Talk:Calendar - for "REAL" programmers: Difference between revisions

added a new talk section for some BCD computers.
(added 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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[[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''' &nbsp; = &nbsp; '''B'''inary '''C'''oded '''D'''ecimal.)
 
Each memory location was &nbsp; (for the most part) &nbsp; a decimal digit.
Each memory location was comprised of five bits:
::* &nbsp; a flag bit (the '''F''' bit), &nbsp; used to indicate a negative number, &nbsp; an &nbsp; ''end-of-field'', &nbsp; or a &nbsp; ''carry''.
::* &nbsp; four bits (the '''8421''' bits), &nbsp; used to indicate which decimal digit was being represented.
 
Additionally, there was a check bit (the '''C''' bit), &nbsp; which isn't used to hold "data" and could not be set or accessed by a programmer. &nbsp; It was used as a parity bit. &nbsp; Every ''decimal digit'' had to have a odd number of bits set, including the '''C''' bit. &nbsp; If not odd, &nbsp; 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":
::::* &nbsp; '''1010''' &nbsp; a record mark
::::* &nbsp; '''1100''' &nbsp; a numeric blank (for punched cards)
::::* &nbsp; '''1111''' &nbsp; 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==