Jag Programmers - High Score Code.

[Curt Vendel]

Enjoy...

 

 

 

;************************************************

; *

; EEPROM Write & Read Primitives *

; *

;************************************************

;

; Hi-Score on-board-cartridge EEPROM primitives

; for use by Jaguar game cartridge developers.

;

; 128 bytes (accessable as 64 words) of non-volatile

; memory are available on Jaguar game cartridges to

; preserve Hi-scores or other game status.

; Data is retained for up to 10 years, and a minimum

; of 10,000 read/write cycles is assured, according to

; product literature.

;

;

;

;

;

; Programmer: Dave Staugas

; Atari, Sunnyvale

; [408] 745-8802

;

; Last Update: 24-Sept-93

;

;

; Equates needed that may already be defined in the JAGUAR.INC file..

;

JOY1 equ $f14000 ;this we'll use as our I/O base address

GPIO_0 equ $f14800 ;General purpose I/O #0

GPIO_1 equ $f15000 ;General purpose I/O #1

;

; Equates derived from the above

; to allow indirect with 16-bit displacement addressing

;

GPIO_0of equ GPIO_0-JOY1 ;offset to GPIO_0 (when addr reg Ax -> JOY1)

GPIO_1of equ GPIO_1-JOY1 ;offset to GPIO_1 (when addr reg Ax -> JOY1)

;

; Commands specific to the National Semiconductor NM93C14

;

; 9-bit commands..

; 876543210

eREAD equ %110000000 ;read from EEPROM

eEWEN equ %100110000 ;Erase/write Enable

eWRITE equ %101000000 ;Write selected register

eEWDS equ %100000000 ;Erase/Write disable (default)

;

;

; DO (data out) - is read on bit0 of JOY1

; DI (data in) - is written on bit0 of GPIO_0

; CS (chip select) - is pulsed low by any access to GPIO_1

;

;

;*****************************************************************

;

; Write a word to EEPROM

;

; entry: d0.w = data to be written

; d1.w = least signifigant 6 bits specify write address (0-63)

;

; exit: all preserved

;

;

eewrite::

movem.l a0/d0-d4,-(sp)

lea JOY1,a0 ;set ptr to EEPROM i/o addresses

;

tst.w GPIO_1of(a0) ;strobe ChipSelect

;

move.w #eEWEN,d2 ;erase/write enable command

bsr out9bits ;send it to EEPROM

;

tst.w GPIO_1of(a0) ;strobe ChipSelect

;

andi.w #$3f,d1 ;force write addr to be legit (0-63)

ori.w #eWRITE,d1 ;form WRITE command

move.w d1,d2

bsr out9bits ;send it to EEPROM

;

move.w d0,d2 ;get 16-bit data word to send

bsr out16bit ; & send it

;

tst.w GPIO_1of(a0) ;strobe ChipSelect

;

nop ;1 us required after CS for status valid

nop

move.w #1,d2

wrwait:

move.w (a0),d3 ;wait until write is complete

and.w d2,d3

beq wrwait

;

move.w #eEWDS,d2 ;get erase/write disable command

bsr out9bits ;send it

;

tst.w GPIO_1of(a0) ;strobe ChipSelect

;

movem.l (sp)+,a0/d0-d4

rts ;we're done

;

;

;

;******************************************************

;

;

; Read a word from EEPROM

;

; entry: d1.w = least signifigant 6 bits specify read address (0-63)

;

; exit: d0.w = data as read from EEPROM

; all other registers preserved

;

eeread::

movem.l a0/d1-d4,-(sp)

lea JOY1,a0 ;set ptr to EEPROM i/o address

;

tst.w GPIO_1of(a0) ;strobe ChipSelect

;

andi.w #$3f,d1 ;force legit read addr

ori.w #eREAD,d1

move.w d1,d2

bsr out9bits

;

moveq #0,d0

moveq #15,d3 ;pick up 17 bits (1st is dummy)

inlp:

tst.w GPIO_0of(a0)

nop

move.w (a0),d1

lsr.w #1,d1

addx.w d0,d0

nop

nop

nop

nop

nop

nop

dbra d3,inlp

;

movem.l (sp)+,a0/d1-d4

rts

;

;

;

;**************************************************************

;

; Subordinate Routines needed by "eewrite"

;

; Serial data sent to device is written to DI, bit0 of GPIO_0

;

; entry:

; a0 -> JOY1

; d2.w = 16-bit data word to write

;

; exit:

; d2.w, d3.l destroyed

;

out16bit:

rol.w #1,d2 ;align 1st serial data bit (bit15) to bit0

moveq #15,d3 ;send 16 bits

bra.s out9lp

;

; entry:

; a0 -> JOY1

; d2.w = 9-bit command to write

;

out9bits:

rol.w #8,d2 ;align 1st serial data bit (bit8) to bit0

moveq #8,d3 ;send 9

out9lp:

move.w d2,GPIO_0of(a0) ;write next bit

nop

nop

nop ;delay next write

nop

nop

nop

rol.w #1,d2 ;adjust bit0 for next datum

dbra d3,out9lp ;go for all 9 or all 16

rts

;

;

[Tyrant]

Isnt that already in the dev manual / examples we've already got? I could be mistaken but Im sure the info on eeprom access was there already, tho perhaps without source.

[Curt Vendel]

I figured, this seemed to be more well commented and it was the source, so it may be just a little more to help out.... Can't hurt, right?

 

 

 

Curt

[Tyrant]

No of course not, just curious as to why you were posting it, how it was different etc (without me having to look it up cause Im in a hurry off out )

[Matthias]

Hello!

 

I figured, this seemed to be more well commented and it was the source, so it may be just a little more to help out....    Can't hurt, right?

 

You are right, it's nice to see this code with comments,

it's really sad that they removed them later.

 

Bye!

Matthias

[Goochman]

Hello!

 

I figured, this seemed to be more well commented and it was the source, so it may be just a little more to help out....    Can't hurt, right?

 

You are right, it's nice to see this code with comments,

it's really sad that they removed them later.

 

Bye!

Matthias

 

Well,

I can tell you working on some large software projects in the early 90's our Project leader would strip out all comments prior to stuff being send to the testing/production source safe enviroments due to storage savings. Every byte counts I guess