collapseos/forth/z80c.fs
Virgil Dupras c56386af02 wip
2020-04-02 23:21:53 -04:00

414 lines
6.2 KiB
Forth

( Core words in z80. This requires a full Forth interpreter
to run, but is also necessary for core.fs. This means that
it needs to be compiled from a prior bootstrapped binary.
This stage is tricky due to the fact that references in
Forth are all absolute, except for prev word refs. This
means that there are severe limitations to the kind of code
you can put here.
You shouldn't define any word with reference to other words.
This means no regular definition. You can, however, execute
any word from our high level Forth, as long as it doesn't
spit word references.
These restrictions are temporary, I'll figure something out
so that we can end up fully bootstrap Forth from within
itself.
Oh, also: KEY and EMIT are not defined here. There're
expected to be defined in platform-specific code.
This unit expects the same conf as boot.fs.
)
( dummy entry for dict hook )
(entry) _
H@ 256 /MOD 2 PC! 2 PC!
( a b c -- b c a )
CODE ROT
HL POPqq, ( C )
DE POPqq, ( B )
BC POPqq, ( A )
chkPS,
DE PUSHqq, ( B )
HL PUSHqq, ( C )
BC PUSHqq, ( A )
;CODE
( a -- a a )
CODE DUP
HL POPqq, ( A )
chkPS,
HL PUSHqq, ( A )
HL PUSHqq, ( A )
;CODE
( a -- )
CODE DROP
HL POPqq,
;CODE
( a b -- b a )
CODE SWAP
HL POPqq, ( B )
DE POPqq, ( A )
chkPS,
HL PUSHqq, ( B )
DE PUSHqq, ( A )
;CODE
( a b -- a b a )
CODE OVER
HL POPqq, ( B )
DE POPqq, ( A )
chkPS,
DE PUSHqq, ( A )
HL PUSHqq, ( B )
DE PUSHqq, ( A )
;CODE
( a b -- a b a b )
CODE 2DUP
HL POPqq, ( B )
DE POPqq, ( A )
chkPS,
DE PUSHqq, ( A )
HL PUSHqq, ( B )
DE PUSHqq, ( A )
HL PUSHqq, ( B )
;CODE
( a b -- )
CODE 2DROP
HL POPqq,
HL POPqq,
;CODE
( a b c d -- a b c d a b )
CODE 2OVER
HL POPqq, ( D )
DE POPqq, ( C )
BC POPqq, ( B )
IY POPqq, ( A )
chkPS,
IY PUSHqq, ( A )
BC PUSHqq, ( B )
DE PUSHqq, ( C )
HL PUSHqq, ( D )
IY PUSHqq, ( A )
BC PUSHqq, ( B )
;CODE
( a b c d -- c d a b )
CODE 2SWAP
HL POPqq, ( D )
DE POPqq, ( C )
BC POPqq, ( B )
IY POPqq, ( A )
chkPS,
DE PUSHqq, ( C )
HL PUSHqq, ( D )
IY PUSHqq, ( A )
BC PUSHqq, ( B )
;CODE
CODE AND
HL POPqq,
DE POPqq,
chkPS,
A E LDrr,
L ANDr,
L A LDrr,
A D LDrr,
H ANDr,
H A LDrr,
HL PUSHqq,
;CODE
CODE OR
HL POPqq,
DE POPqq,
chkPS,
A E LDrr,
L ORr,
L A LDrr,
A D LDrr,
H ORr,
H A LDrr,
HL PUSHqq,
;CODE
CODE XOR
HL POPqq,
DE POPqq,
chkPS,
A E LDrr,
L XORr,
L A LDrr,
A D LDrr,
H XORr,
H A LDrr,
HL PUSHqq,
;CODE
CODE NOT
HL POPqq,
chkPS,
A L LDrr,
H ORr,
HL 0 LDddnn,
JRNZ, L1 FWR ( skip )
( false, make 1 )
HL INCss,
L1 FSET ( skip )
HL PUSHqq,
;CODE
CODE +
HL POPqq,
DE POPqq,
chkPS,
DE ADDHLss,
HL PUSHqq,
;CODE
CODE -
DE POPqq,
HL POPqq,
chkPS,
A ORr,
DE SBCHLss,
HL PUSHqq,
;CODE
CODE *
DE POPqq,
BC POPqq,
chkPS,
( DE * BC -> DE (high) and HL (low) )
HL 0 LDddnn,
A 0x10 LDrn,
( loop )
HL ADDHLss,
E RLr,
D RLr,
JRNC, 4 A, ( noinc )
BC ADDHLss,
JRNC, 1 A, ( noinc )
DE INCss,
( noinc )
A DECr,
JRNZ, -14 A, ( loop )
HL PUSHqq,
;CODE
( Borrowed from http://wikiti.brandonw.net/ )
( Divides AC by DE and places the quotient in AC and the
remainder in HL )
CODE /MOD
DE POPqq,
BC POPqq,
chkPS,
A B LDrr,
B 16 LDrn,
HL 0 LDddnn,
L1 BSET ( loop )
SCF,
C RLr,
RLA,
HL ADCHLss,
DE SBCHLss,
JRNC, L2 FWR ( skip )
DE ADDHLss,
C DECr,
L2 FSET ( skip )
DJNZ, L1 BWR ( loop )
B A LDrr,
HL PUSHqq,
BC PUSHqq,
;CODE
CODE !
HL POPqq,
DE POPqq,
chkPS,
(HL) E LDrr,
HL INCss,
(HL) D LDrr,
;CODE
CODE @
HL POPqq,
chkPS,
E (HL) LDrr,
HL INCss,
D (HL) LDrr,
EXDEHL,
HL PUSHqq,
;CODE
CODE C!
HL POPqq,
DE POPqq,
chkPS,
(HL) E LDrr,
;CODE
CODE C@
HL POPqq,
chkPS,
L (HL) LDrr,
H 0 LDrn,
HL PUSHqq,
;CODE
CODE PC!
BC POPqq,
HL POPqq,
chkPS,
L OUT(C)r,
;CODE
CODE PC@
BC POPqq,
chkPS,
H 0 LDrn,
L INr(C),
HL PUSHqq,
;CODE
CODE I
L 0 IX+ LDrIXY,
H 1 IX+ LDrIXY,
HL PUSHqq,
;CODE
CODE I'
L 2 IX- LDrIXY,
H 1 IX- LDrIXY,
HL PUSHqq,
;CODE
CODE J
L 4 IX- LDrIXY,
H 3 IX- LDrIXY,
HL PUSHqq,
;CODE
CODE >R
HL POPqq,
chkPS,
( 17 == pushRS )
17 CALLnn,
;CODE
CODE R>
( 20 == popRS )
20 CALLnn,
HL PUSHqq,
;CODE
CODE IMMEDIATE
CURRENT LDHL(nn),
HL DECss,
7 (HL) SETbr,
;CODE
CODE IMMED?
HL POPqq,
chkPS,
HL DECss,
DE 0 LDddnn,
7 (HL) BITbr,
JRZ, L1 FWR ( notset )
DE INCss,
L1 FSET ( notset )
DE PUSHqq,
;CODE
CODE BYE
HALT,
;CODE
CODE (resSP)
( INITIAL_SP == RAM+0 )
SP RAMSTART LDdd(nn),
;CODE
CODE (resRS)
IX RS_ADDR LDddnn,
;CODE
CODE SCMP
DE POPqq,
HL POPqq,
chkPS,
L1 BSET ( loop )
LDA(DE),
(HL) CPr,
JRNZ, L2 FWR ( not equal? break early to "end".
NZ is set. )
A ORr, ( if our char is null, stop )
HL INCss,
DE INCss,
JRNZ, L1 BWR ( loop )
L2 FSET ( end )
( 40 == flagsToBC )
40 CALLnn,
BC PUSHqq,
;CODE
CODE CMP
HL POPqq,
DE POPqq,
chkPS,
A ORr, ( clear carry )
DE SBCHLss,
( 40 == flagsToBC )
40 CALLnn,
BC PUSHqq,
;CODE
CODE (find)
HL POPqq,
chkPS,
( 3 == find )
3 CALLnn,
JRZ, L1 FWR ( found )
( not found )
HL PUSHqq,
DE 0 LDddnn,
DE PUSHqq,
JPNEXT,
L1 FSET ( found )
DE PUSHqq,
DE 1 LDddnn,
DE PUSHqq,
;CODE
CODE SCPY
HL POPqq,
chkPS,
DE HERE LDdd(nn),
B 0 LDrn,
L1 BSET ( loop )
A (HL) LDrr,
LD(DE)A,
HL INCss,
DE INCss,
B INCr,
A ORr,
JRNZ, L1 BWR ( loop )
DE A LD(dd)r
HERE DE LD(nn)dd,
;CODE
CODE (im1)
IM1,
EI,
;CODE