I'd like to use strings and arrays in my paged code, but I seem to have reached a blockage whereby, even though my paged-code looks like:

Firstly, a proper thankyou to Boriel for the compiler.   And secondly, also a proper thankyou to Duefectu for the beginner's guide book (I bought a hard copy), which I have read cover to cover (but I did skip the sound/audio sections ).  And I bought a hard copy of Simon G's NextTech book too, again I have read it cover to cover (but skipped the sound/audio parts).

Using Boriel ZXBasic and as little Z80 machine code as I can get away with (until I need to performance tune)... my project is that I am trying to write a quasi "character cell" based application, like being on an old VT100, whereby the application uses all 64KB of the Z80 for itself, and thus no ZX Spectrum ROM, and which internally leverages a poor man's virtual memory framework, whereby I have a supervisor layer of non-paged code running in MMU0/1, which boots from $0000 and jumps over IM1 at $0038 to begin my main code properly at say $0050 where the application begins properly... and so I have my core non-paged system variables mapped in MMU2 and then I have my paged code to run from MMU3 - and then various different aspects of paged application data paging in and out MMU4/5/6, with finally MMU7 again being static non-paged to host the 5KB of screen tile map for an 80x32 screen, with the final 3KB of MMU7 being available for the stack pointer from $FFFE downwards.
phew...
I know my code will never work first time, I get that... but I feel fairly sure that I have the basic (excuse the pun) initial structure of what I want to achieve, with all of my system variables (so far identified) defined at static addresses in MMU2, and my main supervisor MMU paging and also my screen updating routines and keyboard reading routines written (to be permanently resident in MMU0/1) and the first of my paged blocks of code to run from MMU3, and I have gotten the source code clean enough pass through zxbc without the compiler spitting any hard errors... (just lots and lots of warnings)... but I've now hit a roadblock...

I get how I can have many separate pages of 8KB deposited across the ZX Next vast 200+ pages of 8KB across 1.75 MB of RAM, and I get how I can have my code paged in at MMU3 for my application to execute from $6000, and I can get my non-paged supervisor layer code to make calls such as       uw_dummy = USR $6000     to call my paged code in MMU3, and thus wait for a return... but what I don't understand is how I can have many different paged code blocks where each is aware of *ALL* of the available core supervisor routines and their parameter structures and thus able to makes calls back in to the supervisor to run any of the many core system routines...

i.e. how can I make zxbc firstly compile the application core without dropping routines that zxbc thinks are unused, and yet also somehow get the compilations of many different "paged" application code to be aware of the core supervisor routines and their parameters and any return value data types (of functions).

e.g. I get this from my compilation of my "core.bas":
core.bas:115: warning: [W170] Function 's_crash' is never called and has been ignored
core.bas:154: warning: [W170] Function 's_fc_ram_copy' is never called and has been ignored
core.bas:165: warning: [W170] Function 's_clear_screen' is never called and has been ignored
core.bas:126: warning: [W170] Function 's_print_char_at' is never called and has been ignored
core.bas:143: warning: [W170] Function 's_print_string_at' is never called and has been ignored
core.bas:217: warning: [W170] Function 's_display_monitor' is never called and has been ignored
core.bas:283: warning: [W170] Function 'fub_key_get_minutes' is never called and has been ignored

...and I get this for my first stage of my application:
stage-include.bas:37: warning: [W170] Function 's_next_reg' is never called and has been ignored
stage-include.bas:38: warning: [W170] Function 's_return_to_zxos' is never called and has been ignored
stage-include.bas:39: warning: [W170] Function 's_crash' is never called and has been ignored
stage-include.bas:40: warning: [W170] Function 's_fc_ram_copy' is never called and has been ignored
stage-include.bas:42: warning: [W170] Function 's_clear_screen' is never called and has been ignored
stage-include.bas:43: warning: [W170] Function 's_print_char_at' is never called and has been ignored
stage-include.bas:44: warning: [W170] Function 's_print_string_at' is never called and has been ignored
stage-include.bas:45: warning: [W170] Function 's_display_monitor' is never called and has been ignored
stage-include.bas:47: warning: [W170] Function 'fub_key_get_minutes' is never called and has been ignored
stage-include.bas:48: warning: [W170] Function 's_key_wait_for_vblank' is never called and has been ignored
stage-include.bas:49: warning: [W170] Function 's_get_key' is never called and has been ignored
...
stage-init.bas:8: warning: [W170] Function 's_stage_init' is never called and has been ignored
stage-init.bas:20: warning: [W170] Function 's_init_keyboard_table_ZX_keys' is never called and has been ignored
stage-init.bas:21: warning: [W170] Function 's_init_keyboard_table_ZX_symkeys' is never called and has been ignored
stage-init.bas:18: warning: [W170] Function 's_init_load_palette' is never called and has been ignored
stage-init.bas:186: warning: [W170] Function 's_init_load_palette_entry' is never called and has been ignored
stage-init.bas:223: warning: [W170] Function 's_init_clear_screen' is never called and has been ignored
stage-init.bas:26: warning: [W170] Function 's_init_title_screen' is never called and has been ignored

...where stage-include.bas was my attempt to make each "stage" aware of a jump-table of locations of core routines:
Asm
    ; fixed jump table addresses for the linker
    _s_main                          equ $0050
    _s_next_reg                      equ $0053
    _s_return_to_zxos                equ $0056
    _s_crash                         equ $0059
    _s_fc_ram_copy                   equ $005C
    _s_clear_screen                  equ $005F
    _s_print_char_at                 equ $0062
    _s_print_string_at               equ $0065
    _s_display_monitor               equ $0068
    _fub_key_get_minutes             equ $006B
    _s_key_wait_for_vblank           equ $006E
    _s_get_key                       equ $0071
End Asm

' implementation blocks to stop "not implemented" errors
' these contain no code; the equate above handles the address
Sub s_main(): End Sub
Sub s_next_reg(reg As UByte, value As UByte): End Sub
Sub s_return_to_zxos(): End Sub
Sub s_crash(error_code As UByte, error_text As String): End Sub
Sub Fastcall s_fc_ram_copy(src_address As UInteger, dest_address As UInteger, byte_count As UInteger): End Sub
Sub s_clear_screen(): End Sub
Sub s_print_char_at(x As UByte, y As UByte, char As UByte, colour As UByte): End Sub
Sub s_print_string_at(x As UByte, y As UByte, text As String, colour As UByte): End Sub
Sub s_display_monitor(): End Sub
Function fub_key_get_minutes() As UByte: return 0: End Function
Sub s_key_wait_for_vblank(): End Sub
Sub s_get_key(): End Sub


But clearly there is something I'm not getting, and I've reached the limits of capability of AI helper tools.

I had rationalised to myself that my build script should only call to zxbc to produce "-f asm" ASM files... as I expect to have to then somehow "link" the static core ASM and the many paged stage ASM together at some point... and I also seem to have rationalised that I may perhaps need to use     sjasmplus     to assemble my ".nex" package.

Does the above sound achievable?  Or am I asking too much of the "Next" as a platform?  i.e. is the "Next" only any good for paging graphics data, and no good for paging application code?

trying Escape From Cnossus from 2013 getting this error

Error: 'subdivideHigh' is neither an array nor a function.

the line is

wall1 = subdivideHigh(x1, y1, x - 1, y2)

any help please

Looking over an old file of mine that once worked I'm now getting Error: Undefined GLOBAL label . each one is going to a fastcall.

ie

        ld hl, lineMSG
        ld bc, end1-lineMSG
        call myPrint42

calling 

SUB fastcall myPrint42()
ASM
myPrint42:
    push    af
    push    ix
    push    hl
    ld    ix, PRINT42
    CALL    IXCALL
    pop    hl
    pop    ix
    pop    af
    ret
END ASM
END SUB

gives me Error: Undefined GLOBAL label ".myPrint42"

any help please....

I orginally posted this on SpectrumComputing Forum - copied here in case anyone wants to play with it :-)

Hi

Hope this helps someone else :-)

I saw a post by Andy Dansby who writes at https://zxspectrumcoding.wordpress.com/

He has created a fast plot routine, (hellaplot), so I thought I'd try and convert it to a Boriel Basic (BB) subroutine, just for fun and learning - and as it was a single routine.

I had to do a little bit of reading, but also had to ask for help from the BB telegram community, as to begin with the code was crashing the emulator. Turns out it was a simple fix when you know how - FASTCALL was needed when passing parameters for ASM to use from a SUB routine.

Andy's code needs the x/y locations in DE, so I had to do a little bit to get them set up like this - I assume there might be some more efficiency if different registers were used as BB passes from the subroutine call, the first parameter into A, and the second parameter is the second item on the stack (the first being the return address).

When I started, xPos was the first parameter, and yPos the second (as I like x,y), but this meant to get them into DE, took another load (POP DE, LD E with D, LD D with A, compared to POP DE, LD E with A)

So some "non exact" timings - plot included as the library in BB takes about 15 seconds to fill up the screen with "points". Andy's one takes 5 seconds to do the same.

As far as Andy's code goes, I understand the comments, but not exactly how it works :-)

Anyway, code below :

SUB FASTCALL HellaPrint(yPos as UBYTE, xPos as UBYTE)
' HellaPrint prints an x,y pixel
' 0,0 is top left
' Original code by Andy Lansby
' https://zxspectrumcoding.wordpress.com/
' yPos is first, as it save a LD instruction when putting xPos and yPos into DE
ASM

JP START ; Put this in as it's like this on the Wiki ASM desciption - can it be avoided?
X_PositionBits: defb 128,64,32,16,8,4,2,1
; Might there be a quicker way to do the above, so it's not needed every time the program is run? or does it not work like this and is created once at compile time?

START: ; plot d = x-axis, e = y-axis
; A contains the yPos, xPos is on stack.
POP HL ; Pops the return address into HL
POP DE ; xPos is on the stack, and it needs to be in D
LD E, A ; A has our first paramter (yPos), load it into E. D should be Xpos, E should be yPos
PUSH HL ; Puts the return address back onto stack ...
; 166 T states per pixel
XOR A ; reset A to 0 and flags to default
LD A,E ; load Y plot point
RRA ; rotate Right --- divide in half
SCF ; turn on Carry flag-
RRA ; rotate right with the carry flag
OR A ; set flag S on - C flag off
RRA ; rotate Right --- divide in half

LD L,A ; temp store in L
XOR E ; XOR the Y value
AND %11111000 ; mask out bottom 3 bits
XOR E ; XOR the Y value

LD H,A ; store High byte
LD A,D ; load X plot point
XOR L ; XOR the temp value
AND %00000111 ; mask out unwanted bits
XOR D ; XOR the X value
RRCA ; divide by 2
RRCA ; divide by 4
RRCA ; divide by 8

LD L,A ; store Low byte
; now we have the full address
; now use LUT to find which bit to set
LD A,D ; load X plot point
AND %00000111 ; mask out unwanted bits

; use a LUT to quickly find the bit position for the X position
LD DE,X_PositionBits ; load LUT address into DE
ADD A,E ; Add A to E to get offset into table
LD E,A ; E now points to the LUT entry
LD A,(DE) ; load answer into A

; output to screen
OR (HL) ; or with contents of address HL
LD (HL),A ; load address HL with Answer from A
END ASM
END SUB

Hi

HOF.zxbas - Hall of fame procedures
main.zxbas - a demo

Attached is a little "library" for a Hall of Fame / High Score table.

To use it - you need to create two Arrays (at least 2 ...)

Array 1 = UInteger, for scores
Array 2 = String, for names

Probably best to keep to 10 entries, but could be more.  You can have more than 1 HOF, so could have Array2, Arry3 etc etc for say Easy Score, Medium Scores, Hard Scores.  As it passes the Arrays by reference, no other variables are needed.

Completely and utterly free to use, adapt, change, republish how ever you want.

Arraybase is 0

SUB HOF_IntialiseHOF(BYREF HOF_Scores() AS UINTEGER, BYREF HOF_Names() AS STRING, HOF_IntialTopScore as UINTEGER,HOF_InitialName AS STRING)
Use this to initialise the two HOF arrays - with a "highest score, working down to a low score and gives each entry "InitialName".

FUNCTION HOF_HighScore_CheckEntry (HOF_Scores() AS UINTEGER, NewHighScore as UINTEGER) AS BYTE
Returns 1 if the High Score can g into the Arrays.

SUB HOF_HighScore_NewEntry (BYREF HOF_Scores() AS UINTEGER, BYREF HOF_Names() AS STRING, NewHighScore as UINTEGER, NewHighScoreName AS STRING)
Puts the new entries (name & score) into the HOF array.

SUB HOF_Print(BYREF HOF_Scores() AS UINTEGER, BYREF HOF_Names() AS STRING, YPOS as INTEGER, XPOS as INTEGER)
A simple print location, witch prints the Score and Names.  Will carry on printing if you have many entries ...

SUB HOF_PrintSpecial(BYREF HOF_Scores() AS UINTEGER, BYREF HOF_Names() AS STRING)
A "pretty High Score screen", that prints the top 10 scores.

Can probably be improved and made much more efficient.  There are porbably bugs as well (for example not sure what would happen if you had 100 entries with a first high score of 10 ... i think it's probably overflow to 655555 etc.  It includes string.bas and input.bas - not sure if the library needs both of those.

Attached Files

Thumbnail(s)
   

  HOF.zip (Size: 2.98 KB / Downloads: 116)

Please take a look at this simple programme:

Quote: Wrote:--optimize 2  --output-format=tzx --BASIC --autorun --explicit --strict

Hi

I'm looking at using some 3DOS commands, starting to see how I can cat a disk.

I've takend the below code from the +3 manula (pg 200 to 203) which should allow me to get the CAT into memory - the code looks to activate the disk (and for example if I don't attach a disk, it give me abort/retry) but then "reboots"/crashes the emulator back to the +3 menu.

I'm assuming that there might be some incompatibility somewhere between, starting reading, and returning contorl to the program.  Code is below.

Any thoughts?

(PS If the ASM didn't crash, the program wouldn't actually do anything anyway yet, as I've not sorted any output, or any caribles)

ZXStudio doesn't support +3/+2a etc in the included emulator. Requires at least Beta 6 of ZXBasicStudio

Use Project/Configure Project to configure.

Example Compiler Parameters

-O 0 -S 32768 -H 4768  -f tap -B -a

(The bold was auto generated, underscore are the options added "-f tap" to create a tap file, "-B -a" required to Generate the basic file and auto start.

Example Launch External Emulator

C:\zx\projects\DOSTesting\ZXStartFuse.bat

This has to be a batch file, rather than direct to the emulator, %1 and %2 are passed into the batch file for ZXBasicStudio - %1 is the path, and %2 the filename excluding the extension.

ZXStartFuse.bat created in the OS, and renamed to .bat, as it was txt file.

This is a small clear screen, that sort of fades out the screen pixel by pixel to the background colour.  I took it from one of the Melbourne house books, can't remember which one though.

No idea if it breaks anything else, but I've not had any issues.