PR#3
PREFIX /A2OSX.BUILD
LOMEM $A00
INC 1
AUTO 6
				.LIST OFF	
*--------------------------------------
HIS.Init		>LDYAI History.MAX		Get a buffer for History
				>SYSCALL GetMem0.YA
				bcs .9

				txa
				>STA.G HIS.hBuf
				
				lda #0
				>STA.G HIS.Count
				>STA.G HIS.Index
.9				rts
*--------------------------------------
HIS.Add			>LDA.G HIS.hBuf
				beq .9
				
				>SYSCALL GetMemPtr.A
				>STYA ZPPTR1
				
.10				lda #$ff
				jsr HIS.GetA			Y=ending 0
				phy
				tya
				
				sec						add len+1
				>ADC.G CmdBuflen		CmdBuffer length
				pla
				bcc .2					enough room
				
				ldy #$ff				we must remove oldest
				
.12				iny
				lda (ZPPTR1),y			get len of oldest string
				bne .12
				
				tya
*				sec				
				adc ZPPTR1
				sta ZPPTR2
				lda ZPPTR1+1
				adc #0
				sta ZPPTR2+1
				
				ldy #$FF
				
.1				iny
				lda (ZPPTR2),y			move back until String ending 0 found
				sta (ZPPTR1),y
				bne .1
				
				iny
				lda (ZPPTR2),y			move back until Array ending 0 found
				sta (ZPPTR1),y
				bne .1
				
				>DEC.G HIS.Count
				
				bra .10					retry....
				
.2				clc						A = ending O offset
				adc ZPPTR1
				sta ZPPTR1
				bcc .3
				inc ZPPTR1+1
				
.3				ldy #$ff
				
.4				iny
				lda (ZPCMDBuf),y
				sta (ZPPTR1),y
				bne .4

				iny
				sta (ZPPTR1),y			set new array ending 0
*				lda #0				
				>STA.G HIS.Index		Reset Index
				
				>INC.G HIS.Count
					
.9				rts
*--------------------------------------
HIS.GetPrev		>LDA.G HIS.hBuf
				beq HISTORY.RTS
				
				>SYSCALL GetMemPtr.A
				>STYA ZPPTR1
				
				>DEBUG

				>LDA.G HIS.Count
				beq HISTORY.RTS			empty history,nothing to do
				
				>LDA.G HIS.Index
				bne .1
				
				>LDA.G HIS.Count
				
.1				dec
				>STA.G HIS.Index
				
				jsr HIS.GetA

				bra HIS.SetBuf
History.RTS		rts
*--------------------------------------
HIS.GetNext		>LDA.G HIS.hBuf
				beq HISTORY.RTS
				
				>SYSCALL GetMemPtr.A
				>STYA ZPPTR1

				>DEBUG

				>LDA.G HIS.Count
				beq HISTORY.RTS			empty history,nothing to do
				
				>LDA.G HIS.Index
				inc
				>CMP.G HIS.Count
				bne .1
				lda #0
				
.1				>STA.G HIS.Index			
				
				jsr HIS.GetA
				
				bne HIS.SetBuf
				jmp CmdLine.CLR		end of history, just blank buffer
*--------------------------------------
HIS.GetA		tax
				beq .8
				
				ldy #0
				lda (ZPPTR1),y
				beq .9
				
.1				iny
				lda (ZPPTR1),y
				bne .1
				
				dex
				beq .8
				
				iny
				lda (ZPPTR1),y
				bne .1
				
.9				sec						Found ending 0....
				rts
				
.8				clc
				rts
*--------------------------------------
HIS.SetBuf		jsr CmdLine.CLR
				
				ldy #$ff
				
.1				lda (ZPPTR1),y
				sta (ZPCMDBuf),y
				bne .1
				
				jmp CmdLine.PRINT
*--------------------------------------
HIS.Quit		>LDA.G HIS.hBuf
				beq .9
				>SYSCALL FreeMem.A
.9				rts
*--------------------------------------
MAN
SAVE /A2OSX.SRC/SBIN/SHELL.S.HIS
LOAD /A2OSX.SRC/SBIN/SHELL.S
ASM