+- Discussion Forum for all things Microbee (https://microbeetechnology.com.au/forum)
+-- Forum: Microbee Forum (https://microbeetechnology.com.au/forum/forum-1.html)
+--- Forum: Microbee Software and Documentation (https://microbeetechnology.com.au/forum/forum-7.html)
+--- Thread: Common Platforms (/thread-487.html)
Common Platforms - Under4Mhz - 10-05-2022
In terms of hardware support, I'd prefer to support platforms of Microbee that are in common use now.
From what I can see there are three variants (that will effect the software):
Original black and white
Original colour format
Premium colour format
Wide screen (256TC)
Which platforms are people using most now?
RE: Common Platforms - someone - 10-05-2022
The microbee was originally released with a 12MHz pixel dot clock which was subsequently increased to 13.5Mhz to add 80 column support on a standard composite video signal.
A way to detect the difference between the dot clocks is by peeking at the CRTC configuration table in the BASIC or BOOT ROM.
A side effect of the dot clock increase is the pixel aspect ratio becoming narrower.
From this dot clock, all video formats are derived and you're free to choose existing ones or create your own.
Just remember to ensure that the chosen video format is compatible with the microbee keyboard scanning.
Just as a guide, if you look through the forum, the microbee is also capable of the 32x24 colour screen as used by the ZX Spectrum, the 256 x 224 format of the Space Invaders Arcade machine, MSX text and graphics modes & Amstrad CPC text/graphics modes including 160x200, 320x200.
RE: Common Platforms - MbeeTech - 10-05-2022
(10-05-2022, 01:06 PM)Under4Mhz Wrote: In terms of hardware support, I'd prefer to support platforms of Microbee that are in common use now.
From what I can see there are three variants (that will effect the software):
Original black and white
Original colour format
Premium colour format
Wide screen (256TC)
Actually the last 2 are really the same. The 256TC has no difference in capability from the Premium series, with the exception of hardware character flashing.
The screen formats achievable are equal on both. I assume you are referring to the 256TC boot screen menu when mentioning widescreen.
(10-05-2022, 01:24 PM)someone Wrote: Just as a guide, if you look through the forum, the microbee is also capable of the 32x24 colour screen as used by the ZX Spectrum, the 256 x 224 format of the Space Invaders Arcade machine, MSX text and graphics modes & Amstrad CPC text/graphics modes including 160x200, 320x200.While this is true, just for clarity, most (if not all) of these modes mentioned require either standard or non-standard modifications that are not on some models.
For example, the 'Videotex' mod / upgrade was available for standard (non-premium) machines to halve the pixel clock rate to provide 40 columns instead of 80 columns.
The Premium series and 256TC have this mod built in, but the standard machines needed a small board fitted to achieve this.
RE: Common Platforms - ChickenMan - 10-05-2022
"Original black and white" will work on all Microbee's and 3/4 of current games are in that format.
Premiums colour format would be the next choice IMHO.