HALT Right There!

Discussion about ZX80 / ZX81 Software
Post Reply
User avatar
GCHarder
Posts: 345
Joined: Sat Dec 14, 2013 7:46 pm

HALT Right There!

Post by GCHarder »

HALT RIGHT THERE!
By Fred Nachbaur

Syncware News v3n6 Jul.-Aug '86

An explanation of the Z80 HALT command.
Attachments
Halt.zip
Demo program
(2.36 KiB) Downloaded 25 times
David G
Posts: 214
Joined: Thu Jul 17, 2014 7:58 am
Location: 21 North, 156 West

Re: HALT Right There!

Post by David G »

simple but intriguing

Then when I read the text and slowly realized what it is demonstrating

Code: Select all

1 REM _asm
     // Disassembly: 27 bytes @ $4082 (16514)
     L4082:  NOP     
             LD      HL,(400CH)
             LD      B,04H
      LOOP:  INC     HL
             LD      (HL),A
             DJNZ    LOOP
             RET 

     ;16525 entry point
     L408D:  LD      A,80H
             CALL    L4082
             LD      A,00H
             CALL    L4082
             CALL    $0F46  ;BREAK-2 ROM ROUTINE
             RET     NC
             JR      L408D
     END _asm
  10 POKE 16514,0
  20 RAND USR 16525
Post Reply