Undocumented DDFSTRT side-effect.

diff --git a/custom.cpp b/custom.cpp
index fbda5e2792e6b52583444a177aa301ad7d3faeea..9906b61826f29593b102a5d15dba716417afc2ea 100644 (file)
--- a/custom.cpp
+++ b/custom.cpp
@@ -3521,7 +3521,8 @@ static void decide_line (int hpos)
                                start_bpl_dma (hstart);
                                // if ECS: pre-set plf_end_hpos if we have already passed virtual ddfstop
                                if (ecs) {
-                                       if (last_decide_line_hpos < hstart && hstart >= plfstop && hstart - plfstop <= DDF_OFFSET) {
+                                       // DDFSTRT=$18: always skip this condition. For some unknown reason.
+                                       if (last_decide_line_hpos < hstart && hstart >= plfstop && hstart - plfstop <= DDF_OFFSET && hstart != HARD_DDF_START_REAL + DDF_OFFSET) {
                                                plf_end_hpos = plfstop + DDF_OFFSET;
                                                nextstate = plf_passed_stop;
                                        }