Tag Archives: retro

Working on a (C64) handheld probe oscilloscope

These will be available in my shop.

Probably a webpage with measured examples are usefull.

There is a cover for the pogo pin which holds the ground clamp

Handheld device to measure voltages and make screenshots using an application.

Control over serial

  • Select USB device to connect
  • Start a capture to screen
  • Clear (redraw probe screen)
  • Rotate screen for left/right-handed people and easy reading
  • Sample time speed in microseconds
  • 5V reading but 15 volt tolerant, due to the SID pins
  • ??? love to hear ideas

I’m currently working on streaming output.

Below, an example of screenshotting.

Below, measuring outputs from a NE555 (dutch comments)

C64 ROM switcher, Hidden cam viewer, Motorized fader pot and PCB sponsor

Lol, got an email from a PCB sponsor!

Deeply impressed by your blog content which means a lot to electronic enthusiasts.
I'd like to sponsor your project by providing free PCB prototyping,

ROM SWITCHER

I made a rom switcher in the past.
Now I’m using an Arduino to switch Kernal and Character rom.
(Partly idea from Adrian)

Where the F* is my schematic. Ah here it is.

Above right picture:

  • Tactile button (emulates restore key)
  • Red led – reset
  • Yellow led – Exrom
  • Blue leds, Address lines select ROM part in 27512 EPROM
  • Green leds, Address lines select ROM part Character ROM

Motorized Fader Potentiometer

I don’t trust some B&B’s so I made a camera detector.
(I always scan the wifi and Access Points)
This one lets you know if there are IR enabled camera’s.
(Night vision)

Picture 1:

  • 1 = org camera module, IR filter is hard to remove. (See pink color)
  • 2 = other module, IR filter is at bottom
  • 3 = IR Filter, I removed this.

Picture 2:

IR light blast from a “hidden” camera. (I need to adjust focus of lens)

Three display C64 audio monitor

While I made this for my Commodore C64, it is applicable for many things.

It started with some cheap displays from Ali, and some leftover Wemos D1 from my Pressure Lab project.

I Started measuring the audio output from sound devices and from my C64.
I soon discovered that I needed some way to get the offset and amplification correct for the analogue input of a Wemos. (0-3v3)

So a little op-amp circuit was born, but not without some struggles.
I forgot many things about amplifiers. It was one of the first school books I got rid of. (Sorry mister Rafaela)

After searching the internet and posting a question on Reddit I ended up with the following.

R1 and R2 are 100M. The potentiometer P1 allows me to set the offset.
R3 is 1M
C1 is 100nF to decouple the audio signal from the RCA.

R4 is 47K and C2 is 330nF (thanks tycho205)
Cimportant=1/(2πfR2)
where f is the lowest frequency of interest. In this case Cimportant should be about 330nF

LM324 is a quad amplifier, leftover from another project.
Note, the SINGLE RAIL power.

P2 potentiometer is 2M (leftover) and gives me a variable amplifying opportunity.


A = Audio input

B = Setting the offset with P1

C = Setting the amplification

Below input signal (note negative values) above amplified signal with offset!

The displays are 3 Wemos controllers with a cheap I2C display.
These are just fast enough to do FFT.

Analogue in is the output from the OP-amp offsetter ..

CODE

Needs cleaning up, and a better stabilize routine.

New C64 Cartridges

New cartridges stuff.
I’ve bought some in the past, and was gifted some.

Made a case for an own made 8085 cartridge.
In this case, I used a gifted PCB from Bigred (thanks).
This was designed by Venneker.

With a gap for a 40 pins socket to piggyback signals.

https://media.henriaanstoot.nl/c64-cartridge-gap.tgz

Then a new Nordic Replay, this is a new version of the Retro Replay.

Today the TeensyRom, this came without case, so I printed one in fancy dual silk color.

Demos and hacks soon

Mega PC tower and Book

I’ve printed two books using the Lulu service. (One for Tyrone)
When they arrived, I noticed some faults.
Lucky Lulu will be printing them again for me.

The book has over 500 pages and has a nice hardcover.

And I’ve been busy building a Mega Tower with 4 Motherboards.
This will have a superb processing power! .. not.
It houses some old motherboards for hardcore machine coding on real old hardware.

From top to bottom: 8088, 8086, 80386, 80484

Todo:

  • Rework on the cables
  • 3D print an information plaque on the front of each board
  • Add a control panel on each board
  • Maybe some dust cover would be nice

I can remove the boards, and place them on a table.
I’ve made some custom feet for them. Twist and lock by my own design.

Padded feet

The openscad files:

The locking is done by making the cylinder slightly oval by 0.5mm

difference(){
	difference(){
		difference(){
			difference(){
				rotate([90,30,0])
				cylinder(r=30, h=10, $fn=3);
				translate([-20,-20,0])
				cube([40,40,40]);
				}
			rotate([90,0,0])
			translate([0,0,-10])
			cylinder(r=5, h=30, $fn=200);
			translate([0,-5,-10])
			cylinder(r=7, h=30, $fn=200);
			}
		translate([18,-5,-12])
		cylinder(r=4, h=30, $fn=200);
		translate([18,-5,-22])
		cylinder(r=2.2, h=30, $fn=200);
		translate([-18,-5,-12])
		cylinder(r=4, h=30, $fn=200);

		translate([-18,-5,-22])
		cylinder(r=2.2, h=30, $fn=200);
		}
	translate([9,-20,-20])
	cube([40,40,40]);
}

Note the resize for the oval effect

resize([14,14.5,10])
cylinder(r=7, h=10, $fn=200);
translate([0,0,0])
cylinder(r=9, h=3, $fn=200);

When designing above, I also made new knobs for our stove.
Using the white dot, you can see which burner has which knob.

Made a Meatloaf device for C64

Awesome opensource project

https://github.com/idolpx/meatloaf-specialty/tree/main

  • Emulates a floppy drive: Meatloaf plugs into the Commodore 64’s IEC serial port and acts like a virtual floppy drive. This allows you to load software and data stored on its internal flash memory, sd card, or stream it via WiFi using various protocols from servers all over the world.
  • Supports multiple virtual drives: Unlike a single floppy drive, Meatloaf can be configured to emulate up to 26 virtual drives (IDs 4-30). Each virtual drive can have a different disk image loaded, essentially offering the equivalent of having thousands of floppies connected to your C64.
  • Supports additional virtual device types: Printers, a network interface, and more.
  • Connects to the internet: Meatloaf also functions as a WiFi modem, enabling your Commodore 64 to connect to Telnet BBS (bulletin board systems) for communication and sharing information.

https://meatloaf.cc/sc/s/shortcodes.php

Load a prg using a url

LOAD"HTTP://C64.ORG/GAMES_AZ/H/H.E.R.O.PRG",8

Or from a D64 image on your own Windows/Samba server (all known CBM image formats supported):

LOAD"SMB://STORAGE/C64/FAVORITES/PIRATES_A.D64/*",8

Load a random game from the internet

LOAD"ML:ARCADE*",8	

C64 Assembly, KiCad PCB design, and Keyboard Layout switcher

I’ve been busy programming Python and NodeRed for a client.
But these are the things I’ve done in the last days.

C64 Assembly:
Breaking borders, using sprites and multicolor font intro.

It does not look impressive, but I’ve learned a lot.
Found a new way (for me) to open borders and change border colours on predefined raster lines.
Sources will be posted.

KiCad tutorial, posted on YT also because I could not find many resources about the subject online. Maybe it’s helpful

Video editing using Kdenlive.

Edit: Even faster, use Netlabels, no need to join pins.
Press L (uppercase) select pin 1, name 1.
Press and hold insert until all pins named.
Copy paste socket 5 times and goto your PCB tab.

This movie is about creating a backplane for a 6502 SBC I’m building.
It is real-time and below 4 minutes.

Multi Keyboard

My small multitouch screen came in.
This is for my previously mentioned multi-computer case.

It is going to show multiple keyboard layouts for different systems.
(See previous posts about this)

Waveshare display, Raspberry Zero as HID device, using USB and pin emulated keyboards. (c64 matrix, AT (DIN) keyboard, ps2 keyboard)

Some example screens

Vic-20
Photo-realistic
Petscii C64
Another C64

I’m also going to make a layout like the keyboards on my 8085

68000 SBC, C64 Git and SID Player

Working on 68000 Single Board Computer.

Made a clock circuit and busy designing a power-on-reset schematic. I’ve made one before, but this circuit needs RESET and HALT being pulled low.

8mhz 5V

The 68000 being 24 bit address and 16 bit data needs 2x 8-bit roms and 2x 8 bit ram, but i didn’t have the components yet in this picture.

Address decoder using ATF22V10C is also halfway.
Schematics online soon.

Started a protected Git repo for C64 demo and proof of concepts for our old ICECREW group.

Installed Gitea, behind a reverse proxy.
Part of reverse proxy

ProxyRequests Off
ProxyPreserveHost On
SSLProxyVerify none
SSLProxyCheckPeerCN off
SSLProxyCheckPeerName off

<Location />
ProxyPass   http://10.x.y.z:3000/
ProxyPassReverse  http://10.x.y.z:3000/
Require ip 213.10.144.27
Require ip a.b.c.d
Require ip e.f.g.h
</Location>

Gitea config with token login over https

Generate token
Login https://icecrew.henriaanstoot.nl/

Select your profile (upper right)

And select Settings > Applications

Select a name for your token. And press generate

Top screen shows a token, copy this!

Create new project
Press explore (upper left)

Select organisation and icecrew

Press New Repository, give a name and create

(press https when not defaulted, there is NO ssh to this server)

The example is wrong! (Use below changing TOKENHERE and PROJECTNAME

touch README.md
git init -b master
git add README.md
git commit -m "first commit"
git remote add origin https://TOKENHERE@icecrew.henriaanstoot.nl/icecrew/PROJECTNAME.git
git push -u origin master

Clone a project
Goto a project

press HTTPS when not defaulted to this.

git clone https://icecrew.henriaanstoot.nl/icecrew/borderflag.git 

edit .git/config and add your token to the url ! to push

My Sidplayer as an option to select own collection.
And I’ve made a top list

# Best composers (no order)
Ouwehand_Reyn
Tel_Jeroen
Huelsbeck_Chris
Rowlands_Steve
Hubbard_Rob
Daglish_Ben
Follin_Tim
Gray_Matt
Tjelta_Geir
Mibri (from get in the Van)

# Best tunes (no order)
R-Type.sid
Arkanoid.sid
Bottom.sid
Turbo_Outrun.sid
A_Tune_for_Unity.sid
Ohne_Dich_Rammstein.sid

# Start of own collection (not in above collection)
Abyssus_Ignis_[8580].sid
Catastrophe_[8580].sid
Dumb_Terminal_[8580].sid
Get_in_the_Van_[8580].sid
Getting_in_the_Van_[8580].sid
Supercharger_[8580].sid
Tuna_Guitar_[8580].sid

Investigating syncing effect to Sid music.

I got a great tip from Youth who made the Freakandel demo presented at X2024.

> Setup the loop to play the music

> Copy part of the memory to the screen ($0400) in the same loop to look for memory locations that are used as variables for the music. > Looking at

> Memory where the music is stored

> Zeropage ($00-$ff)

> See if there's some useful changes that coincide with for example drums

> For my own tunes, I use a music routine where I can put event markers in the music itself and react to those from the code. That's >how I synced https://www.micheldebree.nl/posts/big_angry_sprite/

> You could also try reading the SID registers for voice 3 (waveform and ADSR), those are the only ones that are not write-only. > Obviously you can then only react to those changes in voice 3.

I used retrodebugger to see which bytes are changing.
Then I wrote a program which changes the background colour to this value.
I also made a program to use a joystick to see which address have the most interesting effect.
(use up)

     1                                       !to "sidbgnd.prg",cbm
     2                          
     3                                  * = $0801
     4                          			
     5                          sysline:	
     6  0801 0b0801009e323036...        !byte $0b,$08,$01,$00,$9e,$32,$30,$36,$31,$00,$00,$00 ;= SYS 2061
     7                          
     8                                  * = $080d 
     9                          
    10  080d 78                 	sei
    11  080e a960               	lda #<irq
    12  0810 a208               	ldx #>irq
    13  0812 8d1403             	sta $314
    14  0815 8e1503             	stx $315
    15  0818 a91b               	lda #$1b
    16  081a a200               	ldx #$00
    17  081c a07f               	ldy #$7f 
    18  081e 8d11d0             	sta $d011
    19  0821 8e12d0             	stx $d012
    20  0824 8c0ddc             	sty $dc0d
    21  0827 a901               	lda #$01
    22  0829 8d1ad0             	sta $d01a
    23  082c 8d19d0             	sta $d019 
    24  082f a900               	lda #$00
    25  0831 200010             	jsr $1000 
    26  0834 58                 	cli
    27  0835 a920               	lda #$20
    28  0837 8d6b08             	sta vector
    29  083a a917               	lda #$17
    30  083c 8d6c08             	sta vector+1
    31  083f a000               	ldy #$00
    32  0841 b93017             hold 	lda $1730,y
    33  0844 8d20d0             	sta $D020
    34  0847 ad00dc             	lda $dc00
    35  084a 2901               	and #$1
    36  084c c901               	cmp #$1
    37  084e f0f1               	beq hold
    38  0850 ad00dc             	lda $dc00
    39  0853 2901               	and #$1
    40  0855 c900               	cmp #$0
    41  0857 f0e8               	beq hold
    42  0859 c8                 	iny
    43  085a 8c6d08             	sty vector+2
    44  085d 4c4108             	jmp hold 
    45                          irq
    46  0860 a901               	lda #$01
    47  0862 8d19d0             	sta $d019 
    48  0865 200310             	jsr $1003 
    49  0868 4c31ea             	jmp $ea31
    50                          
    51                          vector
    52  086b 0000               	!byte $00,$00
    53                                      
    54                          	* = $1000
    55  1000 4c37104c85104c2f...	!binary "Techno_Drums.sid" ,, $7c+2

Raster line with open borders to draw a flag

A fun experiment using opening the C64 border and changing colors on certain rasterlines.

Screenshot (only a little artefact on the lefthand side)

Code (acme)

acme borderflag.asm
x64 +drive8truedrive borderflag.prg

!cpu 650rasterline
!to "borderflag.prg",cbm


* = $0801
    !byte $0d,$08,$dc,$07,$9e,$20,$34
    !byte $39,$31,$35,$32,$00,$00,$00

* = $c000
        sei                     ; turn off interrupts

        ldx #1                  ; enable raster interrupts
        stx $d01a

        lda #<irq       	; set raster interrupt vector
        ldx #>irq
        sta $0314
        stx $0315

        ldy #$f0                ; set first interrupt rasterline
        sty $d012
        lda $d011               ; reset rasterline hi bit
        and #%01111111
        sta $d011

        asl $d019               ; ack VIC interrupts
        cli

loop_until_doomsday
        jmp loop_until_doomsday

irq
	asl $d019       	; ack irq

	lda #$01		; set screenframe and background
	sta $d020
	lda #$02
	sta $d021

	lda #$38        	; wait for line $38
	cmp $d012       	
	bne *-3

	lda #$02		; set screenframe and background
	sta $d020
	lda #$01
	sta $d021

	lda #$f9        	; wait for line $f9C
	cmp $d012       	; just below border in 25 row mode
	bne *-3

	lda $d011       	; switch to 24 row mode ($d011 bit 3 = 0)
	and #$f7        	; %11110111
	sta $d011

	lda #$fd        	; wait for line $fd
	cmp $d012       	; just below border in 25 row mode
	bne *-3

	lda $d011       	; switch back to 25 row mode ($d011 bit 3 = 1)
	ora #$08        	; %00001000
	sta $d011

	jmp $ea31		; exit irq