The Thing about EBCDIC - M186

History of character sets and why the mainframe has to have a different character set and how to deal with it.

[djohnsto]

This is the only youtube channel where I actually love the intros.

[RaymondHng]

20:30 It should be noted that the grouping of the letters on the EBCDIC table (A-I, J-R, S-Z) come from the Hollerith encoding on the IBM 80-column punch card. The topmost row on the card is row 12 followed by row 11, then row 0, row 1, and so on. The letter "A" is a hole punched in row 12 and row 1. The rest of the alphabet:
B 12-2
C 12-3
.
.
.
I 12-9
J 11-1
K 11-2
.
.
,
R 11-9
S 0-2
T 0-3
.
.
.
Z 0-9
The alphabet encoded in three separate groups in the EBCDIC table is in contrast to ASCII encoding where the alphabet is encoded in one contiguous group. Hollerith encoding on punch cards was restricted to no more than three holes per column because too many closely spaced holes created a card with too little structural strength to avoid buckling inside card reading mechanisms.

[stonent]

In the 1960s there were RCA 4000 series logic and TI 7400 Series logic chips which had a lot of variations on BCD functions, BCD encoders, decoders etc. So now we had drop in chips that did many things you would need to do in BCD. TI 7441 through 7449 was almost all BCD related chips.

[grigorytrenin]

This ¤ symbol in the BCD table brought me sweet memories about BK 0010-01 computer (Soviet PDP--11 clone). It had this ¤ symbol in the ASCII table at the point where $ normally is. This character was used everywhere instead of $, for example:
10 CLS
20 A¤="HELLO"
30 PRINT A¤

[RaymondHng]

The Honeywell mainframe I used back in college had both BCD and ASCII encoding. The computer used a 36-bit word-addressable processor. Under the batch-oriented GCOS operating system (General Comprehensive Operating Supervisor), the system encoded data in BCD as six 6-bit characters to fit into a 36-bit word. And under the interactive TSS (Time Sharing System), the system encoded data in ASCII as four 9-bit characters to fit into a 36-bit word. Only 8 out of the 9 bits were used in ASCII encoding.

[the_real_foamidable]

Wow, I love this stuff. I could listen to your presentation for hours. Thanks for the effort.
Greetings from Weimar, Germany.

[RaymondHng]

10:45 On April 12, 1955, Minneapolis-Honeywell started a joint venture with Raytheon called Datamatic to enter the computer market and compete with IBM. In 1960, just five years after embarking on this venture with Raytheon, Minneapolis-Honeywell bought Raytheon's interest in Datamatic and turned it into the Electronic Data Processing division, later Honeywell Information Systems (HIS) of Minneapolis-Honeywell. In 1970, Honeywell acquired GE's computer business forming Honeywell Information Systems. In 1987 HIS merged with Groupe Bull, a global joint venture with Compagnie des Machines Bull of France and NEC Corporation of Japan to become Honeywell Bull. In 1988 Honeywell Bull was consolidated into Groupe Bull and in 1989 renamed to Bull, a Worldwide Information Systems Company. By 1991 Honeywell was no longer involved in the computer business.

[Stosszahlansatz]

"little guy climbing on the wall" ... pretty much the way I felt when I tried to build Hercules on Windows 10. :-)

[jackk]

As an aside, you might mention that z/linux (unlike z/os)uses Unicode and ASCII, like all other implementations of Linux
Instructions for Pack/Unpack ascii and unicode were added to the insruction set awhile back as well.

[maschwab]

Idea for a new program. Examines file, determines best conversion (APL, C, PL/I, etc) for both sides. Would do this by counting for each binary code, where certain values are rarely used except for certain languages.

[vinatron]

Interesting you mentioning the quote site command because the AS/400 also has its own encoding format and you have to do a quote site if you want to transfer a program packed in a save file

[alexparish]

Hi there. I have been following your videos for a long time now & have found them fascinating, however my experience with mainframes has always been from an end users point of view (i am certainly no programmer) To me mainframes are what you user for warehouse stock control or pay roll runs.
I was wondering if there was anything like this setup (or pre installed) in tk4.
Would it be possible that you could do a video on how to setup & use something like this (a simple database or payroll program)
Thanks in advance.

[RaymondHng]

21:11 Should be Lower case/Upper case. There's no such thing as "lower cap".

[benjfischer]

it's really hard to see the text in these videos. The terminal screen itself is a small portion of the video screen size and then the red text on a black screen would be hard to read in any case.

[grappydingus]

183 was the Halloween video, no? I think you misnumbered.

[Yes-cdrq]

Day 1 of asking for video to be called wideo