This is an optional port of Pi1541 (V1.24) to the current Circle bare metal library (as of Jan. 2024, Version 45.3.1).
As almost all Pi model specific bindings which have a counterparts in Circle have been removed. This allows to use the potential of Circle to extend Pi1541 with new functionalities. Some ideas:
- Webserver to download images
- Make options changeable via a WebGUI
- ...
Credits to Stephen (@pi1541) Pi1541 and Pi1541-github, Rene (@rsta2) circle, Stephan (@smuehlst) circle-stdlib for the brilliant base packages!
The following is supposed to work no the the circle based V1.24c, as I've tested those functions a bit:
- Pi1541 on Raspberry models 3B+, PiZero 2W, 4: successful load (JiffyDOS) of some games with fastloaders and GEOS
- LCD Display SSD1306
- Rotary Input
- Option A HW Support
- Buzzer sound output
- PWM/DMA Soundoutput (sounds nicer than in legacy codebase, IMHO)
- USB Keyboard and USB Massstorage (improved over original, see also Bugs below)
- Ethernet or WiFi network (if configured) starts and seeks for a DHCP server, Webserver runs, but one can only control the led so far
Note that Option B hardware (split IECLines) of Pi1541 is not tested (I don't have the necessay hardware). The code uses <somePin>.SetMode(GPIOModeInput) method. This should neither activate PullUp nor PullDown for any of the respective input pins.
If enabled (see below), network is activated in the background. For Wifi it may take a few seconds to connect and retreive the IP Address via DHCP. The IP address is briefly shown on the LCD, once received. One can check the IP address on the screen (HDMI).
The codebase is the publically available Pi1541 code, V1.24 (as of Jan. 2024) with some improvements:
- LED/Buzzer work again as in 1.23
- some bugfixes to avoid crash (missing initializer)
- build support for moden GCCs (-mno-unaligend-access)
- new option
headLess, see below - as a reset button is missing on most PIs, this is mapped to the button combo which selects DriveID 11 (a rare use-case for me)
Still the legacy code can be built with support for all supported hardware variants, include PiZero, Pi1 and Pi2 variants - see build chapter Build. The floppy emulation is entirely untouched, so it's as good as it was/is in V1.24 - which is pretty good, IMHO! Credits to Stephen!
Attention: the operating temperature is substantially higher than with the original kernel (legacy build). It is recommended to use active cooling as of now. Raspeberry PIs normally protect themselves through throtteling. This should work lates at 85C - you may lower this threshold via cmdline.txt using e.g. socmaxtemp=70.
- Make the webserver useful
- Allow static IP Adresses for faster startup, to be configured in
options.txt - Make execution more efficient wrt. CPU usage to keep temperature lower, use throtteling to protect the Pi.
- Provide a helper script to collect all files to make Pi1541 sdcard build easy
- Test more sophisticated loaders (RT behavior)
- PiZero support for circle, as it doesn't make sense due to lack of network support
- Circle Support for all variants of Pi1 and Pi2, as I don't have those to test
- Pi5 support - with support from @rsta, I found that the GPIO performance of the Pi5 is significantly slower than on earlier models due to its changed hardware architecture. Even with some tweaking, Pi1541 misses cycles and emulation breaks. The code is prepared for Pi5, but as of now not working. It requires the circle-development branch as some optimized GPIO functions aren't released yet.
The following options control new functions available:
| Option | Value | Purpose |
|---|---|---|
| netEthernet | 0 or 1 | disable/enable Ethernet network |
| netWifi | 0 or 1 | disable/enable Wifi network |
| headLess | 0 or 1 | disable/enable headless (no HDMI output) |
- Pluging in a USB stick after booting, won't show files on the USB mounted drive and display remains dark. Unplugging/re-plugging works as expected if USB is plugged in at startup
- Pi5 not yet working
One can build the Version 1.24 (+some minor fixes: LED & Buzzer work, build/works with gcc > 10.x). The following compiler suites were used for development:
| Compiler | Package name | Link | Arch |
|---|---|---|---|
| GCC | AArch32 bare-metal target (arm-none-eabi) | download | 32 bit |
| GCC | AArch64 ELF bare-metal target (aarch64-none-elf) | download | 64 bit (RPi4 only) |
Make sure your PATH variable is set appropriately to find the installed compiler suite.
The project is built by:
BUILDDIR=build-pottendo-Pi1541
mkdir $BUILDDIR
cd ${BUILDDIR}
git clone https://github.com/pottendo/pottendo-Pi1541.git
# Checkout (circle-stdlib)[https://github.com/smuehlst/circle-stdlib]:
git clone --recursive https://github.com/smuehlst/circle-stdlib.git
cd circle-stdlib
# configure for Pi3 and Pi Zero 2 W:
./configure -r 3
# alternatively configure for Pi4 32 bit
# ./configure -r 4
# or even Pi4 64 bit
# ./configure -r 4 -p aarch64-none-elf-
# or even Pi5 64 bit, requires circle development branch as of now
# ./configure -r 5 -p aarch64-none-elf-
# Patch Circle sysconfigh on ffconf.h to adapt to Pi1541 needs
cd libs/circle
patch -p1 < ../../../pottendo-Pi1541/src/Circle/patch-circle.diff
cd ../..
# build circle-lib
make
# now build Pi1541 based on circle
cd ${BUILDDIR}/pottendo-Pi1541
make
Depending on the RPi Model and on the chosen build (Circle vs. legacy):
| Model | Version | build cmd | Image Name | Note |
|---|---|---|---|---|
| Pi Zero, 1RevXX, 2, 3 | legacy build | make RASPPI={0,1BRev1,1BRev2,1BPlus,2,3} legacy |
kernel.img |
|
| 3 | circle build | make |
kernel8-32.img |
|
| Pi Zero 2W | circle build | make |
kernel8-32.img |
PWM Sound not upported |
| Pi 4 | circle build | make |
kernel7l.img (32bit), kernel8-rpi4.img (64bit) |
|
| Pi 5 | circle build | make |
kernel_2712.img |
broken, PWM Sound not (yet) supported |
Hint: in case you want to alternatively build for circle-lib and legacy make sure to make clean between the builds!
Now copy the kernel image to your Pi1541 SDCard. Make sure you have set the respective lines config.txt on your Pi1541 SDcard:
Model 3 and earlier - config.txt
arm_freq=1300
over_voltage=4
sdram_freq=500
sdram_over_voltage=1
force_turbo=1
boot_delay=1
# Run in 32-bit mode, 64-bit won't work
arm_64bit=0
enable_uart=1
#gpu_mem=16 # If activated you need start_cd.elf, fixup_cd.dat (Pi3 and Zero 2W) in your root directory
hdmi_group=2
#hdmi_mode=4
hdmi_mode=16
# uncomment as needed for your model/kernel
# Pi 3 & Pi Zero 2W
kernel=kernel8-32.img
# Legacy kernal all models
#kernel_address=0x1f00000
#kernel=kernel.img
in case you use legacy build kernel.img you also have to uncomment the line kernel_address=0x1f00000!
Model 4 - config.txt
# some generic Pi4 configs can remain
# Run in 32-bit mode or set to 1 if 64 bit mode was chosen
arm_64bit=0
#force_turbo=1 # not needed for RPi4's, it's fast enough
[all]
enable_uart=1 # in case you have Pin 14/15 connected via TTL cable
kernel=kernel7l.img
Model 5 - config.txt (boots, but won't run Pi1541 properly)
# some generic Pi5 configs can remain
# Run in 64-bit mode
arm_64bit=1 # must be 64 bit mode
[all]
kernel_address=0x80000
kernel=kernel_2712.img
Uart console on pins 14(TX)/15(RX) gives useful log information.
If enabled, WiFi needs the drivers on the flash card. You can download like this:
cd ${BUILDDIR}/circle-stdlib/libs/circle/addon/wlan/firmware
make
this downloads the necessary files in the current directory.
copy the content to you Pi1541 SDCard in the directory
firmware/
it should look like this:
brcmfmac43430-sdio.bin
brcmfmac43430-sdio.txt
brcmfmac43436-sdio.bin
brcmfmac43436-sdio.clm_blob
brcmfmac43436-sdio.txt
brcmfmac43455-sdio.bin
brcmfmac43455-sdio.clm_blob
brcmfmac43455-sdio.raspberrypi,5-model-b.bin
brcmfmac43455-sdio.raspberrypi,5-model-b.clm_blob
brcmfmac43455-sdio.raspberrypi,5-model-b.txt
brcmfmac43455-sdio.txt
brcmfmac43456-sdio.bin
brcmfmac43456-sdio.clm_blob
brcmfmac43456-sdio.txt
LICENCE.broadcom_bcm43xx
Further you need a file
wpa_supplicant.conf
on the toplevel to configure your SSID:
#
# wpa_supplicant.conf
#
# adjust your country code
country=AT
network={
# adjust your SSID
ssid="REPLACE_WITH_MY_NETWORK_SSI"
# adjust your WiFi password
psk="REPLACYE_WITH_MY_WIFI_PASSWORD"
proto=WPA2
key_mgmt=WPA-PSK
}
Due to some unlikely, unexpected circumstances (e.g. overheating), you may damage your beloved devices (Raspberry Pi, Retro machines, Floppy Drives, C64s, VIC20s, C128s, SDCards, USBSticks, etc) by using this software. I do not take any responsibility, so use at your own risk!
Circle based Pi1541 is distributed in the hope that it will be useful, WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with Pi1541. If not, see http://www.gnu.org/licenses/.
Commodore 1541/1581 emulator for the Raspberry Pi
Pi1541 is a real-time, cycle exact, Commodore 1541 disk drive emulator that can run on a Raspberry Pi 3A, 3B or 3B+. The software is free and I have endeavored to make the hardware as simple and inexpensive as possible.
Pi1541 provides you with an SD card solution for using D64, G64, NIB and NBZ Commodore disk images on real Commodore 8 bit computers such as;- Commodore 64 Commodore 128 Commodore Vic20 Commodore 16 Commodore Plus4
See https://cbm-pi1541.firebaseapp.com/ for SD card and hardware configurations.
On Windows use GNU Tools ARM Embedded tool chain 5.4: https://launchpad.net/gcc-arm-embedded/5.0/5-2016-q2-update and Make: http://gnuwin32.sourceforge.net/packages/make.htm
On dpkg based linux systems install: (Tested on osmc/rpi3)
apt-get install binutils-arm-none-eabi gcc-arm-none-eabi libnewlib-arm-none-eabi libstdc++-arm-none-eabi-newlib
On RHEL/Centos/Fedora systems follow the guide at: https://web1.foxhollow.ca/?menu=centos7arm (Tested on Centos7/x64 with GCC7) https://developer.arm.com/open-source/gnu-toolchain/gnu-rm/downloads/7-2017-q4-major
make
This will build kernel.img
In order to build the Commodore programs from the CBM-FileBrowser_v1.6/sources/ directory, you'll need to install the ACME cross assembler, which is available at https://github.com/meonwax/acme/