Ported the ISA RTC and Memory expansion cards from VARCem's.

Bunch of improvements in the device, memory and MMU handling.
Re-worked the NEAT 286 chipset (ported from VARCem).
Re-worked the ATI 28800 a bit, added Sierra SC1502x ramdac to VGA Wonder XL (Compaq) since it supports such.
Top 384K memory handling improvements (256K top memory too)
Added MCA version of MPU-401 (not tested much, however).
Re-worked the SCAT 286 chipset.

src/machine/m_ps1.c

@@ -28,7 +28,7 @@
  *		boot. Sometimes, they do, and then it shows an "Incorrect
  *		DOS" error message??  --FvK
  *
- * Version:	@(#)m_ps1.c	1.0.9	2018/04/26
+ * Version:	@(#)m_ps1.c	1.0.10	2018/09/02
  *
  * Authors:	Sarah Walker, <http://pcem-emulator.co.uk/>
  *		Miran Grca, <mgrca8@gmail.com>
@@ -512,7 +512,7 @@ ps1_common_init(const machine_t *model)
 {
     machine_common_init(model);
 
-    mem_remap_top_384k();
+    mem_remap_top(384);
 
     pit_set_out_func(&pit, 1, pit_refresh_timer_at);