Notes |
Address |
Name |
Contents |
1 |
16384 |
ERR_NR |
1 less than the report code. Starts off at 255 (for - 1), so PEEK 16384, if it works at all, gives 255. POKE 16384,n can be used to force an error halt: 0 n 14 gives one of the usual reports, 15 n 34 or 99 n 127 gives a non-standard report, and 35 n 98 is liable to mess up the display file. |
X1 |
16385 |
FLAGS |
Various flags to control the BASIC system. |
X2 |
16386 |
ERR_SP |
Address of first item on machine stack (after GOSUB returns). |
2 |
16388 |
RAMTOP |
Address of first byte above BASIC system area. You can poke this to make NEW reserve space above that
area (see chapter 26) or to fool CLS into setting up a minimal display file (chapter 27). Poking RAMTOP has
no effect until one of these two is executed. |
N1 |
16390 |
MODE |
Specified K, L, F or G cursor. |
N2 |
16391 |
PPC |
Line number of statement currently being executed. Poking this has no lasting effect except in the last line
of the program. |
S1 |
16393 |
VERSN |
0 Identifies ZX81 BASIC in saved programs. |
S2 |
16394 |
E_PPC |
Number of current line (with program cursor). |
SX2 |
16396 |
D_FILE |
See chapter 27. |
S2 |
16398 |
DF_CC |
Address of PRINT position in display file. Can be poked so that PRINT output is sent elsewhere. |
SX2 |
16400 |
VARS |
See chapter 27. |
SN2 |
16402 |
DEST |
Address of variable in assignment. |
SX2 |
16404 |
E_LINE |
See chapter 27. |
SX2 |
16406 |
CH_ADD |
Address of the next character to be interpreted: the character after the argument of PEEK, or the NEWLINE at the end of a POKE statement. |
S2 |
16408 |
X_PTR |
Address of the character preceding the marker. |
SX2 |
16410 |
STKBOT |
See chapter 27. |
SX2 |
16412 |
STKEND |
See chapter 27. |
SN1 |
16414 |
BERG |
Calculator's b register. |
SN2 |
16415 |
MEM |
Address of area used for calculator's memory. (Usually MEMBOT, but not always.) |
S1 |
16417 |
not used. |
|
SX1 |
16418 |
DF_SZ |
The number of lines (including one blank line) in the lower part of the screen. |
S2 |
16419 |
S_TOP |
The number of the top program line in automatic listings. |
SN2 |
16421 |
LAST_K |
Shows which keys pressed. |
SN1 |
16423 |
|
Debounce status of keyboard. |
SN1 |
16424 |
MARGIN |
Number of blank lines above or below picture: 55 in Britain, 31 in America. |
SX2 |
16425 |
NXTLIN |
Address of next program line to be executed. |
S2 |
16427 |
OLDPPC |
Line number of which CONT jumps. |
SN1 |
16429 |
FLAGX |
Various flags. |
SN2 |
16430 |
STRLEN |
Length of string type destination in assignment. |
SN2 |
16432 |
T_ADDR |
Address of next item in syntax table (very unlikely to be useful). |
S2 |
16434 |
SEED |
The seed for RND. This is the variable that is set by RAND. |
S2 |
16436 |
FRAMES |
Counts the frames displayed on the television. Bit 15 is 1. Bits 0 to 14 are decremented for each frame set to the television. This can be used for timing, but PAUSE also uses it. PAUSE resets to 0 bit 15, & puts in bits 0 to 14 the length of the pause. When these have been counted down to zero, the pause stops. If the pause stops because of a key depression, bit 15 is set to 1 again. |
S1 |
16438 |
COORDS |
x-coordinate of last point PLOTted. |
S1 |
16439 |
|
y-coordinate of last point PLOTted. |
S1 |
16440 |
PR_CC |
Less significant byte of address of next position for LPRINT to print as (in PRBUFF). |
SX1 |
16441 |
S_POSN |
Column number for PRINT position. |
SX1 |
16442 |
|
Line number for PRINT position. |
S1 |
16443 |
CDFLAG |
Various flags. Bit 7 is on (1) during compute & display mode. |
S33 |
16444 |
PRBUFF |
Printer buffer (33rd character is NEWLINE). |
SN30 |
16477 |
MEMBOT |
Calculator's memory area; used to store numbers that cannot conveniently be put on the calculator stack. |
S2 |
16507 |
not used. |
|