Retro Erik

Working on a NTSC CGA Composite emulator. No CPU overhead!

Styx for the Olivetti PC1. Probably the first game using the Olivettis hidden graphics mode. youtu.be/Z3v6KYRCbh4

Here is the WonderMCA, the MCA #PicoMEM by Vincent Besson / VIBR He started by doing a PicoMEM reverse engineering, Then I helped to adapt the multiplexing to the MCA. It is running the PicoMEM 2 Firmware. #MCA #PS2 r3tr0.net

New video on combining CGA palette flipping with raster bars. youtu.be/2Wez2L9ke-I

#Picomem 2 can now emulate OPL3 ! Then SB16 relatively soon #adlib #adlibtracker

Teaser: Working on the first Olivetti PC1 game. Using both CGA palette flipping and 160x200 in 16 color hidden mode.

Change color for any DOS game to whatever you want with this utility for the Olivetti PC1 youtu.be/uqIDscWm9C0

New video on the Olivetti PC1. youtu.be/OJOHznsd0Gc

Demo Scene Effects on the Olivetti Prodest PC1: my longest YouTube video yet. If you are into demo-scene programming this video is for you. youtu.be/YxFZWqKxw7U

A new version of my CGA-flipping bmp viewer for the Olivetti PC1, can now use 8bit images. Not had for a PC from 1987.

Discovered the Olivetti Prodest PC1's CPU clock isn't 8 MHz — it's 7.159 MHz, derived directly from the video chip's pixel clock (14.318 MHz ÷ 2). This means 1 CPU cycle = exactly 1 pixel. Pixel-perfect beam racing is possible on a 1987 PC clone.

Another big break-true 512 unique colors on the screen in CGA 320x200 Mode 4 on the Olivetti PC1. First image 512 colors, second has 81 unique colors

Better?

By using CGA flipping i just managed 85 unique colors at the same time in CGA mode 4 on the Olivetti PC1

Added some more predefines palettes in my PC1PAL program to change CGA colors to any of the 512 colors on the Olivetti

@StairwayToRetro I ued the Plantronics driver as a base, so i know it well. As far as i know the AGI does not have a driver system, its all integrated into main game engine code. But it would be great since the graphics is already 160x200.

@Retro_Erik To my knowledge, there is already an SCI0 driver using the Plantronics mode in 320x200x16. Why don't you try to write a driver for AGI games in 160x200x16 instead? Am I missing something here?🤔

I just uploaded my Sierra SCI0 driver for the Olivetti PC1 to github. It works, but the conversion from 320 to 160 makes text hard to read. Also no mouse support.

200 unique colors at the same screen on a PC from the 80's with 16 KB VRAM! - original HW. #OlivettiPC #retropc #retrocomputing