Try_MMIO draws below the last device: 7 BARs of up to 2 lines, so 140
pixels, not the 30 that were reserved.

The skin was measured once at startup. Measure it on every redraw and
apply only the difference, so a size the user picked is not discarded.

Name the numbers the height is built from.

@@ -56,6 +56,7 @@ load_libraries l_libs_start,end_l_libs
 	mcall	SF_SYS_MISC,SSF_MEM_ALLOC,4096*4 ; 16 Kb - I hope this will be enough for store of data
 	mov	[store_text_area_start],eax
 ;-----------------------------------------------------------------------------
+	call	calc_window_height	; fit window height to the number of devices

@@ -377,0 +386,4 @@
+	imul	eax, 10 		; each row is 10 pixels
+	add	eax, 110 + 30		; header area + bottom margin (~3 lines)
+	push	eax
+	mcall	48, 4			; get skin height into eax