• Yet another keyboard

    jaromir.sukuba • 02/24/2016 at 09:23 • 2 comments

    Though the old Tesla keybaord I described here and here and described by @Benchoff in #Metal Dome Keyboard is still in my drawer in amount higher than small, I'm looking for alternatives for my MiniBSD.

    I found one in here, for the case the listing is unavailable, here is screenshot

    I dissected the thing on arrival and didn't bother whether it works or not

    There is nothing but 20x8 cm keyboard matrix with 28-pin 1mm pitch FPC connector and tiny PCB containing USB controller

    With the testing pads it looks like perfect breakout board for testing, after cutting the epoxy blob. The keyboard itself looks quite usable and has nice feel

    there are rubber domes under each key and mechanical support

    There are 25 pins used on the 28-pin flex cable, checking all the combinations manually with multimeter would be quite annoying, so I decided to build a test rig.

    Not the cleanest example of engineering work, but for quick testing it is adequate. There is PIC16F1519 on board, testing all combinations of wires for conductivity few times per second and pushing results via serial port. Not exactly interesting thing, but quick and ugly test sources will be available for download in the "files" section.

    After a few minutes of poking the keys and noting the results, I got this nice table

    where line 11 is unused, being apparent on pictures above - or translated into keyboard layout

    For example, pressing key Q connects lines 20 and 7.

    The layout in .xlsx format is available in single package with pictures and sources of test rig.

  • 4.4 BSD-Lite

    jaromir.sukuba • 12/29/2015 at 00:23 • 2 comments

    Well, it's a long time since last update. Today, I sat down to my new board around PIC32MZ2048ECG064

    and configured/complied/loaded LiteBSD system to run on it from internal RC oscillator

    Copyright (c) 1982, 1986, 1989, 1991, 1993
	The Regents of the University of California.  All rights reserved.

4.4BSD-Lite build 0 compiled 2015-12-28
    jarin@plechac:LiteBSD/sys/compile/SDZL.pic32
cpu: PIC32MZ2048ECG064 rev A5, 200 MHz
oscillator: system PLL div 1:2 mult x50
cache: 16/4 kbytes
real mem = 512 kbytes
avail mem = 352 kbytes
using 18 buffers containing 73728 bytes of memory
spi1 at pins sdi=RF1/sdo=RF0/sck=RD1
spi2 at pins sdi=RG7/sdo=RG8/sck=RG6
spi3 at pins sdi=RB9/sdo=RB3/sck=RB14
spi4 at pins sdi=RD11/sdo=RD0/sck=RD10
uart1 at pins rx=RD2/tx=RD3, interrupts 112/113/114
uart2 at pins rx=RB7/tx=RB6, interrupts 145/146/147, console
sd0 at port spi2, pin cs=RG9
sd0: type I, size 498176 kbytes, speed 12 Mbit/sec
sd0a: partition type b7, sector 2, size 204800 kbytes
sd0b: partition type b8, sector 409602, size 32768 kbytes
sd0c: partition type b7, sector 475138, size 102400 kbytes
bpf: lo0 attached
WARNING: preposterous clock chip time -- CHECK AND RESET THE DATE!

starting file system checks.
/dev/rsd0a: 2128 files, 13973 blocks used, 36242 free
/dev/rsd0a: MARKING FILE SYSTEM CLEAN
starting network
clearing /tmp
standard daemons: update.
Mon Dec 28 15:44:43 PST 2015


4.4BSD-Lite (bsd.net) (console)



login: root
Last login: Mon Dec 28 15:44:00 on console
Copyright (c) 1980, 1983, 1986, 1988, 1990, 1991, 1993, 1994
        The Regents of the University of California.   All rights reserved.

4.4BSD-Lite UNIX #1: Fri Apr 01 00:00:00 PDT 1994

Welcome to 4.4BSD-Lite!

erase ^H, kill ^U, intr ^C status ^T
Don't login as root, use the su command.
#

    This is more powerful system than previous one with PIC32MX - only 128kB RAM / 80MHz compared to 512kB RAM and 200MHz of PIC32MZ, not mentioning new OS, so I'm definitely going to employ this MCU on MiniBSD computer.

  • New keyboards layout

    jaromir.sukuba • 10/03/2014 at 18:44 • 0 comments

    Well... four months since last update... the time flies. Brian Benchoff asked about the new keyboard layout, so here is my quick and dirty "drawing" in LibreOffice Calc.

    When Q key is pressed, there is contact on between pins 1 and 6. After pressing J, between 9 and 14. You got the idea.

    It is not very likely to obtain the keyboard outside Czech or Slovakia, though Brian got this keyboard in Apex electronics, LA. However, I managed to get my hands on a few pieces of those keyboards, so I'll be able to source it to interested builders, if any.

  • Laptop case, sneak preview

    jaromir.sukuba • 06/07/2014 at 22:39 • 0 comments

    Well, there was no progress for a few weeks, but recently I got into it again. I had nice few evenings with FreeCad (I'm total beginner in 3D modelling) and designed first revision of a case. It looks like this

    Kind of classical, laptop-like case. Total size is 22x9x2,7cm when closed.

    Unfortunately, it is two centimeters bigger in size than printable area of my 3D printer and I can't make it much smaller due to keyboard size. Time to get bigger 3D printer! :-)

    I'll publish design files on Monday morning.

  • New keyboards

    jaromir.sukuba • 04/27/2014 at 21:42 • 0 comments

    Though I'm quite busy with my sc-fi contest project, I'm doing this small log.

    I got my hands on a few of those sweet vintage keyboards. This is product of former Czecho-Slovakian company named Tesla, I believe it is as old as I am, approximately. I have a few dozens of them, with option to have more. I'm going to base my new BSD laptop on this keyboard.

    There are two color variations. I have lots of the red variant, only two pieces of orange variant.