more work on RAM disk support, added ATTIC/CELLAR RAM test

src/kernal/iec_fast/m65dos_bridge.s

@@ -7,17 +7,18 @@
 
 
 !addr VDOS_INIT    = $4020 +  0 * 2
-!addr VDOS_UNITCHK = $4020 +  1 * 2
-!addr VDOS_UNITSET = $4020 +  2 * 2
-!addr VDOS_UNITNUM = $4020 +  3 * 2
-!addr VDOS_ACPTR   = $4020 +  4 * 2
-!addr VDOS_CIOUT   = $4020 +  5 * 2
-!addr VDOS_LISTEN  = $4020 +  6 * 2
-!addr VDOS_SECOND  = $4020 +  7 * 2
-!addr VDOS_TALK    = $4020 +  8 * 2
-!addr VDOS_TKSA    = $4020 +  9 * 2
-!addr VDOS_UNTLK   = $4020 + 10 * 2
-!addr VDOS_UNLSN   = $4020 + 11 * 2
+!addr VDOS_PRELOAD = $4020 +  1 * 2
+!addr VDOS_UNITCHK = $4020 +  2 * 2
+!addr VDOS_UNITSET = $4020 +  3 * 2
+!addr VDOS_UNITNUM = $4020 +  4 * 2
+!addr VDOS_ACPTR   = $4020 +  5 * 2
+!addr VDOS_CIOUT   = $4020 +  6 * 2
+!addr VDOS_LISTEN  = $4020 +  7 * 2
+!addr VDOS_SECOND  = $4020 +  8 * 2
+!addr VDOS_TALK    = $4020 +  9 * 2
+!addr VDOS_TKSA    = $4020 + 10 * 2
+!addr VDOS_UNTLK   = $4020 + 11 * 2
+!addr VDOS_UNLSN   = $4020 + 12 * 2
 
 
 m65dos_init:
@@ -28,6 +29,14 @@ m65dos_init:
 	jsr (VDOS_INIT)
 	bra m65dos_end_1
 
+m65dos_preload:
+
+	; Preaload RAM disk content, only to be used during KERNAL initialization
+
+	jsr map_DOS_1
+	jsr (VDOS_PRELOAD)
+	bra m65dos_end_1
+
 m65dos_unitchk:                        ; XXX expose to BASIC
 
 	; Checks is the unit number is supported by the internal DOS

src/kernal/init/fce2.hw_entry_reset.s

@@ -64,6 +64,8 @@ hw_entry_reset:
 
 	jsr m65_reset_common     ; RAMTAS, RESTOR, CINT
 
+	jsr m65dos_preload       ; preload RAM disk content
+
 	clc
 	jsr M65_MODESET          ; on MEGA65 go to native mode by default