PCW Plus
Enhanced PCW from monochrome to colour (and sound).
This is time ago definition, kind of imaginary computer, actually enhanced extended system (nowadays emulated and FPGA-ed) derived from the Amstrad PCW / Schneider Joyce. It has colour video and sound capabilities that the classic PCW lacked. Based on certain features that the ANT project, (Arnold Number Two) from the Amstrad/Locomotive development team led by Ronald Perry, would also possess.
The name PCW+ was not used due to the existence of the 9512+ model: + implies a 3.5" drive, while Plus implies colour. (Note that a PCW Plus UK magazine also existed after the 8000 Plus name was dropped).
John Elliot's PCW Joyce emulator supports colour with JOYCE 800x600 driver.
In the evolution of Habisoft's CP/M Box emulator and its research into the PCW system arose the idea to clone the dk'Sound board (existed at that 80´s time as add-on). This had the AY sound chip. And later, thanks to FPGA technology, the PCW was equipped with an accessory that would enable colour video.
Historically, only one commercial program, published by Ocean, "HeadOverHeels" by Ritman and Drummond, supported the AY chip on the PCW.
Habisoft published a series of ports from CPC that expanded the PCW library with more sound: Abbey of Crime; Hero Quest; Knight Lore; Pac Mania; Spirits.
Later, it standardized the possibility of ports from the ZX Spectrum to PCW: Movie; Fat Worm; Nonamed; and Phantomas2/Vampire, which used the PCW's buzzer as the Spectrum's beeper. Some of these also incorporated AY music.
The conversion trail was followed by Kachorro in its Spectrum ports of Barbarian, Coliseum, and Xecutor.
But the possibility of standardizing color options in PCW (Plus) was now opened up with the ColorIN specifications:
Video Modes: PCWplus
0 – PCWclassic monochrome: 2 colors, 720x256.
1 – Groups bits 2 by 2, giving 4 colors; 360x256. User could choose and recolour classic PCW software. [N SuperGameBoy style.]
2 – Same as 4-bit. 16 colors, 180x256. Useful on Interactive Fiction text Adventures with Graphic Window.
3 – 8x1 attribute mode, as Timex/Thomson/MSX/... 8+8 bits are read, the first 8 are background and ink (4+4) and the next 8 are the bitmap. This allows for 16 colors in 360x256, at the cost of using only 2 different colors every 8x1 pixel. Due to the delay, the screen shifts one character to the right. [Reminds N GameBoyColor DX recolouring.]
4 – Experimental, unofficial: 90x256, with 256 direct colors from the 8-bit palette. It therefore ignores the color palette. Enterprise-style, not particularly useful, but colorful.
Regarding the interface:
Port $80 is used to send a value to select a register. Port $81 is for associated data; both support reading and writing. Similar to the operation of integrated circuits such as the PSG or a VDP, it allows sending many values with a minimal interface.
This is how KachorroSoft created the incredible colour ports of AMC and MadMixGame with graphics from the CPC; Phantis from MS-DOS CGA and CPC; and Hundra from the ZX Spectrum.
- PCW Plus enables fantastic loading screens never seen before on 8-bit systems.
Color and sound enhanced versions of Batman and Head Over Heels will follow later. Showcasing the capabilities of the PCW Plus system
- PCWplus technical specifications add too: joystick dk'Tronics and DAC sampler sound.
- Backward compatibility with the classic PCW is maintained in the software.
- PCW Plus is currently supported by the ZEsarUX and CP/M Box emulators.
By numerous FPGA board cores thanks to Steddyman; Rampa; Albconde; ManuTeira and Turri21 (Mister; Mist/SIDI; Poseidon; Calypso; NeptUNO+ ; Sidi64/128 ; Senhor ).
And by Czarnikjak's color add-on board for real PCWclassic using RaspberryPico. https://www.cpcwiki.eu/forum/index.php?msg=246774
- PCWplus FPGA cores allow easily to select 4 colour palettes on classic monochrome software or coder could use Z80 instructions to change colours in Color-IN. Different Palettes choosen through MallarBasic too.
- In parallel, the PCW Wiki project continues its arduous work of preserving and conserving PCW software, graphical and bibliographic material.
- ZesaruX could run PCWplus on RetroGamersLtd. ARMmini machines (as a500mini RGL009 or theSpectrum RGL019) through pcuae firmware.
- PCW Plus library : around 10 games (Colour & Sound) choose automaticaly Colour Palette. By Habisoft : KnightLore ; Head Over Heels enhanced edition ; Nonamed ; Phantomas2 . By KachorroSoft : AMC ; Coliseum ; Mad Mix Game ; Hundra ; Phantis ; Xecutor ; Batman plus edition ...
links:
https://enriqueggalvez.itch.io/
https://www.habisoft.com/pcwwiki/doku.php?id=es:nuevos:indice