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__0a58_fcb → new_file_fcb

This commit is contained in:
Juhani Krekelä 2021-08-01 16:33:37 +03:00
parent f5e568a6e3
commit 3ecb399a46
1 changed files with 23 additions and 13 deletions
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36
edlin.asm
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@ -158,8 +158,11 @@ open_file:
int 0x21
delete_old_bak: ; 01b9
; Borrow the FCB we'll be later using to create the new file with
; Since we are done with the old .BAK before we start using it for
; its main purpose, this is safe
mov si, psp_fcb_1
mov di, __0a58_fcb
mov di, new_file_fcb
mov cx, 9
rep movsb
@ -168,12 +171,19 @@ delete_old_bak: ; 01b9
movsb
mov ah, sys_delete_file
mov dx, __0a58_fcb
mov dx, new_file_fcb
int 0x21
; TODO: Why .$$$? What is this used for?
create_new_file:
; Create the new file we'll be writing to. EDLIN never writes to
; the file we opened for reading, but instead renames that one to
; .BAK and then writes out the changed contents to a new file
;
; The file is called .$$$ until we either exit without saving in
; which case it's deleted, or with saving, in which case it's
; renamed to the original extension
mov al, '$'
mov di, __0a58_fcb + fcb_extension
mov di, new_file_fcb + fcb_extension
stosb
stosb
stosb
@ -194,12 +204,12 @@ setup_file_parameters: ; 01ec
xorw r_ax, r_ax
mov [psp_fcb_1 + fcb_record_low], ax
mov [psp_fcb_1 + fcb_record_high], ax
mov [__0a58_fcb + fcb_record_low], ax
mov [__0a58_fcb + fcb_record_high], ax
mov [new_file_fcb + fcb_record_low], ax
mov [new_file_fcb + fcb_record_high], ax
inc ax
mov [psp_fcb_1 + fcb_record_size], ax
mov [__0a58_fcb + fcb_record_size], ax
mov [new_file_fcb + fcb_record_size], ax
mov dx, file_buffer
movw r_di, r_dx
@ -552,7 +562,7 @@ __043f:
mov ah, sys_set_dta
int 0x21
mov dx, __0a58_fcb
mov dx, new_file_fcb
mov ah, sys_random_block_write
int 0x21
orb r_al, r_al
@ -1248,7 +1258,7 @@ command_q: ; 08a6
cmp al, 'Y'
jne newline
mov dx, __0a58_fcb
mov dx, new_file_fcb
mov ah, sys_close_file
int 0x21
@ -1273,7 +1283,7 @@ command_e: ; 08cd
int 0x21
mov cx, 1
mov dx, __0a58_fcb
mov dx, new_file_fcb
mov ah, sys_random_block_write
int 0x21
@ -1294,11 +1304,11 @@ command_e: ; 08cd
int 0x21
mov si, psp_fcb_1
mov di, __0a58_fcb + fcb_rename_target - 1
mov di, new_file_fcb + fcb_rename_target - 1
mov cx, 6 ; 6*2 = 12 bytes (as we copy words). 1 (drive specifier) + 8 (name) + 3 (extension)
rep movsw
mov dx, __0a58_fcb
mov dx, new_file_fcb
int 0x21
int 0x20
@ -1347,7 +1357,7 @@ quit_prompt db "Abort edit (Y/N)? $" ; 0a45
; 0a58
section .bss
__0a58_fcb resb 37 ; 0a58 … 0a7c
new_file_fcb resb 37 ; 0a58 … 0a7c
__0a7d resb 1