Version 1.1

gidubba.asm

@@ -189,10 +189,7 @@ getarg: load    r0, arg1
         breq    r0, r1, cmderr
         xor     r2, r2
         xor     r2, r0
-        shl     r2
-        shl     r2
-        shl     r2
-        shl     r2
+        shl     r2, 4
         ;Second digit
         load    r0, arg1 + 1
         cleq    r0, r0, hex2n
@@ -208,10 +205,7 @@ getarg: load    r0, arg1
         breq    r0, r1, cmderr
         xor     r2, r2
         xor     r2, r0
-        shl     r2
-        shl     r2
-        shl     r2
-        shl     r2
+        shl     r2, 4
         ;Fourth digit
         load    r0, arg1 + 3
         cleq    r0, r0, hex2n
@@ -229,10 +223,7 @@ getarg: load    r0, arg1
         breq    r0, r1, cmderr
         xor     r2, r2
         xor     r2, r0
-        shl     r2
-        shl     r2
-        shl     r2
-        shl     r2
+        shl     r2, 4
         ;Second digit
         load    r0, arg2 + 1
         cleq    r0, r0, hex2n
@@ -368,11 +359,54 @@ inline: cleq    r0, r0, input
         xor     r0, r0
         brneq   r0, r1, cmdp
 
-        ;Save the line
-        cleq    r0, r0, save
+        ;Restore the buffer start address
+        ;High byte
+        load    r0, bfstrt
+        store   chload + 1, r0
+        ;Low byte
+        load    r0, bfstrt + 1
+        store   chload + 2, r0
 
-        ;Insert the next line
-        breq    r0, r0, nextln
+        ;Store the save address
+        ;High byte
+        load    r0, eoflod + 1
+        store   chsave + 1, r0
+        ;Low byte
+        load    r0, eoflod + 2
+        store   chsave + 2, r0
+
+        ;Load and save a character from the buffer
+        ;Load
+chload: load    r1, buffer
+        ;Save
+chsave: store   buffer + 100, r1
+
+        ;Check for line end
+        load    r2, #a
+        breq    r1, r2, nextln
+
+        ;Increment the buffer address
+        ;Load the address
+        load    r0, chload + 1
+        load    r1, chload + 2
+        ;Increment
+        cleq    r0, r0, incdw
+        ;Store the address
+        store   chload + 1, r0
+        store   chload + 2, r1
+
+        ;Increment the save address
+        ;Load the address
+        load    r0, chsave + 1
+        load    r1, chsave + 2
+        ;Increment
+        cleq    r0, r0, incdw
+        ;Store the address
+        store   chsave + 1, r0
+        store   chsave + 2, r1
+
+        ;Load and save the next character
+        breq    r0, r0, chload
 
 inesc:  load    r0, #20
         store   ffff, r0
@@ -870,10 +904,6 @@ write:  load    r0, #ff
         ;Write
         cleq    r0, r0, prwr
 
-        ;Write an end-of-file
-        load    r0, #1a
-        store   fffd, r0
-
         ;Return to the command prompt
         breq    r0, r0, cmdp
 
@@ -898,20 +928,9 @@ iglead: load    r1, fffd
         ;Check for the RAM limit
         load    r0, chrsto + 1
         load    r1, chrsto + 2
-chkram: load    r2, limit
-        load    r3, limit + 1
-        brneq   r0, r2, chread
-        brneq   r1, r3, chread
-
-        ;Save an end-of-file at the start address
-        load    r0, #1a
-        store   buffer + 100, r0
-
-        ;Print an error and return to the command prompt
-        load    r0, #21
-        store   ffff, r0
-        cleq    r0, r0, newln
-        breq    r0, r0, cmdp
+chkram: cleq    r0, r0, ramchk
+        xor     r2, r2
+        brneq   r1, r2, cmdp
 
         ;Read a character
 chread: load    r1, fffd
@@ -924,12 +943,28 @@ chkend: xor     r2, r2
         breq    r0, r0, chrsto
         ;Empty tape reader
 chkntp: nand    r2, r2
-        brneq   r1, r2, chrsto
+        brneq   r1, r2, chklf
         load    r1, #1a
+        breq    r0, r0, chrsto
+
+        ;Check for a line feed
+chklf:  load    r2, #a
+        load    r3, #0
+        brneq   r1, r2, chrsto
+        load    r1, #d
+        load    r3, #a
 
         ;Store a character
 chrsto: store   buffer + 100, r1
 
+        ;Check for a newline
+        ;Line feed
+        load    r2, #a
+        breq    r2, r3, readlf
+        ;Carriage return
+        load    r2, #d
+        breq    r1, r2, readcr
+
         ;Check for the save end
         load    r2, #1a
         breq    r1, r2, redend
@@ -947,6 +982,22 @@ chrsto: store   buffer + 100, r1
         ;Read the next character
         breq    r0, r0, chkram
 
+        ;Read a newline beginning with a carriage return
+readcr: cleq    r0, r0, readnl
+
+        ;Check for a line feed
+        load    r2, #a
+        breq    r1, r2, chread
+        breq    r0, r0, chkend
+
+        ;Read a newline beginning with a line feed
+readlf: cleq    r0, r0, readnl
+
+        ;Check for a carriage return
+        load    r2, #d
+        breq    r1, r2, chread
+        breq    r0, r0, chkend
+
         ;Return to the command prompt
 redend: breq    r0, r0, cmdp
 
@@ -985,11 +1036,11 @@ sumlop: xor     r1, r1
         xor     r1, r1
         xor     r1, r2
         ;Shift the carry
-        shl     r2
+        shl     r2, 1
 
         ;Check for and store overflow if any
         ;Check
-        rol     r1
+        rol     r1, 1
         breq    r1, r2, nvrflw
         ;Store
         load    r1, #1
@@ -1291,10 +1342,7 @@ bt2hex: xor     r2, r2
         xor     r2, r1
 
         ;Convert the high nibble to a digit
-        ror     r0
-        ror     r0
-        ror     r0
-        ror     r0
+        ror     r0, 4
         cleq    r0, r0, n2hex
 
         ;Load the digit of the low nibble to r1
@@ -1323,6 +1371,12 @@ input:  load    r0, bfstrt
 inloop: load    r1, ffff
 
         ;Check for control characters and the buffer end
+        ;Null
+        load    r2, #0
+        breq    r1, r2, inloop
+        ;FF
+        load    r2, #ff
+        breq    r1, r2, inloop
         ;Delete
         load    r2, #7f
         breq    r1, r2, delbr
@@ -1342,8 +1396,8 @@ inloop: load    r1, ffff
         load    r2, bfsize
         brneq   r0, r2, chstor
 
-        ;Backtrack if at the buffer end
-        load    r2, #8
+        ;Ignore the input and print an underscore if at the buffer end
+        load    r2, #5f
         store   ffff, r2
         breq    r0, r0, inloop
 
@@ -1429,13 +1483,13 @@ escbr:  load    r0, #20
         cleq    r0, r0, newln
 
         ;Return with escape in r2
-        breq    r0, r0, inend
+        ret
 
         ;Print a newline
 eofbr:  cleq    r0, r0, newln
 
         ;Return with End-of-file at r2
-        breq    r0, r0, inend
+        ret
 
         ;Print a line feed
 crbr:   load    r1, #a
@@ -1480,7 +1534,7 @@ endcr:  store   0, r0
 endlf:  store   0, r0
 
         ;Return
-inend:  ret
+        ret
 
         ;***
 
@@ -1625,62 +1679,6 @@ lmterr: load    r0, #21
 
         ;***
 
-        ;Save the line
-
-        ;Restore the buffer start address
-        ;High byte
-save:   load    r0, bfstrt
-        store   chload + 1, r0
-        ;Low byte
-        load    r0, bfstrt + 1
-        store   chload + 2, r0
-
-        ;Store the save address
-        ;High byte
-        load    r0, eoflod + 1
-        store   chsave + 1, r0
-        ;Low byte
-        load    r0, eoflod + 2
-        store   chsave + 2, r0
-
-        ;Load and save a character from the buffer
-        ;Load
-chload: load    r1, buffer
-        ;Save
-chsave: store   buffer + 100, r1
-
-        ;Check for line end
-        load    r2, #a
-        breq    r1, r2, savend
-
-        ;Increment the buffer address
-        ;Load the address
-        load    r0, chload + 1
-        load    r1, chload + 2
-        ;Increment
-        cleq    r0, r0, incdw
-        ;Store the address
-        store   chload + 1, r0
-        store   chload + 2, r1
-
-        ;Increment the save address
-        ;Load the address
-        load    r0, chsave + 1
-        load    r1, chsave + 2
-        ;Increment
-        cleq    r0, r0, incdw
-        ;Store the address
-        store   chsave + 1, r0
-        store   chsave + 2, r1
-
-        ;Load and save the next character
-        breq    r0, r0, chload
-
-        ;Return
-savend: ret
-
-        ;***
-
         ;Find the argument line in the save and store its number
 
         ;Check for the argument
@@ -1791,13 +1789,13 @@ prwr:   load    r0, svstrt
         ;Load a character from the save
 chprwr: load    r1, buffer + 100
 
+        ;Print the character
+prwrch: store   fffe, r1
+
         ;Check for the save end
         load    r2, #1a
         breq    r1, r2, pwend
 
-        ;Print the character
-prwrch: store   fffe, r1
-
         ;Increment the save address
         ;Load the address
         load    r0, chprwr + 1
@@ -1816,6 +1814,79 @@ pwend:  ret
 
         ;***
 
+        ;Check for the RAM limit
+
+        ;Check
+ramchk: load    r2, limit
+        load    r3, limit + 1
+        brneq   r0, r2, ramend
+        brneq   r1, r3, ramend
+
+        ;Save an end-of-file at the start address
+        load    r0, #1a
+        store   buffer + 100, r0
+
+        ;Print an error
+        load    r0, #21
+        store   ffff, r0
+        cleq    r0, r0, newln
+
+        ;Return with an exclamation mark at r1
+        load    r1, #21
+        ret
+
+        ;Return with a null at r1
+ramend: load    r1, #0
+        ret
+
+        ;***
+
+        ;Read a newline
+
+        ;Increment the save address
+        ;Load the address
+readnl: load    r0, chrsto + 1
+        load    r1, chrsto + 2
+        ;Increment
+        cleq    r0, r0, incdw
+        ;Store the address
+        store   chrsto + 1, r0
+        store   lfstor + 1, r0
+        store   chrsto + 2, r1
+        store   lfstor + 2, r1
+
+        ;Check for the RAM limit
+        cleq    r0, r0, ramchk
+        xor     r2, r2
+        brneq   r1, r2, cmdp
+
+        ;Store a line feed
+        load    r1, #a
+lfstor: store   0, r1
+
+        ;Increment the save address
+        ;Load the address
+        load    r0, chrsto + 1
+        load    r1, chrsto + 2
+        ;Increment
+        cleq    r0, r0, incdw
+        ;Store the address
+        store   chrsto + 1, r0
+        store   chrsto + 2, r1
+
+        ;Check for the RAM limit
+        cleq    r0, r0, ramchk
+        xor     r2, r2
+        brneq   r1, r2, cmdp
+
+        ;Read a character
+        load    r1, fffd
+
+        ;Return
+        ret
+
+        ;***
+
         ;Data
 
         ;Variables

readme.md

@@ -1,27 +1,31 @@
-Gidubba v1.0
+Gidubba v1.1
 ============
 
-Gidubba (Sumerian for 'stylus') is a simple line editor for the
-Thingamajig computer architecture. Its git repository can be found at
-https://ahti.space/git/crazyettin/Gidubba and that of Thingamajig at
+Gidubba (Sumerian for 'stylus') v1.1 is a simple line editor for the
+Thingamajig v2.x computer architecture. Its git repository can be found
+at https://ahti.space/git/crazyettin/Gidubba and that of Thingamajig at
 https://ahti.space/git/crazyettin/Thingamajig.
 
-System requirements
+System Requirements
 -------------------
 
-Gidubba requires at least 4 KiB of RAM. It uses a terminal with local
-echo at address FFFF, and optionally a character printer at address FFFE
-and a punched tape reader and punch or a casette drive at FFFD. Do not
-be afraid to modify the code yourself if your setup requires it! (And if
-you do, apologies for the spaghetti.)
+Gidubba requires at least 4 KiB of RAM. It uses an ASCII-compatible
+terminal with local echo at address FFFF, and optionally a character
+printer at address FFFE and a paper tape reader and punch or a cassette
+deck at FFFD. Do not be afraid to modify the code yourself if your setup
+requires it! (And if you do, apologies for the spaghetti.)
 
 Format
 ------
 
 Texts are terminated by an end-of-file (^Z) and lines within them by a
-newline of a carriage return (^M) followed by a line feed (^J). Note
-that the input buffer can store at most 256 characters, including the
-newline.
+newline of a carriage return (^M) followed by a line feed (^J) (CRLF).
+Gidubba is able to read texts without an end-of-file or with different
+newline formatting (CR, LF, or LFCR) and convert them to its native
+format. The characters null (^@) and FF are reserved for indicating tape
+leaders and trailers and an empty tape reader respectively and cannot
+occur within a text. Note that the input buffer can store at most 256
+characters, including the newline.
 
 Usage
 -----
@@ -47,8 +51,8 @@ Commands with two arguments:
 
 Commands with no arguments:
   * P: Print
-  * R: Read from the tape reader or casette drive
-  * W: Write to the tape punch or casette drive
+  * R: Read from the tape reader or cassette deck
+  * W: Write to the tape punch or cassette deck
 
 A delete (^?) discards the preceding character and outputs an underscore
 to the terminal. An escape (^[) discards the contents of the current
@@ -56,8 +60,21 @@ command or line and outputs a backslash and a newline to the terminal. A
 carriage return (^M) or a line feed (^J) inputs a newline and commits
 the current command or line. An end-of-file (^Z) discards the current
 command and halts the computer or discards the current line and returns
-to the command prompt.
+to the command prompt. At the end of the input buffer any input other
+than those described in this paragraph is ignored and an underscore is
+output to the terminal.
 
 There are two kinds of error messages: a question mark (?) for an
 erroneous command and an exclamation mark (!) for lack of RAM.
+
+Changelog
+---------
+
+v1.1
+  * Upgraded for Thingamajig v2.x architecture
+  * Disallowed the use of characters null (^@) and FF in texts
+  * Added the ability to read and convert non-native newline formats
+
+v1.0
+  * Initial release