(09-25-2024 07:18 AM)J-F Garnier Wrote: (09-24-2024 12:00 PM)floppy Wrote: AND: an overtaking of the GAMMA function of the Math module is currently analyzed: however, the BASIC ASM function I got from JF Garnier seems to use stack mechanisms I could not reconduct on Forth/ASM (for sure, the Forth has stack mechanisms). So, the idea is to have a GAMMA Forth/ASM (low prio); however the path to it is still not found. Any hints are welcomed.
The gamma asm code from the Math ROM (the dogam subroutine) should be useable in a Forth primitive, rewriting only the wrapper code to interface with the Forth environment.
The code is referring to a "math scratch stack", like:
Code:
GOSUB =stscr+ store it to math scratch stack
GOSUB =rcscr+ recall from math scratch stack
The HP naming is confusing, because there is also a "Math stack", specific to BASIC, to hold parameters and results during BASIC expression evaluation.
The "math scratch stack" is different, it's a reserved fixed place in the system memory implementing a 4-level stack to hold temporary extended precision values during numeric calculations.
So I believe it's perfectly useable in Forth too.
J-F
+1
it looks like there are several RAM scratch area which could be usefull in case ASM code is getting short in CPU registers.
comments/remarks are welcome.
Code:
2F599 =MTHSTK 5Nibs address of [b]math stack. Or called AVMEME see v3p3086. Available RAM depending of ROM or RAM modules in the ports[/b]
manipulation with following entry points
Code:
0BD8D MPOP1N entry: D1 to Math Stack
uMODES before POP1N+ v3p1366
0BD1C POP1N entry: D1 to Math Stack
Put number from stack into A v3p1362
0BD91 POP1N+ entry: D1 to Math Stack
to POP1N v3p1366
0BC8C POP2N entry: D1 to Math Stack
Put 2x number from stack into A and C v3p1360
(0E8FD POP1R entry: D1 to Math Stack
Same as POP1N, v3p1605)
0E8F7 pop2n+ v3p1604
0BD58 POP2N+ entry: D1 to Math Stack
to POP2N v3p1365
0BD54 MPOP2N entry: D1 to Math Stack
uMODES .. before POP2N v3p1365
0E25B pshstk entry: D1 to current top of Math Stack
push math stack by 16nibs v3 p1558
(NOT like PSHSTK stack pointer,
preserve math stack, v3 p1078)
exit: new D1
(13DB3 STK16? Check free space for 16nibs v3 p2095)
(13DB6 CHKSTK) ??
13E21 D1MST+ Set D1 to MTHSTK and clear all ST, set S8?.. v3 p2096
145FC D1mstk link to D1MSTK v3p2120
1954E D1MSTK Set D1 to MTHSTK (AVMEME) v2p226 v3p2503
1953C MSTKD1 Set MTHSTK to D1 v3p2503, use p2494
1B3DB POPMTH skip item on MTHSTK (for counting/finding MTHSTK items)
18BB8 =AVE=D1 v3p2457
18BBB =AVE=C C(A) new value for AVMEME v3p2457
10489 =C=RAME read in RAMEND v3p1788
18651 =D1=AVE set D1 at AVMEME v3p2436
18658 D1=@D1 v3p2436
1864D GETAVM reads (AVMEME) into C(A)&D1
and (AVMEMS) into D(A) v3p2435
1A476 =D=AVME v3p2552 read AVMEME into D(A)
1A460 =D=AVMS v3p2552 read AVMEMS into D(A)
1A46A D=@D1 v3p2552 keep carry
other reserved RAM area..
Code:
2F871 STMTR0 16Nibs (*4 = 64bits) like A or B or C or D
Code:
2F871 S-R0-0 5nibs
2F876 .. -1 5
2F87B .. -2 5
2F880 .. -3 1
words
Code:
0E04F D0=SR0 D0 linked to S-R0-0 v3p1539
07F7D D1=SR0 D1 linked to S-R0-0 .. D1(5) = STMTRO v3p989
0E05F D1=SR1 D1 linked to S-R0-1 v3p1539
another area..
Code:
2F881 STMTR1 16Nibs
2F881 S-R1-0 5Nibs
2F886 .. -1 5
2F88B .. -2 5
2F890 .. -3 1
words
Code:
none identified for immediate use in Forth ASM
Code:
2F891 STMTD0 5Nibs (20bits) like D0 or D1
words
Code:
1129D RESTD0 restore D0 from STMTD0
another area..
another big area..
Code:
2F8C5 TRFMBF 60Nibs (16+16+16+12) see page v3p2281 p2306
another area..
Code:
2F89B FUNCR0 16Nibs
2F89B F-R0-0 5Nibs
2F8A0 .. -1 5
2F8A5 .. -2 5
2F8AA .. -3 1
words for manipulation
Code:
1C587 SAVD0 save D0 in address stored in F-R0-0 v3p2820
1C578 SAVD1 .. in F-R0-1
1C596 RSTD1 v3p2821 D1 from address in F-R0-1
08C44 rstd1 GOVLNG RSTD1
06832 RSTD0 restore D0 from F-R0-0 v3p822
another area..
Code:
2F8AB FUNCR1 16Nibs
2F8AB F-R1-0 5Nibs
2F8B0 .. -1 5
2F8B5 .. -2 5
2F8BA .. -3 1
2F8BB FUNCD0 5Nibs (20bits) which has same size like D0 or D1
2F8C0 FUNCD1 5Nibs
the scratsch area from the gamma word..
Code:
2F901 SCRTCH with entry points for storing/recovering 4* A/B-data in it
the first 4x16 Nibs are OK for storing data.
The next Nibs have area for exponent storage and could interfer with other scratch area for
timer or display or .. see below, if the area are not selected carefully
words to manipulate
Code:
(2F901 SCRSTO)
0E954 RCSCR pops 15form from math scratch stack into (C,D)
v3p1608 (call GSCPTR,..) uses C(A), P, D0
0E24D stscr GOTO STSCR, v3p1557
0E92C STSCR push 15form (A,B) into math scratch stack (call GSCPTR,..)
v3p1607, update data pointer
0E251 rclw1+ save D0 in R3 and exit with RCLW1 v3p1557
0E257 rclw1 GOTO RCLW1, v3p1557
0E981 RCLW1 move A/B to C/D and math stack entry into A/B v3p1557
uses A,B,C,D, P, D0
0E9B2 RCLW2 ..
0E9C4 RCLW3 ..
0E983 RCL* (P=0 RCL* == RCLW1.. P=3 RCL* == RCLW4)
12AAC ST01 save R0 R1 in RAM SCRTCH v3p1988 SCRTCH(0-15)=R0,
..(16-31) = R1
12AC6 RC01 restore v3p1989
1AF5D STRALL save A-D D0 D1,mode,P,SB in SCRTCH v3p2610
1AFBF RCLALL rcl .. v3p2612
and perhaps more here..
Code:
2F986 RESERV 48*2 „HP-71B Resource Allocations“ = 6*16 = 3* (double float)
define a new word STO2 for save R2 R3 in RESERV ? Or in .. ?
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