Merge pull request #203 from wwarthen/dev

Dev

Source/HBIOS/Build.cmd

@@ -65,15 +65,16 @@ tasm -t%CPUType% -g3 -dIMGBOOT hbios.asm hbios_img.bin hbios_img.lst || exit /b
 :: Build ROM Components
 ::
 
-call :asm dbgmon
-call :asm romldr
-call :asm eastaegg
-call :asm nascom
-call :asm tastybasic
-call :asm game
-call :asm usrrom
-call :asm updater
-call :asm imgpad2
+call :asm dbgmon || exit /b
+call :asm romldr || exit /b
+
+call :asm eastaegg || exit /b
+call :asm nascom || exit /b
+call :asm tastybasic || exit /b
+call :asm game || exit /b
+call :asm usrrom || exit /b
+call :asm updater || exit /b
+call :asm imgpad2 || exit /b
 
 ::
 :: Create additional ROM bank images by assembling components into
@@ -140,8 +141,8 @@ goto :eof
 ::
 
 :: Build ROM components required by UNA
-call :asm dbgmon
-call :asm romldr
+call :asm dbgmon || exit /b
+call :asm romldr || exit /b
 
 :: Create the OS bank
 copy /b romldr.bin + dbgmon.bin + ..\zsdos\zsys_una.bin + ..\cpm22\cpm_una.bin osimg.bin || exit /b

Source/HBIOS/dskyng.asm

@@ -96,9 +96,24 @@ DSKY_REINIT:
 	; FALL THRU
 ;
 DSKY_RESET:
-	; RESET DSKY
+	; RESET DSKY -- CLEAR RAM AND FIFO
 	LD	A,DSKY_CMD_CLR
 	CALL	DSKY_CMD
+;	
+	; 8259 TAKES ~160US TO CLEAR RAM DURING WHICH TIME WRITES TO
+	; DISPLAY RAM ARE INHIBITED.  HIGH BIT OF STATUS BYTE IS SET
+	; DURING THIS WINDOW.  TO PREVENT A DEADLOCK, A LOOP COUNTER
+	; IS USED TO IMPLEMENT A TIMEOUT.
+	LD	B,0			; TIMEOUT LOOP COUNTER
+DSKY_RESET1:
+	PUSH	BC			; SAVE COUNTER
+	CALL	DSKY_ST			; GET STATUS BYTE
+	POP	BC			; RECOVER COUNTER
+	BIT	7,A			; BIT 7 IS DISPLAY RAM BUSY
+	JR	Z,DSKY_RESET2		; MOVE ON IF DONE
+	DJNZ	DSKY_RESET1		; LOOP TILL TIMEOUT
+;
+DSKY_RESET2:
 	RET
 ;
 #IFDEF DSKY_KBD