Assorted tweaks for the DeskPro 386 ROM

devices/pc/bios/compaq/deskpro386/notes.md

@@ -0,0 +1,42 @@
+Debugging Notes
+===
+
+Checkpoint
+---
+This code:
+
+	F000:F9E9 B000          MOV      AL,00
+    F000:F9EB E620          OUT      20,AL
+
+triggers the following warning:
+
+	notice: PIC0(0x20): unsupported OCW2 automatic EOI command: 0x00
+
+and the very next instruction:
+
+	F000:F9ED E6A0          OUT      A0,AL
+	
+triggers the same warning:
+
+	notice: PIC1(0xA0): unsupported OCW2 automatic EOI command: 0x00
+
+Checkpoint
+---
+There's a loop at F000:B5AA that stores 0x4000 DWORDs into RAM (ie, 64Kb), where each DWORD is
+a single-bit left rotation of the preceding DWORD.  This is followed by another loop that loads
+each DWORD and verifies that it contains the appropriate bit.
+
+Then a stack is set up in RAM (at 0030:0100) and the first CALL is issued:
+
+	F000:BC2E E87DEC        CALL     A8AE
+
+There's some CMOS I/O activity, serial and parallel port I/O, more CMOS I/O, and then some EGA I/O.
+
+When arrive here:
+
+	C000:016D B80700        MOV      AX,0007
+    C000:0170 CD10          INT      10
+
+and we complain that the IDTR limit for the real-mode IDT isn't 0x3FF (it's been set to 0xFFFF instead).
+That may be OK, but I need to verify that that's what the ROM intended.  If it is, then I'll probably need
+to change our assertion from "cpu.addrIDTLimit == 0x03FF" to "cpu.addrIDTLimit >= 0x03FF".