MZ-800 course Chapter 2
|2. BASIC-800 ( 1Z016 / 5Z-009 )|
In this part of the chapter you really will encounter extra BASIC instructions,
that is why the word Extra is no longer between quotes. This part will
not only contain the programs, but also an explanation of the new instructions.
It is a pity that we can not show you the most recent instructions,
which will be part of the special GAME-BASIC. You will have to do with
instructions which are familiar to a relatively large number of people.
Later on in this book some programs will be explained. Here we shall
only explain the instructions.
10 POKE $A015,$CD,$64,$1,$9D,$28,$11,$23,
Unfortunately we do not have a tape version.
INVERSE really says it all. With this instruction you can inverse the text displayed on your screen. Inverse in this context means that black becomes white and the other way around. If the fore- and background colours are not black and white, these colours will be switched. This is how INVERSE works:
INVERSEON - The colours will be inverted.
INVERSEON:PRINT"NEPTUNES SOFTWARE";:INVERSE:PRINT"-The best there is."
The instructions PMODE and PSKIP are now inoperable.
10 FOR A=$0 TO $43:READ A$:POKE $FAB+A,VAL("$"+A$):NEXT A:
Adjustments for tape BASIC: 40 DATA ED,5B,D6,9D,C4,D3,5E,D5,EB,CD 60 DATA A6,00,EB,D5,22,D6,9D,E1,11,A4 70 DATA 11,D5,CD,8A,83,D1,21,00,00,1A 110 DATA CD,DA,84,E5,7B,FE,01,28,0D,FE
Usage of CLIST:
When the checklist command is turned on, a verification number appears
after typing a line. When you copy a line from a book which also has
verification numbers, you can see if you have copied the line correctly.
You can also use it when you print out your own listing.
10 DATA 2A,70,10,23,23,23,23,7E,B7,C9,CD,00,57,28,13,21,70,10 20 DATA 11,44,57,01,12,00,ED,B0,2A,70,10,01,10,00,ED,B0,C3,8E 30 DATA 61,CD,00,57,C2,8E,63,21,44,57,11,70,10,01,12,00,ED,80 40 DATA ED,5B,70,10,01,10,00,ED,B0,CD,3E,00,AF,C9 50 FOR A=$5700 TO $5B17:READ A$:POKE A,VAL("$"+A$) 60 NEXT A:POKE $5B17,$42,$43,$CB:POKE $5C99,$A,$57:POKE $5D1D,$25,$75
The functionality of BACK:
If you have issued the NEW command and you did not yet load or type
anything, you can retrieve your listing with the back command. If you
did put something new in memory, you will get an instruction error.
Tape version: 10 POKE $59E9,$42,$4F,$D2 20 POKE $55B0,$CD,$DA,$84,$7B,$1,$CF,$6,$ED,$79,$C9 30 POKE $5C9D,$B0,$55
Diskette-version: 10 POKE $59E9,$42,$4F,$D2 20 POKE $5599,$CD,$51,$85,$7B,$1,$CF,$6,$ED,$79,$C9 30 POKE $5C9D,$99,$55
Functionality of the BOR instruction:
The OFF instruction is no longer usable after running the program above.
10 POKE $5600,$CD,$51,$85,$7B,$32,$15,$56,$C9 20 POKE $5608,$3A,$9B,$10,$32,$1F,$56,$C3,$D9,$5 30 POKE $5611,$23,$D9,$77,$3E,$0,$F6,$40,$D3,$CC,$7E,$EE,$FF 40 POKE $561D,$77,$3E,$7,$F6,$80,$D3,$CC,$C3,$EF,$5 50 POKE $5B21,$42:POKE $5D6,$C3,$8,$56 60 POKE $5EC,$C3,$11,$56:POKE $5D21,$0,$56
For tape BASIC you must replace line 10 with: 10 POKE $5600,$CD,$DA,$84,$7B,$32,$15,$56,$C9
Functionality of BCOLOR:
An example: BCOLOR 1:PRINT"NEPTUNES SOFTWARE";:BCOLOR 2:PRINT"-The best there is."
This was the last extra instruction. Later on there is more about this.
Oh, and by the way: the CCOLOR instruction is unusable.