Appendices

Appendix A - REGISTER BITS

APPENDIX A - Commodore-Amiga PC Hardware Manual

THIS IS THE SYSTEM FILE NAMED "REGBITS".
It is generated and maintained by Commodore-Amiga Hardware Engineering.

REVISION .5 (DEC 04, 1984)

ADKCON 4F W P Audio, Disk, Control write
ADKCONR *08 R P Audio, Disk, Control read

BIT# USE
----- --------------------------------------------------
15 SET/CLR Set/Clear control bit. Determines if bits written with a 1 get set or cleared. Bits written with a zero are always unchanged.
14-13 PRECOMP 1-0 CODE PRECOMP VALUE
------- -----------------------
00 none
01 140 ns
10 280 ns
11 560 ns
12 MFMPREC (1=MFM precomp 0=GCR precomp)
11 UARTBRK Forces a UART break (clears TXD) if true
10 WORDSYNC Enables disk read synchronizing on a word
equal to DISK SYNC CODE, located in address (3F) * 2
09 MSBSYNC Enables disk read synchronizing on the MSB
(most signif. bit) Apple type GCR
08 FAST Disk data clock rate control 1=fast (2 us) 0=slow (4us)
(fast for MFM, slow for MFM or GCR)
07 USE3PN Use audio channel 3 to modulate nothing
06 USE2PN Use audio channel 2 to modulate period of channel 3
05 USE1PN Use audio channel 1 to modulate period of channel 2
04 USE0PN Use audio channel 0 to modulate period of channel 1
03 USE3VN Use audio channel 3 to modulate nothing
02 USE2VN Use audio channel 2 to modulate volume of channel 3
01 USE1VN Use audio channel 1 to modulate volume of channel 2
00 USE0VN Use audio channel 0 to modulate volume of channel 1

NOTE If both period and volume are modulated on the same channel, the period and volume will be alternated. First word xxxxxxxx V7-V0, Second word P15-P0 (etc)
AUDxLCH + 50 W A Audio channel x location (High 3 bits)
AUDxLCL + 51 W A Audio channel x location (Low 15 bits)

This pair of registers contain the 18 bit starting address (location) of Audio channel x (x=0,1,2,3) DMA data. This is not a pointer register and therefore only needs to be reloaded if a different memory location is to be output.
AUDxLEN 52 W P Audio channel x length

This register contains the length (number of words) of Audio channel DMA data.
AUDxPER 53 W P Audio channel x period

This register contains the period (rate) Audio channel x DMA data transfer.
AUDxVOL 54 W P Audio channel x volume

This register contains the volume setting for Audio channel x. Bits 6,5,4,3,2,1,0 specify 65 linear volume levels as shown below.

BITS USE
----- -----------------------------------
15-07 Not used
06 Forces volume to max (64 ones, not zeros)
05-00 Sets one of 64 levels (000000=no output
(111111=63 ones, one zero)
AUDxDAT & 55 W P Audio channel x Data

This register is the audio channel x (x=0,1,2,3) DMA data buffer. It contains 2 bytes of data that are output sequentially (with digital to analog conversion) to the audio output pins. The DMA controller automatically transfers data to this register from RAM. The processor can also write directly to this register. When the DMA data is finished (words output=length) and the data in this register has been used, an audio channel interrupt request is set.
BLTxPTH + *28 W A Blitter Pointer to x (High 3 bits)
BLTxPTL + *29 W A Blitter Pointer to x (Low 15 bits)

This pair of registers contains the 18 bit address of Blitter source (x=A,B,C) or dest. (x=D) DMA data. This pointer must be preloaded with the starting address of the data to be processed by the Blitter. After the Blitter is finished it will contain the last data address (plus increment and modulo).
BLTxMOD *32 W A Blitter Modulo x

This register contains the Modulo for Blitter source (x=A,B,C) or dest (x=D). A Modulo is a number that is automatically added to the address at the end of each line, in order that the address then points to the start of the next line. Each source or destination has its own Modulo, allowing each to be a different size, while an identical area of each is used in the Blitter operation.
BLTAFWM *22 W A Blitter first word mask for source A
BLTALWM *23 W A Blitter last word mask for source A

The patterns in these two registers are "anded" with the first and last words of each line of data from source A into the Blitter. A zero in any bit overrides the data from source A. These registers should be set to all "ones" for fill mode or for line drawing mode.
BLTxDAT & *3A W A Blitter source x data reg.

This register hold source x (x=A,B,C) data for use by the Blitter. It is normally loaded by the Blitter DMA channel, however it may also be preloaded by the microprocessor.
BLTDDAT Blitter destination data register

This register holds the data resulting from each word of Blitter operation until it is sent to a RAM destination. This is a dummy address and cannot be read by the micro. The transfer is automatic during Blitter operation.
BLTCON0 *20 W A Blitter control register 0
BLTCON1 *21 W A Blitter control register 1

These two control registers are used together to control Blitter operations. There are 2 basic modes, area and line, which are selected by bit 0 of BLTCON1, as shown below.

AREA MODE ("normal") LINE MODE (line draw)
---------------------------------------- ------------------------------
BIT# BLTCON0 BLTCON1 BIT# BLTCON0 BLTCON1
----- ----------- ----------- ----- ----------- -----------
15 ASH3 BSH3 15 ASH3 BSH3
14 ASH2 BSH2 14 ASH2 BSH2
13 ASH1 BSH1 13 ASH1 BSH1
12 ASH0 BSH0 12 ASH0 BSH0
11 USEA X 11 1 X
10 USEB X 10 0 X
09 USEC X 09 1 X
08 USED X 08 1 X
07 LF7 X 07 LF7 X
06 LF6 X 06 LF6 SIGN
05 LF5 X 05 LF5 OVF
04 LF4 EFE 04 LF4 SUD
03 LF3 IEE 03 LF3 SUL
02 LF2 FCI 02 LF2 AUL
01 LF1 DESC 01 LF1 SING
00 LF0 LINE (=0) 00 LF0 LINE (=1)

ASH3=0 Shift value of A source
BSH3=0 Shift value of B source and line texture
USEA Mode control bit to use Source A
USEB Mode control bit to use Source B
USEC Mode control bit to use Source C
USED Mode control bit to use Source D
LF7-0 Logic function minterm select lines
EFE Exclusive fill enable
IFE Inclusive fill enable
FCI Fill carry input
DESC Descending (decreasing address) control bit
LINE Line mode control bit
SIGN Line draw sign flag
OVF Line draw r/l word overflow flag
SUD Line draw, Sometimes Up or Down (=AUD*)
SUL Line draw, Sometimes Up or Left
AUL Line draw, Always Up or Left
SING Line draw, Single bit per horiz. line
BLTSIZE *2C W A Blitter start and size (window width, height)

This register contains the width and height of the blitter operation (in line mode width must = 2, height = line length). Writing to this register will start the Blitter, and should be done last, after all pointers and control registers have been initialized.

BIT # 15, 14, 13, 12, 11, 10, 09, 08, 07, 06, 05, 04, 03, 02, 01, 00
h9 h8 h7 h6 h5 h4 h3 h2 h1 h0, w5 w4 w3 w2 w1 w0

h=Height = Vertical lines (10 bits = 1024 lines max)
w= Width = Horiz. pixels (6 bits = 64 words = 1024 pixels max)
BPLxPTH + 70 W A Bit-plane x pointer (High 3 bits)
BPLxPTL + 71 W A Bit-plane x pointer (Low 15 bits)

This pair of registers contains the 18 bit pointer to the address of bit-plane x (x=1,2,3,4,5,6) DMA data. This pointer must be reinitialized by the processor or coprocessor to point to the beginning of bit-plane data every vertical blank time.
BPLxDAT & 88 W D Bit-plane x data (Parallel to serial convert)

These registers receive the DMA data fetched from RAM by the bit-plane address pointers described above. They act as a 6 word parallel to serial buffer for up to 6 memory "Bit-planes". (x=3-6) They are loaded by the display bit-plane DMA controller with data from 6 separate areas of memory. They output to the display most sig. bit first (left to right) simultaneously.
BPL1MOD 84 W A Bit-plane modulo (odd planes)
BPL2MOD 85 W A Bit-plane modulo (even planes)

These registers contain the Modulos for the odd and even bit-planes. A Modulo is a number that is automatically added to the address at the end of each line, in order that the address then points to the start of the next line. Since they have separate Modulos, the odd and even bit-planes may have sizes that are different from each other, as well as different from the Display Window size.
BPLCON0 80 W A D Bit-plane control reg. (misc. control bits)
BPLCON1 81 W D Bit-plane control reg. (horiz. scroll control)
BPLCON2 82 W D Bit-plane control reg. (video priority control)

These registers control the operation of the bit-planes
and various aspects of the display.
BIT# BPLCON0 BPLCON1 BPLCON2
----- ----------- ----------- -----------
15 HIRES X X
14 BPU2 X X
13 BPU1 X X
12 BPU0 X X
11 HOMOD X X
10 DBPPF X X
09 COLOR X X
08 RGB X X
07 X PF2H3 X
06 X PF2H2 PF2PRI
05 X PF2H1 PF2P2
04 X PF2H0 PF2P1
03 LPEN PH1H3 PF2P0
02 LACE PH1H2 PF2P1
01 ERSY PF1H1 PF2P1
00 X PF1H0 PF2P0

HIRES = High resolution (640) mode
BPU = Bit-plane use code 000-110 (NONE through 6 inclusive)
HOMOD = Hold and Modify mode
DBLPF = Double playfield (PF1 = odd PF2 = even bit-planes)
COLOR = Composite video COLOR enable
RGB = Red/Blue/Green enable bit
LPEN = Light pen enable (reset on power up)
LACE = Interlace enable (reset on power up)
ERSY = External Resync (HSYNC, VSYNC pads become inputs)
(reset on power up)
PF2PRI = Playfield 2 (even planes) has priority over
(appears in front of) Playfield 1 (odd planes)
PF2P = Playfield 2 priority mode (with resp. to sprites)
PF1P = Playfield 1 priority mode (with resp. to sprites)
PF2H = Playfield 2 horizontal scroll code
PF1H = Playfield 1 horizontal scroll code
CLXCON 4C W D Collision control

This register controls which bit-planes are included (enabled)

                               	in collision detection, and their required state if included.

                               	It also controls the individual inclusion of odd numbered

                               	sprites in the collision detection, by logically ORing them

                               	with their corresponding even numbered sprite.

                               BIT#  FUNCTION  DESCRIPTION

                               -----   ------------   ----------------

                               15      ENSP7           Enable Sprite 7 (ORed with Sprite 6)

                               14      ENSP5           Enable Sprite 5 (ORed with Sprite 4)

                               13      ENSP3           Enable Sprite 3 (ORed with Sprite 2)

                               12      ENSP1           Enable Sprite 1 (ORed with Sprite 0)

                               11      ENBP6           Enable Bit-Plane 6 (Match reqd. for collision)

                               10      ENBP5           Enable Bit-Plane 5 (Match reqd. for collision)

                               09      ENBP4           Enable Bit-Plane 4 (Match reqd. for collision)

                               08      ENBP3           Enable Bit-Plane 3 (Match reqd. for collision)

                               07      ENBP2           Enable Bit-Plane 2 (Match reqd. for collision)

                               06      ENBP1           Enable Bit-Plane 1 (Match reqd. for collision)

                               05      MVBP6          Match Value for Bit-Plane 6 collision

                               04      MVBP5          Match Value for Bit-Plane 5 collision

                               03      MVBP4          Match Value for Bit-Plane 4 collision

                               02      MVBP3          Match Value for Bit-Plane 3 collision

                               01      MVBP2          Match Value for Bit-Plane 2 collision

                               00      MVBP1          Match Value for Bit-Plane 1 collision

                                          Note: Disabled Bit-Planes cannot prevent collisions.

                                          Therefore if all bit-planes are disabled, collisions

                                          will be continuous, regardless of the match values.

• 07 R D Collision data reg. (Read and clear)
  

                               This address reads (and clears) the collision

                               detection register. _he bit assignments are below.

                               NOTE: Playfield 1 is all odd numbered enabled bit-planes

                                             Playfield 2 is all even numbered enabled bit-planes

                               BIT#  COLLISIONS REGISTERED

                               -----   ------------------------------------

                               15       not used

                               14       Sprite 4 (or 5) to Sprite 6 (or 7)

                               13       Sprite 2 (or 3) to Sprite 6 (or 7)

                               12       Sprite 2 (or 3) to Sprite 4 (or 5)

                               11       Sprite 0 (or 1) to Sprite 6 (or 7)

                               10       Sprite 0 (or 1) to Sprite 4 (or 5)

                               09       Sprite 0 (or 1) to Sprite 2 (or 3)

                               08       Playfield 2 to Sprite 6 (or 7)

                               07       Playfield 2 to Sprite 4 (or 5)

                               06       Playfield 2 to Sprite 2 (or 3)

                               05       Playfield 2 to Sprite 0 (or 1)

                               04       Playfield 1 to Sprite 6 (or 7)

                               03       Playfield 1 to Sprite 4 (or 5)

                               02       Playfield 1 to Sprite 2 (or 3)

                               01       Playfield 1 to Sprite 0 (or 1)

                               00       Playfield 1 to Playfield 2

COLORxx C0 W D Color table xx

                                There are 32 of these registers (xx = 00-31) and they

                                are sometimes collectively called the "Color Palette".

                                They contain 12-bit codes representing

                                RED, GREEN, BLUE colors for RGB systems.

                                One of these registers at a time is selected

                                (by the BPLxDAT serialized video code)

                                for presentation at the RGB video output pins.

                                The table below shows the color register bit usage.

                               BIT#  15, 14, 13, 12    11, 10, 09, 08    07, 06, 05, 04    03, 02, 01, 00
 
                               -----   ---------------     --------------      ---------------     ---------------

                               RGB   X     X    X    X      R3  R2  R1  R0   G3  G2  G1  G0   B3  B2  B1  B0

                               B=blue, G=green, R=red

                               BE=blue enable, GE=green enable, RE=red enable

COPCON *17 W A Coprocessor control register

                               This is a 1-bit register that when set true, allows

                               the Coprocessor to access the Blitter hardware. This

                               bit is cleared by power on reset, so that the

                               Coprocessor cannot access the Blitter hardware.

                               BIT#    NAME    FUNCTION

                               -----     -------     --------------------

                               01        CDANG  Coprocessor danger mode. Allows coprocessor

                                                             access to Blitter if true.

COPJMP1 44 S A Coprocessor restart at first location
COPJMP2 45 S A Coprocessor restart at second location

                              		These addresses are strobe addresses, that when written to

                              		cause the Coprocessor to jump indirect using the address

                              		contained in the First or Second Location registers

                              		described below. The Coprocessor itself can write to these

                              		addresses, causing its own jump indirect.

COP1LCH + 40 W A Coprocessor first location reg. (High 3 bits)
COP1LCL + 41 W A Coprocessor first location reg. (Low 15 bits)
COP2LCH + 42 W A Coprocessor second location reg. (High 3 bits)
COP2LCL + 43 W A Coprocessor second location reg. (Low 15 bits)

                                	These registers contain the jump addresses described above.

COPINS 46 W A Coprocessor inst. fetch identify
This is a dummy address that is generated by the Coprocessor
whenever it is loading instructions into its own instruction
register. This actually occurs every Coprocessor cycle except
for the second (IR2) cycle of the MOVE instruction. The three
types of instructions are shown below.
MOVE Move immediate to dest.
WAIT Wait until beam counter is equal to, or greater than.
(keeps Coprocessor off of bus until beam position
has been reached)
SKIP Skip if beam counter is equal to, or greater than.
(skips following MOVE isnt. unless beam position
has been reached)

MOVE WAIT UNTIL SKIP IF
-------------- --------------- -------------

                       BIT#	IR1	IR2		IR1	IR2		IR1	IR2

----- ---- ---- ---- ----- ---- ----
15 X RD15 VP7 BFD * VP7 BFD *
14 X RD14 VP6 VE6 VP6 VE6
13 X RD13 VP5 VE5 VP5 VE5
12 X RD12 VP4 VE4 VP4 VE4
11 X RD11 VP3 VE3 VP3 VE3
10 X RD10 VP2 VE2 VP2 VE2
09 X RD09 VP1 VE1 VP1 VE1
08 DA8 RD08 VP0 VE0 VP0 VE0
07 DA7 RD07 HP8 HE8 HP8 HE8
06 DA6 RD06 HP7 HE7 HP7 HE7
05 DA5 RD05 HP6 HE6 HP6 HE6
04 DA4 RD04 HP5 HE5 HP5 HE5
03 DA3 RD03 HP4 HE4 HP4 HE4
02 DA2 RD02 HP3 HE3 HP3 HE3
01 DA1 RD01 HP2 HE2 HP2 HE2
00 0 RD00 1 0 1 1

IR1 = First instruction register.
IR2 = Second instruction register.
DA = Destination Address for MOVE instruction. Fetched during IR1 time, used during IR2 time on RGA bus.
RD = RAM Data moved by MOVE instruction at IR2 time.
directly from RAM to the address given by the DA field.
VP = Vertical Beam Position comparison bit.
HP = Horizontal Beam Position comparison bit.
VE = Enable comparison (mask bit).
HE = Enable comparison (mask bit).
* NOTE BFD = Blitter Finished Disable. When this bit is true, the Blitter Finished flag will have no effect on the Coprocessor. When this bit is zero, the Blitter Finished flag must be true (in addition to the rest of the bit comparisons) before the Coprocessor can exit from its wait state, or skip over an instruction. Note that the V7 comparison cannot be masked.
The Coprocessor is basically a 2 cycle machine that requests the bus only during odd memory cycles. (4 memory cycles per ins.) This prevents collisions with Display, Audio, Disk, Refresh, and Sprites, all of which use only even cycles. It therefore needs (and has) priority over only the Blitter and Micro. There are only three types of instructions, MOVE immediate, WAIT until, and SKIP if. All instructions require 2 bus cycles (and two instruction words). Since only the odd bus cycles are requested, 4 memory cycle times are required per instruction. (memory cycles are 280 ns) There are two indirect jump registers COP1LC and COP2LC. These are 18-bit pointer registers whose contents are used to modify the program counter for initialization or jumps. They are transferred to the program counter whenever strobe addresses COPJMP1 or COPJMP2 are written. In addition, COP1LC is automatically used at the beginning of each vertical blank time. It is important that one of the jump registers be initialized and its jump strobe address hit, after power up but before Coprocessor DMA is initialized. This insures a determined startup address, and state.
DIWSTRT 47 W A Display Window Start (upper left vert-hor pos)
DIWSTOP 48 W A Display Window Stop (lower right vert-hor pos)
These registers control the Display window size and position by locating the upper left and lower right corners.

BIT# 15, 14, 13, 12, 11, 10, 09, 08, 07, 06, 05, 04, 03, 02, 01, 00
----- ------------------------------------------------------------------
USE V7 V6 V5 V4 V3 V2 V1 V0 H7 H6 H5 H4 H3 H2 H1 H0

DIWSTRT is vertically restricted to the upper 2/3
of the display (V8 = 0), and horizontally restricted to the left 3/4 of the display (H8 = 0).
DIWSTOP is vertically restricted to the lower 1/2
of the display (V8 = / = V7), and horizontally restricted to the right 1/4 of the display (H8 = 1).
DDFSTRT 49 W A Display data fetch start (Horiz. Position)
DDFSTOP 4A W A Display data fetch stop (Horiz. Position)

These registers control the horizontal timing of the beginning and end of the bit-plane DMA display data fetch. The vertical bit-plane DMA timing is identical to the display windows described above. The bit-plane Modulos are dependent on the bit-plane horizontal size, and on the data fetch window size.

Register bit assignment
-----------------------------
BIT# 15, 14, 13, 12, 11, 10, 09, 08, 07, 06, 05, 04, 03, 02, 01, 00
USE X X X X X X X X H8 H7 H6 H5 H4 X X X
(X bits should always be driven with 0 to maintain upward compatibility)
The tables below show the start and stop timing for different register contents.
DDFSTRT (Left edge of display data fetch)
------------------------------------------------------------------
PURPOSE H8, H7, H6, H5, H4
------------------------ ----------------------
Extra wide (max) * 0 0 1 0 1
wide 0 0 1 1 0
normal 0 0 1 1 1
narrow 0 1 0 0 0
DDFSTOP (Right edge of display data fetch)
---------------------------------------------------------
PURPOSE H8, H7, H6, H5, H4
----------------------- ----------------------
narrow 1 1 0 0 1
normal 1 1 0 1 0
wide (max) 1 1 0 1 1
DMACON 4B W A D P DMA control write (clear or set)
DMACONR *01 R A P DMA control (and Blitter status) read
This register controls all of the DMA channels, and contains Blitter DMA status bits.
BIT# FUNCTION DESCRIPTION
----- ------------- ----------------------------------------------
15 SET/CLR Set/Clear control bit. Determines if bits written with a 1 get set or cleared.
Bits written with a 0 are unchanged.
14 BBUSY Blitter busy status bit (read only).
13 BZERO Blitter logic zero status bit (read only).
12 X
11 X
10 BLTPRI Blitter DMA priority (over CPU Micro)
(also called "Blitter Nasty")
(disables /BLS pin, preventing Micro from stealing any bus cycles while Blitter DMA is running)
09 DMAEN Enable all DMA below
08 BPLEN Bit-plane DMA enable
07 COPEN Coprocessor DMA enable
06 BLTEN Blitter DMA enable
05 SPREN Sprite DMA enable
04 DSKEN Disk DMA enable
03 AUD3EN Audio channel 3 DMA enable
02 AUD2EN Audio channel 2 DMA enable
01 AUD1EN Audio channel 1 DMA enable
00 AUD0EN Audio channel 0 DMA enable
DSKPTH + * 10 W A Disk pointer (High 3 bits)
DSKPTL + * 11 W A Disk pointer (Low 15 bits)
This pair of registers contain the 18-bit address of Disk DMA data. These address registers must be initialized by the processor or Coprocessor before disk DMA is enabled.
DSKLEN * 12 W P Disk length
This register contains the length (number of words) of Disk DMA data. It also contains 2 control bits. These are a DMA enable bit, and a DMA direction (read/write) bit.

BIT#
----- ---------- ----------------------------------------
15 DMAEN Disk DMA Enable
14 WRITE Disk Write (RAM to Disk) if 1
13-0 LENGTH Length (# of words) of DMA data
DSKDAT & *13 W P Disk DMA Data write
DSKDATR &*04 ER P Disk DMA Data read (early read dummy address)
This register is the Disk DMA data buffer. It contains 2 bytes of data that are either sent to (write) or received from (read) the disk. The write mode is enable by bit 14 of the LENGTH register. The DMA controller automatically transfers data to or from this register and RAM, and when the DMA data is finished (Length = 0), it causes a Disk Block Interrupt. See interrupts below.
DSKBYTR *0D R P Disk Data byte and status read This register is the Disk Microprocessor data buffer. Data from the disk (in read mode) is loaded into this register one byte at a time, and the Disk Byte Interrupt request bit is set true. This interrupt bit is mirrored in bit 15 of this address to allow simultaneous reading and polling. The interrupt bit must be cleared however by writing to the INTREQ register.

BIT#
-----
15 DSKBYT Disk byte ready (reset on read)
14 DMAON (disk)
13 DISKWRITE
12 WORDEQUAL (from disk sync circuit)
11-08 X Not used
07-00 DATA Disk byte data
DSKSYNC 3F R P Disk sync register, holds the code for disk read synchronization. See ADKCON bit 10.
INTREQ 4E W P Interrupt Request bits (clear or set)
INTREQR *0F R P Interrupt Request bits (read)
This register contains interrupt request bits (or flags). These bits may be polled by the processor, and if enabled by the bits listed in the next register, they may cause processor interrupts. Both a set and clear operation are required to load arbitrary data into this register. The bit assignments are identical to the Enable register below.
INTENA 4D W P Interrupt Enable bits (clear or set bits)
INTENAR *0E R P Interrupt Enable bits read
This register contains interrupt enable bits. The bit assignments for both the request and enable registers are given below.

BIT# FUNCT LEVEL DESCRIPTION
----- -------- ------- -----------------------------------------------
15 SET/CLR Set/Clear control bit. Determines if bits
written with a 1 get set or cleared. Bits written with a 0 are always unchanged.
14 INTEN Master interrupt (enable only, no request)
13 EXTER 6 External interrupt
12 DSKBYT 5 Disk Byte ready (disk sync)
11 RBF 5 Serial port Receive Buffer Full
10 AUD3 4 Audio channel 3 block finished
09 AUD2 4 Audio channel 2 block finished
08 AUD1 4 Audio channel 1 block finished
07 AUD0 4 Audio channel 0 block finished
06 BLIT 3 Blitter finished
05 VERTB 3 Start of Vertical blank
04 COPER 3 Coprocessor
03 PORTS 2 I/O Ports and timers
02 OVRUN 1 Serial port receiver overrun
01 DSKBLK 1 Disk Block finished
00 TBE 1 Serial port Transmit Buffer Empty
JOY0DAT *05 R D Joystick-mouse 0 data (left vert, horiz)
JOY1DAT *06 R D Joystick-mouse 1 data (right vert, horiz)
These addresses each read a pair of 8-bit mouse counters. 0 = left controller pair, 1 = right controller pair. (4 counters total). The bit usage for both left and right addresses is shown below. Each counter is clocked by signals from 2 controller pins. Bits 1 and 0 of each counter may be read to determine the state of these 2 clock pins. This allows these pins to double as joystick switch inputs.

Mouse counter usage (pins 1-3 = Yclock, pins 2-4 = Xclock)

BIT# 15, 14, 13, 12, 11, 10, 09, 08 07, 06, 05, 04, 03, 02, 01, 00
----- -------------------------------- --------------------------------
0DAT Y7 Y6 Y5 Y4 Y3 Y2 Y1 Y0 X7 X6 X5 X4 X3 X2 X1 X0
1DAT Y7 Y6 Y5 Y4 Y3 Y2 Y1 Y0 X7 X6 X5 X4 X3 X2 X1 X0
Joystick switch usage
To detect these read these

Directions Pin# counter bits
------------- ------ -------------------
Forward 1 Y1 xor Y0 (BIT# 09 xor BIT# 08)
Left 3 Y1
Back 2 X1 xor X0 (BIT# 01 xor BIT#00)
Right 4 X1
JOYTEST *1B W D Write to all 4 Joystick-mouse counters at once.

Mouse counter write test data.
BIT# 15, 14, 13, 12, 11, 10, 09, 08 07, 06, 05, 04, 03, 02, 01, 00
----- -------------------------------- --------------------------------
0DAT Y7 Y6 Y5 Y4 Y3 Y2 xx xx X7 X6 X5 X4 X3 X2 X1 X0
1DAT Y7 Y6 Y5 Y4 Y3 Y2 xx xx X7 X6 X5 X4 X3 X2 X1 X0

CONNECTORS
------------------------------------ PORTIA
loc. dir. sym. pin pin
----- ---- ------ ---- ---------
RIGHT Y RY 9 33
RIGHT X RX 5 32
LEFT Y LY 9 36
LEFT X LX 5 35
POTGO *1A W P Pot Port (4-bit) Direction and Data, and Pot Counter start.
POTINP *0B R P Pot pin data read
This register controls a 4-bit bi-directional I/O port that shares the same 4 pins as the 4 pot counters above.

BIT# FUNCT DESCRIPTION
----- -------- ---------------------------------------------------
15 OUTRY Output enable for Portia pin 33
14 DATRY I/O data Portia pin 33
13 OUTRX Output enable for Portia pin 32
12 DATRX I/O data Portia pin 32
11 OUTLY Output enable for Portia pin 36
10 DATLY I/O data Portia pin 36
09 OUTLX Output enable for Portia pin 35
08 DATLX I/O data Portia pin 35
07-01 X not used
00 START Start pots (dump capacitors, start counters)
REFPTR & * 14 W A Refresh pointer
This register is used as a Dynamic RAM refresh address generator. It is writable for test purposes only, and should never be written by the microprocessor.
SERDAT *18 W P Serial Port Data and stop bits write This address writes data to a Transmit data buffer. Data from this buffer is moved into a serial shift register for output transmission whenever it is empty. This sets the Interrupt Request TBE (transmit buffer empty). A stop bit must be provided as part of the data word. The length of the data word is set by the position of the stop bit.

BIT# 15, 14, 13, 12, 11, 10, 09, 08 07, 06, 05, 04, 03, 02, 01, 00
----- -------------------------------- --------------------------------
USE 0 0 0 0 0 0 0 S D8 D7 D6 D5 D4 D3 D2 D1 D0
Note S = stop bit = 1, D= data bits
SERDATR *0C R P Serial Port Data and Status read This address reads data from a Receive data buffer. Data in this buffer is loaded from a receiving shift register whenever it is full. Several interrupt request bits are also read at this address, along with the data, as shown below.

BIT#
-----
15 OVRUN Serial port receiver overrun
14 RBF Serial port Receive Buffer Full (mirror)
13 TBE Serial port Transmit Buffer Empty (mirror)
12 TSRE Serial port Transmit shift reg. empty
11 RXD RXD pin receives UART serial data for direct bit test by the micro
10 x Not used
09 STP Stop bit
08 STP-DB8 Stop bit if LONG, Data bit if not
07 DB7 Data bit
06 DB6 Data bit
05 DB5 Data bit
04 DB4 Data bit
03 DB3 Data bit
02 DB2 Data bit
01 DB1 Data bit
00 DB0 Data bit
SERPER *19 W P Serial Port Period and control
This register contains the control bit LONG referred to above, and a 15-bit number defining the serial port Baud Rate. If this number is N, then the Baud Rate is 1 bit every (N+1) * .2794 Microseconds.

BIT#
-----
15 LONG Defines Serial Receive as 9-bit word.
14-00 RATE Defines Baud Rate = 1/(N+1) * .2794 microsec.
SPRxPTH + 90 W A Sprite x pointer (High 3 bits)
SPRxPTL + 91 W A Sprite x pointer (Low 15 bits)
This pair of registers contains the 18-bit address of Sprite x (x = 0, 1, 2, 3, 4, 5, 6, 7) DMA data. These address registers must be initialized by the processor or Coprocessor every vertical blank time.
SPRxPOS % A0 W A D Sprite x Vert-Horiz start position data
SPRxCTL % A1 W A D Sprite x Vert stop position and control data
These 2 registers work together as position, size and feature Sprite control registers. They are usually loaded by the Sprite DMA channel during horizontal blank, however they may be loaded by either processor any time.

SPRxPOS register

BIT# SYM FUNCTION
----- ----- --------------------------------------
15-08 SV7-SV0 Start vertical value. High bit (SV8) is in SPRxCTL reg below.
07-00 SH8-SH1 Start horizontal value. Low bit (SH0) is in SPRxCTL reg below.

SPRxCTL register (writing this address disables sprite horizontal comparator circuit)

BIT# SYM FUNCTION
----- ----- ---------------------------------------
15-08 EV7-EV0 End (stop) vert value, low 8 bits
07 ATT Sprite attach control bit (odd sprites)
06-04 X Not used
02 SVB Start vert. value high bit
01 EVB End (stop) vert. value high bit
00 SH0 Start horiz. value low bit
SPRxDATA % A2 W D Sprite x image data register A
SPRxDATB % A3 W D Sprite x image data register B
These registers buffer the Sprite image data. They are usually loaded by the Sprite DMA channel but may be loaded by either processor at any time. When a horizontal comparison occurs, the buffers are dumped into shift registers and serially output to the display, MSB first on the left. Note Writing to the A buffer enables (arms) the sprite. Writing to the SPRxCTL register disables the sprite. If enabled, data in the A and B buffers will be output whenever the beam counter equals the sprite horiztonal position value in the SPRxPOS register.
STREQU & *1C S D Strobe for horiz sync with VB and EQU
STRVBL & *1D S D Strobe for horiz sync with VB (Vert. Blank)
STRHOR & *1E S D P Strobe for horiz sync
STRLONG & *1F S D Strobe for the identification of long horiz line.
One of the first 3 strobe addresses above is places on the dest. addr. bus during the first refresh time slot. The 4th strobe shown above is used during the second refresh time slot of every other line, to identify lines with long counts (228). There are 4 referesh time slots, and any not used for strobes will leave a null (FF) address on the dest. addr. bus.
VPOSR *02 R A Read Vert most sig. bit (and frame flop)
VPOSW *15 W A Write Vert most sig. bit (and frame flop)

BIT# 15, 14, 13, 12, 11, 10, 09, 08, 07, 06, 05, 04, 03, 02, 01, 00
----- ------------------------------------------------------------------
USE LOF -- -- -- -- -- -- -- -- -- -- -- -- -- -- V8
LOF = Long frame (auto toggle control bit in BPLCON0)
VHPOSR *03 R A Read Vert and Horiz position of beam
VHPOSW *16 W A Write Vert and Horiz position of beam

BIT# 15, 14, 13, 12, 11, 10, 09, 08, 07, 06, 05, 04, 03, 02, 01, 00
----- ------------------------------------------------------------------
USE V7 V6 V5 V4 V3 V2 V1 V0 H8 H7 H6 H5 H4 H3 H2 H1
RESOLUTION = 1/160 OF SCREEN WIDTH (280 NS)

Appendix B - REGISTER NAMES

APPENDIX B - Commodore-Amiga PC Hardware Manual

THIS IS THE SYSTEM FILE NAMED "REGNAME". It is generated and maintained by Commodore-Amiga Hardware Engineering. custom IC register allocation preliminary 8/04/83 rhn revised 8/16/83 jgm revised 8/18/83 jgm revised 8/23/83 jgm revised 9/01/83 jgm revised 9/16/83 jgm revised 9/19/83 jgm revised 9/26/83 jgm revised 10/27/83 jgm revised REGNAM.9 11/19/83 jgm revised REGNAME 11/29/83 jgm ______________________________________________________________________ & = Register used by DMA channel only. % = Register used by DMA channel usually, processors sometimes. + = Address register pair. Low word uses DB1-DB15, High word DB0-DB2

• = Address not writable by the Coprocessor.

~ = Address not writable by the Coprocessor unless COPCON is set true. A = Agnus chip, D = Daphne chip, P = Portia chip W = Write, R = Read ER = Early Read. This is a DMA data transfter to RAM, from either the Disk

        or from the Blitter. RAM timing requires data to be on the bus
        earlier than microprocessor read cycles. These transfers are therefore
        initiated by Agnus timing, rather than a read address on the dest. adr. bus.

S = Strobe (write address with no register bits PTL, PTH = 18-bit Pointer that addresses DMA data. Must be reloaded by a processor

        before use (Vertical blank for Bit-plane and Sprite pointers, and
        prior to starting the Blitter for Blitter pointers).

LCL, LCH - 18-bit Location (starting address) of DMA data. Used to automatically

        restart pointers, such as the Coprocessor program counter (during
        vertical blank), and the Audio sample counter (whenever the audio
        length count is finished).

MOD = 15-bit Modulo. A number that is automatically added to the memory address

        at the end of each line to generate the address for the beginning of
        the next line. This allows the Blitter (or the DIsplay Window) to
        operate on (or display) a window of data that is smaller than the
        actual picture in memory. (memory map) uses 15 bits, plus sign extend.

_____________________________________________________________________ NAME ADD R/W CHIP FUNCTION ________ _____ _____ _____ ___________________________________ BLTDDAT & *00 E R A Blitter dest. early read (dummy address) DMACONR *01 R A P DMA control (and Blitter status) read VPOSR *02 R A Read Vert most sig. bit (and frame flop) VHPOSR *03 R A Read Vert and Horiz position of beam DSKDATR & *04 ER P Disk data early read (dummy address) JOY0DAT *05 R D Joystick-mouse 0 data (vert, horiz) JOY1DAT *06 R D Joystick-mouse 1 data (vert, horiz) CLXDAT *07 R D Collision data reg. (read and clear) ADKCONR *08 R P Audio, disk control register read POT0DAT *09 R P Pot counter pair 0 data (vert, horiz) POT1DAT *0A R P Pot counter pair 1 data (vert, horiz) POTINP *0B R P Pot pin data read SERDATR *0C R P Serial Port Data and status read DSKBYTR *0D R P Disk Data byte and status read INTENAR *0E R P Interrupt Enable bits read INTREQR *0F R P Interrupt request bits read

---

DSKPTH + *10 W A Disk pointer (High 3 bits) DSKPTL + *11 W A Disk pointer (Low 15 bits) DSKLEN *12 W P Disk length DSKDAT & *13 W P Disk DMA Data write REFPTR & * 14 W A Refresh pointer VPOSW *15 W A Write Vert most sig. bit (and frame flop) VHPOSW *16 W A Write Vert and horiz position of beam COPCON * 17 W A Coprocessor control register (CDANG) SERDAT * 18 W P Serial Port Data and stop bits write SERPER * 19 W P Serial Port Period and control POTGO * 1A W P Pot count start, pot pin drive enable and data JOYTEST * 1B W D Write to all 4 Joystick-mouse counters at once STREQU & *1C S D Strobe for horiz sync with VB and EQU STRVBL & *1D S D Strobe for horiz sync with VB (Vert. Blank) STRHOR & *1E S D P Strobe for horiz sync STRLONG & *1F S D Strobe for identification of long horiz. line

---

BLTCON0 ~20 W A Blitter control register 0 BLTCON1 ~21 W A Blitter control register 1 BLTAFWM ~22 W A Blitter first word mask for source A BLTALWM ~23 W A Blitter last word mask for source A BLTCPTH + ~24 W A Blitter Pointer to source C (High 3 bits) BLTCPTL + ~25 W A Blitter Pointer to source C (Low 15 bits) BLTBPTH + ~26 W A Blitter Pointer to source B (High 3 bits) BLTBPTL + ~27 W A Blitter Pointer to source B (Low 15 bits) BLTAPTH + ~28 W A Blitter Pointer to source A (High 3 bits) BLTAPTL + ~29 W A Blitter Pointer to source A (Low 15 bits) BLTDPTH + ~2A W A Blitter Pointer to source D (High 3 bits) BLTDPTL + ~2B W A Blitter Pointer to source D (Low 15 bits) BLTSIZE ~2C W A Blitter Pointer to destn D (High 3 bits) ~2D ~2E ~2F

---

BLTCMOD ~30 W A Blitter Modulo for source C BLTBMOD ~31 W A Blitter Modulo for source B BLTAMOD ~32 W A Blitter Modulo for source A BLTDMOD ~33 W A Blitter Modulo for destn. D ~34 ~35

                                         ~36
                                         ~37

BLTCDAT & ~38 W A Blitter source C data reg BLTBDAT & ~39 W A Blitter source B data reg BLTADAT & ~3A W A Blitter source A data reg ~3B ~3C ~3D ~3E DSKSYN ~3F W P Disk sync pattern register for disk read

---

COP1LCH + 40 W A Coprocessor first location reg (High 3 bits) COP1LCL + 41 W A Coprocessor first location reg (Low 15 bits) COP2LCH + 42 W A Coprocessor second location reg (High 3 bits) COP2LCL + 43 W A Coprocessor second location reg (Low 15 bits) COPJMP1 44 S A Coprocessor restart at first location COPJMP2 45 S A Coprocessor restart at second location COPINS 46 W A Coprocessor inst. fetch identify DIWSTRT 47 W A Display Window Start (upper left vert-hor pos) DIWSTOP 48 W A Display Window Stop (lower right vert-hor pos) DDFSTRT 49 W A Dispay bit-plane data fetch start (hor pos) DDFSTOP 4A W A Display bit-plane data fetch stop (hor pos) DMACON 4B W A D P DMA control write (clear or set) CLXCON 4C W D Collision control INTENA 4D W P Interrupt Enable bits (clear or set bits) INTREQ 4E W P Interrupt Request bits (clear or set bits) ADKCON 4F W P Audio, Disk control

---

AUD0LCH + 50 W A Audio channel 0 location (High 3 bits) AUD0LCL + 51 W A Audio channel 0 location (Low 15 bits) AUD0LEN 52 W P Audio channel 0 length AUD0PER 53 W P Audio channel 0 period AUD0VOL 54 W P Audio channel 0 volume AUD0DAT & 55 W P Audio channel 0 data

                                        56
                                        57

AUD1LCH + 58 W A Audio channel 1 location (High 3 bits) AUD1LCL + 59 W A Audio channel 1 location (Low 15 bits) AUD1LEN 5A W P Audio channel 1 length AUD1PER 5B W P Audio channel 1 period AUD1VOL 5C W P Audio channel 1 volume AUD1DAT & 5D W P Audio channel 1 data 5E 5F

---

AUD2LCH + 60 W A Audio channel 2 location (High 3 bits) AUD2LCL + 61 W A Audio channel 2 location (Low 15 bits) AUD2LEN 62 W P Audio channel 2 length AUD2PER 63 W P Audio channel 2 period AUD2VOL 64 W P Audio channel 2 volume AUD2DAT & 65 W P Audio channel 2 data 66 67

---

AUD3LCH + 68 W A Audio channel 3 location (High 3 bits) AUD3LCL + 69 W A Audio channel 3 location (Low 15 bits) AUD3LEN 6A W P Audio channel 3 length AUD3PER 6B W P Audio channel 3 period AUD3VOL 6C W P Audio channel 3 volume AUD3DAT & 6D W P Audio channel 3 data 6E 6F

---

BPL1PTH + 70 W A Bit-plane 1 pointer (High 3 bits) BPL1PTL + 71 W A Bit-plane 1 pointer (Low 15 bits) BPL2PTH + 72 W A Bit-plane 2 pointer (High 3 bits) BPL2PTL + 73 W A Bit-plane 2 pointer (Low 15 bits) BPL3PTH + 74 W A Bit-plane 3 pointer (High 3 bits) BPL3PTL + 75 W A Bit-plane 3 pointer (Low 15 bits) BPL4PTH + 76 W A Bit-plane 4 pointer (High 15 bits) BPL4PTL + 77 W A Bit-plane 4 pointer (Low 15 bits) BPL5PTH + 78 W A Bit-plane 5 pointer (High 3 bits) BPL5PTL + 79 W A Bit-plane 5 pointer (Low 15 bits) BPL6PTH + 7A W A Bit-plane 6 pointer (High 3 bits) BPL6PTL + 7B W A Bit-plane 6 pointer (Low 15 bits) 7C 7D 7E 7F

---

BPLCON0 80 W A D Bit-plane control register (misc. control bits) BPLCON1 81 W D Bit-plane control register (scroll value PF1, PF2) BPLCON2 82 W D Bit-plane control register (priority control) 83 BPL1MOD 84 W A Bit-plane Modulo (odd planes) BPL2MOD 85 W A Bit-plane Modulo (even planes) 86 87 BPL1DAT & 88 W D Bit-plane 1 data (parallel to serial convert) BPL2DAT & 89 W D Bit-plane 2 data (parallel to serial convert) BPL3DAT & 8A W D Bit-plane 3 data (parallel to serial convert) BPL4DAT & 8B W D Bit-plane 4 data (parallel to serial convert) BPL5DAT & 8C W D Bit-plane 5 data (parallel to serial convert) BPL6DAT & 8D W D Bit-plane 6 data (parallel to serial convert)

                                   8E
                                   8F

---

SPR0PTH + 90 W A Sprite 0 pointer (High 3 bits) SPR0PTL + 91 W A Sprite 0 pointer (Low 15 bits) SPR1PTH + 92 W A Sprite 1 pointer (High 3 bits) SPR1PTL + 93 W A Sprite 1 pointer (Low 15 bits) SPR2PTH + 94 W A Sprite 2 pointer (High 3 bits) SPR2PTL + 95 W A Sprite 2 pointer (Low 15 bits) SPR3PTH + 96 W A Sprite 3 pointer (High 3 bits) SPR3PTL + 97 W A Sprite 3 pointer (Low 15 bits) SPR4PTH + 98 W A Sprite 4 pointer (High 3 bits) SPR4PTL + 99 W A Sprite 4 pointer (Low 15 bits) SPR5PTH + 9A W A Sprite 5 pointer (High 3 bits) SPR5PTL + 9B W A Sprite 5 pointer (Low 15 bits) SPR6PTH + 9C W A Sprite 6 pointer (High 3 bits) SPR6PTL + 9D W A Sprite 6 pointer (Low 15 bits) SPR7PTH + 9E W A Sprite 7 pointer (High 3 bits) SPR7PTL + 9F W A Sprite 7 pointer (Low 15 bits)

---

SPR0POS % A0 W A D Sprite 0 Vert-Horiz start position data SPR0CTL % A1 W A D Sprite 0 Vert stop position and control data SPR0DATA % A2 W D Sprite 0 image data register A SPR0DATB % A3 W D Sprite 0 image data register B SPR1POS % A4 W A D Sprite 1 Vert-Horiz start position data SPR1CTL % A5 W A D Sprite 1 Vert stop position and control data SPR1DATA % A6 W D Sprite 1 image data register A SPR1DATB % A7 W D Sprite 1 image data register B SPR2POS % A8 W A D Sprite 2 Vert-Horiz start position data SPR2CTL % A9 W A D Sprite 2 Vert stop position and control data SPR2DATA % AA W D Sprite 2 image data register A SPR2DATB % AB W D Sprite 2 image data register B SPR3POS % AC W A D Sprite 3 Vert-Horiz start position data SPR3CTL % AD W A D Sprite 3 Vert stop position and control data SPR3DATA % AE W D Sprite 3 image data register A SPR3DATB % AF W D Sprite 3 image data register B

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SPR4POS % B0 W A D Sprite 4 Vert-Horiz start position data SPR4CTL % B1 W A D Sprite 4 Vert stop position and control data SPR4DATA % B2 W D Sprite 4 image data register A SPR4DATB % B3 W D Sprite 4 image data register B SPR5POS % B4 W A D Sprite 5 Vert-Horiz start position data SPR5CTL % B5 W A D Sprite 5 Vert stop position and control data SPR5DATA % B6 W D Sprite 5 image data register A SPR5DATB % B7 W D Sprite 5 image data register B SPR6POS % B8 W A D Sprite 6 Vert-Horiz start position data SPR6CTL % B9 W A D Sprite 6 Vert stop position and control data SPR6DATA % BA W D Sprite 6 image data register A SPR6DATB % BB W D Sprite 6 image data register B SPR7POS % BC W A D Sprite 7 Vert-Horiz start position data SPR7CTL % BD W A D Sprite 7 Vert stop position and control data SPR7DATA % BE W D Sprite 7 image data register A SPR7DATB % BF W D Sprite 7 image data register B

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COLOR00 C0 W D Color table 00 COLOR01 C1 W D Color table 01 COLOR02 C2 W D Color table 02 COLOR03 C3 W D Color table 03 COLOR04 C4 W D Color table 04 COLOR05 C5 W D Color table 05 COLOR06 C6 W D Color table 06 COLOR07 C7 W D Color table 07 COLOR08 C8 W D Color table 08

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COLOR09 C9 W D Color table 09 COLOR10 CA W D Color table 10 COLOR11 CB W D Color table 11 COLOR12 CC W D Color table 12 COLOR13 CD W D Color table 13 COLOR14 CE W D Color table 14 COLOR15 CF W D Color table 15

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COLOR16 D0 W D Color table 16 COLOR17 D1 W D Color table 17 COLOR18 D2 W D Color table 18 COLOR19 D3 W D Color table 19 COLOR20 D4 W D Color table 20 COLOR21 D5 W D Color table 21 COLOR22 D6 W D Color table 22 COLOR23 D7 W D Color table 23 COLOR24 D8 W D Color table 24 COLOR25 D9 W D Color table 25 COLOR26 DA W D Color table 26 COLOR27 DB W D Color table 27 COLOR28 DC W D Color table 28 COLOR29 DD W D Color table 29 COLOR30 DE W D Color table 30 COLOR31 DF W D Color table 31

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RESERVED EX

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RESERVED FX NO-OP (NULL) FF

---