This project creates a Z80 based computer from a Panologic thin client by loading a new bit image into the Pano FPGA, no other modifications are needed.
Features:
- 25Mhz Z80 with 64K RAM
- USB keyboard and VGA monitor for console
- USB flash drive provides storage of multiple Floppy and hard disks images
- Compatible with disk images created for the z80pack project
- Compatible with disk images created for the Multicomp project
- ANSI support for keyboard and monitor
- Function key selection of retro "Green Screen" or normal screen modes
- Function key selection of retro or normal control key placement
- RISC-V I/O co-processor
- No soldering required!
Panologic was a Bay Area startup that manufactured tiny thin clients that were connected to a central server. The Pano devices have a Ethernet interface, a few USB ports, audio input and output ports, and one or two video ports.
The first generation (G1) Pano was based on the largest Xilinx Spartan-3E family chip and supported a single VGA monitor.
The second generation (G2) supported two DVI monitors. Revision A and B of the G2 devices were based on the Spartan-6 LX150 which is the largest chip in the family. The revision C G2 device is based on the smaller LX100 device which is still quite large by hobbist standards.
Unfortunately for Panologic, but fortunate for FPGA hobbyists Panologic went out of business in 2012. Shortly thereafter TONS of both new and used Panologic devices started showing up on ebay for very little money since they were pretty much useless without support. Even today (Aug 2020) both versions of the Panologic devices are still readily available on ebay for little.
Tom Verbeure has spent a lot of time reverse engineering the Panologic devices and created an absolute mind blowing raytracing demo that runs on a G1 device. It was the Hackaday article article on his project that originally attracted my attention to the Pano hacking scene.
Tom's article also got the attention of Wenting Zhang who added support for the G1's SDRAM and USB controller as well as making it possible to execute code on a soft processor directly from the SPI flash.
This project was derived directly from his Verilog Boy project.
Disk I/O is provided by a USB flash drive. Multiple CP/M floppy and hard disk images can be stored on a single drive.
The standard FAT filesystem is used so there is no need to use special tools to write images to the drive.
Disk images for the z80pack project can be copied to the USB flash drive and booted directly without any additional configuration.
A classic VT100 "Green Screen" terminal is emulated using a VGA monitor and a USB keyboard. A sufficient subset of the ANSI cursor positioning escape sequences have been implemented to support CP/M programs such as WordStar and WordMaster.
Characters are displayed as green on black again to match legacy monochrome monitors. To provide a closer match to keyboard layouts that were common in the 70's and early 80's the caps lock and left control keys are swapped.
The keys in the numeric keyboard and function keys F1..F4 generate appropriate ANSI escape sequences for programs that might support them. None of the other non-ASCII keys are passed to the Z80 console.
Function keys F5 .. F12 are used by the RISC-V I/O processor to provide run time control of the system.
F5 is used to swap the position of the control and caps lock keys.
F6 is used to toggle the display between green on black, white on black, or black on white.
F7 is used to reset Z80 processor.
- A first generation Panologic thin client (G1, the one with a VGA port)
- A suitable 5 volt power supply
- A USB keyboard
- A USB Mass storage device
- A JTAG programmer to load the bitstream and program code into flash
To program the supplied binary files you use either xc3sprog or iMPACT included with Xilinx ISE 14.7.
To say the very least xc3sprog is a smaller download, but you will need to built it from sources for your system. I recommend that you install it even if you already have installed ISE. I have found xc3sprog to be easier to use, faster, and more reliable than iMPACT.
If you would like to modify fpga portion of the project you will definitely need to download and install ISE.
The free Webpack version of Xilinx ISE 14.7 is used for development. Do NOT download the latest Windows 10 version as it does not support the Spartan 3E family of chips used in the first generation of the Pano device.
Installation is done in two parts. First we prepare a USB flash drive for booting and running the Z80, then we update the Pano's flash with a new image. The image includes the bit stream for the FPGA as well as firmware for the RISC-V I/O processor.
Start out by cloning the pano_z80 repository and changing directory into it.
skip@dell-790:~/pano/working/$ git clone https://github.com/skiphansen/pano_z80.git
Cloning into 'pano_z80'...
remote: Enumerating objects: 345, done.
remote: Total 345 (delta 0), reused 0 (delta 0), pack-reused 345
Receiving objects: 100% (345/345), 9.29 MiB | 6.91 MiB/s, done.
Resolving deltas: 100% (173/173), done.
skip@dell-790:~/pano/working/$ cd pano_z80
skip@dell-790:~/pano/working/pano_z80$
The storage capacity of the USB flash drive isn't important, it's literally impossible to buy a drive that's too small these days. A 256 mb (not gigabyte!) drive is more than sufficient.
The exact degree of USB flash drive compatibility of the USB subsystem is unknown, but it is expected to be reasonable. I have tested with several different devices and they all work, but they were are all "Bulk/Bulk/Bulk" type devices at the low level. "Control/Bulk" and "Control/Bulk/Interrupt" type devices also exist, but I haven't found any to test with.
If a flash drive isn't recognized or doesn't work try a different one.
If you are worried about compatibility the specific device I'm using is a SanDisk Cruzer because it's tiny, cheap and a "name brand".
Unlike more modern operating systems the disk layout is not written to the media itself, it's hardcoded in the CBIOS. Hence drive mappings are defined by the image that is used to boot CP/M.
Disk images created for either the z80pack or Multicomp projects or a mix of both can be used. There are a huge number of disk images are available for download from the z80pack project web page. I've also found a couple of Multicomp images that contain massive collections of CP/M software.
The z80pack project uses one disk image per drive. The stock z80pack CP/M 2.2 CBIOS supports four 241K 8 inch SSSD floppies and two 4mb hard disks. Z80pack disk images have an extension of ".dsk".
Since the Pano_z80 I/O system implements the I/O ports as defined by the z80pack project's drivea.dsk the disk images may be booted directly.
The Multicomp project uses one image file per system which emulates 16 8mb CP/M hard disks (A: to P:). Multicomp disk images have an extension of ".img".
Since the Pano_z80 I/O system is not compatible with Multicomp's CBIOS Multicomp images can not be booted directly. Rather than replacing the system tracks of the Multicomp image with a compatible CBIOS a separate boot image is used for booting.
Two boot images are provided to support Multicomp images, one provides access to all 16 drives within the Multicomp image while the other supports a combination of Multicomp and z80pack images.
There are 3 boot options to chose from:
| Option | Boot disk | Floppies | Z80pack 4mb HD | Multicomp 8mb HD |
|---|---|---|---|---|
| 1 | drivea.dsk | A: -> D: | I: , J: | |
| 2 | boot.dsk | A: -> P: | ||
| 3 | dual.dsk | G: -> H: | I: , J: | A: -> F: |
The drive mappings for the first two boot options are the same as the original projects. This provides compatibility with submit jobs from those projects which assume certain disk mappings.
Boot option #3 allows images from both projects to be mounted simultaneously, however Multicomp drives G: -> P: are not be mounted and are not accessible.
If multiple boot disk images are present on the USB drive the user will be asked to select the desired configuration when the system is booted.
If multiple Multicomp disk images (.img) are present on the USB drive the user will be asked to select the desired configuration image when the system is booted.
Clone the z80pack repository and copy .../z80pack/cpmsim/disks/library/cpm2-1.dsk to the root directory of the USB flash drive naming it "DRIVEA.DSK". This is the CP/M boot disk and it must present.
Copy any other desired floppy disk images to "DRIVEB.DSK", "DRIVEC.DSK", and "DRIVED.DSK". Copy any desired hard disk images to "DRIVEI.DSK" and "DRIVEJ.DSK".
Warning: If the wrong image type is mounted on drive nothing good is likely to happen!
Copy .../pano_z80/fw/z80/srccpm2/boot.dsk to the root directory of the USB flash drive. This is the CP/M boot disk and it must present. Note: this image is only used for booting CP/M, it will not be mounted and will not be visible to CP/M.
Copy the desired Multicomp disk image(s) to the root directory of the USB flash drive. These image(s) must have an extension of ".img".
Copy .../pano_z80/fw/z80/srccpm2/dual.dsk to the root directory of the USB flash drive. This is the CP/M boot disk and it must present. Note: this image is only used for booting CP/M, it will not be mounted and will not be visible to CP/M.
Copy any desired floppy images to the root directory of the USB flash drive naming them "DRIVEG.DSK" and "DRIVEH.DSK", copy any desired z80pack 4mb hard disk images to "DRIVEI.DSK" and "DRIVEJ.DSK".
Copy the desired Multicomp disk image(s) to the root directory of the USB flash drive naming. The images must have an extension of ".img".
Install xc3sprog for your system. If a binary install isn't available for your system the original project can be found here: https://sourceforge.net/projects/xc3sprog/. Sources can be checked out using subversion from https://svn.code.sf.net/p/xc3sprog/code/trunk.
As an alternate if you don't have subversion a fork of the original project can be found here: https://github.com/Ole2mail/xc3sprog.git .
If your JTAG cable is not a Digilent JTAG-HS2 cable then you will need to edit the toplevel Makefile and change XC3SPROG_OPTS for your device.
Refer to the supported hardware web page page or run xc3sprog -c to find the correct cable option for your device.
Now that hard part is over, just run make to flash the new Xilinx bit stream and firmware image
skip@dell-790:~/pano/working/pano_z80$ make
xc3sprog -c jtaghs2 -v -I./fpga/xc3sprog/pano_g1.bit ./xilinx/pano_z80.mcs:W:0:MCS
XC3SPROG (c) 2004-2011 xc3sprog project $Rev: 774 $ OS: Linux
Free software: If you contribute nothing, expect nothing!
Feedback on success/failure/enhancement requests:
http://sourceforge.net/mail/?group_id=170565
Check Sourceforge for updates:
http://sourceforge.net/projects/xc3sprog/develop
Using built-in device list
Using built-in cable list
Cable jtaghs2 type ftdi VID 0x0403 PID 0x6014 Desc "Digilent USB Device" dbus data e8 enable eb cbus data 00 data 60
Using Libftdi, Using JTAG frequency 6.000 MHz from undivided clock
JTAG chainpos: 0 Device IDCODE = 0x21c3a093 Desc: XC3S1600E
Created from NCD file: top.ncd;UserID=0xFFFFFFFF
Target device: 3s1600efg320
Created: 2019/08/11 16:06:27
Bitstream length: 5969696 bits
done. Programming time 1022.5 ms
JEDEC: 20 20 0x14 0x10
Found Numonyx M25P Device, Device ID 0x2014
256 bytes/page, 4096 pages = 1048576 bytes total
Created from NCD file:
Target device:
Created:
Bitstream length: 6764640 bits
Erasing sector 13/13....Writing data page 3303/ 3304 at flash page 3303..
Maximum erase time 635.4 ms, Max PP time 63536 us
Verifying page 3304/ 3304 at flash page 3304
Verify: Success!
USB transactions: Write 16761 read 16394 retries 17404
xc3sprog -c jtaghs2 -v ./xilinx/work/pano_top.bit
XC3SPROG (c) 2004-2011 xc3sprog project $Rev: 774 $ OS: Linux
Free software: If you contribute nothing, expect nothing!
Feedback on success/failure/enhancement requests:
http://sourceforge.net/mail/?group_id=170565
Check Sourceforge for updates:
http://sourceforge.net/projects/xc3sprog/develop
Using built-in device list
Using built-in cable list
Cable jtaghs2 type ftdi VID 0x0403 PID 0x6014 Desc "Digilent USB Device" dbus data e8 enable eb cbus data 00 data 60
Using Libftdi, Using JTAG frequency 6.000 MHz from undivided clock
JTAG chainpos: 0 Device IDCODE = 0x21c3a093 Desc: XC3S1600E
Created from NCD file: pano_top.ncd;HW_TIMEOUT=FALSE;UserID=0xFFFFFFFF
Target device: 3s1600efg320
Created: 2019/10/15 09:03:47
Bitstream length: 5855264 bits
done. Programming time 1000.1 ms
USB transactions: Write 366 read 7 retries 8
skip@dell-790:~/pano/working/pano_z80$
Use iMPACT to program .../xilinx/pano_z80.msc into flash.
- Start iMPACT (Selecting Tools/iMPACT from ISE's menu is one way).
- Double click "Boundary Scan" under iMPACT flows.
- Right click in the Boundary Scan window and select Initialize chain.
- Dismiss the Auto Assign dialog box by clicking No.
- Click Ok on the Device Programming properties dialog.
- Right click the "SPI/BPI ?" box shown above the Xilinx chip and select "Add SPI/BPI flash"
- Navigate to .../xilinx/pano_z80.msc and click Open.
- Select "M25P80" from the drop down box on the dialog and click OK.
- Right click the "Flash" box shown above the Xilinx chip and select "program".
- Click OK on the Device Programming Properties dialog.
- Cross fingers and hope that the program operation will be successful.
Now that the Pano has been updated and a USB flash drive is ready it's time for the moment of truth. Connect a USB keyboard and the USB flash drive to the USB ports and connect a VGA monitor.
Now turn on power and hopefully you'll be greeted by a screen similar to the one at the top of this page.
I've played around with a few CP/M programs briefly and most of what I tried worked fine, however the paint on this project is most definitely still wet. If you find any issues please file a ticket, or better yet fix them and send me pull requests!
NB: While it may be possible to use Windows for development I haven't tried it and don't recommend it.
-
Install the free Webpack version of Xilinx ISE 14.7
-
Follow the instruction in the PicoRV32 repository to install the riscv32ic toolchain.
-
Clone this github repository into
~/pano_z80and change into the root of the repository -
Build the firmware for the RISC-V processor
(cd fw/firmware/;make)
This creates the file ~/pano_z80/fw/firmware/firmware.bin
-
Fire up Xilinx ISE
-
Create the bitstream
~/pano_z80/xilinx/work/pano_top.bit- File -> Open Project -> ~/pano_z80/xilinx/pano_z80.xise
- Double click on 'Generate Programming File'
-
Create the MSC "prom" file with the bit stream and firmware image
- Start iMPACT
- Click "No" to "Automatically create and save a project"
- Open the iMPACT Project file ~/pano_z80/xilinx/pano_z80.ipf
- Double click "Generate File..." under iMPACT Processes
This should create ~/pano_z80/xilinx/pano_z80.mcs.
These targets assumed you have installed xc3sprog, if you haven't, well ... then these won't be very useful after all.
Run "Make prog" from .../sw/firmware to build and program JUST the RISC-V image. This provides a very fast build/debug/edit/build cycle by eliminating the need to touch ISE or iMPACT. A typical build/flash takes less than 10 seconds.
Run "Make reload" to just reload the current .bit file into the Xilinx. It is NOT programmed into flash. This provides an easy way to reset the FPGA and RISC-V processor.
Run "Make prog_fpga" to just flash the current .bit file into the SPI flash.
Run "Make prog_all" from the top level directory to flash the current .bit file and RISC-V firmware.
The RTL hardware includes a output only UART which can be used for debug output while debugging RISC-V firmware. The debug serial port's format is 115200-n-8-1.
Moderate soldering skills or good clip leads are needed to connect a 3.3V compatible serial port to the LED. The LED trace is fairly easy to access, please refer to my pano_man documentation for the location.
The log.h header includes several macros to make debugging easier. Please refer to the source for details.
The inspiration from this project was Grant Searle's Multicomp project. I bought an Cyclone II dev board shortly after discovering Grant's web site a few years ago, but I never got around to doing anything with it. The needed wiring wasn't difficult nor were the parts expensive or hard to find but laziness won the day.
Last year Tom Verbeure's ray tracer project caught my eye and I bought a "few" PanoLogic devices and actually started to do stuff with them.
The Pano devices have a huge potential as a hobbyist device but it's also a steep hill to climb. Luckily I didn't have to climb it alone or my Pano would probably also be sitting around untouched.
I had initially planned on designing my own I/O system like Grant had and then writing a CBIOS to support it. I couldn't use Grant's CBIOS directly since I wanted to use USB flash drives instead of the SD cards that Grant used. However once I discovered the z80pack project I decided to leverage Udo Munk's CBIOS by implementing his I/O system design in hardware. I'm sure this decision saved me hundreds of hours of frustration.
If you build/use/modify this project I'd enjoy hearing about it. You can find my email address in the git log.
Tom Verbeure's reverse engineering efforts and Panologic bring up code made it possible to get projects up and running rapidly without the reverse engineering drudgery. Without Tom's work I would still be thinking of getting involved with FPGAs "some day".
I started this project by cloning Wenting Zhang's VerilogBoy project and then replacing the Gameboy portion with a Z80.
Wenting's contributions of bringing up the LPDDR Ram and USB subsystems on the first generation Panologic device has opened up a window of possibilities for Pano hacking immeasurably. Mr Zhang has my sincere thanks and admiration for his brilliant work.
This project also uses code from several other projects including:
- https://github.com/cliffordwolf/picorv32
- https://github.com/u-boot/u-boot
- https://github.com/MParygin/v.vga.font8x16
- Daniel Wallner's Z80 CPU core
- ChaN's FatFs
- Martin K. Schröder's VT100
- CP/M demo disk from Obsolescence Guaranteed
- Software for the LiNC80
- The HUMONGOUS CP/M software Archives
- The Unofficial CP/M Web site
- The Retrocomputing Archive
Links to other Panologic information can be found on the Pano Hacker's Wiki
My original work (the CP/M I/O system) is released under the GNU General Public License, version 2.
My version of CBIOS is based on Udo Munk's original work, which was published with the following license:
Copyright (c) 1987-2016 Udo Munk
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
My version of CBIOS also includes portions of Grant Searle's original work, which was published with the following license:
"By downloading these files you must agree to the following: The original copyright owners of ROM contents are respectfully acknowledged. Use of the contents of any file within your own projects is permitted freely, but any publishing of material containing whole or part of any file distributed here, or derived from the work that I have done here will contain an acknowledgement back to myself, Grant Searle, and a link back to this page. Any file published or distributed that contains all or part of any file from this page must be made available free of charge. (http://searle.wales//Multicomp/index.html).
All the project files (SW & HW) are licensed under GPL v3.
This project was derived directly form Wenting Zhang's Verilog Boy project which was released under the GPL version 2. license.
Wenting further acknowledged the following:
The PicoRV32 is free and open hardware licensed under the ISC license (a license that is similar in terms to the MIT license or the 2-clause BSD license).
Some firmware code of pano-g1 target are released to public domain.
All other software codes are licensed under GNU GPL 2.0.
All other HDL codes are licensed under OHDL 1.0.
All other text documents are licensed under CC BY-SA 4.0
If you use this material in any way a reference to the author (me :-) ) will be appreciated.