!to "reuvos.prg"
;--------------------------------------------------
; Virtual REU OS V1
;
; Tiny Basic extender for the C64+REU.
; Overview :
; <-D : Detect REU (!!! REWRITES ALL BANKS !!!)
; <-S : Stash Basic RAM ($0801-$A000)
; <-F : Fetch Basic RAM ($0801-$A000)
; <-B,{bank} : switch RAM banks
; <-U,{C64-Adr.},{REU-Adr.},{bank},{bytes},{command}
; :User command
; -------------------------------------------------
; Code : Michael Sachse (cbmhardware /PoL)
; 06.02.2005 : Init runs "Detect", counting banks fixed;
; -------------------------------------------------
; Licence : GPL
; This program is free software; you can redistribute it and/or modify it under the terms of the
; GNU General Public License as published by the Free Software Foundation
; either version 2 of the ; License, or (at your option) any later version.
;
;--------------------------------------------------
* = $c000 ; Start Address 49152
;--------------------------------------------------
reubase= $df00
CHRGET = $0073
TXTPTR = $7A
IERROR = $0300
IMAIN = $0302
IGONE = $0308
GONE = $A7E4
CHKCOM = $AEFD
FRMNUM = $AD8A
GETADR = $B7F7
CHROUT = $FFD2
banks = $90
usebank = $92
banktable = $c600
get = $ffe4 ; to get pressed keys
;--------------------------------------------------
lda #03
sta 45 ; Basic low
lda #08
sta 46 ; Basic high
jsr $a68e ; init
freebanks ldy #$00 ; delete banktable
f1 lda #70
sta banktable,y
iny
cpy #32
bne f1
LDA #$93
JSR $FFD2
lda #1
sta $0286 ; textcolor white
lda #0
sta $d020
sta $d021 ; black is beautiful
ldy #$00
title lda TITLE,y ; text
JSR CHROUT
iny
cpy #40
bne title
jsr redet
INIT LDX #NEWBASIC
STX IGONE
STY IGONE+1
RTS
LDX #$83
LDY #$A4
STX IMAIN ; ($0302)
STY IMAIN+1 ; ($0303)
NEWBASIC JSR CHRGET ; GET CHARACTER
CMP #95 ; IS IT A "<-" ?
BEQ CHK ; YES, CONTINUE
JMP GONE+3 ; NORMAL WORD
CHK JSR CHRGET ; GET NEXT CHARACTER
CMP #$44 ; "D" Detect
BEQ reumain
CMP #$42 ; "B" Bank,?
BEQ getBank
CMP #$53 ; "S" Stash ($0800-$a000)
BEQ stashreu
CMP #$46 ; "F" Fetch ($0800-$a000)
BEQ fetchreu1
CMP #$55 ; "U" User,c64,reu,bank,bytes,command (stash,fetch,swap)
BEQ userreu
JMP (IERROR)
;--------------------------------------------------
redet jsr reudetect ; detect REU (Banks)
rts
reumain jsr reudetect ; detect REU (Banks)
s JMP GONE
;--------------------------------------------------
; Bank change <-B,{bank}
;--------------------------------------------------
getBank JSR WORK1
sta bank+1
sta usebank
s6 JMP STATUS
;--------------------------------------------------
; Stash (Basic RAM $0801-$a000)
;
; Token : <-S
;
; Asks before rewriting if bank is in use. Smart eh ? ;)
;
;--------------------------------------------------
stashreu ldx usebank
lda banktable,x ; check banktable
cmp #85 ; "U" Bank in use
bne doit ; no, skip
ldy #00 ;
t1 lda bankuse,y
JSR CHROUT
iny
cpy #20
bne t1
keyb jsr get ; get keyboard
cmp #89 ; "Y"
beq doit ;
cmp #78 ; "N"
beq exit
bne keyb
doit lda #01
sta c64lo+1
lda #08
sta c64hi+1
lda #$00
sta rbytes+1
lda #$a0
sta rbytesh+1
lda #236
sta config
ldx usebank
lda #85
sta banktable,x
jsr main
exit JMP GONE
;--------------------------------------------------
fetchreu1 jsr fetchreu
rts
;--------------------------------------------------
; User-Token: <-U,c64,reu,bank,bytes,command
;
; Not rookies choice !
;
;--------------------------------------------------
userreu jsr WORK1
sta c64lo+1
stx c64hi+1
jsr WORK1
sta reulo+1
stx reuhi+1
jsr WORK1
sta bank+1
jsr WORK1
sta rbytes+1
stx rbytesh+1
jsr WORK1
sta config
jsr main
ex1 JMP STATUS
;--------------------------------------------------
; Fetch (Basic RAM $0801-$a000)
;
; Token : <-F
;
; Asks before fetching if bank is empty.
;
;--------------------------------------------------
fetchreu ldx usebank
lda banktable,x
cmp #70 ;"F" bank free ?
bne doit1 ; no skip
ldy #00
t4 lda bankempty,y
JSR CHROUT
iny
cpy #23
bne t4
keyb1 jsr get ; get keyboard
cmp #89 ; "Y"
beq doit1
cmp #78 ; "N"
beq ex2
bne keyb1
doit1 lda #01
sta c64lo+1
lda #08
sta c64hi+1
lda #$00
sta rbytes+1
lda #$a0
sta rbytesh+1
lda #237
sta config
jsr main
ex2 JMP GONE
;--------------------------------------------------
; Basic ROM patch
;--------------------------------------------------
WORK1 JSR CHRGET ;
LDA #$2C ; Comma patch
ldy #$00 ; Pointer
CMP($7a),y ; compare
BEQ WORK1 ; Comma, loop
JSR $AD8A ; FRMNUM
JSR $B1BF ; GET C64 Adr.
LDA $65 ; low byte
LDX $64 ; high byte
RTS
;--------------------------------------------------
; Detect REU 1700,1764/50 or 1/2MB
;--------------------------------------------------
reudetect lda #00
sta c64lo+1
lda #$C3
sta c64hi+1
lda #16
sta rbytes+1
lda #00
sta rbytesh+1
sta banks
sta reubase
cmp reubase
beq noreu
bne unsafe
unsafe lda reubase
and #16 ; check bit 4 for REU mem
cmp #16 ; 16 = 256Kbx1
beq regcheck ; yes, touch registers
bne l1 ; no, 1700 ?
l1 lda reubase
and #16 ; check bit 4 for REU mem
cmp #0
beq r1700 ; reu 1700 found
bne noreu ; no ram-type, no reu, no fun ...
regcheck lda reubase
ldx #2
loop1 txa
sta $df00,x ; write to registers 2-5
inx
cpx #5
bne loop1
ldx #02
loop2 txa
cmp $df00,x
bne noreu
inx
cpx #5
bne loop2
jmp rinit
r1700 lda #1
sta banks
lda #reutext
jmp $ab1e
;-------------------------------------------------
rinit ldx #00 ; 1764 wake up
rinit2 lda #128 ; stash
sta config
lda #$12 ; write some crap in ...
sta c64hi+1
stx bank+1
jsr main
inx
cpx #33 ; ... 33 banks into somewhere
bne rinit2
jmp action
noreu lda #notext
jmp $ab1e
;--------------------------------------------------
; Count banks
;--------------------------------------------------
action lda reubase
ldx #$00
stx bank+1 ; reset bank counter
check lda #129 ; fetch : transfer to C64 :
sta config
lda #$C7 ; C64 : $C700
sta c64hi+1
jsr main
lda #128 ; stash
sta config
lda #$C3 ; write dummy bytes
sta c64hi+1
jsr main
jsr bankcheck ; check for existing ram banks
inx
cpx #33 ; try 33
stx bank+1
bne check
;--------------------------------------------------
lda #0 ; restore bordercolor
sta $d020
lda banks ; banks found ?
cmp #4
beq r1764
bne j1
r1764 lda #4
sta banks
dec banks
lda #text1764
jmp $ab1e
j1 cmp #8
beq r512
bne j2
r512 dec banks
lda #reut512
jmp $ab1e
j2 cmp #16
beq r1024
bne j3
r1024 dec banks
lda #reut1024
jmp $ab1e
j3 cmp #20
beq r1764
bne j4
j4 cmp #32
beq r2048
bne j6
r2048 dec banks
lda #reut2048
jmp $ab1e
j6 lda #reuunk
jmp $ab1e
;--------------------------------------------------
; Bank Check
;--------------------------------------------------
bankcheck ldy #$00
l2 lda $C300,y
l6 cmp $C700,y
bne l4 ; bank found ?
beq l3 ; no, check 16 Bytes
l3 iny
cpy #16
bne l2 ; loop
end ldy #00
lda #00
delete sta $C700,y ; delete buffer
iny
cpy #16
bne delete
rts
l4 jmp l5
l5 inc banks ; bank found (inc), border color change and exit
inc $d020
rts
config !byte 252
;--------------------------------------------------
; Bytes and text
;--------------------------------------------------
*=$C300
!scr "---C64-RULEZ!---" ; ;-)
reutext: !text "REU 1700 : 128KB DETECTED",0
text1764: !text "REU 1764 : 256KB DETECTED",0
reut512: !text "REU 1750 : 512KB DETECTED",0
reut1024: !text "REU 1024KB DETECTED",0
reut2048: !text "REU 2048KB DETECTED",0
reuunk: !text "REU PORT DETECTED - BANK ERROR",0
bankerr: !SCR "BANK ERROR"
notext: !text "NO REU",0
bankuse : !SCR "REWRITE BANK [Y/N] ?"
bankempty : !SCR "READ EMPTY BANK [Y/N] ?"
;--------------------------------------------------
; REU TRANSFER ROUTINE
;--------------------------------------------------
main lda config
sta reubase+1
c64lo lda #$00
sta reubase+2
c64hi lda #$C2
sta reubase+3
reulo lda #$00
sta reubase+4
reuhi lda #$00
sta reubase+5
bank lda #00
sta reubase+6 ; Bank
rbytes lda #16
sta reubase+7 ; 16 Bytes
rbytesh lda #$00
sta reubase+8
irq lda #$00
sta reubase+9
lda #$00
sta reubase+10
lda $1
pha
lda #$30 ; RAM
sei
sta $1
sta $ff00
pla
sta $1
cli
rts
;--------------------------------------------------
; Restore TXTPTR and back to command line
;--------------------------------------------------
STATUS
END2 SEC
LDA TXTPTR
SBC #$01
STA TXTPTR
LDA TXTPTR+1
SBC #$00
STA TXTPTR+1
JMP GONE
;--------------------------------------------------
TITLE !SCR " **** VIRTUAL REU OS V1 INSTALLED **** "
flinit !BYTE 73
Letzte Änderung: 2019-01-03 18:14:50
