RomWBW kits in More Detail

Connecting to the RomWBW bus is as easy as plugging in a micro USB cable, and setting your computers terminal software to 115200, 8 bits, 1 stop bit, no parity to the CDC/pico serial port this is automatically detected.

Windows
On Windows Id recommend Terra Term https://tera-term.en.softonic.com/download

Click on setup -> Serial port to configure your USB connection.

Linux
For Linux Minicom a command line serial emulator , which is likely already installed.

Start minicom with the command minicom -D /dev/ttyXXXX where XXXX is the detected serial port.

then CTRL-A P to setup the serial parameters.

Front panel Switches / LED

Writing to Port Zero sets the bits / leds on the front-panel.

Reading from port Zero gives the position of the switches.

Please note that as the 8 lines are shared between the LEDs and switches reading the port will briefly disconnect the drive to the Led’s

5 REM Front Panel LEDs to do CYLON chase 
10 FOR F=0 TO 7
20 OUT 0,2^F
30 GOSUB 100
40 NEXT F
50 FOR F=7 TO 0 STEP -1
60 OUT 0,2^F
70 GOSUB 100
80 NEXT F
90 GOTO 10
100 FOR X = 1 TO 50 : NEXT X : RETURN

For more details on how RomWBW uses the front panel, look into the RomWBW manual.

LCD Emulation

The OLED display on a RomWBW Bus system emulates a 16 character x 4 line LCD display. By Default it is set to port 0xDA / 0xDB and emulates the basic functionality of the LCD driver chip (hd44780).

10 R=218    : REM 0xDA - Register
20 D=219    : REM 0xDB - Data
30 OUT R,56 : REM 0011 1000 - Function 8 bit, 2 lines, 5x8 dot font
40 OUT R,14 : REM 0000 1110 - Display on, cursor on, no blink
50 OUT R,1  : REM 0000 0001 - Clear display
60 INPUT "Text to display";T$
70 FOR A=1 TO LEN(T$)
80 PRINT MID$(T$,A,1);
90 OUT D,ASC (MID$(T$,A,1))
100 NEXT A

SPO256-al2 Speech

Writing bytes from 0-64 to port 0x28 will trigger the appropriate phonym to be played, reading port 0x28 will give a non zero output whilst a phonym is being played.

A tool to compute the phonyms for text speech is here https://extkits.co.uk/sp0256-al2/

5 REM Speak 'RC2040' using allophone data beep port 40 (0x28)
10 FOR A=1 TO 22
20 READ X
30 OUT 40,X
40 WHILE(INP(40)>0)
50 WEND
60 NEXT A
100 DATA 59,2,55,55,19,2,13,48,7,7,11,1,2,13,19,4,40,58,2,13,19,4

Sending a value from 0-127 will change the frequency of the speech roughly clocking the speech from the midi note value frequency .

Beep

Sending a value of 1-127 to 0x29 will send a tone to the speaker, roughly the same frequency as the note values in the midi specification.

10 REM output middle C (256 Hz) Base Port 41 (0x29)
20 REM and turn off afterwards
30 OUT 41,60
40 FOR B=1 TO 200
50 NEXT B
60 OUT 41,0

NeoPixel Port

Currently untested with the WBW board.

But you could connect a string of neo-pixels WS2812 to GPIO 28 on the Pico. and take a look here.

100 rem neopixel repeat test
110 OUT 64,3
120 OUT 65,3
130 c=c+1
140 for p=0 to 2
150 c=c+1
160 gosub 2000
170 next p
180 goto 130
200 end



2000 if c=1 then goto 2100
2010 if c=2 then goto 2200
2030 if c=3 then goto 2300
2040 c=c-3 
2050 goto 2000

2100 r=32:g=0:b=0
2110 goto 3000

2200 r=0:g=32:b=0
2210 goto 3000

2300 r=0:g=0:b=32
2310 goto 3000

3000 out 69,r
3010 out 70,g
3020 out 71,b
3030 out 67,p
3040 return

Sample code

The RomWBW emulation has two serial ports USB and FDTI

The USB port connects at 115200, 8 bits, 1 stop bit

The FTDI port also defaults to 115200, 8 bits, 1 stop bit, but can be changed with the INI file on the SD card.

The primary port is USB, this can be changed to FTDI in the INI file.

This can also be changed in the Pico RomWBW by the switch at the back of the unit.

The front panel can also be used to change the port from Primary / Secondary. For more details look at the RomWBW front panel switches. and the RomWBW monitor I command.

The RomWBW Bus will connect to RC2014 I/O peripherals. It will not work with peripherals that use memory, other processors. There also may be issues with the timing of real time signals.
The RomWBW Bus uses logic levels of 3V3 this will be fine for most RC2014 modules, but some versions of TTL chips may have a problem with this. The lower 8 bit address lines are buffered to 5V as many modules use diode address decode logic.

The RomWBW Bus will first address any i/o port that it is emulating (if its enabled) It will then try to address any module on the RC2014 bus.

Reset
The Reset line is extended from the Pico/RP2350 Z80 line to allow external peripherals to reset the emulation. This is separate from the Pico Run line (which resets the pico)

Halt (Rc2014 Bus only)
Not yet implemented

Interrupts (Rc2014 Bus only)
Not Yet implemented

Wait (Rc2014 Bus only)
The Wait line is not enabled by default, to use it it does need to be enabled (see rc2040.ini) and it needs to be externally pulled high to allow the emulation to run.

Clock (Rc2014 Bus only)
Not Yet implemented

Power

The PicoRomWbw and RomWBW Bus can be powered in a number of ways.
Via USB is the easyest way, just plug in a Micro USBcable.
Via FTDI if the link “FTDI power” is shorted, then the device can be powered from an FTDI or compatible cable.
The RomWBW can also be powered from the RC2014 bus. Please be careful as this can also back feed power via the USB connector. This can be isolated by cutting JP1.

RomWBW Bus
It is also possible to run the RC2014 bus from 3v3 by shorting the other link of JP1, but not only do the RC2014 peripherals need to run with 3V3, but you must be extremely carefull not to connect 5V to the RC2014 bus as this will damage the Controller.

The ports that the emulated peripherals respond to each have their own settings in the ini file.
To change an emulated peripheral i/o port location, set the appropriate port.
To disable an emulated i/o port, set the port number greater than 255.

External i/o ports (Bus version only) are contacted when a request is made for an i/o port not configured for any emulated i/o peripherals. The i/o ports for the external devices must be set by address bus decoding on the i/o peripheral card itself.

The code for the Pico/Pico2 and RP2350 emulation is available on github.

PicoRomWBW https://github.com/ExtremeElectronics/RC2040-ROMWBW. (Pico and Pico2)
RomWBWBus https://github.com/ExtremeElectronics/RomWBW-Bus. (On Board RP2350B only)

Pico / Pico 2 (Pico RomWBW only)
Using Pico RomWBW the processor rp2040 or rp2350 must be selected in the CMakeLists.
Also note that you must use the appropriate rom file to match the Pico Board/Processor as the Pico2 (rp2350) has much more memory available.

RomWBW Bus will only work with the RP2350B processor from the RomWBW Bus repository, and requires the Ext Kits PCB

CPMIDE.id
This file contains the disk geometry for the SD card file system
Python programs to read and write the id files are here https://github.com/ExtremeElectronics/RC2040-ROMWBW/tree/main/Support%20Programs

diskdefs
The diskdefs file allow the FFS system to read the CPM disks with in the img. They follow the CPM tools diskdef specification and can also be used with CPM tools to read an write to the img files.

img file(s)
.img files are the flat file representation of the disk drives. Each img file can hold a number of disk volumes. Take a look at the RomWBW descriptions for more information. https://github.com/wwarthen/RomWBW/tree/master/Doc – Hard Disk Anatomy

.img files are generally created by the RomWBW workflow and can be loaded into an SD card

rom file
.rom files are compiled by the RomWBW workflow and contain the executable CPM “BIOS” for the RomWBW system. They are created specifically for the system that uses them and are configured with the peripherals and memory details.

The ini file is a standard ini file format. It can be either RC2040.ini or RC2014.ini, RC2040 will take preference in the RomWBW systems. Rc2014.ini is accepted for compatibility with the RC2014 SD card interface.

Each section of the ini file is delimitated by a name in square [] brackets. followed by a number of settings each on their own line and ending in a ‘;’

Settings are of the form name = value ;
String values must be enclosed in double inverted comas.

Comments can be added to and line as long as the first character is a ‘#’ the rest of the line will treated as a comment and will be ignored. Blank lines are accepted, and ignored.

All settings have a default value if not referenced in the ini file.

An example of an ini file follows.

#
# RC2040 configuration #
#

[IDE]
#enable IDE
ide = 1 ;
idefilei = "CPMIDE.id";
idefile = "hd1k_combo.img";

#rom file as ROM source
[ROM]
romfile = "RCZ80_std_pico2FPLCD.rom";

#Size of ROM
romsize=0x80000; //512k

[CONSOLE]
#port 0=UART or 1=USB
port = 1;

[EMULATION]
# Serial Type ACIA=0 SIO=1;
serialtype = 1;

inidesc="ROMWBW 1K SIO CPM RP2350 ";

[SPEED]
#Pico overclocking *1000 Mhz
overclock = 250;
 

IDE settings

ROM settings
[ROM]
ovjump : on Rc2040 kits allows the ini file to override the PCB jumpers.
romfile : Rom image to load and boot into.
romsize : Size of rom file in hex. e.g 0x1000
jumpto: jump to address on start of emulation in hex e.g 0x0ff0. Usually 0 on z80 systems.

EMULATION settings
[EMULATION]
inidesc : string description describing ini file shown at boot.
serialtype : 0 Emulate ACIA / 1 Emulate SIO

CONSOLE settings
[CONSOLE]
port : 0 default serial port is USB / 1 default serial port is UART (FTDI)

OverClock Pico Setting
[SPEED]
overclock : 0 No over clock / speed in Mhz to overclock processor (use with caution). usually 250

UART Settings
[UART]
BaudRate : 300 to 115200 (defaults to 115200)
DataBits : 7 / 8
StopBits : 1 / 2
Parity : 0 off / 1 on

PORT Settings
Set Z80 port address (0-0xff) in hex. Setting a port greater than 0xFF disables the peripheral.
[PORT]
pioa : address of IO Port for front panel LEDs and switches.
spo256 : address of the SPO256AL2 speech synth emulation
spo256freq : address to set the SPO256AL2 speech synth frequency
beep : address to set the beep port.
Neo : base address of the neo-pixel driver ports.
DisplayReg : address of the LCD emulation Register port
DisplayData : address of the LCD emulation Data Port

RC2014 bus settings
[BUS]
IoSleep : delay in uS between control signals and data for the external RC2014 bus.
wait : 0 disable wait line / 1 enable wait line

Debug Settings
[DEBUG]
trace : 0 trace off / 0x000001-0xffffff set various trace bits

TRACE_MEM       0x000001
TRACE_IO        0x000002
TRACE_ROM       0x000004
TRACE_UNK       0x000008
TRACE_CPU       0x000010
TRACE_RTC       0x000040
TRACE_SIO       0x000080
TRACE_CTC       0x000100
TRACE_IRQ       0x000400
TRACE_UART      0x000800
TRACE_IDE       0x002000
TRACE_SD        0x008000
TRACE_PPIDE     0x010000
TRACE_ACIA      0x400000
TRACE_BANK      0x800000

watch : 0 no watch : 0xNNNN set Memory location to watch

Sound Settings
[SOUND]
disksounds : 0 disk sounds off / 1 disk sounds on

Compiling RomWBW
To compile a new set of rom and CF images clone the ROMWBW repository from here https://github.com/wwarthen/RomWBW and copy the asm files from https://github.com/ExtremeElectronics/RC2040-ROMWBW/tree/main/Compiling-custom-ROMWBW to the /Source/HBIOS/Config directory. Run the ROMWBW build using the guide in readme in the root of the ROMWBW repository.

After selecting RCZ80 it should give an option to use RCZ80_std_pico or RCZ80_std_picoFP (for front panel support)

Run the rest of the compile and copy the files RCZ80_std_pico.rom and RCZ80_std_pico.rom hd1k_combo.img from the BINARY directory to the RC2040’s SD card

Check the RC2040.ini and ensure the settings point to the new rom and img’s

I haven’t tried the other image options, but I don’t see why they shouldn’t work.

Emulation Software Updating

In general you can update the emulation software by connecting your PicoRomWBW or RomWBWBus to your computer whilst pressing the “boot” button on the processor board.

This will connect a usb external folder that you can drop in a new uf2 file into.

In the root of each github repository there will be a compiled uf2, download and copy this file into your usb folder.
Be careful to download the correct uf2 file

Pico RomWBW either RomWBW2040.uf2 for Pico or RomWBW2350.uf2 for Pico2
RomWBWBus will have a similar uf2 file in its root.

BASIC

FORTH

CPM

CPM Tools

CPM Disk manager