How is your ST/STe color monitor setup?
Posted: 20 Sep 2026 10:23
Hi folks,
I was digging a bit into how the CRT color monitor on the ST/STe as well as on other contemporary machines were setup - looking here at the 320x200 mode (but a similar thing applies to the 640x200 mode on top of the 2:1 pixels of that mode). What I found was
- ATARI in the VDI color modes returned that the pixel dimension wasn't quadratic, but instead a pixel vertically was stretched by about a factor of 1.1 (10%)
- contemporary PC (as long as they weren't in the "new" 320x240 mode) displayed 320x200 with pixels vertically stretched by a factor of 1.2 (20%), effectively making it as large as a 320x240 VGA image (which has quadratic pixels)
- The Apple iigs applied the same 1.2x vertical scaling on its monitor
- On the Amiga it seems to be depending on the NTSC or PAL mode how many lines were displayed (and how the images was stretched vertically)
- Looking at my SC1224 I see a clear difference in height depending on the frequency (50 or 60 Hz) being selected. ATARI''s VDI claim of a 1.1x scaling vertically might work as a middle ground, but it might not be the ground truth.
- You might get away with images scaled vertically by 10% to get reasonable good results on all of these systems (as a 10% difference up or down is tolerable), but a 20% difference (e.g. when using images intended for VGA resolutions or current LCD monitors) is noticable.
So, my questions would be:
- In which mode (50 or 60 Hz) do you use it?
- how is its vertical stretching factor setup or 1:1 pixel matching (e.g. on a modern LCD)?
- In case you have an old ATARI CRT monitor (or you're sure how your ATARI monitor was setup): Was ATARI right with the 1.1x vertical stretching?
I was digging a bit into how the CRT color monitor on the ST/STe as well as on other contemporary machines were setup - looking here at the 320x200 mode (but a similar thing applies to the 640x200 mode on top of the 2:1 pixels of that mode). What I found was
- ATARI in the VDI color modes returned that the pixel dimension wasn't quadratic, but instead a pixel vertically was stretched by about a factor of 1.1 (10%)
- contemporary PC (as long as they weren't in the "new" 320x240 mode) displayed 320x200 with pixels vertically stretched by a factor of 1.2 (20%), effectively making it as large as a 320x240 VGA image (which has quadratic pixels)
- The Apple iigs applied the same 1.2x vertical scaling on its monitor
- On the Amiga it seems to be depending on the NTSC or PAL mode how many lines were displayed (and how the images was stretched vertically)
- Looking at my SC1224 I see a clear difference in height depending on the frequency (50 or 60 Hz) being selected. ATARI''s VDI claim of a 1.1x scaling vertically might work as a middle ground, but it might not be the ground truth.
- You might get away with images scaled vertically by 10% to get reasonable good results on all of these systems (as a 10% difference up or down is tolerable), but a 20% difference (e.g. when using images intended for VGA resolutions or current LCD monitors) is noticable.
So, my questions would be:
- In which mode (50 or 60 Hz) do you use it?
- how is its vertical stretching factor setup or 1:1 pixel matching (e.g. on a modern LCD)?
- In case you have an old ATARI CRT monitor (or you're sure how your ATARI monitor was setup): Was ATARI right with the 1.1x vertical stretching?