I used to draw my network using inkscape, or graphviz. But the last years i’ve been using DrawIO. A friend is drawing his. So i posted some tips.
When using inkscape, i liked the way that i could view more or less details using layers. But editing was hard.
Getting DrawIO:
There is a online version: https://app.diagrams.net/ You can download a AppImage And .. install it in your nextcloud, which is the way i’m using it. (Login as admin, click Apps and search for draw.io)
Some tips on using images .. Below is a example of a Mikrotik switch with connector points.
Use a search engine to look for images, the ones with front facing connectors are easier to use. I always look for images which have a transparent background. Using google you can use below ‘trick’ google > images > tools > color > transparent Just copy-paste into your DrawIO document, it is better to have a large picture which you can resize as the other way around.
Adding connection points:
Left click the image in DrawIO, right mouse and Edit connection points
Now you can place/remove edit connection points.
Due to security reasons i won’t be posting my complete network image ..
Another tip:
Network sheet a friend is working on
Device is not straight, so its harder to get the connections right. Besides that, the lines are below the device. Click line and select bring to front.
In this case designed for my 6502, but it is a generic setup.
I it just a dual 16key matrix decoder merged together. You can probably use this with raspberries, arduinos etc.
I wanted to use 74C923 but these are nowhere to be found. And even then, the number of keys wil be 20. So i am tying together two 74C922 using some logic in a PLD.
First draft
It wil be something like above. Using the data availabe signal i can combine both 16key matrixes. (In theory .. it is all untested)
Another blender project i’m planning to do this week is a movie displaying my logo to overlay on my videos. So i have to render a transparent movie for this.
Howto:
Open a scene, i took the liberty to get one from blenderkit.
Change output to cycles, eevee doesn’t work
Make x/y large enough in output tab. X = 2 * Y !
Next select your camera, and open camera tab
Change Type to panoramic and then you can change panorama type to Equirectangular
Position your camera and hit F12, it wil take a long time!
You get something like this
Use a proper plugin for your website, or view with your VR glasses!
New address decoder in place! Connected RAM/ROM/SID/VIA1/VIA2 and ACIA
ROM
8000-FFFF
SID
7000-700F (sound)
VIA1
6000-60xx (Hex key matrix)
ACIA
6800-68xx (serial)
VIA2
5000-50xx (led test at the moment)
RAM
0000-3FFF
To plan: Bigger maxtrix keyboard and other displays
ACIA 6551
Got a serial connection working between the 6502 and my linux machine!
3 line serial – no hardware handshake
At the moment when a reset occurs , hello is being printed. Text typed in the minicom terminal, is echo-ed back and displayed on the LCD display.
Things learned: Do not trust internet schematics blindly!
The crystal used for the ACIA (pin 6/7 1.8432Mhz needs a 1M ohm resistor parallel over the crystal, and a 30nF capacitor from pin 7 to GND
When using a terminal emulator, and using 3 wires. Disable hardware handshake.
Keyboard rewired.
What didn´t work as planned:
New amplifier schematic for the SID. There is too much noise.
Amplifier with a LM628
Bought a dual power supply (5V and 12V). But this one has a lot of signal noise on the SID part and even my battlestation speakers!
LED test 2nd via
PORTB = $5000 ; VIA PORTB
PORTA = $5001 ; VIA PORTA
DDRB = $5002 ; Data direction register
DDRA = $5003 ; Data direction register
LED = %10000000
.org $8000
reset:
lda #%11100000 ; Set top 3 pins on port A to output
sta DDRA
lda LED
sta PORTA
loop: ; done loop until doomsday
jmp loop
irq:
nmi:
.org $fffa
.word nmi
.word reset
.word irq
ACIA part
ACIA_RX = $6800
ACIA_TX = $6800
ACIA_STATUS = $6801
ACIA_COMMAND = $6802
ACIA_CONTROL = $6803
lda #$00
sta ACIA_STATUS
lda #$0b
sta ACIA_COMMAND
lda #$1f
sta ACIA_CONTROL
I was using zevv’s bucklespring way back since he was beta testing. https://github.com/zevv/bucklespring
Also cool-retro-term, i used whenever i felt nostalgic.
But both at the same time, how much fun is that!
(Both newly installed on my laptop, which i had to reinstall, because i f*cked it up beyond repair. installing openxr stuff. OpenXR is an open, royalty-free standard for access to virtual reality and augmented reality platforms and devices. )
The ATF22V10 is a Programmable Logic Device. This means you can program the logic in the chip.
Internally it looks like a big matrix of connections which you can program to connect/disconnect from certain logic.
It has just a bunch of inputs/outputs
So if we want to have a 7 Segment decoder (you can easily buy a BCD decoder .. but these only work for displaying 0-9 and not 0-9A-F for displaying HEX numbers)
7 Segment display
Binary IN
7 Segment decoded
Displays
D C B A
A B C D E F G
0 0 0 0
1 1 1 1 1 1 0
0
0 0 0 1
0 1 1 0 0 0 0
1
0 0 1 0
1 1 0 1 1 0 1
2
0 0 1 1
1 1 1 1 0 0 1
3
0 1 0 0
0 1 1 0 0 1 1
4
0 1 0 1
1 0 1 1 0 1 1
5
0 1 1 0
1 0 1 1 1 1 1
6
0 1 1 1
1 1 1 0 0 0 0
7
1 0 0 0
1 1 1 1 1 1 1
8
1 0 0 1
1 1 1 1 0 1 1
9
1 0 1 0
1 1 1 0 1 1 1
A
1 0 1 1
0 0 1 1 1 1 1
B
1 1 0 0
1 0 0 1 1 1 0
C
1 1 0 1
0 1 1 1 1 0 1
D
1 1 1 0
1 0 0 1 1 1 1
E
1 1 1 1
1 0 0 0 1 1 1
F
Now we see that segment A is 1 in the case of (0,2,3,5,6,7,8,9,A,C,E,F)
When programming the PLD we can write that as: (note / means inverted a plus is OR, and * is AND) So A is 0 in case of input being (1,4,B,D)
Made a simulation of my new address decoder. It uses a 74LS138 and a bunch of NAND gates. You can safe using 4 NAND gates if you are not going to use split IO
Address
8000-FFFF
ROM
ROM
7000-7FFF
Sound chip
SID
6000-6FFF
Display + cursor
VIA1
5000-5FFF
Keymatrix
VIA2
4800-4FFF
split io
IO
4000-47FF
split io
IO – ACIA
0000-3FFF
Uses clock
RAM
Above part is a single chip 74LS138
UPDATE: Found some 74LS139, so i could have changed some things around.
