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Programming:An example to define a RSX

2024-04-20T22:29:36Z

HAL 6128:

<pre>
;; This program provides the framework for the installation of a Resident System
;; Extension (an RSX).
;;
;; An RSX is a command which is accessed from basic by prexifing the command
;; with the '|' symbol.
;;
;; e.g. An RSX could provide a "MEMEDIT" command, which allows the user
;; to edit the RAM contents. It would be accessed from BASIC by typing:
;;
;; |MEMEDIT
;;
;; This program shows how an RSX is set up. You are free to use this
;; example code to create your own RSX's.
;;
;; Kevin Thacker 1993

.kl_log_ext equ &bcd1

;; this can be any address in the range &0040-&a7ff.
org &8000

;;-------------------------------------------------------------------------------
;; install RSX

ld hl,work_space ;;address of a 4 byte workspace useable by Kernel
ld bc,jump_table ;;address of command name table and routine handlers
jp kl_log_ext ;;Install RSX's

.work_space ;Space for kernel to use
defs 4

;;-------------------------------------------------------------------------------
;; RSX definition

.jump_table
defw name_table ;address pointing to RSX commands

;list of jump commands associated with each command

;The name (in the name_table) and jump instruction
;(in the jump_table), must be in the same
;order.

;i.e. the first name in the name_table refers to the
;first jump in the jump_table, and vice versa.

jp RSX_1_routine ;routine for COMMAND1 RSX
jp RSX_2_routine ;routine for COMMAND2 RSX
jp RSX_3_routine ;routine for COMMAND3 RSX

;; the table of RSX function names
;; the names must be in capitals.

.name_table
defb "COMMAND","1"+&80 ;the last letter of each RSX name must have bit 7 set to 1.
defb "COMMAND","2"+&80 ;This is used by the Kernel to identify the end of the name.
defb "COMMAND","3"+&80 ;commands in ALWAYS in UPPER case, otherwise you'll get errors

defb 0 ;end of name table marker

; Code for the example RSXs

.RSX_1_routine
ret

.RSX_2_routine
ret

.RSX_3_routine
ret
</pre>

[[Category:Programming]]

Source Codes

2023-03-30T11:23:23Z

HAL 6128:

[[Category:Programming]]
''This article contains source codes and programming examples. You may also have a look at''
* [[Programming software]]
* [[BIOS Functions]]
* [[Technical documentation]]s
* [[Locomotive BASIC]]
* [[Type Ins]]

== Assembler ==
*[[Z80_-_undocumented_opcodes|Z80 - undocumented opcodes]]
*[[Where to learn?]]
*[[A little optimization for Z80 Assembler]]

== Algorithms ==
*[[Programming:Bubble sort|Bubble sort]]
*[[Programming:CPC OS floating point routines|CPC OS floating point routines]]
*[[Programming:CRC16|CRC16]]
*[[Programming:CRC32|CRC32]]
*[[Programming:Integer Division|Integer Division]]
*[[Programming:Integer Multiplication|Integer Multiplication]]
*[[Programming:Logarithm|Logarithm]]
*[[Programming:Ultrafast Multiplication|Ultrafast Multiplication]] by [[Prodatron]]
*[[Programming:Fast Square Root|Fast Square Root]]
*[[Programming:Fast 16 bit Square Root|Fast 16 bit Square Root]] by [[User:Executioner|Executioner]]
*[[Programming:Filling memory with a byte|Filling memory with a byte]]
*[[Programming:Square Root|Square Root]]
*[[Programming:Precalculated square|Precalculated square]]
*[[Programming:Maze generation|Maze generation]]
*[[Programming:Random Number Generator|Random Number Generator]]
*[[Programming:Reverse A|Reverse A]]
*[[Programming:Quicksort|Quicksort]]
*[[Programming:Sin/Cos calculation|Sin/Cos calculation]]

== CP/M ==
*[[Programming:A simple 'Hello World' program for CP/M using BDOS|A simple 'Hello World' program for CP/M using BDOS]]
*[[Programming:A simple 'Hello World' program for CP/M using BIOS|A simple 'Hello World' program for CP/M using BIOS]]
*[[Programming:Executing firmware functions from within CP/M 2.1|Executing firmware functions from within CP/M 2.1]]
*[[Programming:Executing firmware functions from within CP/M 2.1 or CP/M plus|Executing firmware functions from within CP/M 2.1 or CP/M plus]]
*[[Programming:Executing firmware functions from within CP/M 2.1|Executing firmware functions from within CP/M 2.1]]
*[[Programming:Executing firmware functions from within CP/M plus|Executing firmware functions from within CP/M plus]]

== CPC Plus ==
*[[Amstrad CPC plus sprite format]]
*[[Programming:Convert CPC sprites to Plus hardware sprites|Convert CPC sprites to Plus hardware sprites]]
*[[Sprites Multiplexing]]
*[[Programming:CPC Plus Hardware Sprites|Hardware sprites]]
*[[Programming:CPC Plus Horizontal scroll|Horizontal scroll]]
*[[Programming:CPC Plus RLE Hardware Sprites|RLE hardware sprites]]
*[[Programming:CPC Plus Screen Splitting|Screen splitting]]
*[[Programming:CPC Plus Vertical scroll|Vertical scroll]]
*[[Operation of Z80 interrupt mode 0 in the CPC plus design]]
*[[Programming:Simple Raster Example 2 (uses CPC plus features)|Simple Raster Example 1 (uses CPC plus features)]]
*[[Programming:Simple Raster Example 3 (uses CPC plus features)|Simple Raster Example 2 (uses CPC plus features)]]
*[[Programming:Unlocking ASIC|Unlocking ASIC]]

== Devices ==
*[[Programming:CPC Booster|CPC Booster]]
*[[Programming:Digiblaster|Digiblaster]]
*[[Programming:Program to save the ROM of the Multiface 2|Program to save the ROM of the Multiface 2]]
*[[Programming:SYMBiFACE II|SYMBiFACE II]]

== File access ==
*[[Programming:An example to read a file byte-by-byte|An example to read a file byte-by-byte]]
*[[Programming:An example to write a file byte-by-byte|An example to write a file byte-by-byte]]
*[[Programming:Read/Write a file quickly byte-by-byte|Read or write a file quickly byte-by-byte]]
*[[Programming:A simple file copier using firmware functions (copies byte-by-byte)|A simple file copier using firmware functions (copies byte-by-byte)]]
*[[Programming:Loading a file|Loading a file]]
*[[Programming:Saving a file|Saving a file]]
*[[Programming:Unlocking a protected basic file|Unlocking a protected basic file]]
*[[Programming:Undo delete of file|Undo delete of file]]

== Floppy disk ==
*[[Programming:A simple disc copier using BDOS functions|A simple disc copier using BDOS functions]]
*[[Programming:A simple disc formatter using BDOS functions|A simple disc formatter using BDOS functions]]
*[[Programming:An example loader|An example loader]]
*[[Programming:Catalog a disc and retrieve a directory|Catalog a disc and retrieve a directory]]
*[[Programming:Detecting an Amstrad or Vortex disc controler|Detecting an Amstrad or Vortex disc controler]]
*[[Programming:Formatting a track on a disc|Formatting a track on a disc]]
*[[Programming:Reading a sector from a disc|Reading a sector from a disc]]
*[[Programming:Reading and writing the boot sector of a SYSTEM/VENDOR disc|Reading and writing the boot sector of a SYSTEM/VENDOR disc]]
*[[Programming:Writing a sector to disc|Writing a sector to disc]]

== Games ==
*[[Programming:Coding a simple BASIC game into Assembly]]

== Graphics ==

*[[Programming:Calculating xpos,ypos to screen address in assembly|Calculating xpos,ypos to screen address]]
*[[Programming:Display a 8-bit number in binary|Display a 8-bit number in binary]]
*[[Programming:Display a 8-bit number in hex|Display a 8-bit number in hex]]
*[[Programming:Display a byte as a 3-digit decimal number|Display a byte as a 3-digit decimal number]]
*[[Programming:Display and update Scores|Display and update Scores]]
*[[Programming:Distorting the screen using register 2 of the CRTC (Horizontal Sync Position)|Distorting the screen using register 2 of the CRTC (Horizontal Sync Position)]]
*[[Programming:Fast plot|Fast plot]]
*[[Programming:Fast Sprites|Fast Sprites]] by [[User:Executioner|Executioner]]
*[[Programming:Fast Textoutput|Fast Textoutput]] by [[Prodatron]]
*[[Fastest_Character_Print_in_Mode_2|Fastest Character Print in Mode 2 in all screen positions]] by [[FG Brain]]
*[[Programming:Hardware scrolling|Hardware Scrolling]] by [[User:Executioner|Executioner]]
*[[Programming:Hardware scrolling 2|Hardware Scrolling 2]]
*[[Programming:Hardware scrolling the screen horizontally byte-by-byte using the CRTC|Hardware scrolling the screen horizontally byte-by-byte using the CRTC]]
*[[Programming:Hardware scrolling the screen using the CRTC|Hardware scrolling the screen using the CRTC]]
*[[Programming:Next / previous line calculation|Next / previous line calculation]]
*[[Programming:Overscan|Overscan]]
*[[Programming:Plotting a sprite using character matrices|Plotting a sprite using character matrices]]
*[[Mode 4 (two bitplane emulation)| 4th Mode of CPCs: Plotting sprites on 2 bitplanes]]
*[[Screen refresh rate|Set the screen refresh rate]]
*[[Programming:Simple Raster Example 1|Simple Raster Example]]
*[[Programming:Simple Split Raster Example 1|Simple Split Raster Example]]
*[[Synchronising with the CRTC and display]]
*[[CRTC change colour (fill) test with precise timing]] by [[User:Matahari|Matahari]]
*[[256 byte Overscan MEGATEXT Intro - (features 50Hz fullscreen scroll)]] by [[User:Matahari|Matahari]]

== Interrupts ==
* [[Reliable use of interrupt mode 2 on the CPC]]

== Keyboard ==
*[[Programming:Keyboard scanning|Keyboard scanning]]
*[[Programming:Keyboard_redefinition|Keyboard redefinition]]

== Cartridges ==
*[[Programming:Cartridges|Cartridges]]
*[[Programming:Crt0Cart|CRT0 for SDCC]] to init a CPR cart

== Other routines ==
*[[Programming:An example boot sector (executed with rsx command CPM)|An example boot sector (executed with rsx command CPM)]]
*[[Programming:An example to define a RSX|An example to define a RSX]]
*[[Programming:Calling a RSX from outside of BASIC|Calling a RSX from outside of BASIC]]
*[[Programming:Dumping the data of BASIC or AMSDOS or an expansion rom|Dumping the data of BASIC or AMSDOS or an expansion rom]]
*[[Programming:Dumping the data of the lower rom|Dumping the data of the lower rom]]
*[[Programming:Storing and Retrieving Screens from the extra 64kb|Storing and Retrieving Screens from the extra 64kb]]

== Sound ==
*[[How to access the PSG via PPI]]
*[[Programming:Tutorial - Understanding the fundamentals of BASIC SOUND and the Firmware SOUND QUEUE|Tutorial - Understanding the fundamentals of BASIC SOUND and the Firmware SOUND QUEUE]]
*[[Programming:Source code to show 0x0ff is always returned when reading PSG port B|Source code to show 0x0ff is always returned when reading PSG port B]]
*[[Programming:Source code to show it is possible to store data in PSG register 14 and 15 (port A and port B)|Source code to show it is possible to store data in PSG register 14 and 15 (port A and port B)]]
*[[Programming:Source code to show it is possible to store data in PSG register 14 and 15 even if the port has been set to input|Source code to show it is possible to store data in PSG register 14 and 15 even if the port has been set to input]]
*[[Programming:Source code to show that some registers always return 0 in some bits|Source code to show that some registers always return 0 in some bits]]
*[[Programming:Source code to show that when a port is read in output mode; the data read will be ANDed with the inputs to that port|Source code to show that when a port is read in output mode; the data read will be ANDed with the inputs to that port]]

== Cross Development ==
*[[Programming:Cross Development|Cross Development]]

[[Category:Source code]]

== General Notes ==

* Memory range for programs is &0040-&a700. This avoids firmware and memory allocated by AMSDOS disc ROM.
This is safe for the purpose of loading and being compatible with the firmware.
After loading, if you disable the firmware, you can re-use the firmware areas as you want, but you need to do everything yourself (scanning keyboard, drawing, sound etc).If you need to use these areas, a common thing to do is to load most into the safe area, some into the screen, and relocate it after loading.
* Programs on cassette and disc have a header that define the load address, length and execution address.

In Pasmo assembler use the "end" mnemonic to define the label which is the execution address and use "--amsdos" to put an AMSDOS header on it.

* Basic programs start at &170.
* Firmware uses interrupt mode 1 of the Z80 (interrupts jump to &0038)
* Lowest place you can LOAD a binary file to with BASIC is &389 e.g.:

openout"d"
memory <address>-1
closeout
load "code",<address>
call <exec>

*Screen is normally at &c000-&ffff. (It can be changed using firmware, or using CRTC R12/R13)
*Stack is normally at &c000 and goes down.
*Extra registers (BC', AF', HL', DE' are reserved by the firmware). Avoid if you are using firmware functions.
*Lower rom (containing OS) can be paged into memory between &0000-&3fff.
*Upper rom is selectable, examples are BASIC and AMSDOS. They can be paged into memory between &c000-&ffff.
*From basic, a game is run with:

RUN"<filename>

keep it in the safe memory ranges and it'll run from cassette and disc.
*Screen is normally 40 crtc chars wide (CRTC R1=40), 25 crtc chars tall (CRTC R6=25). 8 scan lines per char (R9=7). Firmware functions assume this.
*Screen is bitmapped. You must draw/erase your own sprites and text.
*Firmware refreshes the palette every 50th of a second, so you need to turn off the firmware and use the hardware directly, or set the colours using firmware.
*Firmware can be "turned off", by disabling lower ROM, redirecting interrupts and not calling firmware functions.
*Screen can be resized the same as the Spectrum. Provided you do not use hardware scrolling, this gives you extra space although because of the layout of the screen, it's not continuous, it's in 8 seperate blocks, but it's enough to store data and code.

Programming the V9990: Learning by disassembling the "Robot" demo

2023-03-30T11:23:03Z

HAL 6128:

'''<big>V9990 Robot-Demo</big>'''

Demo File:
For executing extract files on a CPC floppy or upload it on the M4 board and change directory into the DSK container (|CD,"ROBOT.DSK").

Run file "ROBOT.BIN" and wait some time. At least a running robot through a forest will be shown.

You should be able to move (left, right, jump up) the robot via cursor keys and fire a bullet with space.

https://www.cpcwiki.eu/index.php/File:Robot.dsk

(there might be some DSK files around where you can't find the "ROBOT.BIN" file. The DSK container attached is a version made by @Geco.

In the case you don't have it you nevertheless can run the demo by executing the files in following 10 order:
# run"clear >
# run"a1 >
# run"a2 >
# run"a3 >
# run"b1 >
# run"b2 >
# run"b3 >
# run"c1 >
# run"c2 >
# run"c3 >
# run"robo)

Programming the V9990: Learning by disassembling the "Robot" demo

2023-03-30T11:22:11Z

HAL 6128:

'''<big>Learning to program the V9990 VDP</big>'''

Having a V9990 VDP attached on my CPC and always eager to learn about and program it.
First steps are reproducing the "Robot" demo which were spread around the net to show little of the capabilities of the VDP V9990 from Yamaha. 

Demo File:
For executing extract files on a CPC floppy or upload it on the M4 board and change directory into the DSK container (|CD,"ROBOT.DSK").

Run file "ROBOT.BIN" and wait some time. At least a running robot through a forest will be shown.

You should be able to move (left, right, jump up) the robot via cursor keys and fire a bullet with space.

https://www.cpcwiki.eu/index.php/File:Robot.dsk

(there might be some DSK files around where you can't find the "ROBOT.BIN" file. The DSK container attached is a version made by @Geco.

In the case you don't have it you nevertheless can run the demo by executing the files in following 10 order:
# run"clear >
# run"a1 >
# run"a2 >
# run"a3 >
# run"b1 >
# run"b2 >
# run"b3 >
# run"c1 >
# run"c2 >
# run"c3 >
# run"robo)

Programming the V9990: Learning by disassembling the "Robot" demo

2023-03-24T18:48:37Z

HAL 6128:

'''<big>Learning to program the V9990 VDP</big>'''

Having a V9990 VDP attached on my CPC and always eager to learn about and program it.
First steps are reproducing the "Robot" demo which were spread around the net to show little of the capabilities of the VDP V9990 from Yamaha. 

'''But how does it works?'''

.... (tbd)

Demo File:
For executing extract files on a CPC floppy or upload it on the M4 board and change directory into the DSK container (|CD,"ROBOT.DSK").

Run file "ROBOT.BIN" and wait some time. At least a running robot through a forest will be shown.

You should be able to move (left, right, jump up) the robot via cursor keys and fire a bullet with space.

https://www.cpcwiki.eu/index.php/File:Robot.dsk

(there might be some DSK files around where you can't find the "ROBOT.BIN" file. The DSK container attached is a version made by @Geco.

In the case you don't have it you nevertheless can run the demo by executing the files in following 10 order:
1. run"clear >

2. run"a1 >

3. run"a2 >

4. run"a3 >

5. run"b1 >

6. run"b2 >

7. run"b3 >

8. run"c1 >

9. run"c2 >

10. run"c3 >11. run"robo)

Programming the V9990: Learning by disassembling the "Robot" demo

2023-03-24T18:48:18Z

HAL 6128:

'''<big>Learning to program the V9990 VDP</big>'''

Having a V9990 VDP attached on my CPC and always eager to learn about and program it.
First steps are reproducing the "Robot" demo which were spread around the net to show little of the capabilities of the VDP V9990 from Yamaha. 

'''But how does it works?'''

.... (tbd)

Demo File:
For executing extract files on a CPC floppy or upload it on the M4 board and change directory into the DSK container (|CD,"ROBOT.DSK").

Run file "ROBOT.BIN" and wait some time. At least a running robot through a forest will be shown.

You should be able to move (left, right, jump up) the robot via cursor keys and fire a bullet with space.

https://www.cpcwiki.eu/index.php/File:Robot.dsk

(there might be some DSK files around where you can't find the "ROBOT.BIN" file. The DSK container attached is a version made by @Geco.

In the case you don't have it you nevertheless can run the demo by executing the files in following 10 order:
1. run"clear >
2. run"a1 >
3. run"a2 >
4. run"a3 >
5. run"b1 >
6. run"b2 >
7. run"b3 >
8. run"c1 >
9. run"c2 >
10. run"c3 >11. run"robo)

Programming the V9990: Learning by disassembling the "Robot" demo

2023-03-24T14:38:39Z

HAL 6128:

'''<big>Learning to program the V9990 VDP</big>'''

Having a V9990 VDP attached on my CPC and always eager to learn about and program it.
First steps are reproducing the "Robot" demo which were spread around the net to show little of the capabilities of the VDP V9990 from Yamaha. 

'''But how does it works?'''

.... (tbd)

Demo File:
For executing extract files on a CPC floppy or upload it on the M4 board and change directory into the DSK container (|CD,"ROBOT.DSK").

Run file "ROBOT.BIN" and wait some time. At least a running robot through a forest will be shown.

You should be able to move (left, right, jump up) the robot via cursor keys and fire a bullet with space.

https://www.cpcwiki.eu/index.php/File:Robot.dsk

(there might be some DSK files around where you can't find the "ROBOT.BIN" file. The DSK container attached is a version made by @Geco.
In the case you don't have you can run the demo by executing it by loading / running the files in following 10 steps:
1. run"clear > 2. run"a1 > 3. run"a2 > 4. run"a3 > 5. run"b1 > 6. run"b2 > 7. run"b3 > 8. run"c1 > 9. run"c2 > 10. run"c3 >11. run"robo)

Programming the V9990: Learning by disassembling the "Robot" demo

2023-03-24T14:37:57Z

HAL 6128:

'''<big>Learning to program the V9990 VDP</big>'''

Having a V9990 VDP attached on my CPC and always eager to learn about and program it.
First steps are reproducing the "Robot" demo which were spread around the net to show little of the capabilities of the VDP V9990 from Yamaha. 

'''But how does it works?'''

.... (tbd)

Demo File:
For executing extract files on a CPC floppy or upload it on the M4 board and change directory into the DSK container (|CD,"ROBOT.DSK").

Run file "ROBOT.BIN" and wait some time. At least a running robot through a forest will be shown.

You should be able to move (left, right, jump up) the robot via cursor keys and fire a bullet with space.

https://www.cpcwiki.eu/index.php/File:Robot.dsk

(there might be some DSK files around where you can't find the "ROBOT.BIN" file. The DSK container attached is a version made by @Geco.
In the case you don't have you can run the demo by executing it by loading / running the files in following order:
1. run"clear
2. run"a1
3. run"a2
4. run"a3
5. run"b1
6. run"b2
7. run"b3
8. run"c1
9. run"c2
10. run"c3
11. run"robo)

Source Codes

2023-03-24T14:32:54Z

HAL 6128:

[[Category:Programming]]
''This article contains source codes and programming examples. You may also have a look at''
* [[Programming software]]
* [[BIOS Functions]]
* [[Technical documentation]]s
* [[Locomotive BASIC]]
* [[Type Ins]]

== Assembler ==
*[[Z80_-_undocumented_opcodes|Z80 - undocumented opcodes]]
*[[Where to learn?]]
*[[A little optimization for Z80 Assembler]]

== Algorithms ==
*[[Programming:Bubble sort|Bubble sort]]
*[[Programming:CPC OS floating point routines|CPC OS floating point routines]]
*[[Programming:CRC16|CRC16]]
*[[Programming:CRC32|CRC32]]
*[[Programming:Integer Division|Integer Division]]
*[[Programming:Integer Multiplication|Integer Multiplication]]
*[[Programming:Logarithm|Logarithm]]
*[[Programming:Ultrafast Multiplication|Ultrafast Multiplication]] by [[Prodatron]]
*[[Programming:Fast Square Root|Fast Square Root]]
*[[Programming:Fast 16 bit Square Root|Fast 16 bit Square Root]] by [[User:Executioner|Executioner]]
*[[Programming:Filling memory with a byte|Filling memory with a byte]]
*[[Programming:Square Root|Square Root]]
*[[Programming:Precalculated square|Precalculated square]]
*[[Programming:Maze generation|Maze generation]]
*[[Programming:Random Number Generator|Random Number Generator]]
*[[Programming:Reverse A|Reverse A]]
*[[Programming:Quicksort|Quicksort]]
*[[Programming:Sin/Cos calculation|Sin/Cos calculation]]

== CP/M ==
*[[Programming:A simple 'Hello World' program for CP/M using BDOS|A simple 'Hello World' program for CP/M using BDOS]]
*[[Programming:A simple 'Hello World' program for CP/M using BIOS|A simple 'Hello World' program for CP/M using BIOS]]
*[[Programming:Executing firmware functions from within CP/M 2.1|Executing firmware functions from within CP/M 2.1]]
*[[Programming:Executing firmware functions from within CP/M 2.1 or CP/M plus|Executing firmware functions from within CP/M 2.1 or CP/M plus]]
*[[Programming:Executing firmware functions from within CP/M 2.1|Executing firmware functions from within CP/M 2.1]]
*[[Programming:Executing firmware functions from within CP/M plus|Executing firmware functions from within CP/M plus]]

== CPC Plus ==
*[[Amstrad CPC plus sprite format]]
*[[Programming:Convert CPC sprites to Plus hardware sprites|Convert CPC sprites to Plus hardware sprites]]
*[[Sprites Multiplexing]]
*[[Programming:CPC Plus Hardware Sprites|Hardware sprites]]
*[[Programming:CPC Plus Horizontal scroll|Horizontal scroll]]
*[[Programming:CPC Plus RLE Hardware Sprites|RLE hardware sprites]]
*[[Programming:CPC Plus Screen Splitting|Screen splitting]]
*[[Programming:CPC Plus Vertical scroll|Vertical scroll]]
*[[Operation of Z80 interrupt mode 0 in the CPC plus design]]
*[[Programming:Simple Raster Example 2 (uses CPC plus features)|Simple Raster Example 1 (uses CPC plus features)]]
*[[Programming:Simple Raster Example 3 (uses CPC plus features)|Simple Raster Example 2 (uses CPC plus features)]]
*[[Programming:Unlocking ASIC|Unlocking ASIC]]

== Devices ==
*[[Programming:CPC Booster|CPC Booster]]
*[[Programming:Digiblaster|Digiblaster]]
*[[Programming:Program to save the ROM of the Multiface 2|Program to save the ROM of the Multiface 2]]
*[[Programming:SYMBiFACE II|SYMBiFACE II]]

== File access ==
*[[Programming:An example to read a file byte-by-byte|An example to read a file byte-by-byte]]
*[[Programming:An example to write a file byte-by-byte|An example to write a file byte-by-byte]]
*[[Programming:Read/Write a file quickly byte-by-byte|Read or write a file quickly byte-by-byte]]
*[[Programming:A simple file copier using firmware functions (copies byte-by-byte)|A simple file copier using firmware functions (copies byte-by-byte)]]
*[[Programming:Loading a file|Loading a file]]
*[[Programming:Saving a file|Saving a file]]
*[[Programming:Unlocking a protected basic file|Unlocking a protected basic file]]
*[[Programming:Undo delete of file|Undo delete of file]]

== Floppy disk ==
*[[Programming:A simple disc copier using BDOS functions|A simple disc copier using BDOS functions]]
*[[Programming:A simple disc formatter using BDOS functions|A simple disc formatter using BDOS functions]]
*[[Programming:An example loader|An example loader]]
*[[Programming:Catalog a disc and retrieve a directory|Catalog a disc and retrieve a directory]]
*[[Programming:Detecting an Amstrad or Vortex disc controler|Detecting an Amstrad or Vortex disc controler]]
*[[Programming:Formatting a track on a disc|Formatting a track on a disc]]
*[[Programming:Reading a sector from a disc|Reading a sector from a disc]]
*[[Programming:Reading and writing the boot sector of a SYSTEM/VENDOR disc|Reading and writing the boot sector of a SYSTEM/VENDOR disc]]
*[[Programming:Writing a sector to disc|Writing a sector to disc]]

== Games ==
*[[Programming:Coding a simple BASIC game into Assembly]]

== Graphics ==

*[[Programming:Calculating xpos,ypos to screen address in assembly|Calculating xpos,ypos to screen address]]
*[[Programming:Display a 8-bit number in binary|Display a 8-bit number in binary]]
*[[Programming:Display a 8-bit number in hex|Display a 8-bit number in hex]]
*[[Programming:Display a byte as a 3-digit decimal number|Display a byte as a 3-digit decimal number]]
*[[Programming:Display and update Scores|Display and update Scores]]
*[[Programming:Distorting the screen using register 2 of the CRTC (Horizontal Sync Position)|Distorting the screen using register 2 of the CRTC (Horizontal Sync Position)]]
*[[Programming:Fast plot|Fast plot]]
*[[Programming:Fast Sprites|Fast Sprites]] by [[User:Executioner|Executioner]]
*[[Programming:Fast Textoutput|Fast Textoutput]] by [[Prodatron]]
*[[Fastest_Character_Print_in_Mode_2|Fastest Character Print in Mode 2 in all screen positions]] by [[FG Brain]]
*[[Programming:Hardware scrolling|Hardware Scrolling]] by [[User:Executioner|Executioner]]
*[[Programming:Hardware scrolling 2|Hardware Scrolling 2]]
*[[Programming:Hardware scrolling the screen horizontally byte-by-byte using the CRTC|Hardware scrolling the screen horizontally byte-by-byte using the CRTC]]
*[[Programming:Hardware scrolling the screen using the CRTC|Hardware scrolling the screen using the CRTC]]
*[[Programming:Next / previous line calculation|Next / previous line calculation]]
*[[Programming:Overscan|Overscan]]
*[[Programming:Plotting a sprite using character matrices|Plotting a sprite using character matrices]]
*[[Mode 4 (two bitplane emulation)| 4th Mode of CPCs: Plotting sprites on 2 bitplanes]]
*[[Screen refresh rate|Set the screen refresh rate]]
*[[Programming:Simple Raster Example 1|Simple Raster Example]]
*[[Programming:Simple Split Raster Example 1|Simple Split Raster Example]]
*[[Synchronising with the CRTC and display]]
*[[CRTC change colour (fill) test with precise timing]] by [[User:Matahari|Matahari]]
*[[256 byte Overscan MEGATEXT Intro - (features 50Hz fullscreen scroll)]] by [[User:Matahari|Matahari]]
*[[Programming the V9990: Learning by disassembling the "Robot" demo]]

== Interrupts ==
* [[Reliable use of interrupt mode 2 on the CPC]]

== Keyboard ==
*[[Programming:Keyboard scanning|Keyboard scanning]]
*[[Programming:Keyboard_redefinition|Keyboard redefinition]]

== Cartridges ==
*[[Programming:Cartridges|Cartridges]]
*[[Programming:Crt0Cart|CRT0 for SDCC]] to init a CPR cart

== Other routines ==
*[[Programming:An example boot sector (executed with rsx command CPM)|An example boot sector (executed with rsx command CPM)]]
*[[Programming:An example to define a RSX|An example to define a RSX]]
*[[Programming:Calling a RSX from outside of BASIC|Calling a RSX from outside of BASIC]]
*[[Programming:Dumping the data of BASIC or AMSDOS or an expansion rom|Dumping the data of BASIC or AMSDOS or an expansion rom]]
*[[Programming:Dumping the data of the lower rom|Dumping the data of the lower rom]]
*[[Programming:Storing and Retrieving Screens from the extra 64kb|Storing and Retrieving Screens from the extra 64kb]]

== Sound ==
*[[How to access the PSG via PPI]]
*[[Programming:Tutorial - Understanding the fundamentals of BASIC SOUND and the Firmware SOUND QUEUE|Tutorial - Understanding the fundamentals of BASIC SOUND and the Firmware SOUND QUEUE]]
*[[Programming:Source code to show 0x0ff is always returned when reading PSG port B|Source code to show 0x0ff is always returned when reading PSG port B]]
*[[Programming:Source code to show it is possible to store data in PSG register 14 and 15 (port A and port B)|Source code to show it is possible to store data in PSG register 14 and 15 (port A and port B)]]
*[[Programming:Source code to show it is possible to store data in PSG register 14 and 15 even if the port has been set to input|Source code to show it is possible to store data in PSG register 14 and 15 even if the port has been set to input]]
*[[Programming:Source code to show that some registers always return 0 in some bits|Source code to show that some registers always return 0 in some bits]]
*[[Programming:Source code to show that when a port is read in output mode; the data read will be ANDed with the inputs to that port|Source code to show that when a port is read in output mode; the data read will be ANDed with the inputs to that port]]

== Cross Development ==
*[[Programming:Cross Development|Cross Development]]

[[Category:Source code]]

== General Notes ==

* Memory range for programs is &0040-&a700. This avoids firmware and memory allocated by AMSDOS disc ROM.
This is safe for the purpose of loading and being compatible with the firmware.
After loading, if you disable the firmware, you can re-use the firmware areas as you want, but you need to do everything yourself (scanning keyboard, drawing, sound etc).If you need to use these areas, a common thing to do is to load most into the safe area, some into the screen, and relocate it after loading.
* Programs on cassette and disc have a header that define the load address, length and execution address.

In Pasmo assembler use the "end" mnemonic to define the label which is the execution address and use "--amsdos" to put an AMSDOS header on it.

* Basic programs start at &170.
* Firmware uses interrupt mode 1 of the Z80 (interrupts jump to &0038)
* Lowest place you can LOAD a binary file to with BASIC is &389 e.g.:

openout"d"
memory <address>-1
closeout
load "code",<address>
call <exec>

*Screen is normally at &c000-&ffff. (It can be changed using firmware, or using CRTC R12/R13)
*Stack is normally at &c000 and goes down.
*Extra registers (BC', AF', HL', DE' are reserved by the firmware). Avoid if you are using firmware functions.
*Lower rom (containing OS) can be paged into memory between &0000-&3fff.
*Upper rom is selectable, examples are BASIC and AMSDOS. They can be paged into memory between &c000-&ffff.
*From basic, a game is run with:

RUN"<filename>

keep it in the safe memory ranges and it'll run from cassette and disc.
*Screen is normally 40 crtc chars wide (CRTC R1=40), 25 crtc chars tall (CRTC R6=25). 8 scan lines per char (R9=7). Firmware functions assume this.
*Screen is bitmapped. You must draw/erase your own sprites and text.
*Firmware refreshes the palette every 50th of a second, so you need to turn off the firmware and use the hardware directly, or set the colours using firmware.
*Firmware can be "turned off", by disabling lower ROM, redirecting interrupts and not calling firmware functions.
*Screen can be resized the same as the Spectrum. Provided you do not use hardware scrolling, this gives you extra space although because of the layout of the screen, it's not continuous, it's in 8 seperate blocks, but it's enough to store data and code.

Source Codes

2023-03-24T14:32:00Z

HAL 6128:

[[Category:Programming]]
''This article contains source codes and programming examples. You may also have a look at''
* [[Programming software]]
* [[BIOS Functions]]
* [[Technical documentation]]s
* [[Locomotive BASIC]]
* [[Type Ins]]

== Assembler ==
*[[Z80_-_undocumented_opcodes|Z80 - undocumented opcodes]]
*[[Where to learn?]]
*[[A little optimization for Z80 Assembler]]

== Algorithms ==
*[[Programming:Bubble sort|Bubble sort]]
*[[Programming:CPC OS floating point routines|CPC OS floating point routines]]
*[[Programming:CRC16|CRC16]]
*[[Programming:CRC32|CRC32]]
*[[Programming:Integer Division|Integer Division]]
*[[Programming:Integer Multiplication|Integer Multiplication]]
*[[Programming:Logarithm|Logarithm]]
*[[Programming:Ultrafast Multiplication|Ultrafast Multiplication]] by [[Prodatron]]
*[[Programming:Fast Square Root|Fast Square Root]]
*[[Programming:Fast 16 bit Square Root|Fast 16 bit Square Root]] by [[User:Executioner|Executioner]]
*[[Programming:Filling memory with a byte|Filling memory with a byte]]
*[[Programming:Square Root|Square Root]]
*[[Programming:Precalculated square|Precalculated square]]
*[[Programming:Maze generation|Maze generation]]
*[[Programming:Random Number Generator|Random Number Generator]]
*[[Programming:Reverse A|Reverse A]]
*[[Programming:Quicksort|Quicksort]]
*[[Programming:Sin/Cos calculation|Sin/Cos calculation]]

== CP/M ==
*[[Programming:A simple 'Hello World' program for CP/M using BDOS|A simple 'Hello World' program for CP/M using BDOS]]
*[[Programming:A simple 'Hello World' program for CP/M using BIOS|A simple 'Hello World' program for CP/M using BIOS]]
*[[Programming:Executing firmware functions from within CP/M 2.1|Executing firmware functions from within CP/M 2.1]]
*[[Programming:Executing firmware functions from within CP/M 2.1 or CP/M plus|Executing firmware functions from within CP/M 2.1 or CP/M plus]]
*[[Programming:Executing firmware functions from within CP/M 2.1|Executing firmware functions from within CP/M 2.1]]
*[[Programming:Executing firmware functions from within CP/M plus|Executing firmware functions from within CP/M plus]]

== CPC Plus ==
*[[Amstrad CPC plus sprite format]]
*[[Programming:Convert CPC sprites to Plus hardware sprites|Convert CPC sprites to Plus hardware sprites]]
*[[Sprites Multiplexing]]
*[[Programming:CPC Plus Hardware Sprites|Hardware sprites]]
*[[Programming:CPC Plus Horizontal scroll|Horizontal scroll]]
*[[Programming:CPC Plus RLE Hardware Sprites|RLE hardware sprites]]
*[[Programming:CPC Plus Screen Splitting|Screen splitting]]
*[[Programming:CPC Plus Vertical scroll|Vertical scroll]]
*[[Operation of Z80 interrupt mode 0 in the CPC plus design]]
*[[Programming:Simple Raster Example 2 (uses CPC plus features)|Simple Raster Example 1 (uses CPC plus features)]]
*[[Programming:Simple Raster Example 3 (uses CPC plus features)|Simple Raster Example 2 (uses CPC plus features)]]
*[[Programming:Unlocking ASIC|Unlocking ASIC]]

== Devices ==
*[[Programming:CPC Booster|CPC Booster]]
*[[Programming:Digiblaster|Digiblaster]]
*[[Programming:Program to save the ROM of the Multiface 2|Program to save the ROM of the Multiface 2]]
*[[Programming:SYMBiFACE II|SYMBiFACE II]]

== File access ==
*[[Programming:An example to read a file byte-by-byte|An example to read a file byte-by-byte]]
*[[Programming:An example to write a file byte-by-byte|An example to write a file byte-by-byte]]
*[[Programming:Read/Write a file quickly byte-by-byte|Read or write a file quickly byte-by-byte]]
*[[Programming:A simple file copier using firmware functions (copies byte-by-byte)|A simple file copier using firmware functions (copies byte-by-byte)]]
*[[Programming:Loading a file|Loading a file]]
*[[Programming:Saving a file|Saving a file]]
*[[Programming:Unlocking a protected basic file|Unlocking a protected basic file]]
*[[Programming:Undo delete of file|Undo delete of file]]

== Floppy disk ==
*[[Programming:A simple disc copier using BDOS functions|A simple disc copier using BDOS functions]]
*[[Programming:A simple disc formatter using BDOS functions|A simple disc formatter using BDOS functions]]
*[[Programming:An example loader|An example loader]]
*[[Programming:Catalog a disc and retrieve a directory|Catalog a disc and retrieve a directory]]
*[[Programming:Detecting an Amstrad or Vortex disc controler|Detecting an Amstrad or Vortex disc controler]]
*[[Programming:Formatting a track on a disc|Formatting a track on a disc]]
*[[Programming:Reading a sector from a disc|Reading a sector from a disc]]
*[[Programming:Reading and writing the boot sector of a SYSTEM/VENDOR disc|Reading and writing the boot sector of a SYSTEM/VENDOR disc]]
*[[Programming:Writing a sector to disc|Writing a sector to disc]]

== Games ==
*[[Programming:Coding a simple BASIC game into Assembly]]

== Graphics ==

*[[Programming:Calculating xpos,ypos to screen address in assembly|Calculating xpos,ypos to screen address]]
*[[Programming:Display a 8-bit number in binary|Display a 8-bit number in binary]]
*[[Programming:Display a 8-bit number in hex|Display a 8-bit number in hex]]
*[[Programming:Display a byte as a 3-digit decimal number|Display a byte as a 3-digit decimal number]]
*[[Programming:Display and update Scores|Display and update Scores]]
*[[Programming:Distorting the screen using register 2 of the CRTC (Horizontal Sync Position)|Distorting the screen using register 2 of the CRTC (Horizontal Sync Position)]]
*[[Programming:Fast plot|Fast plot]]
*[[Programming:Fast Sprites|Fast Sprites]] by [[User:Executioner|Executioner]]
*[[Programming:Fast Textoutput|Fast Textoutput]] by [[Prodatron]]
*[[Fastest_Character_Print_in_Mode_2|Fastest Character Print in Mode 2 in all screen positions]] by [[FG Brain]]
*[[Programming:Hardware scrolling|Hardware Scrolling]] by [[User:Executioner|Executioner]]
*[[Programming:Hardware scrolling 2|Hardware Scrolling 2]]
*[[Programming:Hardware scrolling the screen horizontally byte-by-byte using the CRTC|Hardware scrolling the screen horizontally byte-by-byte using the CRTC]]
*[[Programming:Hardware scrolling the screen using the CRTC|Hardware scrolling the screen using the CRTC]]
*[[Programming:Next / previous line calculation|Next / previous line calculation]]
*[[Programming:Overscan|Overscan]]
*[[Programming:Plotting a sprite using character matrices|Plotting a sprite using character matrices]]
*[[Mode 4 (two bitplane emulation)| 4th Mode of CPCs: Plotting sprites on 2 bitplanes]]
*[[Screen refresh rate|Set the screen refresh rate]]
*[[Programming:Simple Raster Example 1|Simple Raster Example]]
*[[Programming:Simple Split Raster Example 1|Simple Split Raster Example]]
*[[Synchronising with the CRTC and display]]
*[[CRTC change colour (fill) test with precise timing]] by [[User:Matahari|Matahari]]
*[[256 byte Overscan MEGATEXT Intro - (features 50Hz fullscreen scroll)]] by [[User:Matahari|Matahari]]
*[[Programming the V9990: 1. Learning by disassembling the "Robot" demo]]

== Interrupts ==
* [[Reliable use of interrupt mode 2 on the CPC]]

== Keyboard ==
*[[Programming:Keyboard scanning|Keyboard scanning]]
*[[Programming:Keyboard_redefinition|Keyboard redefinition]]

== Cartridges ==
*[[Programming:Cartridges|Cartridges]]
*[[Programming:Crt0Cart|CRT0 for SDCC]] to init a CPR cart

== Other routines ==
*[[Programming:An example boot sector (executed with rsx command CPM)|An example boot sector (executed with rsx command CPM)]]
*[[Programming:An example to define a RSX|An example to define a RSX]]
*[[Programming:Calling a RSX from outside of BASIC|Calling a RSX from outside of BASIC]]
*[[Programming:Dumping the data of BASIC or AMSDOS or an expansion rom|Dumping the data of BASIC or AMSDOS or an expansion rom]]
*[[Programming:Dumping the data of the lower rom|Dumping the data of the lower rom]]
*[[Programming:Storing and Retrieving Screens from the extra 64kb|Storing and Retrieving Screens from the extra 64kb]]

== Sound ==
*[[How to access the PSG via PPI]]
*[[Programming:Tutorial - Understanding the fundamentals of BASIC SOUND and the Firmware SOUND QUEUE|Tutorial - Understanding the fundamentals of BASIC SOUND and the Firmware SOUND QUEUE]]
*[[Programming:Source code to show 0x0ff is always returned when reading PSG port B|Source code to show 0x0ff is always returned when reading PSG port B]]
*[[Programming:Source code to show it is possible to store data in PSG register 14 and 15 (port A and port B)|Source code to show it is possible to store data in PSG register 14 and 15 (port A and port B)]]
*[[Programming:Source code to show it is possible to store data in PSG register 14 and 15 even if the port has been set to input|Source code to show it is possible to store data in PSG register 14 and 15 even if the port has been set to input]]
*[[Programming:Source code to show that some registers always return 0 in some bits|Source code to show that some registers always return 0 in some bits]]
*[[Programming:Source code to show that when a port is read in output mode; the data read will be ANDed with the inputs to that port|Source code to show that when a port is read in output mode; the data read will be ANDed with the inputs to that port]]

== Cross Development ==
*[[Programming:Cross Development|Cross Development]]

[[Category:Source code]]

== General Notes ==

* Memory range for programs is &0040-&a700. This avoids firmware and memory allocated by AMSDOS disc ROM.
This is safe for the purpose of loading and being compatible with the firmware.
After loading, if you disable the firmware, you can re-use the firmware areas as you want, but you need to do everything yourself (scanning keyboard, drawing, sound etc).If you need to use these areas, a common thing to do is to load most into the safe area, some into the screen, and relocate it after loading.
* Programs on cassette and disc have a header that define the load address, length and execution address.

In Pasmo assembler use the "end" mnemonic to define the label which is the execution address and use "--amsdos" to put an AMSDOS header on it.

* Basic programs start at &170.
* Firmware uses interrupt mode 1 of the Z80 (interrupts jump to &0038)
* Lowest place you can LOAD a binary file to with BASIC is &389 e.g.:

openout"d"
memory <address>-1
closeout
load "code",<address>
call <exec>

*Screen is normally at &c000-&ffff. (It can be changed using firmware, or using CRTC R12/R13)
*Stack is normally at &c000 and goes down.
*Extra registers (BC', AF', HL', DE' are reserved by the firmware). Avoid if you are using firmware functions.
*Lower rom (containing OS) can be paged into memory between &0000-&3fff.
*Upper rom is selectable, examples are BASIC and AMSDOS. They can be paged into memory between &c000-&ffff.
*From basic, a game is run with:

RUN"<filename>

keep it in the safe memory ranges and it'll run from cassette and disc.
*Screen is normally 40 crtc chars wide (CRTC R1=40), 25 crtc chars tall (CRTC R6=25). 8 scan lines per char (R9=7). Firmware functions assume this.
*Screen is bitmapped. You must draw/erase your own sprites and text.
*Firmware refreshes the palette every 50th of a second, so you need to turn off the firmware and use the hardware directly, or set the colours using firmware.
*Firmware can be "turned off", by disabling lower ROM, redirecting interrupts and not calling firmware functions.
*Screen can be resized the same as the Spectrum. Provided you do not use hardware scrolling, this gives you extra space although because of the layout of the screen, it's not continuous, it's in 8 seperate blocks, but it's enough to store data and code.

Programming the V9990: Learning by disassembling the "Robot" demo

2023-03-24T14:31:08Z

HAL 6128:

Programming the V9990: Learning by disassembling the "Robot" demo

2023-03-24T14:31:00Z

HAL 6128:

Programming the V9990: Learning by disassembling the "Robot" demo

2023-03-24T14:30:49Z

HAL 6128:

Programming the V9990: Learning by disassembling the "Robot" demo

2023-03-24T14:30:08Z

HAL 6128:

Programming the V9990: Learning by disassembling the "Robot" demo

2023-03-24T14:30:00Z

HAL 6128:

Programming the V9990: Learning by disassembling the "Robot" demo

2023-03-24T14:29:51Z

HAL 6128:

Programming the V9990: Learning by disassembling the "Robot" demo

2023-03-24T14:29:34Z

HAL 6128:

Programming the V9990: Learning by disassembling the "Robot" demo

2023-03-24T14:29:16Z

HAL 6128:

Programming the V9990: Learning by disassembling the "Robot" demo

2023-03-24T14:25:24Z

HAL 6128:

Programming the V9990: Learning by disassembling the "Robot" demo

2023-03-24T14:24:05Z

HAL 6128:

File:Robot.dsk

2023-03-24T14:21:16Z

HAL 6128: The Robot Demo Disk for the Amstrad CPC with a V9990 attached. It's the advanced version. Just start "robot.bin" file.

The Robot Demo Disk for the Amstrad CPC with a V9990 attached.
It's the advanced version. Just start "robot.bin" file.

Programming the V9990: Learning by disassembling the "Robot" demo

2023-03-24T14:19:59Z

HAL 6128:

[[File:Robot.dsk|thumbnail|Robot Demo Disk]]
Having a V9990 VDP attached on my CPC and always eager to learn about and program it. First steps are reproducing the "Robot" demo which were spread around the net to show little of the capabilities of the VDP V9990 from Yamaha.

Programming the V9990: Learning by disassembling the "Robot" demo

2023-03-24T14:18:56Z

HAL 6128: Created page with "Having a V9990 VDP attached on my CPC and always eager to learn about and program it. First steps are reproducing the "Robot" demo which were spread around the net to show lit..."

Having a V9990 VDP attached on my CPC and always eager to learn about and program it. First steps are reproducing the "Robot" demo which were spread around the net to show little of the capabilities of the VDP V9990 from Yamaha.

Source Codes

2023-03-24T14:15:01Z

HAL 6128:

[[Category:Programming]]
''This article contains source codes and programming examples. You may also have a look at''
* [[Programming software]]
* [[BIOS Functions]]
* [[Technical documentation]]s
* [[Locomotive BASIC]]
* [[Type Ins]]

== Assembler ==
*[[Z80_-_undocumented_opcodes|Z80 - undocumented opcodes]]
*[[Where to learn?]]
*[[A little optimization for Z80 Assembler]]

== Algorithms ==
*[[Programming:Bubble sort|Bubble sort]]
*[[Programming:CPC OS floating point routines|CPC OS floating point routines]]
*[[Programming:CRC16|CRC16]]
*[[Programming:CRC32|CRC32]]
*[[Programming:Integer Division|Integer Division]]
*[[Programming:Integer Multiplication|Integer Multiplication]]
*[[Programming:Logarithm|Logarithm]]
*[[Programming:Ultrafast Multiplication|Ultrafast Multiplication]] by [[Prodatron]]
*[[Programming:Fast Square Root|Fast Square Root]]
*[[Programming:Fast 16 bit Square Root|Fast 16 bit Square Root]] by [[User:Executioner|Executioner]]
*[[Programming:Filling memory with a byte|Filling memory with a byte]]
*[[Programming:Square Root|Square Root]]
*[[Programming:Precalculated square|Precalculated square]]
*[[Programming:Maze generation|Maze generation]]
*[[Programming:Random Number Generator|Random Number Generator]]
*[[Programming:Reverse A|Reverse A]]
*[[Programming:Quicksort|Quicksort]]
*[[Programming:Sin/Cos calculation|Sin/Cos calculation]]

== CP/M ==
*[[Programming:A simple 'Hello World' program for CP/M using BDOS|A simple 'Hello World' program for CP/M using BDOS]]
*[[Programming:A simple 'Hello World' program for CP/M using BIOS|A simple 'Hello World' program for CP/M using BIOS]]
*[[Programming:Executing firmware functions from within CP/M 2.1|Executing firmware functions from within CP/M 2.1]]
*[[Programming:Executing firmware functions from within CP/M 2.1 or CP/M plus|Executing firmware functions from within CP/M 2.1 or CP/M plus]]
*[[Programming:Executing firmware functions from within CP/M 2.1|Executing firmware functions from within CP/M 2.1]]
*[[Programming:Executing firmware functions from within CP/M plus|Executing firmware functions from within CP/M plus]]

== CPC Plus ==
*[[Amstrad CPC plus sprite format]]
*[[Programming:Convert CPC sprites to Plus hardware sprites|Convert CPC sprites to Plus hardware sprites]]
*[[Sprites Multiplexing]]
*[[Programming:CPC Plus Hardware Sprites|Hardware sprites]]
*[[Programming:CPC Plus Horizontal scroll|Horizontal scroll]]
*[[Programming:CPC Plus RLE Hardware Sprites|RLE hardware sprites]]
*[[Programming:CPC Plus Screen Splitting|Screen splitting]]
*[[Programming:CPC Plus Vertical scroll|Vertical scroll]]
*[[Operation of Z80 interrupt mode 0 in the CPC plus design]]
*[[Programming:Simple Raster Example 2 (uses CPC plus features)|Simple Raster Example 1 (uses CPC plus features)]]
*[[Programming:Simple Raster Example 3 (uses CPC plus features)|Simple Raster Example 2 (uses CPC plus features)]]
*[[Programming:Unlocking ASIC|Unlocking ASIC]]

== Devices ==
*[[Programming:CPC Booster|CPC Booster]]
*[[Programming:Digiblaster|Digiblaster]]
*[[Programming:Program to save the ROM of the Multiface 2|Program to save the ROM of the Multiface 2]]
*[[Programming:SYMBiFACE II|SYMBiFACE II]]

== File access ==
*[[Programming:An example to read a file byte-by-byte|An example to read a file byte-by-byte]]
*[[Programming:An example to write a file byte-by-byte|An example to write a file byte-by-byte]]
*[[Programming:Read/Write a file quickly byte-by-byte|Read or write a file quickly byte-by-byte]]
*[[Programming:A simple file copier using firmware functions (copies byte-by-byte)|A simple file copier using firmware functions (copies byte-by-byte)]]
*[[Programming:Loading a file|Loading a file]]
*[[Programming:Saving a file|Saving a file]]
*[[Programming:Unlocking a protected basic file|Unlocking a protected basic file]]
*[[Programming:Undo delete of file|Undo delete of file]]

== Floppy disk ==
*[[Programming:A simple disc copier using BDOS functions|A simple disc copier using BDOS functions]]
*[[Programming:A simple disc formatter using BDOS functions|A simple disc formatter using BDOS functions]]
*[[Programming:An example loader|An example loader]]
*[[Programming:Catalog a disc and retrieve a directory|Catalog a disc and retrieve a directory]]
*[[Programming:Detecting an Amstrad or Vortex disc controler|Detecting an Amstrad or Vortex disc controler]]
*[[Programming:Formatting a track on a disc|Formatting a track on a disc]]
*[[Programming:Reading a sector from a disc|Reading a sector from a disc]]
*[[Programming:Reading and writing the boot sector of a SYSTEM/VENDOR disc|Reading and writing the boot sector of a SYSTEM/VENDOR disc]]
*[[Programming:Writing a sector to disc|Writing a sector to disc]]

== Games ==
*[[Programming:Coding a simple BASIC game into Assembly]]

== Graphics ==

*[[Programming:Calculating xpos,ypos to screen address in assembly|Calculating xpos,ypos to screen address]]
*[[Programming:Display a 8-bit number in binary|Display a 8-bit number in binary]]
*[[Programming:Display a 8-bit number in hex|Display a 8-bit number in hex]]
*[[Programming:Display a byte as a 3-digit decimal number|Display a byte as a 3-digit decimal number]]
*[[Programming:Display and update Scores|Display and update Scores]]
*[[Programming:Distorting the screen using register 2 of the CRTC (Horizontal Sync Position)|Distorting the screen using register 2 of the CRTC (Horizontal Sync Position)]]
*[[Programming:Fast plot|Fast plot]]
*[[Programming:Fast Sprites|Fast Sprites]] by [[User:Executioner|Executioner]]
*[[Programming:Fast Textoutput|Fast Textoutput]] by [[Prodatron]]
*[[Fastest_Character_Print_in_Mode_2|Fastest Character Print in Mode 2 in all screen positions]] by [[FG Brain]]
*[[Programming:Hardware scrolling|Hardware Scrolling]] by [[User:Executioner|Executioner]]
*[[Programming:Hardware scrolling 2|Hardware Scrolling 2]]
*[[Programming:Hardware scrolling the screen horizontally byte-by-byte using the CRTC|Hardware scrolling the screen horizontally byte-by-byte using the CRTC]]
*[[Programming:Hardware scrolling the screen using the CRTC|Hardware scrolling the screen using the CRTC]]
*[[Programming:Next / previous line calculation|Next / previous line calculation]]
*[[Programming:Overscan|Overscan]]
*[[Programming:Plotting a sprite using character matrices|Plotting a sprite using character matrices]]
*[[Mode 4 (two bitplane emulation)| 4th Mode of CPCs: Plotting sprites on 2 bitplanes]]
*[[Screen refresh rate|Set the screen refresh rate]]
*[[Programming:Simple Raster Example 1|Simple Raster Example]]
*[[Programming:Simple Split Raster Example 1|Simple Split Raster Example]]
*[[Synchronising with the CRTC and display]]
*[[CRTC change colour (fill) test with precise timing]] by [[User:Matahari|Matahari]]
*[[256 byte Overscan MEGATEXT Intro - (features 50Hz fullscreen scroll)]] by [[User:Matahari|Matahari]]
*[[Programming the V9990: Learning by disassembling the "Robot" demo]]

== Interrupts ==
* [[Reliable use of interrupt mode 2 on the CPC]]

== Keyboard ==
*[[Programming:Keyboard scanning|Keyboard scanning]]
*[[Programming:Keyboard_redefinition|Keyboard redefinition]]

== Cartridges ==
*[[Programming:Cartridges|Cartridges]]
*[[Programming:Crt0Cart|CRT0 for SDCC]] to init a CPR cart

== Other routines ==
*[[Programming:An example boot sector (executed with rsx command CPM)|An example boot sector (executed with rsx command CPM)]]
*[[Programming:An example to define a RSX|An example to define a RSX]]
*[[Programming:Calling a RSX from outside of BASIC|Calling a RSX from outside of BASIC]]
*[[Programming:Dumping the data of BASIC or AMSDOS or an expansion rom|Dumping the data of BASIC or AMSDOS or an expansion rom]]
*[[Programming:Dumping the data of the lower rom|Dumping the data of the lower rom]]
*[[Programming:Storing and Retrieving Screens from the extra 64kb|Storing and Retrieving Screens from the extra 64kb]]

== Sound ==
*[[How to access the PSG via PPI]]
*[[Programming:Tutorial - Understanding the fundamentals of BASIC SOUND and the Firmware SOUND QUEUE|Tutorial - Understanding the fundamentals of BASIC SOUND and the Firmware SOUND QUEUE]]
*[[Programming:Source code to show 0x0ff is always returned when reading PSG port B|Source code to show 0x0ff is always returned when reading PSG port B]]
*[[Programming:Source code to show it is possible to store data in PSG register 14 and 15 (port A and port B)|Source code to show it is possible to store data in PSG register 14 and 15 (port A and port B)]]
*[[Programming:Source code to show it is possible to store data in PSG register 14 and 15 even if the port has been set to input|Source code to show it is possible to store data in PSG register 14 and 15 even if the port has been set to input]]
*[[Programming:Source code to show that some registers always return 0 in some bits|Source code to show that some registers always return 0 in some bits]]
*[[Programming:Source code to show that when a port is read in output mode; the data read will be ANDed with the inputs to that port|Source code to show that when a port is read in output mode; the data read will be ANDed with the inputs to that port]]

== Cross Development ==
*[[Programming:Cross Development|Cross Development]]

[[Category:Source code]]

== General Notes ==

* Memory range for programs is &0040-&a700. This avoids firmware and memory allocated by AMSDOS disc ROM.
This is safe for the purpose of loading and being compatible with the firmware.
After loading, if you disable the firmware, you can re-use the firmware areas as you want, but you need to do everything yourself (scanning keyboard, drawing, sound etc).If you need to use these areas, a common thing to do is to load most into the safe area, some into the screen, and relocate it after loading.
* Programs on cassette and disc have a header that define the load address, length and execution address.

In Pasmo assembler use the "end" mnemonic to define the label which is the execution address and use "--amsdos" to put an AMSDOS header on it.

* Basic programs start at &170.
* Firmware uses interrupt mode 1 of the Z80 (interrupts jump to &0038)
* Lowest place you can LOAD a binary file to with BASIC is &389 e.g.:

openout"d"
memory <address>-1
closeout
load "code",<address>
call <exec>

*Screen is normally at &c000-&ffff. (It can be changed using firmware, or using CRTC R12/R13)
*Stack is normally at &c000 and goes down.
*Extra registers (BC', AF', HL', DE' are reserved by the firmware). Avoid if you are using firmware functions.
*Lower rom (containing OS) can be paged into memory between &0000-&3fff.
*Upper rom is selectable, examples are BASIC and AMSDOS. They can be paged into memory between &c000-&ffff.
*From basic, a game is run with:

RUN"<filename>

keep it in the safe memory ranges and it'll run from cassette and disc.
*Screen is normally 40 crtc chars wide (CRTC R1=40), 25 crtc chars tall (CRTC R6=25). 8 scan lines per char (R9=7). Firmware functions assume this.
*Screen is bitmapped. You must draw/erase your own sprites and text.
*Firmware refreshes the palette every 50th of a second, so you need to turn off the firmware and use the hardware directly, or set the colours using firmware.
*Firmware can be "turned off", by disabling lower ROM, redirecting interrupts and not calling firmware functions.
*Screen can be resized the same as the Spectrum. Provided you do not use hardware scrolling, this gives you extra space although because of the layout of the screen, it's not continuous, it's in 8 seperate blocks, but it's enough to store data and code.