GEOS for the DTV

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Contents

[edit] GEOS on the C64DTV/Hummer

[edit] DTV/Hummer compatible disk images

Go here for disk images. These can be run in VICEplus.

[edit] Todo

  • Shorten REU/DMA routine (overwrites _ToBasic/LoKernal1 routines currently)
  • Extend vsfReanimator to allow x64dtv snapshots as input
  • Create driver for PS/2 mouse on user port

[edit] Patching

This info is for coders only. Users see D64 download above.

  • Download GEOS64.
  • Get everything running in VICE x64.
  • Patch CONFIGURE 2.1.
  • Load GEOS in x64 with 2MB REU.
  • Create ramdisk and copy everything interesting there.
  • Go to monitor. Patch REU routines to use DTV DMA.
  • dump "geos.vsf"
  • Extract first 1856k of REU memory from vsf using a hexeditor
  • Prepend 64k zero bytes to REU memory (will go to $01xxxx on the DTV that is also used for colormem)
  • vsfReanimator geos.vsf 0 0 reumem.bin

[edit] More information

[edit] Code 

/*
CONFIGURE 2.1 -  detect DTV RAM as 1856k REU
a 0fb3
 jsr $c25c
 lda #$1d
 sta $88c3
 lda #$20
 sta $2102
 jmp $c25f
*/

/* Replacement REU code, XA format */

	.word $9eaa
	* = $9eaa

l9eaa	ldy #$93   /* Verify */
	bne exit
l9eae	ldy #$90   /* C64 => REU */
	bne transfer
l9eb2	ldy #$92   /* Swap */
	bne transfer
l9eb6	ldy #$91   /* REU => C64 */

transfer:
	ldx #$0d    /* error flag */
	lda $08
	cmp $88c3   /* max segment */
	bcs exit
	ldx $01     /* save $01 */
	lda #$35
	sta $01
 
	lda #$01    /* enable ext regs */
	sta $d03f

	lda #$00
	sta $d307
	sta $d309
	sta $d31d
	sta $d31e
	lda #$01
	sta $d306
	sta $d308

	lda $06
	sta $d30a  /* Transfer len lo */
	lda $07
	sta $d30b  /* Transfer len hi */

	cpy #$90
	bne t1
tc2r:	jsr c64toreu
	lda #$0d
	bne dodma
t1:	cpy #$91
	bne t2
tr2c:	jsr reutoc64
	lda #$0d
	bne dodma
t2:	jsr c64toreu
	lda #$0f
dodma:	sta $d31f
wait:	lda $d31f
	bne wait

	stx $01
	ldx #$00
exit	lda #$00     /* disable ext regs */
	sta $d03f
	rts

c64toreu:
	/* source */
	lda $02
	sta $d300
	lda $03
	sta $d301
	lda #$40    /* RAM */
	sta $d302

	/* dest */
	lda $04
	sta $d303
	lda $05
	sta $d304
	lda $08
	clc
	adc #$42    /* skip first two 64k segments, RAM */
	sta $d305
	rts

reutoc64:
	/* source */
	lda $04
	sta $d300
	lda $05
	sta $d301
	lda $08
	clc
	adc #$42    /* skip first two 64k segments, RAM */
	sta $d302

	/* dest */
	lda $02
	sta $d303
	lda $03
	sta $d304
	lda #$40    /* RAM */
	sta $d305
	rts

	brk
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