(very OT) Ideal partition schemes (history of partitioning)
galtsev at kicp.uchicago.edu
Sun Aug 30 03:08:21 UTC 2020
> On Aug 29, 2020, at 2:10 PM, Ralf Mardorf <ralf-mardorf at riseup.net> wrote:
> On Sat, 2020-08-29 at 13:24 -0500, Valeri Galtsev wrote:
>> On 8/29/20 1:08 PM, doug at safeport.com wrote:
>>> Wow Poly, Doug, Steve, this is a thread to save. I guess only guys named
>>> Doug have used punched cards. Anyone else used paper tape?? The most
>>> inventive use of punched cards in my past, was when an Alogol system
>>> arrived without a terminal (or card punch) my boss, with a pocket knife,
>>> "punched" the character set. Then until the terminal arrived, tested the
>>> system by programming one card at a time into the card reader. The
>>> tedium was minimized by copious amounts of beer.
>> On a similar note: we had a group of ladies who were "typing" on punch
>> card typing machines. No regular person (programmer) was allowed access
>> to one. Then, after hours if you found bug and needed to make small
>> change, you were "editing" punch cards using point tipped razor to cut
>> new holes, and were plugging holes with those rectangular pieces punched
>> out of cards, found near card duplicator. "Doctored" like that card,
>> however, can damage card reader, so you put it through card duplicator
>> (which is more robust device than card reader), compare duplicate to
>> make sure it is what you need, and then you can leave your modified
>> program to run during night. Otherwise you will have to wait till
>> morning when card punch ladies come to work.
> Forwarding to a pen pal who was involved in electronics already before
> the transistor was invented.
> What? How aged are you folks? I'm from 1966 and when I started with
> computers, I already used 5 ¼ floppy disks.
> Am I a youngster?
My time to confess: I’m 63, not much older than you. What I described was in Russia, which was several (or multiple) years behind the rest of the World. Most of technology was a “replica” what West had designed, developed, invented. To justify the word “most” (not all) in previous phrase, I just have to give example of what was created in Russia, not replicated from “behind the border” development. That was BESM-6 (abbreviation from “Fast Electronic Computing Machine” in Russian) The uniqueness of design I haven’t seen in other computers was: the machine level command system was 3-address one. Namely, each machine level command had 4 fields:
2. address of first operand
3. address of second operand
4. address where to put the result
Here someone should correct me if there is, or rather was, machine like that, as my knowledge of what existed back then is definitely restricted.
Three address system of machine level commands is wasteful on storage, say, compared to wide spread 2 field commands (command + address of operand). However, everything written and compiled with/for that system of machine level commands is much cleaner, I almost said bug free. Take, say, operation: add what is in storage address A to what is in storage address B and put it into storage address C. BESM-6 has one machine level command to do that. With single address command system this is done by sequence of three commands:
1. put what is in storage address A to addition register
2. add what is in storage address B to what is in addition register
3. save addition register to address C
All three commands must always be together, in that sequence, no matter what optimization etc. to program is being done. Assembly code is way less transparent in this case compared to 3 address command system, and to write assembler and compiler to be clean, “bug free”, is way simpler task for 3 operand command system. And programming in assembly language is way simpler.
I really hope, someone mentions other machines with 3 address command system, I really would like to know if the existed. Except BESM-6 which was built of bipolar transistor blocks, and it predecessor BESM-4 build on vacuum tubes.
> I'm used to analog audio and video engineering, analog photography and
> computers with 5 ¼ floppy disks. I just started programming assembly
> without a macro assembler, but after a relatively short time even a
> macro assembler was available.
> "Card reader" nowadays is for something else.
> I used a hole puncher to write on both sides of a single sided 5 ¼
> floppy disk, but have never seen a punch card in reality.
> freebsd-questions at freebsd.org mailing list
> To unsubscribe, send any mail to "freebsd-questions-unsubscribe at freebsd.org"
More information about the freebsd-questions