en:playground:words:dup
dup simply duplicates the top of the stack. It's a code word.
To see how F-PC v3.6 defines DUP, perform below steps.
1. Launch F-PC v3.6 (A famous DOS Forth)
2. Type in: “see dup”. FPC replies:
DUP is Code, load DISASSEM to see it. ok
3. So I type in: “load disassem”.
A file MUST be open to perform this operation.
4. So I type: “open disassem”.
open disassem of 16329 bytes. ok
5. Let's continue: “load disassem”.
Loading..ESC_TO_EXIT 6F6C 61 Stack Empty. OOPS! <--- oops! sounds like there's a problem but it can be ignored.
6. Let's see how DUP is defined. Type: “see dup”
ESC_TO_EXIT 568 8B SP DI MOV, 8B FC .| <---- DUP 's definition start from here 56A FF 0 [DI] PUSH, FF 35 .5 56C 26 ES: 26 & <---- >NEXT 56D AD WORD LODS, AD - 56E FF AX #) JMP, FF E0 .` <---- end of DUP's definition 570 5A DX POP, 5A Z <---- start of the next word's definition 571 58 AX POP, 58 X
en/playground/words/dup.txt · Last modified: 2013-06-06 21:26 by 127.0.0.1