As previously posted, i had an idea to create a dual matrix keyboard mashup using available components.
I mentioned that “it should theoretically work”. But only being using atf22v10c for a couple of days. It was a long shot.
I’ve put it to the test .. and it worked first time.
I can use above, to connect my extended matrix keyboard to a 6522 VIA chip using 5 pins and sending a data available signal to CA1.
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.
It wil be something like above. Using the data availabe signal i can combine both 16key matrixes. (In theory .. it is all untested)
PLD Code
GAL22V10 Address Decoder PHI2 DA0 DA1 D01 D02 D03 D04 D11 D12 D13 D14 GND NC D0 D1 D2 D3 D4 DA NC NC NC NC VCC DA = DA0 + DA1 D0 = D01 & DA0 + D11 & DA1 D1 = D02 & DA0 + D12 & DA1 D2 = D03 & DA0 + D13 & DA1 D3 = D04 & DA0 + D14 & DA1 D4 = DA1 DESCRIPTION Key matrix merger
I’ve got my new keys of the keyboard in today!
My inkscape template (keys are 10/10mm)
Printed on white and red paper
https://media.henriaanstoot.nl/keyboardmatrix.svg
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
Got a serial connection working between the 6502 and my linux machine!
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.
What didn´t work as planned:
New amplifier schematic for the SID. There is too much noise.
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
Whereas i needed to use several logical components to make a address decoder, below i only need one!
cat addressdecoder-fash.PLD
ATF22V10 (GAL22V10)
Address Decoder
PHI2 A15 A14 A13 A12 A11 A10 A9 A8 A7 A6 GND
xx xx RAM ROM SID ACIA VIA1 VIA2 DEV0 DEV1 BANK VCC
/RAM = PHI2 * /A15 * /A14
/ROM = A15 * BANK
/SID = /A15 * A14 * A13 * A12
/VIA1 = /A15 * A14 * A13 * /A12 * /A11
/ACIA = /A15 * A14 * A13 * /A12 * A11
/VIA2 = /A15 * A14 * /A13 * A12
/DEV0 = A15 * /BANK
DESCRIPTION
Address decoder
galasm addressdecoder-fash.PLD # Generates below file which i can flash into the PLD
cat addressdecoder-fash.jed
Used Program: GALasm 2.1
GAL-Assembler: GALasm 2.1
Device: GAL22V10
*F0
*G0
*QF5892
*L0924 11111111111111111111111111111111111111111111
*L0968 11100111111111111111111111111111111111111111
*L1496 11111111111111111111111111111111111111111111
*L1540 11111011011110110111111111111111111111111111
*L2156 11111111111111111111111111111111111111111111
*L2200 11111011011101111011101111111111111111111111
*L2904 11111111111111111111111111111111111111111111
*L2948 11111011011101111011011111111111111111111111
*L3652 11111111111111111111111111111111111111111111
*L3696 11111011011101110111111111111111111111111111
*L4312 11111111111111111111111111111111111111111111
*L4356 11010111111111111111111111111111111111111111
*L4884 11111111111111111111111111111111111111111111
*L4928 01111011101111111111111111111111111111111111
*L5808 01000101010101010100
*L5828 0100000101100100011001000111001001100101011100110111001100100000
*C50fa
*
b734
So one chip replaces schematic below!
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)
| 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)
/QA = /D1 * /C1 * /B1 * A1
+ /D1 * C1 * /B1 * /A1
+ D1 * /C1 * B1 * A1
+ D1 * C1 * /B1 * A1Complete code for galasm
Compiling and burning
GAL22V10
7SEGMENT
Clock D1 C1 B1 A1 D2 C2 B2 A2 NC NC GND
/OE NC NC NC QG QF QE QD QC QB QA VCC
/QA = /D1 * /C1 * /B1 * A1
+ /D1 * C1 * /B1 * /A1
+ D1 * /C1 * B1 * A1
+ D1 * C1 * /B1 * A1
/QB= /D1 * C1 * /B1 * A1
+ /D1 * C1 * B1 * /A1
+ D1 * /C1 * B1 * A1
+ D1 * C1 * /B1 * /A1
+ D1 * C1 * B1 * /A1
+ D1 * C1 * B1 * A1
/QC = /D1 * /C1 * B1 * /A1
+ D1 * C1 * /B1 * /A1
+ D1 * C1 * B1 * /A1
+ D1 * C1 * B1 * A1
/QD= /D1 * /C1* /B1 * A1
+ /D1 * C1 * /B1 * /A1
+ /D1 * C1 * B1 * A1
+ D1 * /C1 * B1 * /A1
+ D1 * C1 * B1 * A1
/QE = /D1 * /C1 * /B1 * A1
+ /D1 * /C1 * B1 * A1
+ /D1 * C1 * /B1 * /A1
+ /D1 * C1 * /B1 * A1
+ /D1 * C1 * B1 * A1
+ D1 * /C1 * /B1 * A1
/QF = /D1 * /C1 * /B1 * A1
+ /D1 * /C1 * B1 * /A1
+ /D1 * /C1 * B1 * A1
+ /D1 * C1 * B1 * A1
+ D1 * C1 * /B1 * A1
/QG = /D1 * /C1 * /B1 * /A1
+ /D1 * /C1 * /B1 * A1
+ /D1 * C1 * B1 * A1
+ D1 * C1 * /B1 * /A1
DESCRIPTION
A 7 segment hex decoder
galasm 7seghex.gal
minipro -p ATF22V10CQZ -w 7seghex.jed
minipro -p ATF22V10CQZ -w 7seghex.jed Found TL866II+ 04.2.129 (0x281) Warning: Firmware is newer than expected. Expected 04.2.128 (0x280) Found 04.2.129 (0x281) VPP=12V Warning! JED file doesn't match the selected device! Declared fuse checksum: 0x98D5 Calculated: 0x98D5 ... OK Declared file checksum: 0x40B3 Calculated: 0x41A8 ... Mismatch! JED file parsed OK Use -P to skip write protect Erasing... 0.33Sec OK Writing jedec file... 5.01Sec OK Reading device... 0.32Sec OK Writing lock bit... 0.35Sec OK Verification failed at address 0x16C6: File=0x01, Device=0x00 < ------------------ Gives error, but burning seems okay henri@zspot:~/projects/galasm$ minipro -p ATF22V10CQZ -r 7seghex.out Found TL866II+ 04.2.129 (0x281) Warning: Firmware is newer than expected. Expected 04.2.128 (0x280) Found 04.2.129 (0x281) Reading device... 0.32Sec OK Gives all zeros as output, but device works!
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 |
UPDATE: Found some 74LS139, so i could have changed some things around.
Try it over here:
I found some stuff while sorting out some old computer stuff.
Way back, when my Amiga was my main computer, i wanted to make my own version. A modular one.
So i started to segmentize the amiga, to put it on several exchangeable cards.
Eurocards are standardized prints 150mm x 100mm, mostly with a DIN41612 connector.
When you make modules you can change/upgrade/test, you can have a very easy interchangeable system using a backplane like this
So i started planning those modules:
I had a nice case which could hold a big backplane, custom powersupply. And a front panel containing drives, leds and knobs. (I know i have more info on this somewhere on my fileserver)
A nice example picture i found on danceswithferrets website
I never finished this project.
I used Tech Manuals and print layouts to understand how things where done.
I started to draw the modules like they where placed on the print on semi transparent (chalk)paper, the kind of paper that was used for electronic and mechanic diagrams.
UPDATE : Bought after selling these
The last days i’ve been selling a lot of my old computers.
They have been in my collection for many years, but now its time to part.
Time for others to enjoy them.
(Instead of posting which ones are being sold and which i’ve still got on this page i’ll make another post)
I started collecting when i studied computer sciences.
It’s a wonder my parents attic wasn’t collapsing.
(They let me store many computers on their attic, let me run a mainframe in the house (previous post) and let me have computer-parties (pre-lan) in their home. (They even left, and gave me the space) .. 15+ teens with computers … there was a pingpong table in the livingroom (besides the other tables in the house ) For all computers.
Then i’ve got even more, when living on my own. (At some point about 140. )
A few years later i got rid of uninteresting computers (to my taste at that time) and incomplete ones. Then i filtered-out the non working.
Still leaving with a lot of computers, i kept these for many years.
Now i only want the ones i’ve worked with, or are special to me.
My first computer was a Commodore Vic-20. Friends had the popular C64. So i kept 2 of both.
In Junior Technical School i’ve used the BBC Acorn a lot (Funny story below)
My then friend Richard had a Atari ST, loads of fun we had with that machine, so i’m keeping a Atari 1040STf.
Another friend used a Apple SE, so that one i also keep for now.
I’ve been programming a lot on 80×86, the first dos PC’s, i’m still looking for a old machine (Laser XT) which i used way back then. But for now i’ve got a Sinclair PC200.
I’ll keep a old Commodore PET 2001, because its cute.
Besides having a cute PET, i’ve got a Holborn System. Made in Holland (Enschede), there are only a few left according to some sites: only 200 made! (Holborn means Holland Born) One of the inventors was from Holten, my birthplace. (Polak)
At school we kept a list of everyone’s collection.
Soo .. the story about the BBC Acorn.
When i was at school outside study hours, i went to the computer lab.
This was one classroom with about 16 BBC Acorns and a master (teacher station). When they saw how enthusiastic i was, i got the key to the classroom. I even got access to the master system. And after a little hacking i’ve gained access to the teachers files.
There was a simple network system, i think it was called Econet.
The teachers system was the only one with a disk station.
I liked the ‘highres’ line graphics you could make on the machines. (640×256)
So i’ve wrote a lot of programs using this mode.
I even wrote a program which drew a 3D robotarm on screen using wireframe graphics.
At that time my mathematics scores where .. bad.
Wasn’t interested i think.
But drawing 3D robotic arms are not possible using mathematics, like using sinus, triangulary etcetera.
So when my mathematics teacher saw my program, he didn’t believe me.
So .. fooling around in the computer lab, i missed start of classes. And later on .. worse .. i almost was not allowed to do my final exams.
I was late several times (and one of the first to leave, …. straight from and to the computer lab. )
I’ve got some programs printed on paper, i will use my leftover BBC Acorn (or a emulator) to capture some screen examples.
Sold stuff
UPDATE : Selling a lot, but i’ve bought some others between 2020-2023
Also a “new” 1084 monitor (CRT for a Commodore 64)
Now i have to look for a VGA Crt to get old vga-register manipulation programs working.
Divers new additions to the 6502 project
Above is my design for a hex keyboard to enter opcodes in hex using a simple monitor program.
i used a 74ls922 which can decode a 4×4 matrix. I’d rather had a 74ls723 which can encode 20 keys.
Nowhere to be found. So i have to think of a new plan.
Now it is configured as follows:
| C | D | E | F |
| 8 | 9 | A | B |
| 4 | 5 | 6 | 7 |
| 0 | 1 | 2 | 3 |
When pressing the alternate key
| addr (to implement) | run (1/2 implemented) | reset (to implement) | |
| step instruction (to implement) | |||
| memory next | |||
| memory previous |
Meanwhile i’ve ordered new keys (the ones i’ve been using for my photomanager project and wnat to have a setup like this:
| ? | ? | addr | run | reset |
| C | D | E | F | ? |
| 8 | 9 | A | B | step |
| 4 | 5 | 6 | 7 | mem next |
| 0 | 1 | 2 | 3 | mem prev |
When you want to show the status of busses and alike, you can’t use a led and restistor directly on the bus, it will require too much current.
So i’ve been using below schematic which uses a darlington array.
Now i can display databus, address bus and i’ve been using this for address decoding logic and hex keyboard.
I’ve implemented a second VIA chip, and ordered components to amplify the SID sound part
UPDATE: 20220823 Sid working
Above is my Kicad design (reverse engineering print below, which was made for my 6802CPU, which i could use to test the 6822 PIA)
The 6822 is simular to 6502 in design. So i’m going to redo this for my 6502.
The 7 segment displays are a start of hex-keyboard/display combo i’m going to post more of in the next days.
Below a part of the rom for the LCD dual line display.
Started to write routines which i can call to manipulate the display. Setting the pointer to a message, setting the line to use and a subset of controlls like: Center, Right, binary to ascii, scrolling, etcetera
lda #0 ; set line number
sta lineno ; store
jsr gotoline ; goto line in display
lda #<message ; get address from message and store for printline subroutine
sta messagestore
lda #>message
sta messagestore+1
jsr printline ; print
lda #1 ; set line number
sta lineno ; store
jsr gotoline
lda #<message2
sta messagestore
lda #>message2
sta messagestore+1
jsr printline
Above additions:
New address decoder
Below left the new graphical display, below right a test board which shows address lines and decoded chip-enable lines.
A15 high -> ROM
A15 && A14 low -> RAM
combination of A15 low and A14 high – A13 and A12 wil select peripherals.
Above is a start of a wirewrapped version, i also started a PCB design in KIcad that will continuously be changed as i alter designs.
UPDATE SID Working! Using new address decoder.
SID = $7000 makesound: lda #0 sta SID+$5 ; Channel1 - attack/decay lda #250 sta SID+$6 ; Channel1 - Sustain/Release lda #$95 sta SID+$0 ; Channel1 - Frequency low-byte lda #$44 sta SID+$1 ; Channel1 - Frequency high-byte lda #%00100001 sta SID+$4 ; SAW + Gate lda #$0f sta SID+$18 ; Volume max