Misunderstanding Computers

Why do we insist on seeing the computer as a magic box for controlling other people?
人はどうしてコンピュータを、人を制する魔法の箱として考えたいのですか?
Why do we want so much to control others when we won't control ourselves?
どうしてそれほど、自分を制しないのに、人をコントロールしたいのですか?

Computer memory is just fancy paper, CPUs are just fancy pens with fancy erasers, and the network is just a fancy backyard fence.
コンピュータの記憶というものはただ改良した紙ですし、CPU 何て特長ある筆に特殊の消しゴムがついたものにすぎないし、ネットワークそのものは裏庭の塀が少し拡大されたものぐらいです。

(original post/元の投稿 -- defining computers site/コンピュータを定義しようのサイト)

Wednesday, July 26, 2023

[NOTE] newline insertion on paste bug in gedit

Intermittent bug: 

gedit inserts newlines on paste under certain conditions involving the contents of the search buffer.

gedit --version reports

gedit - Version 3.28.1

from the command line on Ubuntu, uname --all:

Linux {machine-name} 5.4.0-150-generic #167~18.04.1-Ubuntu SMP Wed May 24 00:51:42 UTC 2023 x86_64 x86_64 x86_64 GNU/Linux

Looking it up, it might be something inherited from the GTK toolbox.

Specific details.

Searching through a text file for lines beginning with a specified string, such as a label in an assembly language source file. Leaving the search string in the search buffer, select, copy, and paste a section of several lines of text including the searched string. 

gedit inserts blank lines (newline character sequences) before occurrences of searched string.

Example:

MESS    DC.L    DOCOL,WARN,AT,ZBRAN
    DC.L    MESS3-*-NATWID
    DC.L    DDUP,ZBRAN    ; -DUP here is a bug from the original 6800 model, at least.
    DC.L    MESS3-*-NATWID
    DC.L    LIT16
    DC.W    4
    DC.L    OFSET,AT,BSCR,SLASH,SUB,DLINE,BRAN
    DC.L    MESS4-*-NATWID
MESS3    DC.L    PDOTQ
    DC.B    6
    DC.B    'err # '    ; 'err # '
    DC.B    0    ; hand align
    DC.L    DOT
MESS4    DC.L    SEMIS

with \nMESS in the search buffer.

But then when I tried it with 

* This should add two 64-bit numbers:
ADD64STK:
    MOVEM.L    (A6)+,D7/D6/D5/D4
ADDLO    ADD.L    D5,D7
ADDHI    ADDX.L    D4,D6
    MOVEM.L    D6/D7,-(A6)
    RTS

it quit inserting the newlines, even in the original example text.





Sunday, July 9, 2023

Website about the TI Series 0100 Calculator Chips

This is another website I want to remember. It gives a lot of detail on early Texas Instruments and related calculators and the electronics that made them work:

http://www.datamath.org/

In particular, this page is dedicated to the TI's series 0100 chips that were in current production with Intel's 4004:

http://www.datamath.org/Chips/TMS0100.htm

 

 

Saturday, May 6, 2023

No, Higher Costs Were Not the Real Reason for the 8088 in the IBM 5051

[This is a reply to a comment on Hackaday: https://hackaday.io/project/190838-ibm-pc-8088-replaced-with-a-motorola-68000]

*****

For some reason, I can't reply directly to your comment with the eejournal opinion piece [https://www.eejournal.com/article/how-the-intel-8088-got-its-bus/], but I suspect my earlier comment was too brief.

Let me try that again:

The 68000 had built-in support for 8-bit peripheral devices, both in the bus signals and the instruction set. Most of the popular implementations, including the Mac, made heavy use of 8-bit parts, and Motorola had application notes on interfacing other company's 8-bit devices as well as their own. You could mix 8-bit peripherals and 16-bit memory without stretching.

Motorola even had an app-note about interfacing the 68000 directly to 8-bit memory, but any decent engineer would have looked at the note and realized that the cost of 16-bit memory was not really enough to justify hobbling the 68000 to 8-bit memory.  That's one of the reasons the 68008 didn't come out until a couple of years later, and the primary reason that very few people used it. There was no good engineering reason for it.

Well, there was one meaningful cost of 16-bit wide memory: You couldn't really build your introductory entry-level model with 4 kB of RAM using just eight 4 kilobit dRAMs. (cough. MC-10.) You were forced to the next level up, 8 kB. 

IBM knew that the cost of RAM was coming down, and that they would be delivering relatively few with the base 16 kB RAM (16 kilobit by 8 wide) configuration. Starting at 32 kB (16 kilobit by 16) would not have killed the product. Similarly, the cost of the 68000 would come down, and they knew that.

Management was scared of that.

Something you don't find easily on the Internet about the history of the IBM Instruments S9000 was when the project started. My recollection was that it started before the 5150. It was definitely not later. It had much more ambitious goals, and a much higher projected price tag, much more in line with IBM's minicomputer series. There was a reason for the time it took to develop and the price they sold it at. But even many of the sales force in the computer industry didn't understand the cost of software and other intangible development costs.

Consider how much damage the 5150 did to IBM's existing desktop and minicomputer lines. Word Processing? Word Perfect was one of the early killer apps for the 8088-based PC. Spreadsheet? Etc.

IBM management knew too well that if they sold the 5150 with a 68000 in it instead of the 8088, a lot of their minicomputer customers were going to be complaining to high heavens about the price difference. They knew the answer, but their experience showed them that the too many of the customers would not believe it.

That was the real reason. They hoped the 8088 would be limited enough to give them time to maintain control of the market disruption.

I think they were wrong. But it would have taken a level of foresight and vision that very few of management withing IBM had.(very few outside IBM, either.), to take the bull by the horns and drive the disruption.

*****

Anyway, my point was that higher cost wasn't the real reason any more than the (at the time, much-rumored) technical deficiencies of the 68000.

Saturday, March 11, 2023

Mapping the Panasonic Let's Note Japanese Keyboard to the Hatari Emulator

I never owned an ST family computer, which might have been a tactical error on my part. It would have been close to an unadorned 68000-based machine in the way that the Radio Shack/Tandy Color Computer was an unadorned 6809-based machine.

I have been using the Atari ST emulator (simulator) Hatari as a platform for converting the fig Forth model for the 6800 to the 68000.

The keyboard on this Japanese Panasonic Let's Note does not map well to Atari ST keyboard. The default mapping leaves important keys like equal (=) unavailable. (Some keys are available by using the FN key to select the ten-key pad that starts on the 7 key.)

 For comparison, the Atari ST (US) keyboard is laid out like this:

!@#$%^&*() _+~
1234567890 -=`

QWERTYUIOP{}
qwertyuiop[] del

ASDFGHJKL:"  |
asdfghjkl;'  \

ZXCVBNM<>?
zxcvbnm,./

And it's precisely around where the equals key is, that the keyboard mapping goes wonky.

I've been doing almost all the source code editing in Gedit, under Ubuntu, just using Hatari for assembling and test runs. But I'm now into some really difficult debugging sessions, and the mapping of the keyboard is getting in the way. 

So today I dug into Hatari's keyboard remapping, invoked something like:

hatari -k keymap.text

on the command line. 

In the source code for Hatari, there are some utilities in the tests/keymap directory for looking at what SDL sees the keyboard generating (if I got this right) -- listkeys.c and checkkeys.c. I downloaded the source code from the git repository and changed to the tests/keymap directory, and ran make, and got the executables there. Don't need them in the general path, you can execute them in place with

./listkeys

and 

./checkkeys

They gave me some clues and not much more. Taking a look at the example keymap file in the source was also not very enlightening. And neither was the man page from SDL:

man SDLKey

But after working through those, and after some reading in forums and playing around with Hatari's remapping a bit. I figured out what to put in the keymap file: 

Each line consists of the key you want to remap, a comma, and the SDL (?) scancode. 

Sort of. 

Figuring out the scancodes was a bit tricky. First, I tried the codes I learned from the checkkeys and listkeys utilities to see how they would work:

-,45
^,94
@,64
[,91
],93
;,59
:,58
/,47
\,92
The results weren't even close to what I wanted.

So I used a little trick involve perverse keyboard mappings. What I did was line up the alphabet keys and just arbitrarily mapped almost all of them to sequential codes:

-,45
a,1
b,2
c,3
d,4
f,5
g,6
h,7
j,8
k,9
l,10
m,11
n,12
o,13
p,14
q,15
r,16
s,17
u,18
v,19
w,20
y,21
z,22

(The mapping for hyphen was the one I was able to make sense of from the utilities, but it turned out not to be one I am using.)

This is better than random guessing because it allows testing a bunch of the scan codes at once, and it helps you remember which ones you've tried. You can add the ones that look like they work at the top, like I did with hyphen, so you can test them -- and so you don't forget them.

I think I gleaned one scancode from the sequence 1 to 22, then similarly gleaned a few more from the next set, starting at scancode 23 to about 43 temporarily and perversely mapped to key a through y. 

(I left e, i, t, and x undefined to allow typing the exit command, and, after the first set, I left z un-assigned so I could use ctrl-Z to invoke the debugger.)

But I couldn't figure out how to map individual scancodes. Each remapping seems to be done as a pair, which is kind of awkward. 

Ultimately, I used this file:

-,12
[,26
],27
^,13

and, while it makes the equals key available, it maps it to the caret/tilde key -- which leaves caret and tilde unavailable.

It's not a good fit. It matches neither the keycaps on the PC keyboard nor the layout of the Atari ST keyboard. 

But I think it will allow me to proceed with debugging.

So I'll leave this post here for my own notes and post a link here to a Hatari forum for the developers, if I can figure out the appropriate forum.