Proposed Assembler Commands

Sounds tedious.

LDAA A ADAA B STAA C

PDP-11:

MOVB A, C ADDB B, C

The PDP-11 had an elegant, symmetric, beautiful instruction set. I haven't programmed one in decades, but I can still mentally assemble most common instructions (into octal!)

John

So that's why they're extinct!

John

That doesn't change the fact that S/370 still lives in the soul of the z/Series. ;-)

Yes, in the later 90's they became the "z/Series". The 360 architecture still lives in there somewhere. ;-)

Yes, most of the industry was p-chanel, I thought Moto was too but it was a long time ago. ;-) I remember when IBM was contemplating its navel trying to figure out why they were n-ch and everyone else was p-ch. "What did we miss?". ;-)

That wasn't unusual, at the time. The 8085 had similar issues.

The Intel instruction set never bothered me, in fact I rather liked it. Moto was too easy. ;-) I did like processors with more index registers though. The one I think is unnecessarily weird is the 8051. After ~20 years it still lives, so...

Yes. Some time back I was following a bickup truck down I89 with the license plate EIEIO. Thinking it was a PPC type with strange sense of humor, I pulled up along side. Nope, McDonald's Tree Farms. ;-)

Wasn't it the 6800 (or perhaps 6502??) that had the LSEX (Load with Sign EXtended)?

Same for the X86 architecture in current microprocessors. AMD showed Intel it was a bad idea to ignore the old legacy code in the 64-bit cpu's.

My editor is the old Borland SPRINT editor from 1988. It ran on the first IBM PC's at 4.77MHz, and it runs great on a 200MHz machine. I expect it will still run long after I'm gone:)

Mike Monett

But sadly lacked the necessary hardware for multiplication.

Best regards, Spehro Pefhany

Back in the 70s when I taught Assembly I used to work with a guy who sported a T-shirt which displayed the Hex for "Exchange Byte 69" on the back.

We also had a list which included things like: RWT Rewind and wipe tape IAC Ignore all commands DPL Destroy progam and loop etc.

Regretfully I don't have a list and have long forgotten most of them; but HCF is one that I remember.

Dave

You often strike me as prone to boorishness.

The 8088, with its segmented addressing scheme, was commonly recognized as a bitch to program. IBM's choice of that uP hampered development of software for the PC for years, until the '386 with its flat addressing and VM support appeared.

There you go again. An examination of the 1802 registers and instruction set shows many of the characteristics that later uP's claimed to be RISC had. I'm not going to attempt your enlightenment or worry about your boorish suspicions.

In article , keith wrote: [...]

RCA 1802 had a SEX instruction.

I read in sci.electronics.design that keith wrote (in ) about 'Proposed Assembler Commands', on Sun, 1 May 2005:

They didn't take the holistic view?

In article , John Larkin wrote: [...]

You've obviously never seen the RCA CDP1802's instruction set.

Imagine you have 3, 1 byte variable in memory and wish to do C = A + B here's the code for it (If my memory is working today):

LDI low(A) .. Load the low part of an address PLO R2 .. Put into the low part of the reg LDI high(A) .. Same for the high byte PHI R2

LDI low(B) .. Load the low part of an address PLO R3 .. Put into the low part of the reg LDI high(B) .. Same for the high byte PHI R3

LDI low(C) .. Load the low part of an address PLO R4 .. Put into the low part of the reg LDI high(C) .. Same for the high byte PHI R4

LDN R2 SEX R3 ADD STD R4

That right folks only 16 instructions needed for that.

I read in sci.electronics.design that keith wrote (in ) about 'Proposed Assembler Commands', on Sun, 1 May 2005:

You can score one over a boring mathematician by asking if he knows why

(That last one was actually DCA, deposit and clear accumulator.)

The PDP-8 had interesting micro-operations. In one instruction, you could do

CLA CLL CMA ROL clear acc; clear link; complement accumulator; rotate left

which loaded 4094 into the accumulator. So there were all sorts of constants you could cobble up in one instruction.

The original PDP-8 was made from discrete-transistor modules.

The original PDP-8 was made from discrete-transistor modules, probably a few hundred transistors.

John

was

Oh, my! I've been saying the *exact* same thing in .chips (for years) in reference to the Itanic. One doens't strand $billions in software. (see: IBM+FS).

My fav editor gave up the ghost about then. I loved EPM, but it went the way of 16bit addressing. I still try to find E-like editors.

Nah, they went back to bipolar. ;-)

Indeed there was a study to figure out why "we're wrong". IIRC, the answer was that "they" can't afford the technology, but it's better, which I think was proven to be right.

I often suspect that you haven't a clue what you're talking about.

Ok, what is *your* definiton of RISC? I suspect we're going to be "enlightened" here.

I do believe the 1802 is outta this world! IIRC is't on the Pioneers and Voyagers. Wonderful accomplishments!

BTW, I like the ISA of the NSC PACE. It was the first 16bit "microprocessor", though it had an 8bit ALU. The skip instrucitons (Decrement nnd SKip if Zero, SKip if And Zero, etc.) were quite nice, if one had to program in assembler.