* QL WORLD DIY TOOLKIT JULY 1989 - MEM device driver, * Version 1.0, copyright Luca Pivato & Simon N Goodwin. * mem_ptr equ 24 Current MEM pointer buff_id equ 28 Word ID of buffer chan_link equ 30 Channel list pointer buff_addr equ 34 Buffer start address buff_flag equ 38 Word persistence flag * start lea.l serio_ptrs,a0 Set up SERIO linkage lea.l io_ready,a2 move.l a2,(a0)+ lea.l fetch_byte,a2 move.l a2,(a0)+ lea.l send_byte,a2 move.l a2,(a0)+ lea.l io_pointer,a0 Set up device linkage lea.l io_code,a2 move.l a2,(a0)+ lea.l open_code,a2 move.l a2,(a0)+ lea.l close_code,a2 move.l a2,(a0)+ lea.l linkage,a0 Link the MEM device moveq #32,d0 MT.LIOD key trap #1 rts Return D0 to caller * linkage dc.l 0 Link to next device io_pointer dc.l 0 Pointer to I/O code dc.l 0 Pointer to OPEN code dc.l 0 Pointer to CLOSE code * buff_ptr dc.l 0 Start of buffer list chan_ptr dc.l 0 Start of channel list * * Code to handle TRAP #3 calls: IO.PEND, FBYTE, FLINE, * FSTRG, SBYTE, SSTRG, EXTOP, POSAB, POSRE, LOAD, SAVE * io_code cmp.b #9,d0 Call to FS.EXTOP? beq vector_a2 move.l mem_ptr(a0),a5 A5 -> MEM address cmp.b #66,d0 Call to FS.POSAB? beq.s set_abspos cmp.b #67,d0 Call to FS.POSRE? beq.s set_relpos move.w 234,a2 Use IO.SERIO vector jsr (a2) Do other serial I/O serio_ptrs dc.l 0 Pointer for IO.PEND dc.l 0 Pointer for IO.FETCH dc.l 0 Pointer for IO.SEND rts Return from SERIO * set_abspos tst.l d1 Negative parameter? bpl.s use_posn move.l buff_addr(a0),d1 Get default base use_posn move.l d1,a5 Set position bra.s set_memptr set_relpos adda.l d1,a5 Offset position move.l a5,d1 Return new value bra.s set_memptr send_byte move.b d1,(a5)+ bra.s set_memptr fetch_byte move.b (a5)+,d1 set_memptr move.l a5,mem_ptr(a0) Reset MEM pointer io_ready moveq #0,d0 rts * * Code to handle TRAP #2 calls: OPEN and CLOSE * open_code subq.l #6,a7 Make space on stack move.l a7,a3 A3 -> parameters move.w 290,a2 Use IO.NAME vector jsr (a2) bra.s exit_open Name faulty bra.s exit_open Parameters faulty bra.s open_ok Name parsed OK name_spec dc.w 3 Length of name dc.b 'MEM' dc.w 3 Max. 3 parameters dc.w -1,-1 Buffer number dc.w ' _',-1 _ Buffer size dc.w 2,'PT' Permanent/Temporary * open_ok move.l a3,a5 A5 -> parameters moveq #40,d1 40 bytes needed move.w 192,a2 MM.ALCHP vector jsr (a2) Allocate memory beq.s do_buffers Go on if RAM permits exit_open addq.l #6,a7 Deallocate stack space tst.l d0 Error code is in D0 rts * do_buffers move.w (a5),d7 Get buffer ID move.w d7,buff_id(a0) Keep buffer ID bmi.s exit_open No buffer, exit set_flag move.w 4(a5),buff_flag(a0) Keep P/T flag move.l a0,a4 Save channel base lea.l buff_ptr,a3 Search buffer list bsr.s scanner Does the buffer exist? beq.s new_one No it doesn't lea.l 6(a3),a0 A0 -> Start of buffer moveq #0,d0 OPENed without errors bra.s set_addr Tell the channel * new_one move.w 2(a5),d1 Was a size specified? bmi.s no_size If not, complain! addq.w #8,d1 Allow for a header ext.l d1 D1 = total buffer size moveq #0,d2 Permanent allocation moveq #24,d0 MT.ALCHP key trap #1 Try to allocate memory tst.l d0 Did that work? bne.s no_room If not, complain move.l a0,d2 Keep buffer base move.w d7,(a0)+ Record buffer ID lea.l buff_ptr,a3 Extend the buffer list move.l (a3),(a0)+ move.l d2,(a3) Start with new buffer sub.w #24,d1 Ignore header bytes move.w d1,(a0)+ Store buffer length set_addr move.l a0,buff_addr(a4) Record buffer start move.l a0,mem_ptr(a4) Initialise pointer lea.l chan_ptr,a3 Extend channel list move.l (a3),chan_link(a4) lea.l buff_id(a4),a2 move.l a2,(a3) move.l a4,a0 A0 -> Channel block bra.s exit_open * no_room move.l a4,a0 Retrieve channel bsr.s lose_chan moveq #-3,d0 No room for the buffer bra.s exit_open Report OUT OF MEMORY no_size bsr.s lose_chan moveq #-15,d0 Size needed but absent bra.s exit_open Report BAD PARAMETER * scanner move.l a3,a2 Find the ID in D7.W move.l (a2),d0 Try the next link beq.s not_found No such luck, quit move.l d0,a3 A3 -> Buffer ID.W cmp.w (a3)+,d7 Is it what we want? bne.s scanner If no, try the next found_it tst.l d0 Yes, return A2 & A3 not_found rts Return D0=0 if absent * close_code lea.l buff_id(a0),a4 Get list position lea.l chan_ptr,a3 Purge channel list bsr.s purge_list move.w (a4),d7 Is a buffer in use? bmi.s lose_chan No, just zap channel subq.w #1,buff_flag(a0) Is buffer permanent? beq.s lose_chan Yes, just zap channel lea.l chan_ptr,a3 Is the buffer busy? bsr.s scanner Search channel list bne.s lose_chan If busy keep buffer move.l buff_addr(a0),a4 Find buffer subq.l #8,a4 Include header lea.l buff_ptr,a3 Scan buffer list bsr.s purge_list Un-link buffer exg a4,a0 Swap pointers over moveq #25,d0 MT.RECHP key trap #1 Deallocate buffer move.l a4,a0 Restore channel base lose_chan move.w 194,a2 MM.RECHP vector vector_a2 jmp (a2) Deallocate channel * purge_list move.l a3,a2 Remove link to (A4) move.l (a2),d0 beq.s bizarre No more - abort! move.l d0,a3 A3 -> Buffer ID.W addq.l #2,a3 Skip buffer ID cmp.l a4,d0 Have we found it? bne.s purge_list No, look further move.l (a3),(a2) De-list the entry bizarre rts * end