Default Addr OSBYTE BBC &236 &A6 *FX166 Base of OSBYTE variable lo &90 Elk:same &237 &A7 *FX167 Base of OSBYTE variable hi &01 Elk:same &238 &A8 *FX168 Base of extended vectors lo &9F Elk:same &239 &A9 *FX169 Base of extended vectors hi &0D Elk:same &23A &AA *FX170 Base of ROM info table address lo &A1 Elk:same &23B &AB *FX171 Base of ROM info table address hi &02 Elk:same &23C &AC *FX172 Base of keyboard table lo &xx Elk:same &23D &AD *FX173 Base of keyboard table hi &xx Elk:same &23E &AE *FX174 Base of VDU variables lo &00 Elk:same &23F &AF *FX175 Base of VDU variables hi &03 Elk:same Default Addr OSBYTE BBC &240 &B0 *FX176 CFS/Vertical sync Timeout counter &00 Elk:same &241 &B1 *FX177 Current input buffer number &00 Elk:same &242 &B2 *FX178 Keyboard interrupt processing flag &FF Elk:slightly different &243 &B3 *FX179 Primary OSHWM (default PAGE) &00 Elk:same Master:ROM semaphore &244 &B4 *FX180 Current OSHWM (PAGE) &00 Elk:same &245 &B5 *FX181 RS423 input mode &01 Elk:same &246 &B6 *FX182 Character explosion state &00 Elk:same Master:NoIgnore &247 &B7 *FX183 CFS/RFS selection, CFS=0 ROM=2 &00 Elk:same &248 &B8 *FX184 Video ULA control register copy &00 Elk:? &249 &B9 *FX185 Palette setting copy &00 Elk:ROM semaphore &24A &BA *FX186 ROM number selected at last BRK &00 Elk:same &24B &BB *FX187 ROM number of BASIC &FF Elk:same &24C &BC *FX188 Current ADC channel number &04 Plus1:same &24D &BD *FX189 Highest ADC channel number &04 Plus1:same &24E &BE *FX190 ADC conversion 0/8bit/12bit &00 Plus1:same &24F &BF *FX191 RS423 busy flag (bit 7=0, busy) &FF Elk:slightly different &250 &C0 *FX192 ACIA control register copy &56 Elk:unused, Plus1 uses different location &251 &C1 *FX193 Flash counter &19 Elk:same &252 &C2 *FX194 Flash mark period count &19 Elk:same &253 &C3 *FX195 Flash space period count &19 Elk:same &254 &C4 *FX196 Keyboard auto-repeat delay &32 Elk:same &255 &C5 *FX197 Keyboard auto-repeat rate &08 Elk:same &256 &C6 *FX198 *EXEC file handle &00 Elk:same &257 &C7 *FX199 *SPOOL file handle &00 Elk:same &258 &C8 *FX200 Break/Escape handing &00 Elk:same &259 &C9 *FX201 Econet keyboard disable flag &00 Elk:same &25A &CA *FX202 Keyboard status, machine-dependant &20 Elk:same \ BBC, Master: Compact: Elk: Apple: \ b2-b0 reserved b2-b0=extend \ b3=1 shift pressed shift pressed \ b4=0 caps lock caps lock b4=0 caps lock b4=shift \ b5=0 shift lock shift lock b5=1 func b5=ctrl \ b6=1 ctrl pressed ctrl pressed b6=1 shift \ b7=1 shift enabled shift enabled b7=1 ctrl &25B &CB *FX203 Serial buffer minimum &09 Elk:something else &25C &CC *FX204 Serial ignore flag &00 Elk:expansion key offset &25D &CD *FX205 Cassette/RS423 flag (0=CFS, &40=RS423) &00 Elk:expansion key length &25E &CE *FX206 Econet OSBYTE/OSWORD interception flag &00 Elk:same &25F &CF *FX207 Econet OSRDCH interception flag &00 Elk:same &260 &D0 *FX208 Econet OSWRCH interception flag &00 Elk:same &261 &D1 *FX209 Speech enable/disable flag (&20/&50) &50 Elk:unused Master:unused &262 &D2 *FX210 Sound supression flag &00 Elk:same &263 &D3 *FX211 BELL channel number &03 Elk:same &264 &D4 *FX212 BELL amplitude/Envelope number &90 Elk:same &265 &D5 *FX213 BELL pitch &64 Elk:same &266 &D6 *FX214 BELL duration &06 Elk:same &267 &D7 *FX215 b7=Banner Display, b0=Boot Error &81 Elk:same &268 &D8 *FX216 Length of current soft key string &00 Elk:same &269 &D9 *FX217 Lines printed since last paged halt &00 Elk:same &26A &DA *FX218 0-(Number of items in VDU queue) &00 Elk:same &26B &DB *FX219 TAB key value &09 Elk:external sound &26C &DC *FX220 ESC key value &1B Elk:same \ :\ The following are input buffer code interpretation variables for \ :\ bytes entered into the input buffer with b7 set (ie 128-255). \ :\ The standard keyboard only enters characters &80-&BF with the \ :\ function keys, but other characters can be entered, for instance \ :\ via serial input of via other keyboard input systems. \ :\ 0=ignore key \ :\ 1=expand as soft key \ :\ 2-&FF add to base for ASCII code &26D &DD *FX221 Chars &C0-&CF &01 Elk:same &26E &DE *FX222 Chars &D0-&CF &D0 Elk:same &26F &DF *FX223 Chars &E0-&EF &E0 Elk:same &270 &E0 *FX224 Chars &F0-&CF &F0 Elk:same &271 &E1 *FX225 Chars &80-&8F function key &01 Elk:same &272 &E2 *FX226 Chars &90-&AF Shift+function key &80 Elk:same &273 &E3 *FX227 Chars &A0-&AF Ctrl+function key &90 Elk:same &274 &E4 *FX228 Chars &B0-&AF Ctrl+Shift+function key &00 Elk:same &275 &E5 *FX229 ESCAPE key status (0=ESC, 1=ASCII) &00 Elk:same &276 &E6 *FX230 ESCAPE action &00 Elk:same &277 &E7 *FX231 USER 6522 Bit IRQ mask &FF Elk:kbd temp ws &278 &E8 *FX232 6850 ACIA Bit IRQ bit mask &FF Elk:something else &279 &E9 *FX233 System 6522 IRQ bit mask &FF Elk:soft key offset &27A &EA *FX234 Tube presence flag &00 Elk:same &27B &EB *FX235 Speech processor presence flag &00 Elk:unused Master:unused &27C &EC *FX236 Character destination settings &00 Elk:same &27D &ED *FX237 Cursor key editing status &00 Elk:same \****************** Soft Reset high water mark *************************** &27E &EE *FX238 unused Extend/Master:Base of keypad &00 Elk:unused &27F &EF *FX239 unused Extend:Shadow state &00 Elk:unused &280 &F0 *FX240 Country code &00 Elk:same &281 &F1 *FX241 User flag &00 Elk:same &282 &F2 *FX242 Serial ULA control register copy &64 Elk:different &283 &F3 *FX243 Offset to current TIME value &05 Elk:same &284 &F4 *FX244 Soft key consistancy flag &FF Elk:same &285 &F5 *FX245 Printer destination &01 Elk:same &286 &F6 *FX246 Printer ignore character &0A Elk:same \****************** Hard Reset High water mark *************************** &287 &F7 *FX247 Break Intercept Vector JMP opcode &00 Elk:same &288 &F8 *FX248 Break Intercept Vector address low &00 Elk:same &289 &F9 *FX249 Break Intercept Vector address high &00 Elk:same &28A &FA *FX250 unused Extend/Master:VDU memory &00 Elk:same &28B &FB *FX251 unused Extend/Master:Display memory &00 Elk:same &28C &FC *FX252 Current language ROM number &FF Elk:same &28D &FD *FX253 ROM paged in at last BRK &00 Elk:same &28E &FE *FX254 Memory available/Keyboard setting &00 Elk:same &28F &FF *FX255 Startup options &00 Elk:same