This repo contains 8085 emulator

• this 8085 emulator emulates almost all instructions accept few (see TODO.
• it does not emulates at same speed though (3.2MHz) but at speed of host system.
• it comes with 64K ram.

How to use?

• write your assembly code as usual with few things in mind.

• // this is 8085 assembly program to sort numbers
  LXI H,3000
  MVI M,6
  LXI H,3001
  MVI M,1
  LXI H,3002
  MVI M,5
  LXI H,3003
  MVI M,2
  LXI H,3004
  MVI M,4
  LXI H,3005
  MVI M,3
  hlt
  // this is comment
  %execute
  %getmemory 3000 3010
  MVI B,5
  START:
  LXI H,3000
  MVI C,5
  BACK:
  MOV A,M
  INX H
  CMP M
  JC SKIP
  JZ SKIP
  MOV D,M
  MOV M,A
  DCX H
  MOV M,D
  INX H
  SKIP:
  DCR C
  JNZ BACK
  DCR B
  JNZ START
  HLT
  %execute
  %getregister
  %getmemory 3000 3010
  q
  

• // at beginning of line indicate comment.
• label: should not follow any instruction but newline.
• MOV M,A this type to instruction showld not contain space between comma(,) and oprands.
• % sign following command is used to tell emulator what to do.
• every file must end with q to mark end.

%instructions:

• %execute executes instructions above can be called multiple times.
• %getregisterprints register contents.
• %getmemory start end returns memory content in range.
• %setpc location set position of PC registor from here execution starts.
• %setmemory location set position of memory where instruction is to be stored.
• %initmemory set memory content to 0.

NOTE:

• default PC=0 start memory=0 SP=65520
• every registor and memory is 0 initially.
• before execution HLT must be there else there uill be infinite loop.

OUTPUT:

######################
# Address  #  Value  #
######################
#   3000  #     6    #
#   3001  #     1    #
#   3002  #     5    #
#   3003  #     2    #
#   3004  #     4    #
#   3005  #     3    #
#   3006  #     0    #
#   3007  #     0    #
#   3008  #     0    #
#   3009  #     0    #
#   3010  #     0    #
######################
########################
# Register  #  values  #
########################
#    A      #     5    #
#    B      #     0    #
#    C      #     0    #
#    D      #     3    #
#    E      #     0    #
#    H      #    11    #
#    L      #   189    #
#    SP     # 65520    #
#    IR     #   118    #
#    PC     #    61    #
#    S      #     0    #
#    Z      #     1    #
#    AC     #     0    #
#    P      #     1    #
#    CY     #     0    #
#    BC     #     0    #
#    DE     #   768    #
#    HL     #  3005    #
########################
######################
# Address  #  Value  #
######################
#   3000  #     1    #
#   3001  #     2    #
#   3002  #     3    #
#   3003  #     4    #
#   3004  #     5    #
#   3005  #     6    #
#   3006  #     0    #
#   3007  #     0    #
#   3008  #     0    #
#   3009  #     0    #
#   3010  #     0    #
######################

How to execute file?

• using commandline java -Dfile.encoding=UTf-8 -jar 8085-emulator.jar in.file
• run JAR directly and enter in prompt java -Dfile.encoding=UTf-8 -jar 8085-emulator.jar > Enter file name to execute: in.file

References

https://www.jameco.com/Jameco/Products/ProdDS/52062.pdf http://www.eazynotes.com/notes/microprocessor/notes/opcodes-table-of-intel-8085.pdf https://www.tutorialspoint.com/microprocessor/microprocessor_8085_architecture.htm https://www.geeksforgeeks.org/microprocessor-tutorials/ (8085)