VolksForth/8080/CPM/cpmfiles/vf-bufs.fth
2024-11-10 13:15:24 +01:00

215 lines
5.7 KiB
Forth

\ *** Block No. 94, Hexblock 5e
\ buffer mechanism 20Oct86 07Oct87
Variable prev 0 prev ! \ Listhead
| Variable buffers 0 buffers ! \ Semaphor
$408 Constant b/buf \ physikalische Groesse
\ \\ Struktur eines Buffers: 0 : link
\ 2 : file
\ 4 : blocknummer
\ 6 : statusflags
\ 8 : Data ... 1 Kb ...
\ Statusflag bits : 15 1 -> updated
\ file : -1 -> empty buffer, 0 -> no fcb, direct access
\ else addr of fcb ( system dependent )
\ *** Block No. 95, Hexblock 5f
\ search for blocks in memory 30Jun86
| Variable pred
\ DE:blk BC:file HL:bufadr
Label thisbuffer? ( Zero = this buffer )
H push H inx H inx M A mov C cmp 0=
?[ H inx M A mov B cmp 0= ?[ H inx M A mov E cmp
0= ?[ H inx M A mov D cmp ]? ]? ]? H pop ret
Code (core? ( blk file -- adr\blk file )
IP H mvx Ipsave shld
user' offset D lxi UP lhld D dad
M E mov H inx M D mov
B pop H pop H push B push D dad xchg
prev lhld
thisbuffer? call 0= ?[
\ *** Block No. 96, Hexblock 60
\ search for blocks in memory 30Jun86
Label blockfound
D pop D pop 8 D lxi D dad H push ' exit @ jmp ]?
[[ pred shld
M A mov H inx M H mov A L mov
H ora 0= ?[ IPsave lhld H IP mvx Next ]?
thisbuffer? call 0= ?]
xchg pred lhld D ldax A M mov
H inx D inx D ldax A M mov D dcx
prev lhld xchg E M mov H inx D M mov
H dcx prev shld
blockfound jmp end-code
\ *** Block No. 97, Hexblock 61
\ (core? 29Jun86
\ \\
\
\ | : this? ( blk file bufadr -- flag )
\ dup 4+ @ swap 2+ @ d= ;
\
\ | : (core? ( blk file -- dataaddr / blk file )
\ BEGIN over offset @ + over prev @ this?
\ IF rdrop 2drop prev @ 8 + exit THEN
\ 2dup >r offset @ + >r prev @
\ BEGIN dup @ ?dup 0= IF rdrop rdrop drop exit THEN
\ dup r> r> 2dup >r >r rot this? 0=
\ WHILE nip REPEAT
\ dup @ rot ! prev @ over ! prev ! rdrop rdrop
\ REPEAT ;
\ *** Block No. 98, Hexblock 62
\ (diskerr 29Jul86 07Oct87
: (diskerr
." error! r to retry " key $FF and
capital Ascii R = not Abort" aborted" ;
Defer diskerr
' (diskerr Is diskerr
Defer r/w
\ *** Block No. 99, Hexblock 63
\ backup emptybuf readblk 20Oct86
: backup ( bufaddr -- ) dup 6+ @ 0<
IF 2+ dup @ 1+ \ buffer empty if file = -1
IF input push output push standardi/o
BEGIN dup 6+ over 2+ @ 2 pick @ 0 r/w
WHILE ." write " diskerr
REPEAT THEN 4+ dup @ $7FFF and over ! THEN drop ;
: emptybuf ( bufaddr -- ) 2+ dup on 4+ off ;
| : readblk ( blk file addr -- blk file addr )
dup emptybuf
input push output push standardi/o >r
BEGIN over offset @ + over r@ 8 + -rot 1 r/w
WHILE ." read " diskerr REPEAT r> ;
\ *** Block No. 100, Hexblock 64
\ take mark updates? core? 10Mar86 19Nov87
| : take ( -- bufaddr) prev
BEGIN dup @ WHILE @ dup 2+ @ -1 = UNTIL
buffers lock dup backup ;
| : mark ( blk file bufaddr -- blk file )
2+ >r 2dup r@ ! offset @ + r@ 2+ ! r> 4+ off
buffers unlock ;
| : updates? ( -- bufaddr / flag)
prev BEGIN @ dup WHILE dup 6+ @ 0< UNTIL ;
: core? ( blk file -- addr /false ) (core? 2drop false ;
\ *** Block No. 101, Hexblock 65
\ block & buffer manipulation 20Oct86 18Nov87
: (buffer ( blk file -- addr )
BEGIN (core? take mark REPEAT ;
: (block ( blk file -- addr )
BEGIN (core? take readblk mark REPEAT ;
: buffer ( blk -- addr ) isfile@ (buffer ;
: block ( blk -- addr ) isfile@ (block ;
: (blk-source ( -- addr len)
blk @ ?dup IF loadfile @ (block b/blk exit THEN
tib #tib @ ;
' (blk-source IS source
\ : isfile@ ( -- addr ) isfile @ ;
\ *** Block No. 102, Hexblock 66
\ block & buffer manipulation 05Oct87
: update $80 prev @ 6+ 1+ ( Byte-Order! ) c! ;
: (save-buffers ( -- ) buffers lock
BEGIN updates? ?dup WHILE backup REPEAT save-dos-buffers
buffers unlock ;
' (save-buffers IS save-buffers
: empty-buffers ( -- ) buffers lock prev
BEGIN @ ?dup WHILE dup emptybuf REPEAT buffers unlock ;
: flush save-buffers empty-buffers ;
\ *** Block No. 103, Hexblock 67
\ Allocating buffers 10Oct87
Variable first
: allotbuffer ( -- )
first @ r0 @ - b/buf 2+ u< ?exit
b/buf negate first +! first @ dup emptybuf
prev @ over ! prev ! ;
: freebuffer ( -- ) first @ limit b/buf - u<
IF first @ backup prev
BEGIN dup @ first @ - WHILE @ REPEAT
first @ @ swap ! b/buf first +! THEN ;
: all-buffers BEGIN first @ allotbuffer first @ = UNTIL ;
| : (init-buffers prev off limit first ! all-buffers flush ;
' (init-buffers IS init-buffers
\ *** Block No. 125, Hexblock 7d
\ Default Disk Interface: read/write 14Feb88
Target Dos also
| : rec# ( 'dosfcb -- 'rec# ) &33 + ;
: (r/w ( adr blk file r/wf -- flag ) >r
dup 0= Abort" no Direct Disk IO supported! " >dosfcb
swap rec/blk * over rec# 0 over 2+ c! !
r> rot b/blk bounds
DO I dma! 2dup IF rec@ drop
ELSE rec! IF 2drop true endloop exit THEN THEN
over rec# 0 over 2+ c! 1 swap +!
b/rec +LOOP 2drop false ;
' (r/w Is r/w
: list ( blk -- )
scr ! ." Scr " scr @ u.
l/s 0 DO
cr I 2 .r space scr @ block I c/l * + c/l -trailing type
LOOP cr ;