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Talk:Calendar - for "REAL" programmers: Difference between revisions
Talk:Calendar - for "REAL" programmers (view source)
Revision as of 02:12, 29 October 2020
, 3 years agoadded a new talk section for some BCD computers.
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==Delete?==
Far too specific. --[[User:Paddy3118|Paddy3118]] 03:35, 31 May 2011 (UTC)
:Looks like maybe it's just for fun maybe. I suggest removing the task tag and moving it to a subpage of the user who made it's user page. --[[User:Mwn3d|Mwn3d]] 03:45, 31 May 2011 (UTC)
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===Examples===
;Example 12-bit computer architectures
*[[wp:PDP-8|PDP-8]]
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[[User:NevilleDNZ|NevilleDNZ]] 05:04, 31 May 2011 (UTC)
=== Discussion Cont.===
:Not decision, discussion. And you`ve made a great case! --[[User:Paddy3118|Paddy3118]] 05:43, 31 May 2011 (UTC)
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Actually - kind of - I agree with you... 6-bit is the criteria. Although I have never heard of a strictly lower case hardware platform.
:I think that is because older devices such as the teletype ksr-33 (or a selectric with an APL type ball or any of a variety of others) would only print upper case. (The teletype handled ascii but lower case letters looked like upper case characters.
BTW: The first time I encountered such a computer, it was a [[wp:Prime Computer|Pr1me]] I remember trying being rather bamboozled about how to get the damned thing out of uppercase, including looking for a toggle under the keyboard. It took a little while to dawn on me that it could ''only'' '''do''' upper case. The [[wp:ZX80|ZX80]] code was also UPPERCASE, the ZX was so nice to program that the UPPERCASE restriction didn't seem to matter.
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[[User:NevilleDNZ|NevilleDNZ]] 05:14, 1 June 2011 (UTC)
=== Create another algorithm? ===
:The task description says "Create another algorithm", yet the Algol solutions are identical (except for the case).--[[User:Abu|Abu]] 15:06, 31 May 2011 (UTC)
I get your drift.... rewording task: Provide an algorithm ... presented entirely without lowercase. ThanX for pointing it out. [[User:NevilleDNZ|NevilleDNZ]] 03:58, 1 June 2011 (UTC)
=== Examples, BCD machines ===
;Example 5-bit computer architectures
* [[wp:IBM_1620|IBM 1620]]
* [[wp:IBM_1620|IBM 1710]]
* [[wp:IBM_1620|IBM 1720]]
The '''IBM 1620''' (and the others above) had a magnetic-core memory with BCD encoding.
<br>('''BCD''' = '''B'''inary '''C'''oded '''D'''ecimal.)
Each memory location was (for the most part) a decimal digit.
Each memory location was comprised of five bits:
::* a flag bit (the '''F''' bit), used to indicate a negative number, an ''end-of-field'', or a ''carry''.
::* four bits (the '''8421''' bits), used to indicate which decimal digit was being represented.
Additionally, there was a check bit (the '''C''' bit), which isn't used to hold "data" and could not be set or accessed by a programmer. It was used as a parity bit. Every ''decimal digit'' had to have a odd number of bits set, including the '''C''' bit. If not odd, a "parity bit" error light was lit and the computer went into a wait (stopped) state.
There wasn't a method to indicate lowercase letters.
Characters used two consecutive decimal digits.
There were three special "numbers":
::::* '''1010''' a record mark
::::* '''1100''' a numeric blank (for punched cards)
::::* '''1111''' a group mark
All opcodes were two decimal digits.
::::::::::::::::::: -- [[User:Gerard Schildberger|Gerard Schildberger]] ([[User talk:Gerard Schildberger|talk]]) 02:12, 29 October 2020 (UTC)
==another ASCII version==
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</pre>
-- [[User:Gerard Schildberger|Gerard Schildberger]] ([[User talk:Gerard Schildberger|talk]]) 18:31, 21 November 2013 (UTC)
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