; ================================================================ ; Example source with target 'o' or '80' ; ZX80 tape file / snapshot ; Copyright (c) Günter Woigk 1994 - 2017 ; mailto:kio@little-bat.de ; ================================================================ ; "o" and "80" files are the same and used for saving ZX80 programs. ; The file consists of the raw ram data as saved by the ZX80 tape saving routine. ; The data is save from and loaded back to address $4000++. ; The file can only store one program, not a whole tape with multiple programs. ; ; --------------------------------------------------------------- ; Notes: ; ZX80 files do not have filenames ; ZX80 files cannot be autostarted. ; The data is loaded to address $4000++ ; The data contains the whole system area, Basic program, and VARS. ; Video memory is NOT included in ZX80 files. ; the last byte of a (clean) file should be $80 (the last byte of VARS) ; The system area should contain proper data. ; $400A (2 bytes) defines the data end address (used to calculate the file length). ; $4028++ may be misused for whatever purpose. ; ; While loading, the data at address $400A/400B is overwritten. After this they contain ; the real data end address of the data loaded and define when loading will stop. :-) ; ; Files should usually not exceed 16 kBytes. ; The memory detection procedure in both ZX80 and ZX81 stops after 16 kBytes (at $8000), ; ; ; --------------------------------------------------------------- ; The Character Set ; --------------------------------------------------------------- ; ; $00 $01 $02 $03 $04 $05 $06 $07 $08 $09 $0A $0B $0C $0D $0E $0F ; spc " gra gra gra gra gra gra gra gra gra gra £ $ : ? ; ; $10 $11 $12 $13 $14 $15 $16 $17 $18 $19 $1A $1B $1C $1D $1E $1F ; ( ) - + * / = > < ; , . 0 1 2 3 ; ; $20 $21 $22 $23 $24 $25 $26 $27 $28 $29 $2A $2B $2C $2D $2E $2F ; 4 5 6 7 8 9 A B C D E F G H I J ; ; $30 $31 $32 $33 $34 $35 $36 $37 $38 $39 $3A $3B $3C $3D $3E $3F ; K L M N O P Q R S T U V W X Y Z ; ; --------------------------------------------------------------- #target o ; output file is saved with filename extension ".o" ;#target 80 ; output file is saved with filename extension ".80" #charset ZX80 ; enable character set translation for strings and character literals ; --------------------------------------------------------------- ; THE SYSTEM VARIABLES ; --------------------------------------------------------------- ; ; Note: the names of the system variables are taken from the original Nine Tiles Assembly Listing. ; Example values are taken AS AN EXAMPLE ONLY from Breakout (Macronics, 1980) ; #code SYSVARS, 0x4000, 0x28 ERR_NR db $FF ; 1 16384 $4000 IY+$00 One less than report code. FLAGS db $04 ; X1 16385 $4001 IY+$01 Various Flags to control BASIC System: ; 7 1-Syntax off 0-Syntax on ; 6 1-Numeric result 0-String result ; 5 1-Evaluating function (not used) ; 3 1-K cursor 0-L cursor ; 2 1-K mode 0-L mode. ; 0 1-No leading space 0-Leading space. PPC dw $FFFE ; 2 16386 $4002 IY+$02 Line number of current line. P_PTR dw $434A ; N2 16388 $4004 IY+$04 Position in RAM of [K] or [L] cursor. E_PPC dw 0 ; 2 16390 $4006 IY+$06 Number of current line with [>] cursor. VARS dw _VARS ; $4349 ; X2 16392 $4008 IY+$08 Address of start of variables area. E_LINE dw end_of_file ; $434A ; X2 16394 $400A IY+$0A Address of start of Edit Line. D_FILE dw end_of_file+2 ; $434C ; X2 16396 $400C IY+$0C Start of Display File. DF_EA dw end_of_file+$242 ; $458C ; X2 16398 $400E IY+$0E Address of the start of lower screen. DF_END dw end_of_file+$245 ; $458F ; X2 16400 $4010 IY+$10 Display File End. DF_SZ db 2 ; X1 16402 $4012 IY+$12 Number of lines in lower screen. S_TOP dw 0 ; 2 16403 $4013 IY+$13 The number of first line on screen. X_PTR dw 0 ; 2 16405 $4015 IY+$15 Address of the character preceding the [S] marker. OLDPPC dw 0 ; 2 16407 $4017 IY+$17 Line number to which continue jumps. FLAGX db 0 ; N1 16409 $4019 IY+$19 More flags: ; 7 1-K mode 0-L mode. ; 6 1-Numeric result 0-String result ; 5 1-Inputting 0-Editing T_ADDR dw $07A2 ; N2 16410 $401A IY+$1A Address of next item in syntax table. SEED dw 0 ; U2 16412 $401C IY+$1C The seed for the random number. FRAMES dw $7484 ; U2 16414 $401E IY+$1E Count of frames shown since start-up. DEST dw $4733 ; N2 16416 $4020 IY+$20 Address of variable in statement. RESULT dw $3800 ; N2 16418 $4022 IY+$22 Value of the last expression. S_POSN_X db $21 ; X1 16420 $4024 IY+$24 Column number for print position. S_POSN_Y db $17 ; X1 16421 $4025 IY+$25 Line number for print position. CH_ADD dw $FFFF ; X2 16422 $4026 IY+$26 Address of next character to be interpreted. #assert $ == $4028 ; -------------------------------------- ; BASIC code and variables, Machine code ; -------------------------------------- ; #code _BASIC #code _VARS ;#code _DFILE ; The ZX80 stopped writing to tape at E_LINE (the edit line). ; So neither the edit line nor the display file are stored in the tape file. #code _BASIC ; add code for Basic starter here ; add basic program and/or machine code here ; The machine code must be hidden somehow in the basic program or in the variables #code _VARS ; add basic variables and/or machine code here db 0x80 ; end marker for basic variables end_of_file: #end