IBM Model F Bigfoot with Arduino, Ubuntu Linux

tigpha

31 Aug 2015, 22:19

Hi DT folk. I bought a Bigfoot from Blaise170 (Thanks Blaise! :-)) about a month ago, and set about reviving the beastie.

I followed the example give in IBM Model F Bigfoot with arduino micro, win7 64bit and successfully reproduced the same result on Ubuntu Linux. I wrote a lot of notes and took a few photos in the process, which I plan to share.

There is a hardware snag with the Bigfoot: all the keys work, except for the space-bar. The spring feels as if it buckles, but the hammer (flipper? paddle?) doesn't appear to move. The Bigfoot needed disassembly because the space-bar was detached, and I seem to have made a mistake during reassembly. Or the flapper thing has stuck. I suppose that I can't avoid another disassembly.

May I request some helpful advice, on repairing Bigfoots?

User avatar
Khers

31 Aug 2015, 22:25

From doing some repair work on my Bigfoot I remember that getting the spacebar right when putting it all back together was a pain in the butt. However, there is a guide by JBert showing you how to make it all go together nicely with the flipper and everything. Plus if you follow his advice, you'll soften up that spacebar considerably as well.

tigpha

31 Aug 2015, 22:32

Brilliant! That looks very promising indeed. I shall give that a try. Thank you Khers.

tigpha

01 Sep 2015, 12:43

The result is a fully functioning Bigfoot. The space-bar flipper thing was jammed at a angle, and could not move freely. Using flossing thread to hold the flipper in place during reassembly did the trick. I took pictures of the process that I plan to include here soon. Thanks Khers, and JBert.

User avatar
Khers

01 Sep 2015, 16:51

Cool! Model F is just the best (in my book at least). The Bigfoot might not be the most sought after of Fs (rather the least) but bringing one back to life was very pleasant nonetheless :)

tigpha

06 Sep 2015, 17:42

The 30 year old Bigfoot meets my nine year old daughter. She loves it: "You can tell when a key is pressed!" My wife calls it a magpie, as it makes as much racket as a mob of magpies fighting.
Tiff+Bigfoot.jpg
Tiff+Bigfoot.jpg (302.25 KiB) Viewed 1811 times
It dwarfs the Apple Mini Aluminium, just behind it. Not as portable as the Mini!

The images on the left screen is a tease of work in progress...

(edit: figured out the image inline trick)

tigpha

06 Sep 2015, 22:23

A few more words to describe what I did to revive the Bigfoot. The Arduino software is Soarer_Controller_v1.20_beta4, and I use Ubuntu Trusty 14.04 to compile the tools and to upload the software.

The inspiration came from Laser, and IBM Model F Bigfoot with arduino micro, win7 64bit. Thanks Laser.

Installation of software tools in Ubuntu:

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sudo apt-get update && sudo apt-get install arduino arduino-core libusb-dev
I use the Arduino Micro, simply because I happen to have one to hand. Soarer's Controller is written for the Teensy, but it seems that it might operate on any ATMEL based hardware.

Take a snapshot of the TTY devices and the USB devices before plugging in the Arduino:

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ls -1 /dev/tty* > Before-tty
lsusb > Before-USB
Plug in the Arduino and take another snapshot:

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ls -1 /dev/tty* > After-tty
lsusb > After-USB
Show the differences:

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diff Before-USB After-USB
6a7
> Bus 002 Device 017: ID 2341:8037 Arduino SA
diff Before-tty After-tty
65a66
> /dev/ttyACM0
Unpack Soarer's Keyboard Controller firmware

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mkdir "Soarer's Converter"
cd "Soarer's Converter"
unzip ../Soarer_Controller_v1.20_beta4.zip
tar -zxf Soarer_sctools_v1.20_beta4_linux.tar.gz
This is what the 'tree' command reveals:

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tree
.
├── configs
│   ├── 6112884.sc
│   ├── bigfoot.sc
│   ├── kevex-blank.sc
│   ├── kevex-retrete.sc
│   └── mini_matrix.sc
├── docs
│   ├── controller.html
│   ├── images
│   │   └── bullet.png
│   └── style1.css
├── firmware
│   ├── Soarer_Controller_v1.20_beta4_at90usb1286.hex
│   ├── Soarer_Controller_v1.20_beta4_at90usb646.hex
│   └── Soarer_Controller_v1.20_beta4_atmega32u4.hex
└── tools
    ├── scas
    ├── scboot
    ├── scdis
    ├── scinfo
    ├── scrd
    ├── scwr
    ├── Soarer_sctools_v1.20_beta4_linux.tar.gz
    ├── Soarer_sctools_v1.20_beta4_macosx.tar.gz
    ├── Soarer_sctools_v1.20_beta4_source.zip
    └── Soarer_sctools_v1.20_beta4_win32.zip

5 directories, 21 files
Program the Arduino with the precompiled firmware, specifying the correct device for the -P option, in this example /dev/ttyACM0:

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cd firmware
sudo avrdude \
-p atmega32u4 \
-P /dev/ttyACM0 \
-c avr109 \
-U flash:w:Soarer_Controller_v1.20_beta4_atmega32u4.hex
The 'sudo' part is necessary, otherwise the following error is the result:

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avrdude: ser_open(): can't open device "/dev/ttyACM0": Permission denied
It also may be necessary to add 'dialout' group to the login account, and to log-out and log-in again to make the change take effect:

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sudo usermod -a -G dialout $USER
An example of the output of 'avrdude':

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$> avrdude -p atmega32u4 -P /dev/ttyACM0 -c avr109 -U flash:w:Soarer_Controller_v1.20_beta4_atmega32u4.hex

Connecting to programmer: .
Found programmer: Id = "CATERIN"; type = S
    Software Version = 1.0; No Hardware Version given.
Programmer supports auto addr increment.
Programmer supports buffered memory access with buffersize=128 bytes.

Programmer supports the following devices:
    Device code: 0x44

avrdude: AVR device initialized and ready to accept instructions

Reading | ################################################## | 100% 0.00s

avrdude: Device signature = 0x1e9587
avrdude: NOTE: "flash" memory has been specified, an erase cycle will be performed
         To disable this feature, specify the -D option.
avrdude: erasing chip
avrdude: reading input file "Soarer_Controller_v1.20_beta4_atmega32u4.hex"
avrdude: input file Soarer_Controller_v1.20_beta4_atmega32u4.hex auto detected as Intel Hex
avrdude: writing flash (17726 bytes):

Writing | ################################################## | 100% 1.32s

avrdude: 17726 bytes of flash written
avrdude: verifying flash memory against Soarer_Controller_v1.20_beta4_atmega32u4.hex:
avrdude: load data flash data from input file Soarer_Controller_v1.20_beta4_atmega32u4.hex:
avrdude: input file Soarer_Controller_v1.20_beta4_atmega32u4.hex auto detected as Intel Hex
avrdude: input file Soarer_Controller_v1.20_beta4_atmega32u4.hex contains 17726 bytes
avrdude: reading on-chip flash data:

Reading | ################################################## | 100% 0.14s

avrdude: verifying ...
avrdude: 17726 bytes of flash verified

avrdude: safemode: Fuses OK (H:CB, E:D8, L:FF)

avrdude done.  Thank you.
Soarer's tools, 'scinfo', 'scas' etc are offered with source code. The precompiled tools are 32-bit versions, which don't work on 64-bit Ubuntu unless a pile of 32-bit libraries are installed. I decided to recompile these tools for my 64-bit Ubuntu installation instead:

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cd Soarer_Controller_v1.20_beta4/tools
mkdir SOURCE
cd SOURCE
unzip ../Soarer_sctools_v1.20_beta4_source.zip
cd build/linux
make
Check the result with Soarer's tools:

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sudo ./scinfo
An example of what to expect:

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cd Soarer_Controller_v1.20_beta4/tools
$> sudo ./scinfo
[sudo] password:
scinfo v1.10
scinfo: looking for Soarer's Converter: found
scinfo: sending info request: ok
device: ok

Protocol Version: v1.00
Code Version: v1.20
Max Settings Version: v1.03
Current Settings Version: v0.00
SRAM Size: 2560 bytes
SRAM Free: 1793 bytes
EEPROM Size: 1024 bytes
EEPROM Free: 1020 bytes
Now to upload the configuration file. The `scaswr.bat` file in the Win32 archive shows what to do. First compile the configuration file to binary using 'scas':

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cd Soarer_Controller_v1.20_beta4/tools/SOURCE/bin
./scas ../../../configs/bigfoot.sc ../../../configs/bigfoot.scb
Example output:

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scas v1.20
No errors. Wrote: ../../../configs/bigfoot.scb
Next, write the compiled configuration to the Arduino with the 'scwr' tool:

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sudo ./scwr ../../../configs/bigfoot.scb
Output:

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scwr v1.10
scwr: looking for Soarer's Converter: ../common/hid_LINUX.c:175, vid=16c0 pid=47d
rawhid_open, max=1
device: vid=16C0, pic=047D, with 4 iface
  type 3, 1, 1
  type 3, 0, 0
    IN endpoint 3
  hid interface (generic)
  descriptor, len=21
  tag: 4, val FF31
  tag: 8, val 74
  type 3, 0, 0
    IN endpoint 2
  hid interface (generic)
  descriptor, len=220
  tag: 4, val 1
  tag: 8, val 6
  type 3, 0, 0
    IN endpoint 4
    OUT endpoint 5
  hid interface (generic)
  descriptor, len=28
  tag: 4, val FF99
  tag: 8, val 2468
found
scwr: reading file: 118 bytes: ok
scwr: sending info request: ok
device: ok
protocol version check: converter=1.00, scwr=1.00: ok
settings version check: converter=1.03, file=1.03: ok
settings length check: max=1018, file=116 bytes: ok
scwr: sending write request for 116 bytes: ok
device: ok
device: ready
scwr: sending 60 bytes: ok
device: ok
device: ready
scwr: sending 56 bytes: ok
device: ok
device: complete
Note that the debugging output is enabled in the example above. In the file tools/SOURCE/common/hid_LINUX.c:

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#define printf(...)  // comment this out for lots of info



Connect the Arduino to the IBM Bigfoot DB15 cable. The second column "Pin" is the IBM pin numbering on the Logic Board. The 5291 Maintenance Library manual shows that the IBM numbering convention is different to IDC convention, so be aware!

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| DB15 Pin | Pin | Duty           | Atmel |
|----------|-----|----------------|-------|
|        1 |  20 | GND            |       |
|        2 |  18 | GND            |       |
|        3 |  12 | GND            |       |
|        4 |  13 | +5V            |       |
|        5 |  17 | Count  1       |   PB0 |
|        6 |   1 | Count  2       |   PB1 |
|        7 |   3 | Count  4       |   PB2 |
|        8 |   4 | Count  8       |   PB3 |
|        9 |   8 | Count 16       |   PB4 |
|       10 |   9 | Count 32       |   PB5 |
|       11 |  10 | Count 64       |   PB6 |
|       12 |  19 | Matrix Strobe  |   PD1 |
|       13 |  11 | +Key Depressed |   PD0 |
|       14 |  14 | Frame Ground   |       |
|          |   2 | Not Used       |       |
|          |   5 | Not Used       |       |
|          |   6 | Not Used       |       |
|          |   7 | Not Used       |       |
|          |  15 | Not Used       |       |
|          |  16 | Not Used       |       |
I used a DB15 socket salvaged from an ancient PC ISA sound card, which had a DB15 joystick port. The pin numbers on that are also rearranged, so I needed to expand the table above:

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| Ribbon | DB15 Pin | Duty           | Atmel pin | Arduino micro pin |
|--------|----------|----------------|-----------|-------------------|
|      1 |        1 | GND            |           |                   |
|      2 |        9 | Count 16       |  28 PB4   | J5-13 IO8         |
|      3 |        2 | GND            |           |                   |
|      4 |       10 | Count 32       |  29 PB5   | J5-14 IO9         |
|      5 |        3 | GND            | PAD GND   | J6-04 GND         |
|      6 |       11 | Count 64       |  30 PB6   | J5-15 IO10        |
|      7 |        4 | +5V            |  34 +5V   | J6-06 +5V         |
|      8 |       12 | Matrix Strobe  |  19 PD1   | J5-07 D2/SDA      |
|      9 |        5 | Count  1       |   8 PB0   | J5-02 RXLED/SS    |
|     10 |       13 | +Key Depressed |  18 PD0   | J5-08 D3/SCL      |
|     11 |        6 | Count  2       |   9 PB1   | J6-01 SCK         |
|     12 |       14 | Frame Ground   |           |                   |
|     13 |        7 | Count  4       |  10 PB2   | J5-01 MOSI        |
|     14 |       15 | Not Used       |           |                   |
|     15 |        8 | Count  8       |  11 PB3   | J6-02 MISO        |
The complete picture of connections to the Arduino:

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Ribbon           Duty   Atmel    Arduino           Arduino   Atmel  Duty       Ribbon
                                         +-------+
    13       Count  4     PB2       MOSI |#      | SCK       PB1    Count  2   11
     9       Count  1     PB0   RXLED/SS |       | MISO      PB3    Count  8   15
                          PD3      D1/TX |       | VIN
                          PD2      D0/RX |       | GND              Frame+GND  5+12
                                   RESET |       | RESET
   1+3         Ground                GND |       | 5V               +5V         7
     8  Matrix Strobe     PD1         D2 |       |
    10  Key Depressed     PD0         D3 |       |
                          PD4         D4 |       | A5        PF0
                          PC6         D5 |       | A4        PF4
                          PD7         D6 |       | A3        PF4
                          PE6         D7 |       | A2        PF5
     2       Count 16     PB4        IO8 |       | A1        PF6
     4       Count 32     PB5        IO9 |       | A0        PF7
     6       Count 64     PB6       IO10 |       | AREF
                          PB7       IO11 |       | 3V3
                          PD6       IO12 |       | IO13      PC7
                                         +-------+
The result:
DB15-ribbon-arduino.jpg
DB15-ribbon-arduino.jpg (178.49 KiB) Viewed 1791 times
I have a collection of photos showing the internals of the Bigfoot. These were taken while cleaning, and reassembly photos show how I reinserted the space bar with the help of dental floss and a spanner. Photos will follow soon that will reveal how that odd combination worked.


Soarer explains that the IBM Bigfoot contains only a demultiplexer and a cap-sense chip, and no microcontroller. There's no need to rip any of the original electronics out to be replaced by the Arduino/Teensey, just connect to the original DB15 and cable, or plug directly into the 20-pin IDC connector on the Keyboard Logic Card (as it is called in the 5291 Maintenance Library manual for the IBM terminal).

I found another discussion about adapting the Xwhatsit Grand Unified IBM Capsense USB Controller to be used on the IBM Bigfoot. It seems that the lack of microcontroller was not noticed there. In effect, the Xwhatsit controller hardware also has a demultiplexer, and uses the ATMEL analogue comparator inputs to detect keypresses. The IBM Bigfoot provides this, and potentially the Xwhatsit ATMEL controller software code could be used after minor edits. I may try that to replace Soarer's Controller software.

idollar
i$

06 Sep 2015, 23:39

Thanks a lot for your comprehensive post.

User avatar
Laser
emacs -nw

26 Dec 2015, 11:59

Great thread! :)

tigpha

26 Dec 2015, 18:40

Hi Laser, thanks for visiting. I hope to add some information on using the Sparkfun Pro Micro as an alternative to the Arduino. The Pro Micro appears to be ready much quicker after power-on than the Arduino, which should remove a minor frustration when used daily.

User avatar
Laser
emacs -nw

26 Dec 2015, 20:31

That would be nice :)

(also - would be interesting to see an alternative software solution, given the fact that Soarer only provided a binary).

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