NAM    mach_coco
         TTL    CoCo machine routines

         PSECT  mach_coco3,0,0,0,0,mach_init

         VSECT
         ENDSECT

PIA0Base equ   $FF00
PIA1Base equ   $FF20
DAT.Regs equ   $FFA0

mach_init:
* CoCo 3 Initialization Code
         clr   $FFD9      go into fast mode
         
* Setup MMU
         ldx   #DAT.Regs
         leay  MMUTbl,pcr
         ldb   #16      
MMULoop  lda   ,y+      
         sta   ,x+
         decb
         bne   MMULoop

* Setup video
         leau  CC3Regs,pcr      point to video setup data
         ldx   #$FF90
Loop1    ldd   ,u++             get the bytes
         std   ,x++             save in the hardware
         cmpx  #$FFA0
         bcs   Loop1

* Set palettes up
         leau  PalTbl,pcr
         ldy   #$FFB0           palette register
         ldb   #16
         lbsr  CopyRtn

* Initialize PIAs
         ldx   #PIA1Base  RG - Initialize the PIA 1
         ldd   #$FF34
         clr   1,x      cassette motor off, 0,x is DDR
         clr   3,x      2,x is DDR
         deca           A = $FE
         sta   ,x       cassette bit 0 input, all others output
         lda   #$F8     bits 7-3 output, bits 2-0 input
         sta   2,x      set DDR
         stb   1,x      0,x not DDR
         stb   3,x      2,x not DDR
         clr   2,x
         lda   #$02     RS-232 bit hi
         sta   ,x       set it

         lda   #$FF     all outputs
         ldx   #PIA0Base
         clr   1,x      0,x is DDR
         clr   3,x      2,x is DDR
         clr   ,x       all inputs
         sta   2,x      all outputs
         stb   1,x      0,x is not DDR
         stb   3,x      2,x is not DDR
         clr   2,x

         rts
        
CopyRtn  clra
         tfr   d,x
Copy1    ldb   ,u+
         stb   ,y+
         leax  -1,x
         bne   Copy1
         rts

* MMU
MMUTbl
         fcb   $38,$39,$3A,$3B,$3C,$3D,$3E,$3F
         fcb   $38,$39,$3A,$3B,$3C,$3D,$3E,$3F

* GIME register default values
CC3Regs  fcb   $EC        CC2, MMU, IRQ, Vector page, SCS
         fcb   $00        map type 0
         fcb   $00        no FIRQ
         fcb   $00        no IRQ
         fdb   $0900      timer
         fcb   $00        unused
         fcb   $00        unused
         fcb   $00
         fcb   $00
         fcb   $00
         fcb   $00
         fdb   $0FE0
         fcb   $00
         fcb   $00

* Palette register default colors
PalTbl
         fcb   $12      green
         fcb   $36
         fcb   $09      blue
         fcb   $24      red
         fcb   $3F      white
         fcb   $1B      cyan
         fcb   $2D      magenta
         fcb   $26
         fcb   $00      black
         fcb   $12      green
         fcb   $00      black
         fcb   $3F      white
         fcb   $00      black
         fcb   $12      green
         fcb   $00      black
         fcb   $26
 

         endsect