VDG Detection
Alex Evans via Coco <coco-uNHYcr1XS/wmlAP/[email protected]> Sun, 21 Dec 2025 10:05:46 -0500
| Newsgroups | gmane.comp.hardware.tandy.coco |
|---|---|
| Message-ID | <CAD7WSBSCKfUzacHfMrDQJdQkXwvT6JBKZ9dh3-D2T65yUX6Quw@mail.gmail.com> |
In the ROM Diagnostics thread, there is the question of whether or not it is possible to detect through software whether an MC6847 or an MC6847T1 was present. An idea was presented that there may be a difference in the bumper of lines per frame. I came up with some code to test this possibility, but I only have access to a machine with an MC6847. I have managed to get a null result using xroar (in both cases 262 for NTSC and 312 for PAL). If there's anyone is willing to post results from actual hardware to confirm this null result is accurate, it would be greatly appreciated. Attached you will find the source code for the test as well as DECB and DragonDOS binaries. Thank you. -- Coco mailing list Coco-uNHYcr1XS/wmlAP/[email protected] https://pairlist5.pair.net/mailman/listinfo/coco
linesdra.bin
(application/octet-stream, 146 B) - not displayed
lines.asm
(application/octet-stream, 681 B) - not displayed
linescc.bin
(application/octet-stream, 154 B) - not displayed