Atom and Single Board retro-Computers

[davewoo999]

Unzip the blank.zip and rename to boot.vhd.
Open disk management (right click start menu)
Action - Attach vhd - browse to the boot.vhd should open up as new drive letter.
Copy the files and folders from the unzipped AtomArchive to the new drive letter.
Right click drive letter in explorer and 'eject'
copy boot.vhd to sd card I put mine in a folder /AcornAtom
Should work but I will test again in the next couple of days to make sure

Merry Christmas
Dave

[TheCorfiot]

Thanks Dave, will try now

[TheCorfiot]

Carried that out step by step but end result is the same i'm afraid.. "Not Ready"

I placed the file in fat/Games/AcornAtom/boot.vhd on my main SD
and then selected it from the menu

[davewoo999]

I just tried it and it worked. Confused.
I will work on it tomorrow (or the next day)
I think its time for a Christmas drink.

[hoglet]

Does pressing BREAK after mounting the disk image help at all?

(You need to do this on a real Atom)

[TheCorfiot]

Does pressing BREAK after mounting the disk image help at all?

(You need to do this on a real Atom)

Makes no difference sadly

[davewoo999]

Does pressing BREAK after mounting the disk image help at all?

(You need to do this on a real Atom)

Makes no difference sadly

Try the zip file on this post. https://misterfpga.org/viewtopic.php?p=14944#p14944
Unzip and place in the AcornAtom OR games/AcornAtom folder, make sure there is only ONE folder on the SD.

[hoglet]

That thread is quite an interesting read; several people seem to be having issues.

I'm sorry I don't have a DE10-Nano - if I did I would be happy to help out debugging this.

I have a couple of suggestions (as someone who knows very little about MiSTer)

1. "Put in in the AcornAtom" folder is a bit ambiguous - do you mean /AcornAtom, /games/AcornAtom or somewhere else. I would imagine the main MiSTer firmware looks in a specific place, and will only auto-mount a boot.vhd file if it's found in that place. Be really specific here.

2. What version of the main MiSTer firmware are people using? It's this component that's providing the virtual hard drive emulation, and it's quite possible old versions have bugs. Maybe you could post the instructions for how to check the version that is running?

Dave

[davewoo999]

Dave
Thanks for your suggestions. I will be more specific in future.
I think that there is a problem in my MiSTer firmware connection, but I cannot reproduce it myself.

Its a bit like going to a sweet factory when you are a child, its fascinating but your only interested in the end product.
I need to get into the factory and do some work to understand the firmware side.
There is only a few hundred lines of C code 'how hard can it be '
It will keep me amused during the lockdown.

[AlanD]

Hello Dave

Looks familiar

https://gitlab.com/victor.trucco/zx-spe ... -cores.git


Aland

[davewoo999]

It would appear that I may have fixed the SD card access problem on the MiSTer.
All my fault --
I had AVR8 running at 32Mhz which caused no problem for direct SD access but failed for some when running through the MiSTer SD card access.
I woke up this morning thinking that as I had reduced the access from 16 to 8 bit, the core was now working for some who had problems but not all.
I thought that it may be a speed issue as it takes longer to get the 8 bits.
Had I read the notes Alexey Melnikov (sorgelig ) had put in his sdcard verilog code I would have realised that 32Mhz was to fast.
Dropping the speed to 16Mhz as in your original code sorted it.

Note to self - read the authors notes.

[gob33]

Antonio Villena (Spain) has done its own version of the Mister with an alternative IO+USB board replacing the 2 original extensions boards for the DE10.

Its IO board makes a rather complete machine. It includes a R-2R DAC with VGA output (Scart or YPbPr via an adpter), jack audio output (analog and optical), jack audio input (for tape loading), secondary microSD slot, DB9 joystick port with splitters, 7 USB, leds and push buttons, ON/OFF switch.

All inside a nice laser cut transparent acrylic case.

To play games with the DB9 port you need download cores from this unofficial repository.
There is a BBC DB9 core. DB9 is 0 lag because have direct connect to the fpga, and USB not.

The bill is ~370 / 400+ EUR without keyboard with is expensive to play the Atom progs. But you can also run other retro machines...

[gob33]

The Chloe 280SE is an interesting project based on an FPGA.
The hardware and FPGA core are based on the existing ZX-Uno.
Technicaly they implemented a 16-bit Z80-instruction compatible processor (like a 65816)
The SE Basic IV interpreter is derived in part from the Timex Sinclair 1000.
The OS kernel is the most cryptic part of the project, being reverse engineered from a firmware for the divMMC SD card interface, but source code is provided.
The long term goal is to replace the current FPGA core with a dedicated 16-bit core that will provide a number of additional features.
But that core will remain compatible with the standard ZX-Uno hardware.
They have done their own WASD keyboard:

Chloe 280SE specifications:

The Chloe 280SE is a 16-bit personal color computer implemented as an FPGA core for a board derived from the ZX-Uno.
It has the following features (subject to change):

CPU: R80 (16-bit Z80-instruction compatible processor)
Interrupt: 60Hz (programmable)
ROM: 40K (BASIC and OS)
RAM: 512K

• 128K pageable in 16K chunks at the top of RAM.
• Two exclusive banks of 64K, pageable in 8K chunks across the address space.

BASIC: SE Basic IV 4.2 Cordelia (23K, Microsoft BASIC compatible, extensible)
OS: UnoDOS 3 (ROM-based, FAT32 compatible, API compatible with esxDOS 0.8.5)
Custom Chips:

• Alicia VDP (visual display processor)
• Arturo FPU (floating point unit)
  • Addition.
  • Subtraction.
  • Multiplication.
  • Division.
• Cola GLU (general logic unit)
  • General I/O.
  • Memory paging.
• Lambda DMA (dynamic memory access)
  • 24-bit linear memory access.
  • Blitter functions.
• Laura PSG (programmable sound generator)

Video:

• NTSC / 60FPS.
• 32K VRAM (mirrors main RAM).
• User programmable raster interrupt.
• 256 colors (G3R3B2).

Software Video Modes:

• 240 x 192 with 16 colors (palette of 256), 8 x 1 attributes, 40 column x 24 row text
• 480 x 192 with 2 colors (palette of 256), 80 column x 24 row text.

Physical Video Modes:
Chloe:

• 160x200
• 320x200
• 640x200

Timex:

• 256 x 192, 8 x 8 attributes, 16 / 64 colors (palette of 256)
• 256 x 192, 8 x 1 attributes 16 / 64 colors (palette of 256)
• 512 x 192, 2 colors (palette of 256)

Audio:

• Six voices with two noise channels provided by dual Yamaha YM2149F cores.
• 8-bit DAC (digital to analog converter).
• 1-bit DAC.
• MIDI controller.
• Stereo mixer.

Ports:

• Video out (DVI-I including VGA support, and composite NTSC).
• Stereo audio out (3.5mm)
• Mono audio in (3.5mm).
• Keyboard (PS/2).
• Mouse (PS/2).
• Joystick x 2 (Atari D-type, configurable).
• MMC (Micro SD).
• Power (USB-C).

Alicia VDP overview:

Note: The Alicia video display processor (VDP) has been specified, but not yet implemented in an FPGA core. For now, only the legacy modes are supported.

The Alicia video display processor provides the display for the Chloe.
It has a 32K frame buffer (shared with main RAM).
It generates a progressive 720 x 240 pixel picture that is line-doubled to 720 x 480.
The programmable area can contain up to 128,000 pixels. The chip has a fixed palette of 256 colors (G3R3B2). The chip supports various combinations of resolution, color depth, encoding, line data format and frame buffer size. But again, only certain combinations are supported. Any screen line can use any display mode, although there are some practical limitations on this. Through the use of palette switching it is possible to display all 256 colors on screen in any screen mode. The following resolutions are supported:

• 160 x 200 (wide pixels)
• 256 x 192
• 320 x 200
• 512 x 192 (tall pixels)
• 640 x 200 (tall pixels)

The following color depths are supported:

• 2 color
• 4 color
• 16 color
• 64 color
• 256 color

The following encodings are supported:

• 2 bits per pixel
• 4 bits per pixel
• 8 bits per pixel
• attributes (byte)
• attributes (cell)

The following line data formats are supported:

• arbitrary
• high-byte offset
• linear

The following frame buffer sizes are supported:

• 7 K
• 12 K
• 32 K

[gob33]

You know the ZX Spectrum Next ? ManuFerhi (Spain) has cloned it (Issue 2B) to a board called N-GO with approval of ZX NEXT team members.

It is 100% compatible, same form factor to use the same cases, also solves the problem of power and reset via HDMI and adds protection ESD.
It also includes dual SPI flash selectable through a switch, the main flash houses the ZX Spectrum Next system and the secondary flash the ZXDOS system / ZX-Uno cores.

It is possible to 3D print a small case Acorn typed to put this board inside and run the Atom / BBC cores of the ZX Next.
And add a custom keyboard...

N-GO, ZX Next Clon

N-GO, ZX Spectrum Next Clone (BBC emu at 30:00)

Carcasa N-GO 3D Printed

Carcasa N_GO, 3

[gob33]

To make an FPGA Atom, project Julia (Amiga 600 like) gives the files for a 3D printed case.
You'll get a package for RaspberryPi form factor boards.
But you can use EVERY BOARD you like. This is designed with extension cables from inside to outside so you can place a board somewhere inside the case, drill holes through the bottom, fix it and use the extension cables (2x USB, Ethernet, HDMI). If you need some special connections, there is a place for one standard PCI bracket. Supported boards.

There is a modification for the SIDI board by Armand López.

It can be printed in 2 pieces only on a large printer.
If you dont have one, use JLCPCB print service or Craftcloud

Facebook Page
Facebook Group

[gob33]

8bitsforever has released a MIST clone fpga board.
They called it Miss FPGA.
Technically the chips arrangement is adapted for the Amiga A500 case so that you can run BBC / Atom mist cores but with an Amiga keyboard. You just have to put an big "Acorn" sticker on the Amiga logo.

Miss FPGA Review & Demo

[gob33]

Lee 'Legion' Smith has issued a new version of its MisterFPGA case:

It uses the Multisystem board to have most commons ports (VGA, HDMI, USB, ...)

The modular 3D print is interesting by having the keyboard detached from the rest of the case so that it can be adapted.

https://www.youtube.com/watch?v=SEKKvxdV0tk

[gob33]

Another possible Atom emulation that avoids resorting to 3D printing is to use a MisterFPGA board and a mini-ITX case.
Im thinking of the combination of the MiSTer Mini-ITX Ironclad Plus inside a Checkmate 1500 Mini for example.
Then you have the Atom and BBC cores (and many others) and you build a custom PC Usb keyboard with red function keys.

MiSTer FPGA goes ITX!
See also : New experimental MiSTer emulator

The jammix board has a jamma connector: Finally I got my hands on a MiSTer FPGA Retro Gaming Setup | MVG

[Grasshopper]

I've got my eye on one of these C64 (or VIC20) styled cases for my MiSTer:

https://myretrocomputer.com/

[gob33]

Andrew Mathieu did its own adaptation of Lee "Legion" Smith 3D printed case for the Commodore X16.
The result is excellent, I dont see traces of plastic deposit, its printer is very good.
Its design could be worked a little more in Blender or Solidworks to approach an Atom or BBC case:

The parts are split so they fit on a 230x230mm print bed and with that the side pods have to be printed 45° diagonally. Without splits the largest piece would be 380x225mm (base plate). The overall size of the case is 395x240x65mm. You need to find a suitable ten-keyless keyboard to integrate. The stands I've modelled fit the Xtrify K4 keyboard which is available in a retro colour scheme.

Commodore X16 forum
Files

[gob33]

The Cerberus 2080 is a micro-ATX 8 bits computer supporting both the Z80 and the 65C02 CPUs.
It has been designed by Bernardo Kastrup for educational purpose: all is clean and very well documented. No FGPA.
The interesting points are the compatibility with Acorn MOS through RubyOS and BBC Basic 4 that runs on it.

Only one of the 8-bit CPUs can run at a time. The BIOS code is available as an Arduino sketch in the ATMega328p, and can be modified and uploaded quickly using the Arduino IDE and an FTDI cable. But the Byte Attic's original BIOS has also some defaults (not passing control chars and ESC key, unidirectionnal, limitation to 32k 80% full). See the alternate BIOS.
Porting Atom should not be difficult: virtual ROMs take place in the full 64KRAM.

Hackaday
You have a very interesting video playlist of 21 episodes describing all the conception.
The main criticism is that there is always a processor unused whether you are for z80 or for 6502.
Better if the z80 was an ARM instead or something like a "Tube" connector / PiTubeDirect with logic inside the CAT.
And the little ATMega328 replaced by a bigger one like ATMega648P or an STM32duino

[Volhout]

Hi gob33,

No FPGA, but 3 CPLD's....

Volhout

[gob33]

TreatStock makes relation between customers and 3D printing manufacturers

[gob33]

David Rumball made an updated Microbox II board MB2K2 built around an XMOS XU216, sold $140 assembled and tested on Tindie.
The XU216 has 512KB of internal RAM, 2000 Mips. The PCB has VGA, USB, PS/2, serials.
Each of the 16 RISC cores in the XU216 map onto one of the individual LSI chips in the system being emulated.
XMOS microcontroller has its origins in the Transputer processor from INMOS (used by the Atari ATW800), RTOS in incorporated in their XC programming language, their IDE is based on Eclipse.

XMOS devices seem able to drive hardware fast, but at the same time run higher-level code that would normally be running in user space.
You don't have the same memory space as you'd have in a full system running a big OS, but often you don't need that.

The philosophy with the Propeller micro-controller from Parallax Inc. is similar to that of XMOS: use general purpose processors to implement functionality in software that would otherwise be done in hardware peripherals, e.g. UARTS, SPI, I2C, PWM motor controls etc.
Doing things that way means no need for a complicated operating system or any worries about interrupt processing and gets you deterministic timing of your code execution. Prior to the arrival of the XMOS, the Propeller was the only device of this nature generally available for a few dollars.

Currently the MB2K2 emulates a 6809 and FLEX, but there’s nothing to stop the emulation of other systems. David Rumball Github.

The old first Microbox SBC produced by Micro Concepts in England, and designed by Dave Rumball.(1985)
Microbox II 6809 Single Board Computer

[gob33]

8bitsforever (Barcelone - Spain) has released an I/O board designed to fit a MiSTer FPGA (Terasic DE-10 Nano) inside an Mini ITX PC case (170x170mm).
The MistressITX is similar to the IronClad Plus board.

[gob33]

The Agon Light™ is another modern small 8-bit microcomputer by Bernardo Kastrup (The Byte Attic), successor of its Cerberus 2080 board.

It uses an eZ80F92 running at 18.432MHz (in order to direct continuous address 16 MB of memory without a MMU) in communication with an ESP32 at 240 MHz. Agon's architecture takes inspiration from the classical mainframe + terminal structure. These two main subsystems that constitute Agon™ (namely, the eZ80 processor subsystem and the ESP32 A/V 'terminal') can be programmed in standard C with freely-available tools, such as the Arduino IDE and Zilog's ZDS-II IDE. Instead of having to program kernel code in assembly so to write to an EPROM, you can simply write C code, compile it with free tools, and upload your firmware into the eZ80's and the ESP32's embedded flash memories.

512Kb SRAM, 128Kb of flash memory built into the eZ80, μSD-card, VGA 64 colors, PS/2, USB, 20 GPIOs, 2 audio channels.

Official firmware: BBC Basic 4 for the Z80 with inline Z80 assembler (tweaked version of R.T.Russell), Agon MOS, CP/M, Zeal OS
Audio and video is handled by the VPD (Visual Display Processor), an ESP32 running custom firmware on top of the FabGL ESP32 library.
The VDP takes a BBC Basic text output stream as input. It will process any valid BBC Basic VDU command through FabGL to the VGA.
FabGL also implements: an Audio Engine, a Graphical User Interface (overlapping windows, mouse handling and a lot of widgets), a Game Engine and an ANSI/VT Terminal. A large set of functions available to the programmer.

Dean Belfield's github repository is public, you can participate. See also its Twitter account.
The system is very flexible.

Agon light™ electronic design overview

NOTE 1: The Z80 compatibility is not very useful for the Acorn machines and constitutes an obstacle. The board is more suitable for Amstrad Locomotive Basic or Sinclair Spectrum. Althrough the eZ80 is an efficient processor, could the processor subsystem be replaced by a 65C02 plus a 24bit address trick like the one used on the KimKlone ? Then a GPIO must be installed too.

The KimKlone's guy expands 6502 to 16M address space by intercepting the databus and re-mapping unused opcodes and clever use of the spurious signals generated by the cpu when executing other undefined opcodes, adds a few registers to make the whole thing transparent from an assembler programmers point of view. In other words, there is no difference to the programmer between native and newly minted instructions.

NOTE 2: The ESP32 @ 240Mhz of the terminal subsystem can emulate a 6502 (like for EhBASIC).

NOTE 3: Another comparable eZ80 project is Konstantin Dimitrov's Z20X with CPU on its own small PCB, a bus expander compatible with the RC2014 modular z80 computer.

[gob33]

I am wondering if Atom (or BBC) system could be transfered on the final Commander X16 prototype by "th 8 bits Guy". The X16 is a 65C02 @ 8 Mhz. It has a VERA fpga board that provides video and the source has been released under MIT license. The modern X16 ROM code is public too and can be reprogrammmed on board through a jumper.

[gob33]

OLIMEX bulgarian company founder Tsvetan Usunov has created a new, improved, lower-cost version of AGON Light (fully compatible with the original) and plans to sell it in a few days, before Christmas, for the special holiday price of just EUR 50 (!), fully assembled, programmed and tested.
Now the board will be available to all EU users without Brexit at afordable price.

In the past OLIMEX had quite bad experience with the pseudo open source project named "Maximite".
They designed a board based on the Maximite original hardware and named it "DuinoMite".
When they approached the author about adding support for their board (as it has more features than its original design),
he refused at first to support it and then closed the sources. After that Olimex gives up.
After exchanging a few words with Bernardo Kastrup via Twitter, Tsvetan Usunov became confident that Agon is a true open source hardware project.

To read:
Maximite creator Geoff Graham, explains its problems with the "DuinoMite" and OLIMEX and Open Source.

"Agon Light is the fastest and cheapest 8-bit microcomputer ever made; and in addition, Agon Light is the world's sole standalone, instant-on, BASIC-programmed microcontroller that dispenses with a host PC and sketch compilation. This allows projects to be controlled from the immediacy of a BASIC interpreter's prompt."

They plan to do also a metal box like the one they have for LIME2.

JLPCB prototype boards are purple, production will be red as usual.

As OLIMEX has previous experience with the ESP32-WROOM-32 on board, they added an UEXT (Universal-EXTension) connector which allows Agon Light to be connected to: temperature sensors, environmental air quality sensors, pressure, humidity, gyroscope, light, RS485, LCDs, LED matrix, relays, Bluettooth, Zigbee, Lora, GSM, RFID reader, GPS, Pulse, EKG, RTC etc.
These are their current modules /sensors plugging in the UEXT connector:

MOD-IRDA to send and receive IR commands
MOD-RS485-ISO to connect to machines with RS485 interface
MOD-MAG to measure magnetic field
MOD-BME280 to precisely measure pressure, temperature, humidity
MOD-LTR-501ALS to measure light and color
MOD-LCD2.8RTP LCD with touch panel for remote User Display and Interface
MOD-IO four relay module for switching on and off devices
MOD-RFID1356MIFARE RFID card reader

Could then be commanded through BBC Basic...

Byte Attic twittter
OLIMEX twitter

[BigEd]

That's an interesting board, but I think it uses a Z80 of some sort, not an FPGA?

[gob33]

See 2 posts above. Zilog continued to evolve the Z80 family on the contrary of Western Design Center MOS 65xx.
As the Agon system has 2 separate parts communicating with serial link, the design could be modified in theory with efforts.
A 65816 + additionnal circuitry here would be inferior to the eZ80 solution.
In fact the Agon has all to make an Amstrad evolution instead of a BBC one, perhaps a port of Locomotive Basic ?