TECHNOTES FOR Advanced Demuffin 1.1 Written by The Stack Copyright 1983 Corrupt Computing

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TECH-NOTES FOR Advanced Demuffin 1.1 Written by The Stack Copyright 1983 Corrupt Computing If you want source code for any of Corrupt Computing's line of utilities, just contact THE INSPECTOR on THE TWILIGHT PHONE. ================================================================ ZERO PAGE LOCATIONS $22 WNDTOP These 2 zero page locations, WNDTOP and WNDBTM, $23 WNDBTM are used so that the character that the character output routines in the monitor will output characters only in the window below the first 3 lines and above the bottom 2 lines. The top 3 and bottom 2 lines are used for title lines and status display. These locations should be restored to normal upon return from your RWTS if it uses them, although most RWTS's don't use these reserved monitor locations. $26 GBASL These 2 zero page locations are used by many $27 GBASH routines throughout Advanced Demuffin, such as the PRINT routine and the routines to display the status codes on the disk map, but they do not need to be saved before going to your RWTS. Many RWTS's, including RWTS 3.3, use these locations in several places. $36 CSWL CSWL and CSWH should always point to the address $37 CSWH of the current character output routine. Advanced Demuffin sets these locations to point to $FDF0, the standard character output routine. Note that the outputed characters will no longer go through DOS as there may be no DOS in the machine. Advanced Demuffin changes the contents of these locations to point to $Cx00 when a number from 1-7 is pressed during a conversion or after a conversion is completed, where x is the number pressed. These locations should be restored to point to $FDF0 if your RWTS uses them in any way. Most RWTS's, including RWTS 3.3, don't use them at all. $4A TEMP1 Although most RWTS's don$, use these locations, $4B TEMP2 they are used as scratch locations by Advanced $4C TEMP3 Demuffin and are VERY IMPORTANT! Be sure and save them if your RWTS even looks at them. The most important location to save is $4B, which contains the page number that the current sector is being loaded into. Note that this is a duplicate of the X register upon entry into the user's IOB module at $1400. PRE-PROGRAM NON-ZERO PAGE LOCATIONS $200 BUF Page 2, the character input buffer, is used as a buffer to hold the file name of the RWTS or IOB module to be loaded. This page may be used by your RWTS, but your RWTS may not reside in the area between $200-$21E (unless you don't plan on loading anything), as this portion of page 2 will be destroyed upon a load. $3F2 RESET Advanced Demuffin sets this pointer to pnint to $FF59. This means that whenever the RESET key is pressed, the Apple will jump into the monitor. If this is not desired, $12C9 (low byte) and $12CE (high byte) may be changed to have the RESET key go wherever you want it to go including $801 (Advanced Demuffin entry). $12C9 normally contains a $59 and $12CE normally contains an $FF. $3F5 AMPVEC Advanced Demuffin sets up these locations to $3F8 CTYVEC jump to the Advanced Demuffin entry point ($801) when Applesoft recieved the "&" command and when the monitor recieved the CTRL-Y command. This provides a useful way to get back into Advanced Demuffin after exit. $400-$7FF Many times Advanced Demuffin displays data and status marks on the screen by storing this data directly into this area of memory. This includes all marks on both the track map and the disk map as well as numbers on the bottom screen line, and dashes and other messages on the 3rd and 23rd lines. INTER-PROGRAM LOCATIONS $800 This is the location where Advanced Demuffin is designed to run at. This location contains an $EA (NOP) as the byte at $800 is often replaced by a $00. This is NOT the entry point to Advanced Demuffin ($801 is the entry) although if there is an $EA here it won't make any difference if you use this as the entry. $801 START0 This is the entry point to Advanced Demuffin 1.1 where there are two instructions, SEI and CLD, before the actual START of Advanced Demuffin. $803 START This is the actual start of the program which sets CSWL and CSWH to point to the monitor routine COUT1, sets the RESET, AMPVEC, and CTYVEC as mentioned above (see appropriate label), sets the full screen as a window except for the top 3 and the bottom 2 lines, clears the screen, puts the title at the top, the status line at bottom, and starts off the program by displaying the menu. $F1E IOB This is the IOB that Advanced Demuffin uses when it uses RWTS. The built-in IOB module (IOB33) which is described below, as well as the default user IOB module (at $1400) also use this IOB. The default contents of this IOB are described in detail below: $F1E:01 60 IOB DFB $01,$60 $F20:01 DRIVE DFB $01 $F21:00 VOLUME DFB $00 $F22:00 TRACK DFB $00 $F23:00 SECTOR DFB $00 $F24:2F 0F DW DCT $F26:00 DPAGL DFB $00 $F27:80 DPAG DFB $80 $F28:00 00 DFB $00,$00 $F2A:01 CODE DFB $01 $F2B:00 ERROR DFB $00 $F2C:00 60 01 DFB $00,$60,$01 $F2F:00 01 DCT DFB $00,$01 $F31:EF D8 DFB $EF,D8 Note that the slot number used by Advanced Demuffin could easily be changed bu changing $F1F to the $x0 where x is the slot number of the desired drive. $F33 IOB33 This is the built-in IOB module used to write to 3.3 formatted disks. A disassembled listing of it is included below: $F33- IOB33 STY SECTOR ;Store sector $F36- STX DPAG ;and page number $F39- LSR A ;Convert phase # to track # $F3A- STA TRACK ;and store it $F3D- LDA DRV ;Check # of drives $F40- STA DRIVE ;and store it as drive to write to $F43- THERE LDA #2 ;Set command code to write $F45- STA CODE ;and store it $F48- JSR GORWTS ;and go to 3.3 RWTS to write it $F4B- LDA #1 ;Restore read $F4D- STA CODE ;command code $F50- LDA ERROR ;Check for an error $F53- BCC RTS4 ;Exit if none $F55- CMP #$10 ;Write protect error? $F57- SEC ;Keep carry set $F58- BNE RTS4 ;Not write protect, exit w/carry set $F5A- LDY #$27 ;Display write protected $F5C- MOV4 LDA WPER1,Y ;error message $F5F- STA SCLN1,Y ;an``xsk whether $F62- LDA WPER2,Y ;to continue or $F65- STA SCLN2,Y ;start over $F68- DEY $F69- BPL MOV4 $F6B- JSR PRINT ;Print 3 beeps $F6E- DFB $07,$07,$87 $F71- KEY10 JSR KEYIN ;Read a key - go back to menu if esc $F74- CMP #$C3 ;Continue? $F76- BEQ CONTIN ;Yes, branch $F78- CMP #$D3 ;Start over? $F7A- BNE KEY10 ;No $F7C- PLA ;Yes $F7D- PLA) ;Pull return address off stack $F7E- JSR REPLNS ;Replace top 2 lines w/ title lines $F81- JMP GOTVAL `Ao ?xtts over $F84- CONTIN JSR REPLNS $F87- BMI THERE ;Always taken $13FA-$13FB These 2 bytes are unused $13FC-$13FF These 4 bytes are reserved for the address and the length of the IOB module 8^sn it is being loaded. Advanced Demuffin loads the first sector from the track/sector list of the IOB module at $13FC. Since the first 4 bytes of this sector contain the address and the length of the file, those bytes reside in these locations. Therefore, the actual IOB module will start at $1400 (just below). $1400 IOBM This is the user IOB module. The LOAD NEW IOB MODULE will load a file into thi s area (see above). A disassembled listing of the default user IOB module is included in the main manual. $1419-$14FB These bytes between the user IOB module and RWTS 3.3 are left free for an IOB module longer than the default one. This allows an IOB module to take up as much as $FC bytes total. $14FC-$14FF These 4 bytes are unused. $1500-$1CDB RWTS 3.3 resides in this area of memory. It is just standard RWTS that has been relocated to run at this address. Advanced Demuffin uses the entry at $1A00. Below are some other locations used as scratch by Advanced Demuffin. These may be looked at by your IOB module in determining various options about how it is to read sectors from the source disk if desired. $1CE0 SCVER This location contains either a $0C or a $0F for 13 and 16 sector modes, respectively. $1CE1 STPHS This location contains phase number to start reading data from the disk with. It defaults to $00. (Since it is a phase #, a $01 would mean track .5, etc.) $1CE2 ENPHS ENPHS is the same as STPHS except that it contains the last phase to read data from. $1CE3 STSEC STSEC contains the first sector within the phase specified by STPHS that data should be read from. $1CE4 ENSEC ENSEC contains the last sector within the phase specified by ENPHS that data should be read from. $1CE5 CRPHS This location contains the current phase that data is being read from. $1CE6 CRSEC This location contains the current sector that data is being read from. $1CE7 BGSEC BGSEC contains the sector number within the phase specified by BGPHS (below) that data has started being read from this pass. i.e. If you are converting an entire 16 sector disk with the default options and the default buffer size ($70 pages), during the first pass BGPHS and BGSEC will both contain a $00 (phase 00, sector 00 was the start phase, sector in this pass). During the second pass, BGPHS and BGSEC will contain $0E and $00, respectively. (The second pass started with track 07, sector 00 and track 07 is phase $0E). $1CE8 BGPHS See above. $1CE9 BYPHS This byte contains the increment in phases. i.e. The default increment, 1.0, would be $02. $1CEA NRETRY This byte contains the maximum number of retries (normally $01). $1CEB RETRY This byte is used as a counter counting down from the maximum number of retries to $00. On the first attempt to read a sector, RETRY will equal NRETRY. If the carry is set upon return from the user's IOB module, RETRY will be decreased. If it is less than zero, a read error will result. If not, a read will be re- attempted. This process will continue until the sector either reads correctly or until RETRY is less than zero. $1CEC DRV This location contains either a one or a two respective to the number of drives being used. The built-in IOB module uses this location to determine which drive to write data to. $1CED-$1CEF These 3 bytes are unused $1CF0 BUFST BUFST contains the page number of the start of the buffer. This buffer is used to store data read off the source disk. By changing this location and/or BUFEN (below) you can easily change the buffer size and the location of Advanced Demuffin's buffer. This location normally contains a $20 meaning that the buffer normally starts at $2000. $1CF1 BUFEN BUFEN contains the page number of the first page not to be included in Advanced Demuffin's buffer (see above). i.e. If this location contained a $90 (the default value) and BUFST (see above) contained a $20 (the default again) the buffer would reside from $2000 to $8FFF (which it normally does). However, this byte may be changed from a $90 to another value, such as a $B8, making the buffer much larger. In this example, your buffer would be $9800 bytes long! This will, of course, erase DOS when you attempt to convert the disk; but no problem - Advanced Demuffin does not require DOS anyway. (Not even for loading RWTS and IOB modules!) Another use for changing this byte the one before it is to move the buffer to a different place. i.e. If you had a hi-res screen on hi-res page 1 ($2000-$3FFF) that you wanted to keep in memory, you could simply change BUFST ($1CF0) to $40, forcing the buffer to start at $4000 instead of $2000 - saving your screen. $1F00 DIRSEC This page is used as a scratch page when loading sectors from the disk. i.e. When loading a RWTS or an IOB module, the directory sector containing the name of the file to load will be read into this page. The track and sector of the track/sector list will be found and the track/sector list will then be loaded here. $BD00 USRRWTS This is address JuMPed to by the default user RWTS. You should either have an RWTS here or the IOB module should be changed to point to a different location. Note the $BD00 does not necessarily have to be the start of the RWTS when using the default user IOB module, it must be the ENTRY POINT of the RWTS. In fact, most RWTS's have a STARTING ADDRESS of $B800 but an ENTRY POINT at $BD00. Keep this in mind when you load an RWTS module from disk. $C000 KEYBD These are the only hardware locations used by $C010 KEYCLR Advanced Demuffin other than during the screen dump where $Cx00 is JSRed to (where x is the slot number). The following monitor routines are used by Advanced Demuffin: $F847 GBASCALC $FB2F INIT $FC58 HOME $FD8E CROUT $FDED COUT $FDF0 COUT1 $FF59 MONITOR ------------------------------------------------------------------------------- ACTUALLY DEMUFFINING A DISK: ------------------------------------------------------------------------------- Using Castle Wolfenstein as an example. (I used this because it is the only thing that I that have that wasn't cracked!) 1) Boot up Castle Wolfenstein. Before the cursor appears press CTRL-C. The one character buffer in the keyboard will remember it and when DOS asks for a character it will give the CTRL-C. The CTRL-C will cause Castle Wolfenstein's hello program to break into BASIC after it is loaded. 2) Enter the monitor with "CALL-151". Enter "4000

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