This configuration is specifically for the SC126, Z180 Motherboard.
The latest release of this Firmware is detailed in the table below.
| Name | Wayne Warthen’s RomWBW |
| Build name | Small Computer SC126 |
| Build date | 2025-05-21 |
| Platform | SCZ180 |
| Configuration | sc126_std |
| Version | v3.5.1 |
| Download ROM image | RomWBW-SCZ180_sc126_std v3.5.1 Dated 2025-05-21 |
| Suggested ROM label | RomWBW SCZ180_sc126 |
| Device Programming: | |
| Code size | 512k bytes |
| Checksum | 02EB 6AD3 (MiniPro 6.85, SST39SF040) |
| Recommended IC | SST39SF040-70 |
The firmware is supplied (above) as a binary format file, which is suitable for use by most PROM programmers.
RomWBW’s documentation can be found here.
The very latest version, source code and documentation for RomWBW can be found here.
Supported devices
This version of RomWBW supports the following devices.
| Device | I/O Address |
| Z180 CPU (eg. Z8S180xx), including: * Two asynchronous serial ports * Clock serial I/O for SD card * Timer | 0xC0 (to 0xFF) |
| Memory: (linear, no MMU) 512k Flash, 512k RAM | n/a |
| LCD module (alpha-numeric) | 0xDA (to 0xDB) not enabled |
| UART single channel serial #1 | 0x80 (to 0x87) |
| UART single channel serial #2 | 0x88 (to 0x8F) |
| UART single channel serial #3 | 0xA0 (to 0xA7) |
| UART single channel serial #4 | 0xA8 (to 0xAF) |
| Z80 SIO dual channel serial #1 | 0x80 (to 0x83) |
| Z80 SIO dual channel serial #2 | 0x84 (to 0x87) |
| ACIA single channel serial #1 | 0x80 (to 0x81) not enabled |
| ACIA single channel serial #2 | 0x40 (to 0x41) not enabled |
| Real-time clock (DS1302) (shares SD card enable address) | 0x0C |
| Floppy disk (RCWDC) | 0x50 |
| 8-bit IDE direct on CPU bus Compact Flash controller | 0x10 (to 0x17) |
| PPIDE (parallel port IDE) | 0x20 |
| SD card enable bit (shares real-time clock address) | 0x0C |
| USB device #1 (CH375/376) | 0x3E |
| USB device #2 (CH375/376) | 0x3C |
| Front panel / diagnostic LEDs | 0x0D |
| Front panel config. switches | 0x00 |
| Status LED | not enabled |
| Z80 CTC quad counter/timer | not enabled |
| Sound (AY chip) | not enabled |
The lack of specific support does not exclude the use of other hardware. It just means the ROM does not do anything specific with it. Some additional hardware can be enabled by customising RomWBW, which is quite easy to do.
Supported modules
This version of RomWBW supports the following 80-pin RCBus modules (SC700 series)
| RCBus-80pin (700 series) | Function | I/O address |
| SC715 | Compact Flash interface | 0x10 (to 0x17) |
| SC716 | Z80 SIO/2 dual serial #1 Z80 SIO/2 dual serial #2 | 0x80 (to 0x83) 0x84 (to 0x87) |
| SC719 | Digital I/O module (front panel LEDs & switches) | 0x00 |
| SC725 | Z80 SIO serial + CTC (requires 7.3728MHz oscillator or CLK2) | SIO: 0x80 (to 0x83) CTC: 0x88 (to 0x8B) CTC not enabled |
| SC729 | Compact Flash interface | 0x10 (to 0x17) |
Plus the following 40-pin RCBus modules (SC600 series)
| RCBus-40pin (600 series) | Function | I/O address |
| SC604 | Compact Flash interface | 0x10 (to 0x17) |
| SC603 | Z80 SIO/2 dual serial #1 Z80 SIO/2 dual serial #2 | #1: 0x80 (to 0x83) #2: 0x84 (to 0x87) |
| SC605 | Digital I/O module (front panel LEDs & switches) | 0x0D / 0x00 |
| SC613 | Compact Flash interface | 0x10 (to 0x17) |
It also supports the following older modules (SC100 series)
| RCBus (100 series) | Function | I/O address |
| SC104 | Z80 SIO/2 dual serial #1 Z80 SIO/2 dual serial #2 | 0x80 (to 0x83) 0x84 (to 0x87) |
| SC129 | Digital I/O module (front panel LEDs & switches) | 0x0D / 0x00 |
| SC132 | Z80 SIO/0 dual serial #1 Z80 SIO/0 dual serial #2 | 0x80 (to 0x83) 0x84 (to 0x87) |
| SC135 | Digital outputs (front panel LEDs) | 0x0D |
| SC136 | Digital inputs (from panel switches) | 0x00 |
| SC145 | Compact Flash interface | 0x10 (to 0x17) |
The lack of specific support does not exclude the use of other hardware. It just means the ROM does not do anything specific with it.
Incompatible modules
Modules not compatible with this configuration:
| Device | Comment |
| SC706 SC708 SC722 SC730 SC601 SC108 SC153 | Only one CPU supported and it needs to be a Z180 |
| SC705 SC610 SC612 SC139 | Serial ACIA not enabled |
| SC707 SC714 SC721 SC602 SC143 SC150 SC151 SC152 | Only 1MB linear memory supported |
| SC110 | Serial module requires bus clock 7.3728MHz |
| SC611 | Only one SD card driver supported |
Release Notes
The Z180’s internal I/O is set to the range 0xC0 to 0xFF.
OLDER RELEASES
RomWBW v3.4
The latest release of this Firmware is detailed in the table below.
| Name | Wayne Warthen’s RomWBW |
| Build name | Small Computer SC126 |
| Build date | 2023-12-31 |
| Platform | SCZ180 |
| Configuration | sc126 |
| Version | v3.4.0 |
| Download ROM image | SC126 RomWBW SCZ180_126 v3.4.0 Dated 2023-12-31 |
| Device Programming: | |
| Code size | 512k bytes |
| Checksum | 02F2 5737 (MiniPro 6.85, SST39SF040) |
| Recommended IC | SST39SF040-70 |
| Core Components: | |
| HBIOS | Version 3.4.0, 2023-12-31 |
| Included Apps: | |
| – CamelForth | Version 1.02, 2021-09-07 |
| – CP/M | Version 2.2, CBIOS v3.4.0 [WBW] |
| – Monitor | Version unknown |
| – NASCOM BASIC | Version 4.7b |
| – Tasty BASIC | Version 0.3.0 |
| – Z-System | Version 1.1, CBIOS v3.4.0 [WBW] |
The firmware is supplied (above) as a binary format file, which is suitable for use by most PROM programmers.
RomWBW’s documentation can be found here.
The very latest version, source code and documentation for RomWBW can be found here.
Supported devices
This version of RomWBW supports the following devices.
| Device | I/O Address |
| Z180 CPU (eg. Z8S180xx), including: * Two asynchronous serial ports * Clock serial I/O for SD card * Timer | 0xC0 (to 0xFF) |
| Memory: (linear, no MMU) 512k Flash, 512k RAM | n/a |
| SD card enable bit (shares real-time clock address) | 0x0C |
| Real-time clock (DS1302) (shares SD card enable address) | 0x0C |
| Status LED | n/a |
| Diagnostic LEDs | 0x0D |
| Front panel switches | 0x00 |
| Serial #1 (SIO, but no CTC) | 0x80 (to 0x83) |
| Serial #2 (SIO, but no CTC) | 0x84 (to 0x87) |
| 8-bit IDE direct on CPU bus Compact Flash controller | 0x10 (to 0x17) |
| PPIDE | 0x20 |
| Sound (AY chip) | 0x68 |
| Floppy disk | 0x50 |
| USB device #1 (CH375/376) | 0x3E |
| USB device #2 (CH375/376) | 0x3C |
The lack of specific support does not exclude the use of other hardware. It just means the ROM does not do anything specific with it.
Supported modules
This version of RomWBW supports the following 80-pin RCBus modules (SC700 series).
| RCBus-80pin (700 series) | Function | I/O address |
| SC715 | Compact Flash interface | 0x10 (to 0x17) |
| SC716 | Z80 SIO/2 dual serial #1 Z80 SIO/2 dual serial #2 | 0x80 (to 0x83) 0x84 (to 0x87) |
| SC719 | Digital I/O module (used for diagnostic LEDs) | 0x00 |
| SC725 | Z80 SIO serial + CTC (requires 7.3728MHz oscillator or CLK2) | 0x80 (to 0x83) |
It also supports the following older modules (SC100 series)
| RCBus (100 series) | Function | I/O address |
| SC104 | Z80 SIO/2 dual serial #1 Z80 SIO/2 dual serial #2 | 0x80 (to 0x83) 0x84 (to 0x87) |
| SC129 | Digital I/O module (used for diagnostic LEDs) | 0x00 |
| SC132 | Z80 SIO/0 dual serial #1 Z80 SIO/0 dual serial #2 | 0x80 (to 0x83) 0x84 (to 0x87) |
| SC145 | Compact Flash interface | 0x10 (to 0x17) |
The lack of specific support does not exclude the use of other hardware. It just means the ROM does not do anything specific with it.
Incompatible modules
Modules not compatible with this configuration:
| Device | Comment |
| SC706 SC708 SC108 SC153 | Only one CPU supported and it needs to be a Z180 |
| SC705 SC139 | Serial ACIA not supported |
| SC707 SC714 SC143 SC150 SC151 SC152 | Only 1MB linear memory supported |
| SC110 | Serial module requires bus clock 7.3728MHz |
Release Notes
The Z180’s internal I/O is set to the range 0xC0 to 0xFF.
RomWBW v3.2
The latest release of this Firmware is detailed in the table below.
| Name | Wayne Warthen’s RomWBW |
| Platform | SCZ180 |
| Configuration | 126 |
| Release | v3.2.0, 2023-03-18 |
| Download | SC126 RomWBW SCZ180_126 v3.2.0 Dated 2023-03-21 |
| Device Programming: | |
| Code size | 512k bytes |
| Checksum | 02EA 3EA1 (MiniPro 6.85, SST39SF040) |
| Recommended IC | SST39SF040-70 |
| Core Components: | |
| HBIOS | Version 3.2.0, 2023-03-18 |
| Included Apps: | |
| – CamelForth | Version 1.02 |
| – CP/M | Version 2.2, CBIOS v3.2.0 [WBW] |
| – Monitor | Version unknown |
| – NASCOM BASIC | Version 4.7b |
| – Tasty BASIC | Version 0.3.0 |
| – Z-System | Version 1.1, CBIOS v3.2.0 [WBW] |
The firmware is supplied (above) as a binary format file, which is suitable for use by most PROM programmers.
RomWBW’s documentation can be found here.
The very latest version, source code and documentation for RomWBW can be found here.
Supported Devices
- SC126 Z180 motherboard
- Z180 CPU (eg. Z8S180xx)
- Z180’s asynchronous serial ports
- Status LEDs at 0x0D
- Real Time Clock at 0x0C
- SD card at 0x0C
- Compact Flash at 0x10
The lack of specific support does not exclude the use of other hardware. It just means the ROM does not do anything specific with it.
Supported Modules
- Processor and memory:
- Memory:
- Serial ports:
- Timer:
- Baud rate generation:
- Mass storage (SD card):
- Mass storage (Compact Flash card)
- Self-test status display:
The lack of specific support does not exclude the use of other hardware. It just means the ROM does not do anything specific with it.
Release Notes
The Z180’s internal I/O is set to the range 0xC0 to 0xFF.
RomWBW v3.0
The latest release of this Firmware is detailed in the table below.
| Name | Wayne Warthen’s RomWBW |
| Platform | SCZ180 |
| Configuration | 126 |
| Release | v3.0 |
| Download | SC126 RomWBW SCZ180_126 2020-03-23 |
| Device Programming: | |
| Code size | 512k bytes |
| Checksum | 02CE 1495 (MiniPro 6.6, SST39SF040) |
| Recommended IC | SST39SF040-70 |
| Core Components: | |
| HBIOS | Version 3.0, 2020-03-27 |
| Included Apps: | |
| – CamelForth | Version 1.02 |
| – CP/M | Version 2.2, CBIOS v3.0 [WBW] |
| – Monitor | Version unknown |
| – NASCOM BASIC | Version 4.7b |
| – Tasty BASIC | Version unknown |
| – Z-System | Version 1.1, CBIOS v3.0 [WBW] |
The firmware is supplied (above) as a binary format file, which is suitable for use by most PROM programmers.
RomWBW’s documentation can be found here.
The very latest version, source code and documentation for RomWBW can be found here.
Supported Devices
- SC126 Z180 motherboard
- Z180 CPU (eg. Z8S180xx)
- Z180’s asynchronous serial ports
- Status LEDs at 0x0D
- Real Time Clock at 0x0C
- SD card at 0x0C
- Compact Flash at 0x10 for loading CP/M
The lack of specific support does not exclude the use of other hardware. It just means the ROM does not do anything specific with it.
Supported Modules
- Processor and memory:
- Memory:
- Serial ports:
- Timer:
- ?
- Baud rate generation:
- Mass storage (SD card):
- Mass storage (Compact Flash card)
- Self-test status display:
The lack of specific support does not exclude the use of other hardware. It just means the ROM does not do anything specific with it.
Release Notes
The Z180’s internal I/O is set to the range 0xC0 to 0xFF.
Small Computer Central 