Mercurial > vba-clojure

     1 (ns com.aurellem.assembly

     2   (:use (com.aurellem gb-driver vbm title items))

     3   (:import [com.aurellem.gb_driver SaveState]))

     4 

     5 (defn mid-game []

     6   (read-state "mid-game"))

     7 

     8 (defn inject-assembly

     9   ([^SaveState state

    10    program-counter registers

    11    assembly-code]

    12   (let [scratch-memory (memory state)]

    13     ;; inject assembly code

    14     (dorun (map (fn [index val]

    15                   (aset scratch-memory index val))

    16                 (range program-counter

    17                        (+ program-counter (count assembly-code)))

    18                 assembly-code))

    19     (-> state

    20         (write-memory! scratch-memory)

    21         (write-registers! registers)

    22         (PC! program-counter)))))

    23 

    24 (defn inject-item-assembly

    25   ([^SaveState state assembly-code]

    26      (inject-assembly state (inc item-list-start)

    27                       (registers state)

    28                       assembly-code))

    29   ([assembly-code]

    30      (inject-item-assembly @current-state assembly-code)))

    31 

    32 (defn info

    33   ([^SaveState state]

    34      (println (format "PC: 0x%04X" (PC state)))

    35      (println "Instruction:"

    36               (format "0x%02X" (aget (memory state) (PC state))))

    37      state))    

    38 

    39 (defn print-interrupt

    40   [^SaveState state]

    41   (println (format "IE: %d" (IE state)))

    42   state)

    43 

    44 (defn print-listing [state begin end]

    45   (dorun (map 

    46           (fn [opcode line]

    47             (println (format "0x%04X:  0x%02X" line opcode)))

    48           (subvec  (vec (memory state)) begin end)

    49           (range begin end)))

    50   state)

    51 

    52 (defn run-assembly

    53   ([info-fn assembly n]

    54      (let [final-state

    55            (reduce (fn [state _]

    56                      (tick (info-fn state)))

    57                    (inject-item-assembly

    58                      (mid-game) assembly)

    59                    (range n))]

    60        final-state))

    61   ([assembly n]

    62      (run-assembly info assembly n)))

    63 

    64 (def buttons-port 0xFF00)

    65 

    66 (defn A [state]

    67   (bit-shift-right (bit-and 0x0000FF00 (AF state)) 8))

    68 

    69 (defn binary-str [num]

    70   (format "%08d"

    71           (Integer/parseInt

    72            (Integer/toBinaryString num) 10)))

    73 

    74 (defn view-register [state name reg-fn]

    75   (println (format "%s: %s" name

    76                    (binary-str (reg-fn state))))

    77   state)

    78 

    79 (defn view-memory [state mem]

    80   (println (format "mem 0x%04X = %s" mem

    81                    (binary-str (aget (memory state) mem))))

    82   state)

    83 

    84 (defn trace [state]

    85   (loop [program-counters []

    86          opcodes []]

    87     (let [frame-boundary?

    88           (com.aurellem.gb.Gb/tick)]

    89       (println (count opcodes))

    90       (if frame-boundary?

    91         [program-counters opcodes]

    92         (recur

    93          (conj program-counters

    94                (first (registers @current-state)))

    95          (conj opcodes

    96                (aget (memory @current-state)

    97                      (PC @current-state))))))))

    98   

    99 (defn good-trace []

   100   (-> (mid-game) (tick) (IE! 0)

   101       (set-inv-mem [0x00 0x00 0X00 0x00])

   102       (PC! item-list-start)(print-interrupt)

   103       (info) (tick) (info) (tick) (info)))

   104 

   105 (defn read-down-button []

   106   (-> (tick (mid-game))

   107       (IE! 0) ; disable interrupts

   108       (inject-item-assembly

   109        ;; write 00010000 to 0xFF00 to select joypad

   110        [0x18   ;D31D                    ; jump over          

   111         0x01   ;D31E                    ; the next 8 bits

   112                                         ;D31F

   113         (Integer/parseInt "00100000" 2) ; data section 

   114         

   115         0xFA   ;D320                    ; load (D31F) into A

   116         0x1F   ;D321      -->       

   117         0xD3   ;D322      -->  D31F     

   118 

   119         0xEA   ;D323                    ; load (A), which is 

   120         0x00   ;D324      -->           ; 00010000, into FF00

   121         0xFF   ;D325      -->  FF00     

   122         

   123         0x18   ;D326                    ; this is the place where

   124         0x01   ;D327                    ; we will store whether

   125         0x00   ;D328                    ; "down" is pressed.

   126 

   127         0xFA   ;D329                    ; (FF00) -> A

   128         0x00   ;D32A                   

   129         0xFF   ;D32B

   130 

   131         0xCB   ;D32C                    ; Test whether "down"

   132         0x5F   ;D32D                    ; is pressed.

   133 

   134         0x28   ;D32E                    ; if down is pressed,

   135         0x03   ;D32F                    ; skip the next section 

   136                                         ; of code.

   137         ;; down-is-not-pressed

   138         0xC3   ;D330

   139         0x1D   ;D331                    ; return to beginning

   140         0xD3   ;D332

   141         

   142         ;; down-is-pressed 

   143         0xEA   ;D334                    ; write A to D328 if 

   144         0x28   ;D335                    ; "down" was pressed

   145         0xD3   ;D336

   146 

   147         0xC3   ;D330

   148         0x1D   ;D331                    ; return to beginning

   149         0xD3   ;D332

   150         ])))

   151 

   152 (defn test-read-down []

   153  (= (view-memory (step (step (read-down-button) [:d])) 0xD328)

   154     (view-memory (step (step (read-down-button))) 0xD328)))

   155 

   156 (defn count-frames []

   157   (-> (tick (mid-game))

   158       (IE! 0) ; disable interrupts

   159       (inject-item-assembly

   160        [0x18   ;D31D                    ; jump over          

   161         0x02   ;D31E                    ; the next 2 bytes

   162         0x00   ;D31F                    ; frame-count

   163         0x00   ;D320                    ; v-blank-prev

   164         

   165         0xFA   ;D321

   166         0x41   ;D322                    ; load (FF41) into A

   167         0xFF   ;D323                    ; this contains mode flags

   168         

   169         ;; if we're in v-blank, the bit-1 is 0

   170         ;; and bit-2 is 1  Otherwise, it is not v-blank.

   171         0xCB   ;D324                     ; test bit-1 of A

   172         0x4F   ;D325                         

   173 

   174         0xC2   ;D326                     ; if bit-1 is not 0

   175         0x44   ;D327                     ; GOTO not-v-blank

   176         0xD3   ;D328

   177         

   178         0xCB   ;D329                     ; test bit-0 of A 

   179         0x47   ;D32A

   180 

   181         0xCA   ;D32B                     ; if bit-0 is not 1

   182         0x44   ;D32C                     ; GOTO not-v-blank

   183         0xD3   ;D32D

   184         

   185         ;;; in v-blank mode

   186 

   187            ;; if v-blank-prev was 0,

   188            ;; increment frame-count

   189 

   190         0xFA   ;D32E                    ; load v-blank-prev to A

   191         0x20   ;D32F

   192         0xD3   ;D330

   193         

   194         0xCB   ;D331

   195         0x47   ;D332                    ; test bit-0 of A 

   196 

   197         0x20   ;D333                    ; skip next section

   198         0x07   ;D334                    ; if v-blank-prev was not zero 

   199         

   200            ;; v-blank was 0, increment frame-count

   201         0xFA   ;D335                    ; load frame-count into A

   202         0x1F   ;D336

   203         0xD3   ;D337                   

   204 

   205         0x3C   ;D338                    ; inc A

   206 

   207         0xEA   ;D339                    ; load A into frame-count

   208         0x1F   ;D33A

   209         0xD3   ;D33B

   210 

   211            ;; set v-blank-prev to 1

   212         0x3E   ;D33C                    ; load 1 into A

   213         0x01   ;D33D                    

   214 

   215         0xEA   ;D33E                    ; load A into v-blank-prev

   216         0x20   ;D33F

   217         0xD3   ;D340

   218 

   219         0xC3   ;D341                   ; return to beginning

   220         0x1D   ;D342

   221         0xD3   ;D343

   222 

   223         ;;; not in v-blank mode

   224            ;; set v-blank-prev to 0

   225         0x3E   ;D344                    ; load 0 into A        

   226         0x00   ;D345

   227 

   228         0xEA   ;D346                    ; load A into v-blank-prev

   229         0x20   ;D347

   230         0xD3   ;D348

   231 

   232         0xC3   ;D349                   ; return to beginning

   233         0x1D   ;D34A

   234         0xD3   ;D34B

   235         ])))

   236 

   237 (defn step-count-frames []

   238   (-> (read-down-button)

   239       (info)

   240       (tick)  ;; skip over data section

   241       (info)  

   242       (view-register "Register A" A)

   243       (tick)  ;; load-data into A

   244       (view-register "Register A" A)

   245       (info)

   246       (view-memory 0xFF00)

   247       (tick) ;; load A into 0xFF00

   248       (view-memory 0xFF00)

   249       (info)

   250       (tick)

   251       (info)

   252       (tick)

   253       (info)

   254       (tick)

   255       (info)

   256       (tick)

   257       (info)

   258       (tick)

   259       (info)

   260       (tick)

   261       (print-inventory)))

   262 

   263 (defn test-count-frames []

   264   (= 255 (aget (memory ((apply comp (repeat 255 step))

   265                         (count-frames)))

   266                0xD31F)))

   267 

   268 ;; specs for main bootstrap program

   269 ;; starts in "mode-select" mode

   270 ;;   Each button press takes place in a single frame.

   271 ;;   mode-select-mode takes one of the main buttons

   272 ;;   which selects one of up to eight modes

   273 ;;   mode 1 activated by the "A" button

   274 ;;   the next two button presses indicates the start

   275 ;;   memory location which to which the bootstrap

   276 ;;   program will write.

   277 ;;   This is done by using each of the eight buttons to

   278 ;;   spell out an 8 bit number.  The order of buttons is

   279 ;;   [:d :u :l :r :start :select :b :a]

   280 ;;   [:a :start :l]  -->  00101001

   281 

   282 ;;   the next button press determines how many bytes are to be

   283 ;;   written, starting at the start position.

   284 

   285 ;;   then, the actual bytes are entered and are written to the

   286 ;;   start address in sequence.

   287 

   288 (defn input-number-assembly []

   289   [0x18   ;D31D                    ; jump over          

   290    0x02   ;D31E                    ; the next 2 bytes

   291    0x00   ;D31F                    ; frame-count

   292    0x00   ;D320                    ; v-blank-prev

   293    

   294    0xFA   ;D321

   295    0x41   ;D322                    ; load (FF41) into A

   296    0xFF   ;D323                    ; this contains mode flags

   297    

   298    ;; if we're in v-blank, the bit-1 is 0

   299    ;; and bit-2 is 1  Otherwise, it is not v-blank.

   300    0xCB   ;D324                     ; test bit-1 of A

   301    0x4F   ;D325                         

   302 

   303    0xC2   ;D326                     ; if bit-1 is not 0

   304    0x44   ;D327                     ; GOTO not-v-blank

   305    0xD3   ;D328

   306    

   307    0xCB   ;D329                     ; test bit-0 of A 

   308    0x47   ;D32A

   309 

   310    0xCA   ;D32B                     ; if bit-0 is not 1

   311    0x44   ;D32C                     ; GOTO not-v-blank

   312    0xD3   ;D32D

   313    

   314         ;;; in v-blank mode

   315 

   316    ;; if v-blank-prev was 0,

   317    ;; increment frame-count

   318 

   319    0xFA   ;D32E                    ; load v-blank-prev to A

   320    0x20   ;D32F

   321    0xD3   ;D330

   322    

   323    0xCB   ;D331

   324    0x47   ;D332                    ; test bit-0 of A 

   325 

   326    0x20   ;D333                    ; skip next section

   327    0x07   ;D334                    ; if v-blank-prev was not zero 

   328    

   329    ;; v-blank was 0, increment frame-count

   330    0xFA   ;D335                    ; load frame-count into A

   331    0x1F   ;D336

   332    0xD3   ;D337                   

   333 

   334    0x3C   ;D338                    ; inc A

   335 

   336    0xEA   ;D339                    ; load A into frame-count

   337    0x1F   ;D33A

   338    0xD3   ;D33B

   339 

   340    ;; set v-blank-prev to 1

   341    0x3E   ;D33C                    ; load 1 into A

   342    0x01   ;D33D                    

   343 

   344    0xEA   ;D33E                    ; load A into v-blank-prev

   345    0x20   ;D33F

   346    0xD3   ;D340

   347 

   348    0xC3   ;D341                   ; GOTO input handling code

   349    0x4E   ;D342

   350    0xD3   ;D343

   351 

   352         ;;; not in v-blank mode

   353    ;; set v-blank-prev to 0

   354    0x3E   ;D344                    ; load 0 into A        

   355    0x00   ;D345

   356 

   357    0xEA   ;D346                    ; load A into v-blank-prev

   358    0x20   ;D347

   359    0xD3   ;D348

   360 

   361    0xC3   ;D349                   ; return to beginning

   362    0x1D   ;D34A

   363    0xD3   ;D34B

   364 

   365    0x00   ;D34C                   ; these are here 

   366    0x00   ;D34D                   ; for glue

   367    

   368    

   369         ;;; calculate input number based on button presses

   370    0x18   ;D34E                    ;  skip next 3 bytes

   371    0x03   ;D34F

   372                                         ;D350

   373    (Integer/parseInt "00100000" 2) ;  select directional pad

   374                                         ;D351

   375    (Integer/parseInt "00010000" 2) ;  select buttons

   376    0x00   ;D352                    ;  input-number

   377 

   378    ;; select directional pad, store low bits in B

   379    

   380    0xFA   ;D353                    ; load (D350) into A

   381    0x50   ;D354      -->       

   382    0xD3   ;D355      -->  D31F     

   383    

   384    0xEA   ;D356                    ; load (A), which is 

   385    0x00   ;D357      -->           ; 00010000, into FF00

   386    0xFF   ;D358      -->  FF00     

   387 

   388    0x06   ;D359

   389                                         ;D35A

   390    (Integer/parseInt "11110000" 2) ; "11110000" -> B 

   391    0xFA   ;D35B                    ; (FF00) -> A

   392    0x00   ;D35C                   

   393    0xFF   ;D35D

   394 

   395    0xCB   ;D35E                    ; swap nybbles on A

   396    0x37   ;D35F

   397    0xA0   ;D360                    ; (AND A B) -> A

   398    0x47   ;D361                    ; A -> B

   399 

   400    ;; select buttons store bottom bits in C

   401    

   402    0xFA   ;                        ; load (D351) into A

   403    0x51   ;          -->       

   404    0xD3   ;          -->  D31F     

   405    

   406    0xEA   ;                        ; load (A), which is 

   407    0x00   ;          -->           ; 00001000, into FF00

   408    0xFF   ;          -->  FF00     

   409 

   410    0x0E   ;    

   411    (Integer/parseInt "00001111" 2) ; "00001111" -> C 

   412 

   413    0xFA   ;                        ; (FF00) -> A

   414    0x00   ;                       

   415    0xFF   ;    

   416    

   417    0xA1   ;                        ; (AND A C) -> A

   418    0x4F   ;                        ; A -> C

   419 

   420    ;; combine the B and C registers into the input number

   421    0x79   ;                        ; C -> A

   422    0xB0   ;                        ; (OR A B) -> A

   423    0x2F   ;                        ; negate A

   424 

   425    0xEA   ;                        ; store A into input-number

   426    0x52   ;

   427    0xD3   ;

   428 

   429    0xC3   ;                        ; return to beginning

   430    0x1D   ;    

   431    0xD3   ;    

   432    ])

   433 

   434 (defn input-number []

   435   (-> (tick (mid-game))

   436       (IE! 0) ; disable interrupts

   437       (inject-item-assembly (input-number-assembly))))

   438   

   439 (defn test-input-number

   440   "Input freestyle buttons and observe the effects at the repl."

   441   []

   442   (set-state! (input-number)) 

   443   (dotimes [_ 90000] (step (view-memory @current-state 0xD352))))

   444 

   445 (defn write-memory-assembly []

   446   [0x18   ;D31D                    ; jump over          

   447    0x02   ;D31E                    ; the next 2 bytes

   448    0x00   ;D31F                    ; frame-count

   449    0x00   ;D320                    ; v-blank-prev

   450    

   451    0xFA   ;D321

   452    0x41   ;D322                    ; load (FF41) into A

   453    0xFF   ;D323                    ; this contains mode flags

   454    

   455    ;; if we're in v-blank, the bit-1 is 0

   456    ;; and bit-2 is 1  Otherwise, it is not v-blank.

   457    0xCB   ;D324                     ; test bit-1 of A

   458    0x4F   ;D325                         

   459 

   460    0xC2   ;D326                     ; if bit-1 is not 0

   461    0x44   ;D327                     ; GOTO not-v-blank

   462    0xD3   ;D328

   463    

   464    0xCB   ;D329                     ; test bit-0 of A 

   465    0x47   ;D32A

   466 

   467    0xCA   ;D32B                     ; if bit-0 is not 1

   468    0x44   ;D32C                     ; GOTO not-v-blank

   469    0xD3   ;D32D

   470    

   471         ;;; in v-blank mode

   472 

   473    ;; if v-blank-prev was 0,

   474    ;; increment frame-count

   475 

   476    0xFA   ;D32E                    ; load v-blank-prev to A

   477    0x20   ;D32F

   478    0xD3   ;D330

   479    

   480    0xCB   ;D331

   481    0x47   ;D332                    ; test bit-0 of A 

   482 

   483    0x20   ;D333                    ; skip next section

   484    0x07   ;D334                    ; if v-blank-prev was not zero 

   485    

   486    ;; v-blank was 0, increment frame-count

   487    0xFA   ;D335                    ; load frame-count into A

   488    0x1F   ;D336

   489    0xD3   ;D337                   

   490 

   491    0x3C   ;D338                    ; inc A

   492 

   493    0xEA   ;D339                    ; load A into frame-count

   494    0x1F   ;D33A

   495    0xD3   ;D33B

   496 

   497    ;; set v-blank-prev to 1

   498    0x3E   ;D33C                    ; load 1 into A

   499    0x01   ;D33D                    

   500 

   501    0xEA   ;D33E                    ; load A into v-blank-prev

   502    0x20   ;D33F

   503    0xD3   ;D340

   504 

   505    0xC3   ;D341                   ; GOTO input handling code

   506    0x4E   ;D342

   507    0xD3   ;D343

   508 

   509         ;;; not in v-blank mode

   510    ;; set v-blank-prev to 0

   511    0x3E   ;D344                    ; load 0 into A        

   512    0x00   ;D345

   513 

   514    0xEA   ;D346                    ; load A into v-blank-prev

   515    0x20   ;D347

   516    0xD3   ;D348

   517 

   518    0xC3   ;D349                   ; return to beginning

   519    0x1D   ;D34A

   520    0xD3   ;D34B

   521 

   522    0x00   ;D34C                   ; these are here 

   523    0x00   ;D34D                   ; for glue

   524    

   525    

   526         ;;; calculate input number based on button presses

   527    0x18   ;D34E                    ;  skip next 3 bytes

   528    0x03   ;D34F

   529                                         ;D350

   530    (Integer/parseInt "00100000" 2) ;  select directional pad

   531                                         ;D351

   532    (Integer/parseInt "00010000" 2) ;  select buttons

   533    0x00   ;D352                    ;  input-number

   534 

   535    ;; select directional pad, store low bits in B

   536    

   537    0xFA   ;D353                    ; load (D350) into A

   538    0x50   ;D354      -->       

   539    0xD3   ;D355      -->  D31F     

   540    

   541    0xEA   ;D356                    ; load (A), which is 

   542    0x00   ;D357      -->           ; 00010000, into FF00

   543    0xFF   ;D358      -->  FF00     

   544 

   545    0x06   ;D359

   546                                         ;D35A

   547    (Integer/parseInt "11110000" 2) ; "11110000" -> B 

   548    0xFA   ;D35B                    ; (FF00) -> A

   549    0x00   ;D35C                   

   550    0xFF   ;D35D

   551 

   552    0xCB   ;D35E                    ; swap nybbles on A

   553    0x37   ;D35F

   554    0xA0   ;D360                    ; (AND A B) -> A

   555    0x47   ;D361                    ; A -> B

   556 

   557    ;; select buttons store bottom bits in C

   558    

   559    0xFA   ;D362                    ; load (D351) into A

   560    0x51   ;D363      -->       

   561    0xD3   ;D364      -->  D31F     

   562    

   563    0xEA   ;D365                    ; load (A), which is 

   564    0x00   ;D366      -->           ; 00001000, into FF00

   565    0xFF   ;D367      -->  FF00     

   566 

   567    0x0E   ;D368

   568           ;D369

   569    (Integer/parseInt "00001111" 2) ; "00001111" -> C 

   570 

   571    0xFA   ;D36A                    ; (FF00) -> A

   572    0x00   ;D36B                   

   573    0xFF   ;D36C

   574    

   575    0xA1   ;D36D                    ; (AND A C) -> A

   576    0x4F   ;D36E                    ; A -> C

   577 

   578    ;; combine the B and C registers into the input number

   579    0x79   ;D36F                    ; C -> A

   580    0xB0   ;D370                    ; (OR A B) -> A

   581    0x2F   ;D371                    ; negate A

   582 

   583    0xEA   ;D372                    ; store A into input-number

   584    0x52   ;D373

   585    0xD3   ;D374

   586 

   587    0xC3   ;D375                    ; GOTO state machine

   588    ;;0x1D

   589    0x80   ;D376

   590    0xD3   ;D377

   591 

   592    0x00   ;D378

   593    0x00   ;D379

   594    0x00   ;D37A

   595    0x00   ;D37B                   ; these are here because 

   596    0x00   ;D37C                   ; I messed up :(

   597    0x00   ;D37D

   598    0x00   ;D37E

   599    0x00   ;D37F

   600    

   601    ;; beginning of main state machine   

   602    0x18   ;D380                    ; Declaration of variables

   603    0x05   ;D381                    ;  5 variables:

   604    0x00   ;D382                    ;    current-mode

   605    0x00   ;D383                    ;    bytes-left-to-write

   606    0x00   ;D384                    ;    start-point

   607    0x00   ;D385                    ;    unused

   608    0x00   ;D386                    ;    unused

   609 

   610 

   611    ;; banch on current mode

   612    0xFA   ;D387                    ; load current-mode (0xD382)

   613    0x82   ;D388                    ; into A

   614    0xD3   ;D389

   615    0x00   ;D38A

   616 

   617 

   618    ;;  GOTO Mode 0 (input-mode) if current-mode is 0

   619    0xFE   ;D38B

   620    0x00   ;D38C                    ; compare A with 0x00

   621 

   622    0xCA   ;D38D                    ; goto Mode 0 if A == 0

   623    0xA8   ;D38E

   624    0xD3   ;D38F

   625 

   626    ;; GOTO Mode 1 (set-length) if current-mode is 1

   627    0xFE   ;D390

   628    0x01   ;D391                    ; compare A with 0x01

   629 

   630    0xCA   ;D392                  

   631    0xB1   ;D393 

   632    0xD3   ;D394                    ; goto Mode 1 if A == 1

   633 

   634    ;; GOTO Mode 2 (set-start-point) if current mode is 2

   635    0xFE   ;D395                    

   636    0x02   ;D396                    ; compare A with 0x02

   637 

   638    0xCA   ;D397

   639    0xBF   ;D398

   640    0xD3   ;D399                    ; goto Mode 2 if A == 2

   641 

   642    0x00   ;D39A

   643    0x00   ;D39B

   644    0x00   ;D39C

   645    0x00   ;D39D

   646    0x00   ;D39E

   647    0x00   ;D39F

   648    0x00   ;D3A0

   649    0x00   ;D3A1

   650    0x00   ;D3A2

   651    0x00   ;D3A3

   652    0x00   ;D3A4

   653    ;; End of Mode checking, goto beginning

   654    0xC3   ;D3A5

   655    0x1D   ;D3A6

   656    0xD3   ;D3A7

   657 

   658 

   659    ;; Mode 0 -- input-mode mode

   660    ;;     means that we are waiting for a mode, so set the mode to

   661    ;;     whatever is currently in input-number.  If nothing is

   662    ;;     entered, then the program stays in input-mode mode

   663 

   664    ;;   set current-mode to input-number

   665    0xFA   ;D3A8                    ; load input-number (0xD352) 

   666    0x52   ;D3A9                    ; into A

   667    0xD3   ;D3AA

   668 

   669    0xEA   ;D3AB                    ; load A into current-mode

   670    0x82   ;D3AC                    ; (0xD382)

   671    0xD3   ;D3AD

   672 

   673    0xC3   ;D3AE                    ; go back to beginning

   674    0x1D   ;D3AF

   675    0xD3   ;D3B0

   676    ;; End Mode 0

   677 

   678 

   679    ;; Mode 1 -- set-length mode

   680    ;;      This is the header for writing things to memory.

   681    ;;      User specifies the number of bytes to write.

   682    ;;      Mode is auto advanced to Mode 2 after this mode

   683    ;;      completes.

   684 

   685    ;;      Set bytes left to write to input-number;

   686    ;;      set current-mode to 0x02.

   687    0xFA   ;D3B1                   ; load input-number (0xD352)

   688    0x52   ;D3B2                   ; into A

   689    0xD3   ;D3B3

   690    

   691    0xEA   ;D3B4                   ; load A into bytes-left-to-write

   692    0x83   ;D3B5                   ; (0xD383)

   693    0xD3   ;D3B6

   694 

   695    0x3E   ;D3B7                   ; load 0x02 into A.

   696    0x02   ;D3B8

   697    

   698    0xEA   ;D3B9                   ; load A to current-mode

   699    0x82   ;D3BA                   ; advancing from Mode 1 to 

   700    0xD3   ;D3BB                   ; Mode 2

   701    

   702    0xC3   ;D3BC                   ; go back to beginning

   703    0x1D   ;D3BD

   704    0xD3   ;D3BE

   705    ;; End Mode 1

   706 

   707 

   708    ;; Mode 2 -- set start-point mode

   709    ;;      Final part of the header for writing things to memory.

   710    ;;      User specifies the start location in RAM to which 

   711    ;;      data will be written.

   712    ;;      Mode is auto advanced to Mode 3 after this mode completes.

   713 

   714    ;;      Set start-point to input-number;

   715    ;;      set current mode to 0x03.

   716    0xFA   ;D3BF                   ; load input-number (0xD352)

   717    0x52   ;D3C0                   ; into A

   718    0xD3   ;D3C1

   719 

   720    0xEA   ;D3C2                   ; load A into start-point

   721    0x84   ;D3C3                   ; (0xD384)

   722    0xD3   ;D3C4

   723 

   724    0x3E   ;D3C5                   ; load 0x03 into A.

   725    0x03   ;D3C6

   726 

   727    0xEA   ;D3C7                   ; load A to current-mode,

   728    0x82   ;D3C8                   ; advancing from Mode 2 to 

   729    0xD3   ;D3C9                   ; Mode 3.

   730    

   731    0xC3   ;D3CA                   ; go back to beginning

   732    0x1D   ;D3CB

   733    0xD3   ;D3CC

   734    ;;End Mode 2

   735    

   736    0x00   ;D3CD

   737    0x00   ;D3CE

   738    0x00   ;D3CF

   739    0x00   ;D3D0

   740    0x00   ;D3D1

   741    0x00   ;D3D2

   742    0x00   ;D3D3

   743    0x00   ;D3D4

   744    0x00   ;D3D5

   745    0x00   ;D3D6

   746 

   747    ;; Mode 3 -- write bytes mode

   748    ;;      This is where RAM manipulation happens.

   749    ;;      User supplies bytes every frame, which are written

   750    ;;      sequentially to 

   751 

   752 

   753 

   754 

   755    0xC3   ;                        ; Complete Loop

   756    0x1D   ;    

   757    0xD3   ;    

   758 

   759    

   760    

   761    ])

   762 

   763 

   764 (def frame-count 0xD31F)

   765 (def input 0xD352)

   766 (def current-mode 0xD382)

   767 

   768 (defn write-memory []

   769   (-> (tick (mid-game))

   770       (IE! 0) ; disable interrupts

   771       (inject-item-assembly (write-memory-assembly))))

   772 

   773 (defn test-write-memory []

   774   (set-state! (write-memory))

   775   (dorun

   776    (dotimes [_ 5000]

   777      (view-memory (step @current-state) current-mode))))

   778
author	Robert McIntyre <rlm@mit.edu>
date	Fri, 16 Mar 2012 20:48:12 -0500
parents	d6f2a06cb128
children	e85b53994fac