CODING - On the packer MS-PACK.

SoundTrack:! -0;) -: BY SECTOR AFTER INSTY
__________________________________________


(C) Max / CYBERAX Software
Supplement: dAn!! L
__________________________________________



                 - - -


   It's about packer MS-PACK, but rather on DEPACKER'e, which 
he attaches to the compressed file.


   In its original form UNPACKER MS-PACK'a should work with 
illicit interrupts. Also does not provide the possibility of 
its separation from the block (for example, in your program a 
lot of compressed files and does not make sense all of them 
have an extractor - enough one instance).


   The work enabled interrupt is useful if you want to unzip 
chtolibo not braking at the same music or animatsiyu.V this 
case, the music hangs in IM 2, and DEPACKER works in native 
mode. 


   To implement all the above and
are the following two programs.


   The first program, in BASIC. It is intended to separate from 
DEPACKER'a compress the block. When run, it

Requests to enter the file name (no more than 7 letters).
She then writes to the disk block without unpacker. Go to the 
source file name is added an apostrophe. The length of the 
resulting block will be less than the block on DEPACKER'om

247 bytes.

1 INPUT "Name:"; A $: RANDOMIZE USR VAL

   "15619": REM: LOAD A $ CODE
2 LET O = VAL "PEEK 23782 + 256 * PEEK 23783:

   LET A = VAL "PEEK (O +233) + 256 * PEEK (O +

   234) ": LET L = VAL" 3 + PEEK (O +239) +

   256 * PEEK (O +240) "
3 FOR J = NOT PI TO VAL "4": POKE VAL "O +

   238 + J ", PEEK VAL" A - 4 + J ": NEXT J
4 RANDOMIZE USR VAL "15619": REM: SAVE

   A $ + "'" CODE VAL "O + 238", L



   The second program - in assembler. This
is, in fact, DEPACKER.
(Frankly, I did not understand the algorithm of the unpacker. I 
just replaced it with a stack of all operations on the 
operations of the register IX, and also tried fit the new 
version DEPACKER'a 256 bytes.)




        ORG 40000
;+---------------------------------------+
;|*** MS-PACK UNPACKER WITH INTERRUPT *** |
;|---------------------------------------|
; | Originally written by 'MICROSPACE', |
; | Remixed by Max 'CYBERAX Software' |
;+---------------------------------------+
UNPACK LD C, 16

        LD B, C

        LD D, 3

        EXX

        LD HL, SOURCE
; Address packed block without UNPACKER'a.
, (How to unpack)
; Unit must be received by the previous prog; rammkoy in BASIC.

        LD DE, BUF

        LD BC, 5

        LDIR

        PUSH HL

        POP IX

        LD DE, DESTIN
; Memory address where will be
; Unpacking.

        LD H, B

        EXX

        CALL POP_HL

        JR ENTRY
FIRST CALL POP_AF

        EXX

        LD (DE), A

        INC DE

        EXX
ENTRY CALL NEWBIT

        JR NC, FIRST

        LD E, 2
L1 XOR A

        CALL NEWBIT

        RLA

        CALL NEWBIT

        RLA

        CP D

        JR C, MET1

        ADD A, E

        LD E, A

        CP 1917

        JR NZ, L1

        XOR A
MET1 ADD A, E

        CP 5

        JR NC, MET2

        CP 2

        JR NZ, MET3

        EXX

        LD C, A
L3 CALL POP_AF

        LD L, A

        LD A, E

        SCF

        SBC A, L

        LD L, A

        LD A, D

        SBC A, H

        LD H, A

        LDIR

        LD H, B

        EXX

        JR ENTRY
L2 EXX

        CALL POP_AF

        INC A

        JR Z, END

        INC A

        JR NZ, MET4

        CALL POP_BC

        JR MET5
MET4 ADD A, 15

        JR NC, MET6

        INC B

        JR MET6
MET2 JR Z, L2

        DEC A
MET3 EXX
MET6 LD C, A
MET5 EXX

        CALL NEWBIT

        EXX

        JR C, L3

        EXX

        XOR A

        LD E, D
L4 CALL NEWBIT

        RLA

        DEC E

        JR NZ, L4

        CP 2

        JR NC, MET7

        INC A
LOOP EXX

        LD H, A

        JR L3
MET7 CALL NEWBIT

        RLA

        CP 8

        JR NC, MET8

        DEC A

        JR LOOP
MET8 CALL NEWBIT

        RLA

        CP 1923

        JR NC, MET9

        SUB 9

        JR LOOP
MET9 CALL NEWBIT

        RLA

        AND 31

        CP 1931

        JR C, LOOP

        CALL POP_AF

        JR LOOP
END LD HL, BUF

        LD C, 5

        LDIR
; If you use this
; Decompressor from BASIC, here it is desirable
; Insert commands restore the register
; HL '(another BASIC messed up ...).

        RET
NEWBIT ADD HL, HL

        DJNZ MET

        LD B, C
POP_HL LD L, (IX)

        LD H, (IX +1)
FIN INC IX

        INC IX
MET RET
POP_DE LD E, (IX)

        LD D, (IX +1)

        JR FIN
POP_BC LD C, (IX)

        LD B, (IX +1)

        JR FIN
POP_AF LD A, (IX)

        JR FIN +2
BUF DEFS 5
SIZE EQU $-DEPACK



   SOURCE DESTIN address and chosen not
arbitrarily. Rather arbitrarily, but according to certain 
rules. Let the length of the source block (nezapakovannogo) is 
LEN1, and the length of the packed (without UNPACKER'a) - LEN2. 
There are two cases: 

1) Let us specify an address DESTIN, then the address of SOURCE 
can range from 16,384 to DESTIN-LEN2 or in the range of

DESTIN + LEN1-LEN2 65536-LEN2.


2) You can fix the address of SOURCE, then
DESTIN may lie in the range of 16,384
to SOURCE-LEN1 + LEN2 or SOURCE + LEN2 to
65536-LEN1.



   This is true provided that LEN1
more LEN2 (ie, if the block a little,
but it has shrunk), otherwise the formula
do not fit. Moreover, if such unit is not separated extractor, 
the latter generally not be able to extract the block

correctly (eg, reset).


  In conclusion a few words.


   Reworked so UNPACKER a bit slower of the original (it
even without taking into account the time occupied by the 
processing of IM 2). If you want maximum speed, we can proceed 
as follows: start with original UNPACKER interrupt enable ... 


   To do this, separate procedure
unpacking from a block and alter its origin
similar to my version.

   When you call to adjust the parameters of the SOURCE and 
DESTIN so that the distance between these blocks has increased 
by as much bytes, how much enters the stack handler

IM 2 (or more).

   I will explain a little bit. Original DEPACKER
when you start put a stack on the block zapachenny
and begins to unpack the address DESTIN, while the decompressed 
block increases up and packed 'escapes' from him,

decreasing in length. Bytes are packed
block removed commands POP. The most interesting thing that the 
end of the decompressed block will never 'catch up' started to 
unpack, as between them on clearance at 5 bytes. If we 
artificially increase this gap (or modifying SOURCE DESTIN), 
then we can save here registers and return address in the 
processing of IM 2. 

   I should also note that the second method I do not
tested, and this is the first successful in
one of my programs.


                  *



   In addition, from the editors, or as done in DEJA VU.



   To suffer for long and do not ask
manually address and if you do not have to work
with preemption, then the
The following manipulations:

1) pack MS-PACK'om code files and cool
crazy about compression ratio (if
multiple files, of course, pack them
all).

2) Run the following program from on

   Basic'e:


   10 CLEAR 25000

   20 INPUT "MS:"; N $

   22 IF N $ = "" THEN GO SUB 100: GO TO 20

   25 RANDOMIZE USR 15619: REM: LOAD N $ CODE

   26 IF PEEK 23823 <> 0 THEN GO TO 20

   28 LET LEN = PEEK 23784 +256 * PEEK 23785

   30 LET AD = PEEK 23782 +256 * PEEK 23783:

      LET AD2 = AD +36: LET AD3 = AD +231

   40 POKE AD3, PEEK AD2: POKE AD3 +1,

      PEEK (AD2 +1)

   50 INPUT "NEW:"; M $

   1960 IF M $ = "" THEN GO SUB 100: GO TO 50

   70 RANDOMIZE USR 15619: REM: SAVE M $ CODE

      AD3, LEN-231

   80 GO TO 20

   100 RANDOMIZE USR 15619: REM: CAT

   110 RETURN



   3) Enter the name zapkovannogo MS-PACK'om
file (line 20) if no such file exists,
nothing happens, otherwise ask for a name the new file, and 
after enter the name of the new file is written to address

Old address 231, length LENGTH OF OLD-231,
ie at 231 bytes shorter!


   4) Create a universal depaker, assembliruya in your favorite 
assembler next listing:



        ORG # 5B00


LL5B00 LDDR; or LDIR see below

        LD H, B

        POP DE

        EXX

        POP HL

        JR LL5B0E
LL5B08 DEC SP

        POP AF

        EXX

        LD (DE), A

        INC DE

        EXX
LL5B0E ADD HL, HL

        DJNZ LL5B13

        POP HL

        LD B, C
LL5B13 JR NC, LL5B08

        LD E, # 02
LL5B17 XOR A

        ADD HL, HL

        DJNZ LL5B1D

        POP HL

        LD B, C
LL5B1D RLA

        ADD HL, HL

        DJNZ LL5B23

        POP HL

        LD B, C
LL5B23 RLA

        CP D

        JR C, LL5B2E

        ADD A, E

        LD E, A

        CP # 11

        JR NZ, LL5B17

        XOR A
LL5B2E ADD A, E

        CP # 05

        JR NC, LL5B5C

        CP # 02

        JR NZ, LL5B5F

        EXX

        LD C, A
LL5B39 DEC SP

        POP AF

        LD L, A

        LD A, E

        SCF

        SBC A, L

        LD L, A

        LD A, D

        SBC A, H

        LD H, A

        LDIR

        LD H, B

        EXX

        JR LL5B0E
LL5B49 EXX

        DEC SP

        POP AF

        INC A

        JR Z, LL5BAA

        INC A

        JR NZ, LL5B55

        POP BC

        JR LL5B61
LL5B55 ADD A, # 0F

        JR NC, LL5B60

        INC B

        JR LL5B60
LL5B5C JR Z, LL5B49

        DEC A
LL5B5F EXX
LL5B60 LD C, A
LL5B61 EXX

        ADD HL, HL

        DJNZ LL5B67

        POP HL

        LD B, C
LL5B67 EXX

        JR C, LL5B39

        EXX

        XOR A

        LD E, D
LL5B6D ADD HL, HL

        DJNZ LL5B72

        POP HL

        LD B, C
LL5B72 RLA

        DEC E

        JR NZ, LL5B6D

        CP # 02

        JR NC, LL5B7F

        INC A
LL5B7B EXX

        LD H, A

        JR LL5B39
LL5B7F ADD HL, HL

        DJNZ LL5B84

        POP HL

        LD B, C
LL5B84 RLA

        CP # 08

        JR NC, LL5B8C

        DEC A

        JR LL5B7B
LL5B8C ADD HL, HL

        DJNZ LL5B91

        POP HL

        LD B, C
LL5B91 RLA

        CP # 17

        JR NC, LL5B9A

        SUB # 09

        JR LL5B7B
LL5B9A ADD HL, HL

        DJNZ LL5B9F

        POP HL

        LD B, C
LL5B9F RLA

        AND # 1F

        CP # 1F

        JR C, LL5B7B

        DEC SP

        POP AF

        JR LL5B7B
LL5BAA LD HL, LL5BBC

        LD C, # 2005

        LDIR

        LD HL, # 0000
LL5BB2 EQU $ - # 02

        EXX

        LD SP, # 0000
LL5BB6 EQU $ - # 02

        EI; or DI

        RET;

        NOP; or JP # nnnn NOP; /
LL5BBC NOP

        NOP

        NOP

        NOP
LL5BC0 NOP


; Run depakera input hl = address of the file
; Without depakera
DEPACK DI

        LD (LL5BB6), SP

        EXX

        LD (LL5BB2), HL

        LD C, # 1910

        LD B, C

        LD D, # 03

        EXX

        LD SP, HL

        POP HL

        LD (LL5BE2), HL

        POP HL

        LD DE, LL5BC0

        LD BC, # 0005

        LDDR

        POP HL

        POP DE

        POP BC

        LD SP, # 0000
LL5BE2 EQU $ - # 02

        JP LL5B00



   Comments: universal extractor
occupies less than 256 bytes! Traditionally located in the 
printer buffer from the address # 5B00. (In this case, the 
address will start is # 5BC1 = label DEPACK). At the entrance 
to a pair of HL, you must specify the address loaded

block codes without depakera (what happened in paragraph 3). To 
avoid problems with imposing decompressed data to another

not unpacked, I advise you to load a file from the
address specified in the catalog! Unpacking
will occur in the address that was
given in the MS-PACK'e.


   For example, we have packaged MS-PACK'om
file:


         "FILE" CODE 49152,10000;



   Process it BASIC'om (paragraphs 2 and 3)
obtain a new file without depakera:


         "FILE +" CODE 49383,9769;



   To unzip the file, put
unpacking at # 5B00 and extract follows:


        LD HL, 49383

        JP # 5BC1; label DEPACK


   Unpack the file at a given
when packed in MS-PACK'e (eg # C000).



   And, finally, a little nuance - if
package file, the longer the initial
(And this may be, if we pack a small file or already zapachenny 
file - it is can be seen on the compression ratio given in 
percentage), then you must change depaker, at # 5B00 not put 
LDDR and LDIR! Thus it makes sense to pack and small files (2 
sectors). 


   As a result, if guided by the number of sectors is 90% of 
cases can save one sector in the file!



   If we use the method that results in MAX, then 96% saves one
sector! And most importantly - there is a possibility
choice!

   MS-PACK good packs are small text files. If you pack the 
large code blocks, use HRUST 1.0, surely it will show the best 
result, but and the ability to save the file without the 
wrapper provided by the author. 


   Continue to give the floor MAX'u.

-----------------------------------------********* 
********************************* 
----------------------------------------- 


     Download and run the BASIC files.



   I think everyone knows how to boot'ah usually
run the program. File name throws
in line BASIC (instead of spaces in the command RUN ""), then 
this string starts. 

   In this article I'll show you how you can
download and run the BASIC program without
use of such tricks.

   The program in Listing written with the active use of 
fragments ROM TR-DOS, so do not be surprised its clumsy form.



   Suppose there is a specific file that you want to run. Also 
assume that we know the title of the file (16 bytes). For 
BitTorrent will use a driver able to read 'B' sector to the 
'HL' with tracks and sectors 'DE' (label LOAD). Oposlya load, 
the driver must enter the last track and sector of the variable 
# 5CF4. 

   CLEAR is desirable to have installed on
65367.

   The first thing perekinem heading to the HEADER, equal to 
23,773. File number is desirable to put on # 5D1E. Then run 
prog following: 


BAS_RUN LD DE, (23635) Home Base. etc.

        LD HL, (23641) Region. Ed. line

        DEC HL

        PUSH HL

        PUSH DE

        AND A

        SBC HL, DE
; In HL have a length of old beisik-prog,
, Ie one that is (or is not)
; In memory to boot.

        LD DE, (HEADER +9)
; In DE have a header length of a new beat, sika, ie the fact 
that you want to ship. 

        PUSH DE

        PUSH HL

        LD HL, 5

        ADD HL, DE
The length of the new prog increased by 5 bytes.

        LD (23771), HL
; Stuck in a variable, as in TR-DOS.

        POP HL

        POP BC

        POP DE

        POP HL

        PUSH BC

        CALL # 19E5
; Remove the old BASIC, shifting memory.

        POP BC

        CALL # 1655
; Reserve a room for the new.

        INC HL

        LD BC, (HEADER +11)
, Took a header length of the new BASIC
And without the program variables.

        ADD HL, BC
; Added the address of the beginning.

        LD (23627), HL
, Set the system variable VARS.

        LD HL, (23635)
; HL - to be shipped.

        LD A, (23772)
; Byte length.

        LD B, A

        LD DE, (HEADER +14)
; DE - track and sector.

        LD (# 5CF4), DE

        DEC B

        INC B

        CALL NZ, LOAD
And if there is shipping - Georgia.

        LD A, (23771)

        AND A

        JR Z, NOLOW
, Is equal to zero if the low byte length?

        PUSH HL

        LD DE, (# 5CF4)

        LD HL, BUF

        LD B, 1

        CALL LOAD
; Gruzanuli last sector in the buffer.

        POP DE

        LD BC, (23,771)

        LD B, 0

        LD HL, BUF

        LDIR
The residue was transferred where necessary.
NOLOW LD HL, (23641)

        DEC HL

        LD (HL), 128
; Have brought just in case the marker end.

        INC HL

        INC HL

        LD E, (HL)

        INC HL

        LD D, (HL)
, Took the line auto-

        LD (23618), DE
, And have brought it to the acc. variable.

        XOR A

        LD (23620), A
; Neutral earthing operator number in the string.

        LD (23824), A

        CALL # 16B0
; Do not remember exactly what it seems clean
; Stack calculator.

        LD HL, (23635)

        DEC HL

        LD (23639), HL
; Did RESTORE.

        LD HL, (23613)

        LD (23827), HL

        EXX

        LD HL, 10072

        EXX

        LD IY, # 5C3A

        LD (IY), 255

        SET 7, (IY +1)

        RES 5, (IY +1)
; Other settings.

        JP 7037; launch ...
BUF DEFS 256; loading buffer.


   Have this very program better in the display area. It would 
be nice to clean the screen before transferring control to the 
ROM, as is makes the TR-DOS.


   For example, instead of JP 7037:



        LD HL, 7037

        PUSH HL

        JP 3435



   In conclusion I wish to thank Fedin PY for the book "A 
complete description and full disassembler TR-SOS 5.04T (5.03).