; Commodore plus/4 and
; Commodore 16 Memory Map
;
; V1.1 9 Dec 1994
; Annotated and updated by Cameron Kaiser with grateful acknowledgement to
; Mike Dailly
; http://www.scotch.demon.co.uk/
; http://www.retrobits.com/ckb/secret/
Label Hex Addr. Decimal Loc. Description
PDIR $0000 0 7501 on-chip data-direction register
PORT $0001 1 7501 on-chip 8-bit Input/Output register
SRCHTK $0002 2 Token 'search' looks for (run-time stack)
ZPVEC1 $0003-0004 3-4 Temp (renumber)
ZPVEC2 $0005-0006 5-6 Temp (renumber)
CHARAC $0007 7 Search character
ENDCHR $0008 8 Flag: scan for quote at end of string
TRMPOS $0009 9 Screen column from last TAB
VERCK $000A 10 Flag: 0 = load 1 - verify
COUNT $000B 11 Input buffer pointer / No. of subsctipts
DIMFLG $000C 12 Flag: Default Array DIMension
VALTYP $000D 13 Data type: $FF = string $00 = numeric
INTFLG $000E 14 Data type: $80 = integer, $00 = floating
DORES $000F 15 Flag: DATA scan/LIST quote/garbage coll
SUBFLG $0010 16 Flag: subscript ref / user function coll
INPFLG $0011 17 Flag: $00 = INPUT, $43 = GET, $98 = READ
TANSGN $0012 18 Flag TAN siqn / comparison result
CHANNL $0013 19 Flag: INPUT prompt
LINNUM $0014-0015 20-21 Temp: integer value
TEMPPT $0016 22 Pointer: temporary string stack
LASTPT $0317-0018 23-24 Last temp string address
TEMPST $0019-0021 25-33 Stack for temporary strings
INDEX1 $0022-0023 34-35 Utility pointer area
INDEX2 $0024-0025 36-37 Utility pointer area
RESHO $0026 38
RESMOH $0027 39
RESMO $0028 40
RESLO $0029 41
$002A 42
TXTTAB $002B-002C 43-44 Pointer: start of BASIC text
VARTAB $002D-002E 45-46 Pointer: start of BASIC variables
ARYTAB $002E-0030 47-48 Pointer: start of BASIC arrays
STREND $0031-0032 49-50 Pointer: end of BASIC arrays (+1)
FRFTOP $0033-0034 51-52 Pointer: bottom of string storage
FRESPC $0035-0036 53-54 Utility string pointer
MEMSIZ $0037-0038 55-56 Pointer: highest address used by BASIC
CURLIN $0039-003A 57-58 Current BASIC line number
TXTPTR $003B-003C 59-60
FNDPNT $003D-003F 61-62
DATLIN $003F-0040 63-64 Current DATA line number
DATPTR $0041-0042 65-66 Pointer: Current DATA item address
INPPTR $0043-0044 67-68 Vector: INPUT routine
VARNAM $0045-0046 69-70 Current BASIC variable name
VARPNT $0047-0048 71-72 Pointer: Current BASIC variable data
FORPNT $0049-004A 73-74 Pointer: Index variable for FOR/NEXT
OPPTR $0048-004C 75-76
OPMASK $004D 77
DEFPNT $004E-004F 78-79
DSCPNT $0050-0051 80-81
$0052 82
HELPER $0053 83
JMPER $0054 84
SIZE $0055 85
OLDOV $0056 86
TEMPF1 $0057 87
HIGHDS $0058-0059 88-89
HIGHTR $005A-005B 90-91
$005C 92
LOWDS $005D-005E 93-94
LoWTR $005F 95
EXPSGN $0060 96
FACEXP $0061 97 Floating-point accumulator #1: exponent
FACHO $0062 98 Floating accum. #1: mantissa
FACMOH $0063 99
FACMO $0064 100
FACLo $0065 101
FACSGN $0066 102 Floating accum. #1: sign
SGNFLG $0067 103 Pointer: series evaluation constant
BITS $0068 104 Floating accum. #1: overflow digit
ARGEXP $0069 105 Floating-point accumulator #2: exponent
ARGHO $006A 106 Floating accum. #2: mantissa
ARGMOH $006B 107
ARGMO $006C 108
ARGLO $006D 109
ARGSGN $006E 110 Floating accum. #2: sign
ARISGN $006F 111 Sign comparison result: accum. #1 vs #2
FACOV $0070 112 Floating accum. #1. low-order (rounding)
FBUFPT $0071-0072 113 Pointer: cassette buffer
AUTINC $0073-0074 115-116 Increment value for auto (0 = off)
MVDFLG $0075 117 Flag if 10K hires allocated
KEYNUM $0076 118
KEYSIZ $0077 119
SYNTMP $0078 120 Used as temp Eor indirect loads
DSDESC $0079-0078 121-123 Descriptor for DSS
TOS $007C-037D 124-125 Top of run time stack
TMPTON $007E-007F 126-127 Temps used by music (tone & volume)
VOICNO $0080 128
RUNMOD $0081 129
POINT $0082 130
GRAPHM $0083 131 Current graphic mode
COLSEL $0084 132 Current color selected
MC1 $0085 133 Multicolor 1
FG $0086 134 Foreground color
SCXMAX $0087 135 Maximum # of columns
SCYMAX $0088 136 Maximum # of rows
LTFLAG $0089 137 Paint-left flag
RTFLAG $008A 138 Paint-Right flag
STOPNH $008B 139 Stop paint if not BG (Not same Color)
GRAPNT $008C-008D 140-141
VTEMP1 $008E 142
VTEMP2 $008F 143
STATUS $0090 144 Kernal I/O status word: ST
STREY $0091 145 Flag: STOP key / RVS key
SPVERR $0092 146 Temp
VERFCK $0093 147 Flag: 0 = load, 1 = verify
C3PO $0094 148 Plag: serial bus - output char buffered
BSOUR $0095 149 Buffered character for serial bus
XSAV $0096 150 Temp for basin
LDTND $0097 151 # of open files / index to file table
DFLTN $0098 152 Default input device (0)
DFLTO $0099 153 Default output (CMD) device (3)
MSGFLG $009A 154 Flag: $80 = direct mode $00 = program
SAL $009B 155 Tape pass 1 error log
SAH $009C 156 Tape pass 2 error log
EAL $009D 157
EAH $009E 158
T1 $009F-00A0 159-160 Temp data area
T2 $00A1-00A2 161-162 Temp data area
TIME $00A3-00A5 163-165 Real-time jiffy clock (approx) 1/60 sec
R2D2 $00A6 166 Serial bus usage (EOI on output)
TPBYTE $00A7 167 Byte to be written/read on/off tape
BSOUR1 $00A8 168 Temp used by serial routine
FPVERR $00A9 169
DCOUNT $00AA 170
FNLEN $00A8 171 Length of current file name
LA $00AC 172 Current logical fiie number
SA $00AD 173 Current seconda.y address
FA $00AE 174 Current device number
FNADR $00AF-00B0 175-176 Pointer: current file name
ERRSUM $00B1 177
STAL $00B2 178 I/O start address
STAH $00B3 179
MEMUSS $00B4-00B5 180-181 Load ram base
TAPEBS $00B6-00B7 182-183 Base pointer to cassette base
TMP2 $00B8-00B9 184-185
WRBASE $00BA-00BB 186-187 Pointer to data for tape writes
IMPARM $00BC-00BD 188-189 Pointer to immediate string for primms
FETPTR $00BE-00BF 190-191 Pointer to byte to be fetched in bank fetc
SEDSAL $00C0-00C1 192-193 Temp for scrolling
RVS $00C2 194 RVS field flag on
INDX $00C3 195
LSXP $00C4 196 X position at start
LSTP $00C5 197
SFDX $00C6 198 Flag: shift mode for print
CRSW $00C7 199 Flag: INPUT or GET from keyboard
PNT $00C8-00C9 200-201 Pointer: current screen line address
PNTR $00CA 202 Cursor column on current line
QTSW $00CB 203 Flag: editor in quote mode, $00 = no
SEDT1 $00CC 204 Editor temp use
TBLX $00CD 205 Current cursor physical line number
DATAX $00CE 206 Temp data area
INSRT $00CF 207 Flag: insert mode, >0 = # INSTs
$00D0-$00D7 208-215 Area for use by speech software
$00D8-00E8 216-232 Area for use by application software
CIRSEG $00E9 233 Screen line link table / editor temps
USER $00EA-00EB 234-235 Screen editor color IP
KEYTAB $00EC-00ED 236-237 Key scan table indirect
TMPKEY $00EE 238
NDX $00EF 239 Index to keyboard queue
STPFLG $00F0 240 Pause flag
TO $00F1-00F2 241-242 Monitor ZP storage
CHRPTR $00F3 243
BUFEND $00F4 244
CHKSUM $00F5 245 Temp for checksum calculation
LENGTH $00F6 246
PASS $00F7 247 Which pass we are doing str
TYPE $00F8 248 Type of block
USE4DY $00F9 249 (B.7 = 1)=> for wr, (B.6 = 1)=> for rd
XSTOP $00FA 250 Save xreg for quick stopkey test
CURBNK $00FB 251 Current bank configuration
XoN $00FC 252 Char to send for a x-on (RS232)
XoFF $00FD 253 Char to send for a x-off (RS232)
SEDT2 $00FE 254 Editor temporary use
LOFBUF $00FF 255
FBUFFR $0100-$010F 256-271
SAVEA $0110 272 Temp Locations for
SAVEY $0111 273 ... for Save and
SAVEX $0112 274 ... Restore
COLKEY $0113-0122 275-289 Color/luminance table in RAM
SYSSTK $0124-01FF 291-511 System stack
BUF $0200-0258 512-606 Basic/monitor input buffer
OLDLIN $0259-025A 601-602 Basic storage
OLDTXT $025B-025C 603-604 Basic storage
$025D-02AC 605-684 BASIC/DOS INTERFACE AREA
XCNT $025D DOS loop counter
PNBUFR $025E-026D Area for filename
DOSF1L $026E DOS filename 1 length
DOSDS1 $026F DOS disk drive 1
DOSF1A $0270-0271 DOS filename 1 addr
DOSF2L $0272 DOS filename 2 length
DOSDS2 $0273 DOS disk drive 2
DOSF2A $0274-0275 DOS filename 2 addr
DOSLA $0276 DOS logical address
DOSEA $0277 DOS phys addr
DOSSA $0278 DOS secordary address
DOSDID $0279-027A DOS disk identifier
DIDCHK $0278 DOS DID flag
DOSSTR $027C DOS output string buffer
DOSSPC $027D-02AC Area used to build DOS string
Graphics Variables
XPOS $02AD-02AE 685-686 Current x position
YPOS $02AE-02B0 687-688 Current y position
XDEST $02B1-02B2 689-690 X coordinate destination
YDEST $02B3-02B4 691-692 Y coordinate destination
XABS $02B5-02B6 693-694
YABS $02B7-0288 69S-696
XSGN $02B9-02BA 697-69B
YSGN $02BB-028C 699-700
FCT1 $02BD-02BE 701-702
FCT2 $02BF-02C0 703-704
ERRVAL $02C1-02C2 705-706
LESSER $02C3 707
GREATR $02C4 708
ANGSGN $02C5 709 Sign of angle
SINVAL $02C6-02C7 710-711 Sine of value of angle
COSVAL $02C8-02C9 712-713 Cosine of value of angle
ANGCNT $02CA-02CB 714-715 Temps for angle distance routines
Start of multiply defined area #1
$02CC 716 Placeholder
BNR $02CD 717 Pointer to begin no.
ENR $02CE 718 Pointer to end no.
DOLR $02CF 719 Dollar flag
FLAG $02DO 720 Comma flag
SWE $02D1 721 Counter
USGN $02D2 722 Sign exponent
UEXP $02D3 723 Pointer to exponent
VN $02D4 724 # of digits before decimal point
CHSN $02D5 725 Justify flag
VF $02D6 726 # of pos before decimal point (field)
NF $02D7 727 # of pos after decimal point (field)
POSP $02D8 728 +/- flag (field)
FESP $02D9 729 Exponent flag (field)
ETOF $02DA 730 Switch
CFORM $02D8 731 Char counter (field)
SNO $02DC 732 Sign no.
BLFD $02DD 733 Blank/star flag
BEGFD $02DE 734 Pointer to beginning of field
LFOR $02DF 735 Length of format
ENDFD $02E0 736 Pointer to end of field
XCENTR $02CC-02CD 716-717
YCENTR $02CE-02CF 718-719
XDIST1 $02D0-02D1 720-721
YDIST1 $02D2-02D3 722-723
XDIST2 $02D4-02D5 724-725
YDIST2 $02D6-02D7 726-727
$02D8-02D0 728-729 Placeholder
COLCNT $02DA 730 Characters column counter
ROWCNT $02DB 731 Characters row counter
STRCNT $02DC 732
Start of multiply defined area #2
XCORD1 $02CC-02CD 716-717
YCORD1 $02CE-02CF 718-719
BOXANG $02D0-02D1 720-721 Rotation angle
XCOUNT $02D2-02D3 722-723
YCOUNT $02D4-02D5 724-725
BXLENG $02D6-02D7 726-727 Length of a side
XCORD2 $02D8-02D9 728-729
YCORD2 $02DA-02DB 730-731
XCIRCL $02CC-02CD 716-717 Circle center, x coordinate
YCIRCL $02CE-02CF 718-719 Circle center, y coordinate
XRADUS $02D0-02D1 720-721 X radius
YRADUS $02D2-02D3 722-723 Y radius
ROTANG $02D4-02D5 724-725 Rotation angle
ANGBEG $02D8-02D9 728-729 Arc angle start
ANGEND $02DA-02DB 730-731 Arc angle end
XRCOS $02DC-02DD 732-733 X radius * cos (rotation angle)
YRSIN $02DE-02DF 734-735 Y radius * sin (rotation angle)
XRSIN $02E0-02E1 736-737 X radius * sin (rotation angle)
YRCOS $02E2-02E3 738-739 Y radius * cos (rotation angle)
Start of multiply defined area #3
$02CC 716 Placeholder
KEYLEN $02CD 717
KEYNXT $02CE 718
STRS2 $02CE 719 String length
GETTYP $02D0 720 Replace string mode
STRPTR $02D1 721 String position counter
OLDBYT $02D2 722 Old bit map byte
NEWBYT $02D3 723 New string or bit map byte
$02D4 724 Placeholder
XSI2E $02D5-02D6 725-726 Shape column length
YSIZE $02D7-02D8 727-728 Shape row length
XSAVE $02D9-02DA 729-730 Temp for column length
STRADR $02D8-02DC 731-732 Save shape string descriptor
BITIDX $02DD 733 Bit index into byte
SAYSIZ $02DE-02E1 734-737 Temporary work locations
CHRPAG $02E4 740 High byte addr of char ROM for char cmd
LITCNT $02E5 741 Temp for gshape
SCALEM $02E6 742 Scale mode flag
WIDTH $02E7 743 Double width flag
FILFLG $02E8 744 Box fill flag
BITMSK $02E9 745 Temp for bit mask
NUMCNT $02EA 746
TRCFLG $02EB 747 Flags trace mode
T3 $02EC 748
T4 $02ED-02EE 749-750
VTEMP3 $02EF 751 Graphic temp storage
VTEMP4 $02F0 752
VTEMP5 $02F1 753
ADRAY1 $02E2-02F3 754-755 Ptr to routine: convert float to integer
ADRAY2 $02F4-02F5 756-757 Ptr to routine: convert integer to float
BNKVEC $02FE-02FF 766-767 Vector for function cartridge users
IERROR $0300-0301 768-769 Indirect Error (Output Error in .X)
IMAIN $0302-0303 770-771 Indirect Main (System Direct Loop)
ICRNCH $0304-0305 772-773 Indirect Crunch (Tokenization Routine)
IOPLOP $0306-0307 774-775 Indirect List (Char List)
IGONE $0308-0309 776-777 Indirect Gone (Character Dispatch)
IEVAL $030A-0303 778-779 Indirect Eval (Symbol Evaluation)
IESCLK $030C-030D 780-781 Escape token crunch
IESCPR $030E-030F 782-783
IESCEX $0310-0311 784-785
ITIME $0312-0313 786-787
CINV $0314-0315 7B8-789 IRQ Ram Vector
CBINV $0316-0317 790-791 BRK Instr RAM Vector
IOPEN $0318-0319 792-793 Indirects for Code
ICLOSE $031A-031B 794-795
ICHKIN $031C-031D 796-797
ICKOUT $031E-031F 798-799
ICLRCH $0320-0321 800-801
IBASIN $0322-0323 802-803
IBSOUT $0324-Q325 804-805
ISTOP $0326-0327 806-807
IGETIN $0328-0329 808-809
ICLALL $032A-032B 810-811
USRCMD $032C-032D 812-813
ILOAD $032E-032E 814-815
ISAVE $0330-0331 816-817 Savesp
TAPBUF $0333-03F2 819-1010 Cassette tape buffer
WRLEN $03F3-03F4 1011-1012 Length of data to be written to tape
RDCNT $03F5-03F6 1013-1014 Length of data to be read from tape
INPQUE $03F7-0436 1015-1078 RS-232 input queue
ESTARL $0437-0454 1079-1108
ESTAKH $0455-0472 1109-1138
CHRGET $0473-0478 1139-1144
CHRGOT $04?9-0484 1145-1156
QNUM $0485-0493 1157-1171
INDSUB $0494-04A1 1172-1185 Shared ROM fetch sub
ZERO $04A2-04A4 1186-1188 Numeric constant for Basic
INDTXT $04A5-04AF 1189-1199 Txtptr
INDIN1 $04B0-04BA 1200-1210 Index & Index1
INDIN2 $04BB-04C5 1211-1221 Index2
INDST1 $04C6-04D0 1222-1232 Strng1
INDLOW $04D1-04DB 1233-1243 Lowtr
INDFMO $04DC-04E6 1244-1254 Facmo
PUFILL $04E7 1255 Print using fill symbol [space]
PUCOMA $04E8 1256 Print using comma symbol [;]
PUDOT $04E9 1257 Print using D.P. symbol [.]
PUMONY $04EA 1258 Print using monetary symbol [$]
TMPDES $04EB-04EE 1259-1262 Temp for instr
ERRNUM $04EF 1263 Last error number
ERRLIN $04F0-04F1 1264-1265 Line # of last error
TRAPNO $04F2-04F3 1266-1267 Line to go on error
TMPTRP $04F4 1268 Hold trap no. temporarily
ERRTXT $04F5-04E6 1269-1270
OLDSTR $04F7 1271
TMPTXT $04F8-04F9 1272-1273
TMPLIN $04FA-04F8 1274-1275
MTIMLO $04FC-04FD 1276-1277 Table of pending jiffies (2's comp)
MTIMHI $04FE-04FF 1278-1279
USRPOK $0500-0502 1280-1282
KERNDX $0503-0507 1283-1287
DEJAVU $0508 1288 'cold' or 'warm' start status
LAT $0509-0512 1289-1298 Logical file numbers
FAT $0513-051C 1299-1308 Primary device numbers
SAT $051D-0526 1309-1318 Secondary addresses
KEYD $0527-0530 1319-1328 IRQ keyboard buffer
MEMSTR $0531-0532 1329-1330 Start of memory [1000]
MSIZ $0533-0534 1331-1332 Top of memory [FD00]
TIMOUT $0535 1333 IEEE timeout flag
FILEND $0536 1334 File end reached = 1, 0 otherwise
CTALLY $0537 1335 # of chars left in buffer (for R & W)
CBUFVA $0538 1336 # of total valid chars in buffer (R)
TPTR $0539 1337 Ptr to next char in buffer (for R & W)
FLTYPE $053A 1338 Contains type of current cass file
COLOR $053B 1339 Active attribute byte
FLASH $053C 1340 Character flash flag
$053D 1341 FREE
HIBASE $053E 1342 OC Base location of screen (top) [0C]
XMAX $053F 1343
RPTFLG $0540 1344 Key repeat flag
KOUUT $0541 1345
DELAY $0542 1346
SHFLAG $0543 1347 Shift flag byte
LSTSHF $0544 1348 Last shift pattern
KEYLOG $0545-0546 1349-1350 Indirect for keyboard table setup
MODE $0547 1351 shift, C=
AUTODN $0548 1352 Auto scroll down flag (0=on,0off)
LINTMP $0549 1353
ROLFLG $054A 1354
FORMAT $054B 1355 Monitor non-zpage storage
MSAL $054C-054E 1356-1358
WRAP $054F 1359
TMPC $0550 1360
DIFF $0551 1361
PCH $0552 1362
PCL $0553 1363
FLGS $0554 1364
ACC $0555 1365
XR $0556 1366
YR $0557 1367
SP $0558 1368
INYL $0559 1369
INVH $055A 1370
CMPFLG $055B 1371 Used by various monitor routines
BAD $055C 1372
KYNDX $055D 1373 Used for programmable keys
KEYIDX $055E 1374
KEYBUF $055F-0566 1375-1382 Table of P.F. lengths
PKY9UF $0567-05E6 1383-1510 P.F. Key storage area
KDATA $05E7 1511 Temp for data write to kennedy
RDYCMD $05E8 1512 Select for kennedy read or write
KDYNUM $05E9 1513 Kennedy's dev #
RDYPRS $05EA 1514 Rennedy present = $ff, else = $00
KDYTYP $05EB 1515 Temp for type of open for kennedy
SAVRAM $05EC-06E8 1516-1771 1 page used by banking routines
PAT $05EC-05EF 1516-1519 Physical Address Table
LNGJMP $05F0-05F1 1520-1521 Long jump address
FETARG $05F2 1522 Long jump accumulator
FETXRG $05F3 1523 Long jump x register
FETSRG $05F4 1524 Long jump status register
AREAS $05F5-065D 1525-1629 RAM areas for banking
ASPECH $065E-06EB 1630-1771 RAM area for speech
STKTOP $06EC-07AF 1772-1967 BASIC run-time stack
WROUT $07B0 1968 Byte to be written on tape
PARITY $07B1 1969 Temp for parity calc
TT1 $07B2 1970 Temp for write-header
TT2 $07B3 1971 Temp for write-header
RDBITS $07B5 1973 Local index for READBYTE routine
ERRSP $07B6 1974 Pointer into the error stack
FPERRS $07B7 1975 Number of first pass errors
DSAMP1 $07B8-07B9 1976-1977 Time constant
DSAMP2 $07BA-07BB 1978-1979 Time constant
ZCELL $07BC-07BD 1980-1981 Time constant
SRECOV $07BE 1982 Stack marker for stopkey recover
DRECOV $07BF 1983 Stack marker for dropkey recover
TRSAVE $07C0-07C3 1984-1987 params passed to RDBLOK
RDETMP $07C4 1988 Temp stat save for RDBLOK
LDRSCN $07C5 1989 # consec shorts to find in leader
CDERRM $07C6 1990 # Errors fatal in RD countdown
VSAVE $07C7 1991 Temp for Verify command
T1PIPE $07C8-a7CB 1992-1995 Pipe temp for T1
ENEXT $07CC 1996 Read error propagate
FOR RS-232
UOUTQ $07CD 1997 User chracter to send
UOUTFG $07CE 1998 0 = empty ; 1 = full
SOUT9 $07CF 1999 System character to send
SOUNFG $07D0 2000 0 = empty ; 1 = full
INOFPT $07D1 2001 Pntr to front of input queue
INQRPT $07D2 2002 Pntr to rear of input queue
INQCNT $07D3 2003 # of chars in input queue
ASTAT $07D4 2004 Temp status for ACIA
AINTMP $07D5 2005 Temp for input routine
ALSTOP $07D6 2006 FLG for local pause
ARSTOP $07D7 2007 FLG for remote pause
APRES $07D8 2008 FLG to indicate presence of ACIA
RLUDES $07D9-07E4 2009-2020 Indirect routine downloaded
SCBOT $07E5 2021 Screen bottom (0...24)
SCTOP $07E6 2022 Screen top
SCLF $07E7 2023 Screen left (0...39)
SCRT $07E8 2024 Screen right
SCRDIS $07E9 2025 Negative = scroll out
INSFLG $07EA 2026 Insert mode: FF = on, 00 = off
LSTCHR $07EB 2027
LOGSCR $07EC 2028
TCOLOR $07ED 2029
BITABL $07EE-07F1 2030-2033
SAREG $07F2 2034 Registers for SYS command
SXREG $07F3 2035
SYREG $07F4 2036
SPREG $07F5 2037
LSTX $07F6 2038 Key scan index
STPDSB $07F7 2039 Flag to disable CTRL-S pause
RAMROM $07F8 2040 MSB for monitor fetches from ROM=0;RAM=
1
COLSW $07F9 2041 MSB for color/lim table in RAM=0;ROM=1
FFRMSK $07FA 2042 ROM mask for split screen
VMBMSK $07FB 2043 VM base mask for split screen
LSEM $07FC 2044 Motor lock semaphore for cassette
PALCNT $07FD 2045 PAL tod
TEDATR $0800-0BFF 2048-3071 TED attribute bytes
TEDSCN $0C00-0FFF 3072-4095 TED character pointers
BASBGN $1000- 4096- Start of BASIC text area
BMLUM $1800-1BFF 6144-7167 Luminance for bit map screen
BMCOLR $1C00-1FFF 7168-8191 Color for bit map
Commodore 16 and plus/4 Memory Configuration
$0000 System memory
$0800 Color memory (Text)
$0C00 Video matrix (Text)
$1000 Beginning of BASIC RAM (without graphics)
$1800 Luminance (Graphics)
$1C00 Colour table (Graphics)
$2000 Graphics screen data
$4000 Beginning of BASIC RAM (with graphics)
$8000 ROM BANK LOW (BASIC)
$C000 BASIC expansions
$D000 Character table
$D800 Operating system
$FC00 Routines for switching banks
$FD00 End of BASIC RAM, I/O area
According to the schematics diagram, $FD00-$FF3F contains the following,
regardless of the RAM/ROM banking configuration:
$FD00-FD0F: 6551 ACIA (for the RS232, only on the +4. 4 registers.)
$fd00-fd03 ACIA 6551A used for RS232
(rsstar register bits)
0 - Parity error bit
1 - Framing error bit
2 - Receiver buffer overrun bit
3 - Unused bit
4 - CTS signal missing bit
5 - Unused bit
6 - DSR signal missing bit
7 - Break detected bit
$fd00 DATA port
$fd01 STATUS port
$fd02 COMMAND port
$fd03 CONTROL port
$fd04-fd07 ACIA copy
$fd08-fd0b ACIA copy
$fd0c-fd0f ACIA copy
$FD10-FD1F: 6529B (1 register, drives 8 I/O-lines on the +4 user port)
$fd10 PIO 6529B User Port PIO (P0-P7)
Bit 2 (P2) is used to detect
if play on cassette is pressed
(CST sense)
$fd11-fd1f PIO copies
$FD20-FD2F: not mapped
$FD30-FD3F: 6529B (1 register, keyboard scan. The other 8 lines come from TED)
$fd30 PIO 6529B Keyboard PIO Keyboard Matrix Connector
P0 15
P1 18
P2 7
P3 12
P4 11
P5 10
P6 5
P7 1
$fd31-fd3f PIO copies
$FD40-FDCF: not mapped
$fdd0-fddf ADDR CLK used for module select?
in the schematic this is
the clk/in for 4 D-FlipFlops
located in the 74LS175 chip which generates
the C1,C2 low/high signals
$FDE0-FEBF: not mapped (but may be slots for additional drives not supported
by the 1551)
$FEC0-FEFF: TIA mappings for 1551 disk drives #9 and #8
$fec0-fedf TIA 6523A if you have a CBM 1551 as device #9
then the TIA located in the paddle of
you drive will appear at this location
for details see $fee0-feff
$fee0-feff TIA 6523A if you have a CBM 1551 as device #8
then the TIA located in the paddle of
your drive will appear at this location
$fee0 TIA PORT A (DATA)
$fee1 TIA PORT B (STATUS)
$fee2 TIA PORT C (HANDSHAKE)
$fee3 TIA PORT A data direction register
$fee4 TIA PORT B data direction register
$fee5 TIA PORT C data direction register
$fee6 not connected
$fee7 not connected
$fee8-feef TIA copy
$fef0-fef7 TIA copy
$fef8-feff TIA copy
$FF00: TED (registers shown below)
$FF40: ROM
*** TED registers ***
0 Timer 1 low
1 Timer 1 high
2 Timer 2 low
3 Timer 2 high
4 Timer 3 low
5 Timer 3 high
R# Bit 7 6 5 4 3 2 1 0
---------------------------------------------------------------------
6 Test ECM BMM Blank Rows Y2 Y1 Y0
7 RVS off PAL Freeze MCM Columns X2 X1 X0
8 Keyboard Latch
9 IRQ I-T3 - I-T2 I-T1 I-LP I-RAS -
A - EI-T3 - EI-T2 EI-T1 EI-LP EI-RAS RC8
B RC7 RC6 RC5 RC4 RC3 RC2 RC1 RC0
C - - - - - - C9 CUR8
D CUR7 CUR6 CUR5 CUR4 CUR3 CUR2 CUR1 CUR0
E SND1-7 SND1-6 SND1-5 SND1-4 SND1-3 SND1-2 SND1-1 SND1-0
F SND2-7 SND2-6 SND2-5 SND2-4 SND2-3 SND2-2 SND2-1 SND2-0
10 - - - - - - SND2-9 SND2-8
11 SND-REL Noise V2-SEL V1-SEL VOL3 VOL2 VOL1 VOL0
12 - - BMB2 BMB1 BMB0 R-Bank S1-9 S1-8
13 CB5 CB4 CB3 CB2 CB1 CB0 SCLOCK Status
14 VM4 VM3 VM2 VM1 VM0 - - -
15 - LUM2 LUM1 LUM0 COLOR3 COLOR2 COLOR1 COLOR0
16 - LUM2 LUM1 LUM0 COLOR3 COLOR2 COLOR1 COLOR0
17 - LUM2 LUM1 LUM0 COLOR3 COLOR2 COLOR1 COLOR0
18 - LUM2 LUM1 LUM0 COLOR3 COLOR2 COLOR1 COLOR0
19 - LUM2 LUM1 LUM0 COLOR3 COLOR2 COLOR1 COLOR0
1A - - - - - - BRE9 BRE8
1B BRE7 BRE6 BRE5 BRE4 BRE3 BRE2 BRE1 BRE0
1C - - - - - - - VL8
1D VL7 VL6 VL5 VL4 VL3 VL2 VL1 VL0
1E H8 H7 H6 H5 H4 H3 H2 H1
1F - BL3 BL2 BL1 BL0 VSUB2 VSUB1 VSUB0
3E Write switches on ROM bank
3F Write switches on RAM bank
$FF0E 65294 Voice #1 frequency, bits 0-7
$FF0F 65295 Voice #2 frequency, bits 0-7
$FF10 65296 Voice #2 frequency, bits 8 & 9
(bit 0 is bit 8, bit 1 is bit 9)
$FF11 65297 Bits 0-3 : Volume control
Bit 4 : Voice #1 select
Bit 5 : Voice #2 select
Bit 6 : Voice #2 noise select
Bit 7 : Sound reload
$FF12 65298 Bit 0-1 : Voice #1 frequency, bits 8 & 9
Bit 2 : TED data fetch ROM/RAM select
Bits 0-5 : Bit map base address
$FF13 65299 Bit 0 : Clock status
Bit 1 : Set single clock
Bits 2-7 : Character data base address
$FF14 65309 Bits 3-7 : Video matrix/color memory base address
$FF15 65301 Background color register
Bits 0-3 : Color
Bits 4-6 : Luminance
$FF16 65302 Color register #1
Bits 0-3 : Color
Bits 4-6 : Luminance
$FF17 65303 Color register #2
Bits 0-3 : Color
Bits 4-6 : Luminance
$FF18 65304 Color registes #3
Bits 0-3 : Color
Bits 4-6 : Luminance
$FF19 65305 Color register #4
Bits 0-3 : Color
Bits 4-6 : Luminance
$FF1A 65306 Bit map reload
$FF1B 65307 Bit map reload
$FF1C 65308 Bit 0 : Vertical line bit 8
$FF1D 65309 Bits 0-7 : Vertical line bits 0-7
$FF1E 65310 Horizontal position
$FF1F 65311 Blink, vertical sub address
$FF3E 65342 ROM select
$FF3F 65343 RAM select
BANKING JUMP TABLE
$FCF1 64753 JMP to cartridge IRQ routine
$FCF4 64756 JMP to PHOENIX routine
$FCF7 64759 JMP to LONG FETCH routine
$FCFA 64762 JMP to LONG JUMP routine
$FCFD 64765 JMP to LONG IRQ routine
UNOFFICIAL JUMP TABLE
$FF49 65353 JMP to define function key routine
$FF4C 65356 JMP to PRINT routine
$FF4F 65359 JMP to PRIMM routine
$FF52 65362 JMP to ENTRY routine
$FF80 65408 RELEASE # OF KERNAL (MSB: 0 = NTSC ; 1 = PAL)
KERNAL JUMP TABLE
; NAME ADDRESS DESCRIPTION
; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
CINT $FF81 65409 Initialize screen editor
IOINIT $FF84 65412 Initialize I/O devices
RAMTAS $FF87 65415 Ram test
RESTOR $FF8A 65418 Restore vectors to initial values
VECTOR $FF8D 65421 Change vectors for user
SETMSG $FF90 65424 Control O.S. messages
SECND $FF93 65427 Send SA after LISTEN
TKSA $FF96 65430 Send SA after TALK
MEMTOP $FF99 65433 Set/Read top of memory
MEMBOT $FF9C 65436 Set/Read bottom of memory
SCNKEY $FF9F 65439 Scan keyboard
SETTMO $FFA2 65442 Set timeout in DMA disk
ACPTR $FFA5 65445 Handshake serial bus or DMA disk byte in
CIoUT $FFA8 65448 Handshake serial bus or DMA disk byte out
UNTLR $FFAB 65451 Send UNTALK out serial bus or DMA disk
UNLSN $FFAE 65454 Send UNLISTEN out serial bus or DMA disk
LISTN $FFB1 65457 Send LISTEN out serial bus or DMA disk
TALK $FFB4 65460 Send TALK out serial bus or DMA disk
READSS $FFB7 65463 Return I/O STATUS byte
SETLFS SEF8A 65466 Set LA, FA, SA
SETNAM $FFBD 65469 Set length and FN address
OPEN $FFC0 65472 Open logical file
CLOSE $FFC3 65475 Close logical file
CHKIN $FFC6 65478 Open channel in
CHOUT $FEC9 65481 open channel out
CLRCH $FECC 65484 Close I/O channels
8ASIN $FFCF 65487 Input from channel
BSOUT $FFD2 65490 output to channel
LOADSP $FFD5 65493 Load from file
SAYESP $FFD8 65496 Save to file
SETTIM $FFDB 65499 Set internal clock
RDTIM $FFDE 65502 Read internal clock
STOP $FFE1 6S50S Scan STOP key
GETIN $FFE4 65508 Get character from queue
CLALL $FFE7 65511 Close all files
UDTIM $FFEA 65514 Increment clock
SCRORG $FFED 65517 Screen org.
PLOT $FFF0 65520 Read/Set X,Y coord of cursor
IOBASE $FFF3 65523 Return location of start of I/O
Letzte Änderung: 2019-01-03 11:17:17
