The Importance of Terminology's Quality
sln at netherlands.com
sln at netherlands.com
Sat Aug 23 01:14:10 CEST 2008
On Fri, 22 Aug 2008 11:11:09 -0400, George Neuner <gneuner2 at comcast.net> wrote:
>On Thu, 21 Aug 2008 02:30:27 GMT, sln at netherlands.com wrote:
>>On Wed, 20 Aug 2008 21:18:22 -0500, rpw3 at rpw3.org (Rob Warnock) wrote:
>>>Martin Gregorie <martin at see.sig.for.address.invalid> wrote:
>>>| I was fascinated, though by the designs of early assemblers: I first
>>>| learnt Elliott assembler, which required the op codes to be typed on
>>>| octal but used symbolic labels and variable names. Meanwhile a colleague
>>>| had started on a KDF6 which was the opposite - op codes were mnemonics
>>>| but all addresses were absolute and entered in octal. I always wondered
>>>| about the rationale of the KDF6 assembler writers in tackling only the
>>>| easy part of the job.
>>>In the LGP-30, they used hex addresses, sort of, but the opcodes
>>>(all 16 of them) had single-letter mnemonics chosen so that the
>>>low 4 bits of the character codes *were* the correct nibble for
>>>the opcode! ;-}
>>>[Or you could type in the actual hex digits, since the low 4 bits
>>>of *their* character codes were also their corresponding binary
>>>nibble values... "but that would have been wrong".]
>>> The LGP-30 character code was defined before the industry had
>>> yet standardized on a common "hex" character set, so instead of
>>> "0123456789abcdef" they used "0123456789fgjkqw". [The "fgjkqw"
>>> were some random characters on the Flexowriter keyboard whose low
>>> 4 bits just happened to be what we now call 0xa-0xf]. Even worse,
>>> the sector addresses of instructions were *not* right-justified
>>> in the machine word (off by one bit), plus because of the shift-
>>> register nature of the accumulator you lost the low bit of each
>>> machine word when you typed in instructions (or read them from
>>> tape), so the address values you used in coding went up by *4*!
>>> That is, machine locations were counted [*and* coded, in both
>>> absolute machine code & assembler] as "0", "4", "8", "j", "10",
>>> "14", "18", "1j" (pronounced "J-teen"!!), etc.
>>>Rob Warnock <rpw3 at rpw3.org>
>>>627 26th Avenue <URL:http://rpw3.org/>
>>>San Mateo, CA 94403 (650)572-2607
>>Whats os interresting about all this hullabaloo is that nobody has
>>coded machine code here, and know's squat about it.
>A friend of mine had an early 8080 micros that was programmed through
>the front panel using knife switches ... toggle in the binary address,
>latch it, toggle in the binary data, latch it, repeat ad nauseam. It
>had no storage device initially ... to use it you had to input your
>program by hand every time you turned it on.
>I did a little bit of programming on it, but I tired of it quickly.
>As did my friend - once he got the tape storage working (a new prom)
>and got hold of a shareware assembler, we hardly ever touched the
>switch panel again. Then came CP/M and all the initial pain was
>forgotten (replaced by CP/M pain 8-).
>>I'm not talking assembly language. Don't you know that there are routines
>>that program machine code? Yes, burned in, bitwise encodings that enable
>>machine instructions? Nothing below that.
>>There is nobody here, who ever visited/replied with any thought relavence that can
>>be brought foward to any degree, meaning anything, nobody....
>What are you looking for? An emulator you can play with?
>Machine coding is not relevant anymore - it's completely infeasible to
>input all but the smallest program. My friend had a BASIC interpreter
>for his 8080 - about 2KB which took hours to input by hand and heaven
>help you if you screwed up or the computer crashed.
I'm not looking for anything didn't you know?
I guess I wasn't talking assembly language, I was talking machine language.
The language behind the op codes, the one that takes cycles per 'op'eration.
It is entirely disgusting to listen to a littany of old time has beens who
did or did not work on old time cpu's that did or did not have an accumulator.
I worked with many cpu's at the assembly level, hell my first endevour was
writing dissasemblers, like Zilogs and pass through's to gain a whole different
I moved on, but before I did, I fully understood everyting I touched.
I've programmed over 14 million lines of code in my lifetime, but who gives
a rats ass.
Cpu's aren't complicated, far from it. Its having to eat the dubious constructs
of higher level languages built on those platforms.
Get your head out of the ground!
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