

[snip]

Your nym IS fart breather.

Wow. All of those long wires had to pose a nightmare with crosstalk, etc.

What are you , dial up?

It's actually better to wire things that way than in nice "neat" orderly rows and columns of wires ("Manhattan" style)... you tend to just add a bit of noise everywhere, rather than having some traces all in a row next to, e.g., clock line that get hammered.

At the frequencies and (more importantly) edges rates that the Z80 (and 8088 and 6502 and...) used, Jan's wiring style works fine. I've done boards up to

30MHz that way, and I've read that if you use a board with a ground plane, that sort of rats nest wiring can work even up to 100MHz with wirewrapping.

:

Two loads, op, store. Ok, 75%. It was still a PITA. That's why I liked the 8051. Besides the neat peripherals, there were so many places to get data from without moves. The instruction set is kinky though. Of course RISC pretty much solves the excessive load/store issues and kinky instruction sets.

I thought I did.

Not when you are trying to push toward wire speeds in packet handling routines and processes.

Assembler still has its place.

ing

that was kinda what I was trying to say. C for all the noncritical stuff and assembler for the few things that require the speed or control.

-Lasse

" Near wire speed" was always a pipe dream with all the overhead. These guys are fast!

says...>

:

I read your statement as it was suited to moving data around. Oops :)

Back in those daze, soon after the Z80 came out, there was what i will call a story even tho the source working in Intel stated it as a fact. Some person or persons in Intel took the rubies to make the 8080, copied them, and then altered them into a totally unuseable form that looked good but made trash product. The copies went with these person(s) who then made the changes that they wanted (but were ignored and bashed my management at Intel) and started their own company : to make what they called the Z80. And there were a number of those close to that group as well as some management types that knew damn well what happened and who did that. Management, etc refused to do anything about this outright sabatoge and theft. Intel was damn lucky they had a goodly stockpile of good wafers at that time..enough to last while they re-did a whole new set of rubies.

End story.

Larkin

RISC operates on registers, so anything to do with memory will will have to be done with a load and/or a store

-Lasse