gregallenwarner Posted August 28, 2014 Share Posted August 28, 2014 I was wondering if anybody could help me with some Assembly techniques for using the SAMS extended memory. Assembly is really the only language I'm interested in writing in at the moment. I'm specifically wondering about broader techniques here, not the basic how to control the card stuff. That much I'm familiar with. I know how to page in and out the various banks of memory. What I'm more interested in is any programming techniques that people have come up with for making efficient use of it. For example: 1. How do you use the TI's address space? Do you select an area of the TI's memory space to designate a code region, and another area a data region? 2. Where do you place the code for switching banks? What's the strategy behind switching banks in the middle of a running program? 3. Do you have executable code that resides in multiple banks? How do you switch between them? How do you make a call to a subroutine that exists in another bank? 4. How does this all impact the linking loader? How do you load a program into multiple banks? Do you have to write your own loader? Also, is there any difference in loading code based on whether it's an EA3 or EA5 program? Sorry for the wall of questions. I've never used the SAMS before, so it's proper usage is a bit of a mystery to me. 2 Quote Link to comment Share on other sites More sharing options...
TI-Sissy Posted August 28, 2014 Share Posted August 28, 2014 wall of questions. i like it! ur lucky, i don't understand much of this stuff here. i don't know enough to even ask questions! Quote Link to comment Share on other sites More sharing options...
+adamantyr Posted August 28, 2014 Share Posted August 28, 2014 I've had a lot of the same questions! There's definitely a case here of having to write your program in a particular fashion to take full advantage. I had considered for my CRPG how I may use it... For example, I'd probably have separate "modules" of executable code for the two primary modes, travel and combat, that occupy the same pages of memory, while common utilities, switching mechanisms, and so forth are kept in a "page zero" area, which remains constant. Data storage would definitely be in pages... the 4k of "travel map" would be swapped out for buffer space for combat, for example. However, given I don't HAVE a SAMS card and a general disinclination to hooking up my potential-fire-hazard PEB which isn't compatible with my CF card reader system, I haven't really explored this... I really want to make sure the finished game works on the hardware, and I'm hoping I can make everything fit in the standard 32k with an 8k RAM Supercart. (I do own now a "SuperSpace II" cartridge with four 8k pages, which I'll resort to if need be, but that's definitely going to make accessibility hard! I may have to write a SAMS version in emulation only at that point.) Adamantyr Quote Link to comment Share on other sites More sharing options...
RobertLM78 Posted August 28, 2014 Share Posted August 28, 2014 The memory, as I understand, is accessed through 8k pages. The SAMS is cool, but kind of a PITA. That's why I dig the Geneve so much - no faffing with paged memory. Quote Link to comment Share on other sites More sharing options...
Willsy Posted August 28, 2014 Share Posted August 28, 2014 It's 4k pages but yeah - a PITA. 1 Quote Link to comment Share on other sites More sharing options...
+Lee Stewart Posted August 28, 2014 Share Posted August 28, 2014 And—those 4K pages map to the 32K card's space—and only that space. So, no 32K card; but, you probably already knew that. There are several Micropendium articles on it (see WHTech site). ...lee 1 Quote Link to comment Share on other sites More sharing options...
RXB Posted August 28, 2014 Share Posted August 28, 2014 The memory, as I understand, is accessed through 8k pages. The SAMS is cool, but kind of a PITA. That's why I dig the Geneve so much - no faffing with paged memory. Hmm sorry no! SAMS is organized as 4K pages. Quote Link to comment Share on other sites More sharing options...
RobertLM78 Posted August 28, 2014 Share Posted August 28, 2014 Hmm sorry no! SAMS is organized as 4K pages. Yes, that was clarified by Willsy 3 posts back Quote Link to comment Share on other sites More sharing options...
RXB Posted August 28, 2014 Share Posted August 28, 2014 (edited) If you want to play around with it is in Clasic99 RXB supports SAMS As RXB does all the management of SAMS pages for you all you have to do is load a program SAMS lower 8K and use it then switch banks. I wrote a game that loads over 400K of screens from VDP to the SAMS. It transfers then back and forth and saves your progress to the SAMS. SAMS Assembly loader and show how to use it. Edited August 28, 2014 by RXB 1 Quote Link to comment Share on other sites More sharing options...
gregallenwarner Posted August 29, 2014 Author Share Posted August 29, 2014 Thanks, Rich. To be honest, rather than knowing how the RXB user makes use of the SAMS, I'm much more interested in how RXB itself makes use of it. Is there a memory manager present that keeps track of pages under the hood? What kind of memory structure do you use to store this data? Quote Link to comment Share on other sites More sharing options...
Asmusr Posted August 29, 2014 Share Posted August 29, 2014 I actually have a SAMS card but I'm not aware of any software except RXB (which I don't have) that uses it. I have thought about using it for a game with a big map that is updated dynamically, in which case I would simply swap in the active page/screen into low memory. But for something like Sabre Wulf with highly repetitive graphics it's not really necessary, and for static data you could just as well use a ROM cart. Quote Link to comment Share on other sites More sharing options...
+InsaneMultitasker Posted August 29, 2014 Share Posted August 29, 2014 I know there is/was documentation out there, perhaps part of the RAG assembler package and the AMS package. The process is not overly difficult to map pages in and out. I believe the following information comes from an article in Micropendium written by Bruce Harrison. ACCESS and MAPPING To use other than the default setup, you have to do two things. First, you have to "turn on" the card's memory in the >4000 block and write to the mapping registers there. Second, you have to "turn on" the mapper function to make what you've written into the >4000 block take effect. The first step in all this is to set Register 12 to the value >1E00, which is the CRU address of the AMS card. Now doing a SBO 0 instruction will enable the >4000 memory block for reading and writing. In that block, each word starting with >4000 and ending with >401E acts to control what page maps into what memory location. The subroutine AMSINI (see sidebar) initializes all the mapping registers to power-up condition. Thus, for example, >4004 is set for page 2, >4006 to page 3, etc. In our own program, we're mapping things into the >A000 through >F000 blocks. Thus the registers we write to in >4000 are at >4014 thru >401E. To make a mapping selection, we write the desired page number to the high order byte of the control register. Let's take a concrete example. Suppose we want pages 4, 5 and 6 of the AMS to behave as if they were at >A000, >B000, and >C000. It's this easy: LI R12,>1E00 CRU ADDRESS SBO 0 TURN ON CARD'S >4000 BLOCK LI R1,>0400 PAGE NUMBER IN LEFT BYTE LI R3,>4014 MAPPING REGISTER FOR >A000 BLOCK MOV R1,*R3+ WRITE TO >4014 AND ADD 2 TO R3 AI R1,>100 LEFT BYTE OF R1=5 MOV R1,*R3+ WRITE 5 TO >4016 AND ADD 2 TO R3 AI R1,>100 LEFT BYTE OF R1=6 MOV R1,*R3 WRITE 6 TO LEFT BYTE AT >4018 This sets the registers, but does not actually start the mapper working. To put the mapping in effect, we have to perform one more operation: SBO 1 TURN ON THE MAPPER Now that the mapper is turned on, anything written to >A000 thru >CFFF will actually be written into pages 4 thru 6 of the AMS memory instead of into pages >A thru >C. Similarly, any memory reading from >A000 thru >CFFF will actually read the contents of pages 4 thru 6 of the AMS memory. Thus your program can write and read as if to >A000 thru >CFFF, but the mapper will make things actually access the pages 4 thru 6 in the AMS card. You can turn off access to the card's >4000 block and still leave the mapper in effect by the instruction SBZ 0. (Provided R12 still contains >1E00.) You can turn off the mapper by SBZ 1, and then the areas >A000 thru >CFFF will revert to "normal", reading and writing to pages >A thru >C of the AMS card. In the finished AMS version of Video Titler, the program works by frames, where each frame accounts for three pages of the AMS memory. We use an odd-even scheme, so that odd numbered frames (1,3,5,...19) go into pages mapped to >A000 thru >CFFF, and even numbered ones go into pages mapped to >D000 thru >FFFF. This way the program always has immediate access to two frames at any given time. Let's say for example that the user asks to load a TI-Artist picture (with color) into Frame 1. We take the desired frame number, multiply that by three, add one, then put that in the left byte of a workspace register. Since this is an odd frame, we use the mapping registers at >4014 thru >4018, and put 4, 5, and 6 into the left bytes of those mapping registers, respectively. (For an even page, we'd use >401A thru >401E.) Now when the program reads the file, it dumps the contents of the pattern and color parts into >A000 thru >CFFF, which really goes into pages 4 thru 6 of the AMS memory. In similar fashion, frame 2 goes into pages 7 thru 9, frame 3 into pages 10 thru 12, frame 4 goes to pages 13 thru 15, and so on until frame 20, which goes into pages 61 thru 63. Clear as mud? Look at Part Two of the Sidebar, which may help. Meanwhile, how about a little different perspective? The AMS Owner's Viewpoint The Super AMS card is a most welcome and needed addition to the TI 99/4A. The physical aspects are a well-made, high-quality card which inserts in place of the 32K card. In normal use, it duplicates the 32K card exactly, except for the absence of an indicator light. In expanded mode, the card provides from 128K to 1 meg of paged memory, depending on the chips installed. There are three disks of software provided with the card, of which two are archived. Included is an excellent memory tester that writes and reads to every bit. This assures the user that everything is functioning properly. Also included is an excellent disk copy program, AMS Copy. The program reads an entire 720 sector disk into memory, then writes to the copy disk in one pass. Contents of the master disk remain in memory, allowing as many copies to be made as needed without re-reading. Also there were two games, which I could not get to run. The remainder of the software is mainly for programmers and of little consequence for the end user. So, aside from testing the memory and copying disks, what can be done with the Super AMS card? Well, prior to the middle of July, the answer was "not too much." Enter Bruce Harrison. When I first purchased the Super AMS card back in May at Cleveland, Bruce rather poo-pooed it, saying that he could write any program for the TI and keep it well within the 32K space. No argument here. Then I posed the hypothetical question....how many titles could the Video Titler program hold in 256K of memory? To which Bruce answered, "I'll think about it." Well, Bruce did a lot of thinking and a lot of programming. The result.... the Video Titler can now hold up to twenty color graphic files in memory on a 256K card. Super. They are instantly available using any of the many different wipes in the program. If you make a mistake, or change your mind, any frame can be reloaded without changing the others. The sequence can also be started at any frame. Anyone who has previously used the Video Titler will most certainly appreciate the new features, added versatility, speed, and power of the new AMS Video Titler. The entire operation of paging twenty titles into memory, then using them is totally seamless and transparent to the user. It is as though the TMS9900 had twenty address lines. Substantial documentation is included with the program, but I dare say that most folks won't read them. Aside from possibly looking up which keys to use for what wipes, the Titler is that easy to use. When you are ready to quit, the Titler returns nicely to the E/A menu screen. It's rather ironic.... To the best of my knowledge, Bruce Harrison is the first programmer outside of the SAMS development team to make any real productive software for the Super AMS card. Yet, he is the one programmer that never received a card to use. The AMS Video Titler beta copy worked flawlessly the very first time. This is a real tribute to outstanding programming ability. Programmer's Update Since the above was written, I have received a set of the AMS documentation and an offer of a card from David Ormand of the SW99ers. David has been sent a copy of the AMS Video Titler and a letter accepting the offer of a card to use for programming and testing my new products designed for use with AMS. * SIDEBAR PART ONE - A TEST PROGRAM * COMPLETE AS SHOWN * * TEST PROGRAM FOR AMS CARD * SPECIAL BY B. HARRISON * FOR TITLER AMS VERSION * AMST/S REF KSCAN,VMBW DEF START KEYADR EQU >8374 Key-unit address KEYVAL EQU >8375 Reported keystroke STATUS EQU >837C GPL STATUS BYTE GPLWS EQU >83E0 GPL workspace GR4 EQU GPLWS+8 GPL Reg 4 GR6 EQU GPLWS+12 GPL Reg 6 STKPNT EQU >8373 stack pointer LDGADD EQU >60 load grom address address XTAB27 EQU >200E a storage location GETSTK EQU >166C get stack START LWPI WS LOAD OUR WORKSPACE BL @AMSINI USE AMS INITIALIZE SUBROUTINE (BELOW) C R1,@>401E AMS CARD PRESENT? 0=NO 401E=0F0F=YES JNE NOAMS IF NO AMS CARD, JUMP AHEAD SBO 1 TURN ON MAPPER CLR R1 R1=0 CLR R4 R4=0 MOV R1,@>401E SET >F000 TO PAGE >00 MOV R1,@>F000 SET FIRST WORD PAGE 0 TO 0 LI R3,>8000 R3 TO PAGE >80 MOV R3,@>401A SET >D000 TO PAGE >80 LI R1,>0F00 START AT PAGE 15 AMSLP1 AI R1,>100 ADD ONE PAGE INC R4 INC NUMBER FOUND MOV R1,@>401C SET >E000 TO PAGE 16, 17, 18, ETC. MOV R1,@>E000 LOAD >E000 WITH PAGE # C R1,@>E000 DID IT LOAD? JNE AMSDO IF NOT, WE'RE BEYOND LAST PAGE C @>F000,@>E000 CHECK PAGE 0 FOR CHANGE JEQ AMSDO IF EQUAL, JUMP CI R1,>9000 LIMIT NUMBER? JL AMSLP1 IF LESS, REPEAT C @>D000,@>E000 CHECK PAGE 80 FOR CHANGE JNE AMSLP1 IF NOT EQUAL, REPEAT AMSDO DEC R4 ONE LESS (R4 EQUALLED PAGE NOT FOUND) MOV R4,@AMS SAVE NUMBER OF PAGES ABOVE 15 BL @AMSINI AMS INITIALIZE (BACK TO "NORMAL") SBZ 0 TURN OFF CARD - MAPPER STILL ON SBZ 1 TURN OFF MAPPER JMP REPORT JUMP TO REPORT SECTION NOAMS LI R0,11*32+3 ROW 12, COL 4 LI R1,NOSTR NO AMS MESSAGE BL @DISSTR DISPLAY THAT JMP KEYEX JUMP TO EXIT ROUTINE REPORT LI R0,10*32+3 ROW 11, COL 4 LI R1,PGSTR PAGES STRING BL @DISSTR DISPLAY THAT A R2,R0 ADD LENGTH TO POINTER MOV @AMS,R3 GET NUMBER OF PAGES PAST 15 MOV R3,@>835E PUT AT >835E BL @SHWINT SHOW NUMBER ON SCREEN LI R0,12*32+3 ROW 13, COL 4 LI R1,FRMSTR FRAMES STRING BL @DISSTR SHOW THAT A R2,R0 ADD LENGTH CLR R2 CLEAR R2 LI R1,3 SET R1 TO 3 DIV R1,R2 DIVIDE R2-R3 BY 3 AI R2,4 ADD 4 FOR PAGES 4 THRU 15 MOV R2,@>835E QUOTIENT PLUS 4 (FRAMES) TO >835E BL @SHWINT SHOW THAT NUMBER (1/3 OF PAGES NUM + 4= FRAMES) KEYEX BLWP @KSCAN SCAN KEYBOARD LIMI 2 ALLOW INTS LIMI 0 STOP INTS CB @ANYKEY,@STATUS KEY STRUCK? JNE KEYEX IF NOT, REPEAT LWPI GPLWS LOAD GPL WORKSPACE B @>6A BACK TO GPL INTERPRETER * * SUBROUTINES SECTION * * AMSINI SETS AMS CARD TO "POWER-UP" CONDITION * AMSINI LI R12,>1E00 AMS CRU BASE SBO 0 TURN ON AMS LI R1,>FEFF (THIS IS ->0101) LI R0,>4000 START OF MEMORY AMSLP AI R1,>0101 ADD 1 PAGE MOV R1,*R0+ MOVE 2 BYTES TO MEM-MAPPER CI R0,>4020 ALL DONE? JLT AMSLP NO, INIT MORE RT RETURN * * DISSTR DISPLAYS STRING POINTED BY R1 AT SCREEN * LOCATION POINTED TO BY R0 * DISSTR MOVB *R1+,R2 LENGTH BYTE TO R2 JEQ DISX IF ZERO, SKIPIT SRL R2,8 RT JUST BLWP @VMBW WRITE STRING TO SCREEN A R2,R1 ADD LENGTH TO POINTER DISX RT * * FOR SHWINT, FIRST PUT INTEGER AT >835E, * AND POINT R0 AT DESIRED LOCATION * THEN BL @SHWINT * SHWINT BLWP @GPLLNK USE GPLLNK VECTOR DATA >2F7C DATA FOR INT TO STRING MOVB @>8361,R2 LENGTH TO R2 SRL R2,8 RT JUST. MOVB @>8367,R1 ADDR TO R1 SRL R1,8 RT JUST AI R1,>8300 ADD OFFSET BLWP @VMBW WRITE STRING RT * GENERAL PURPOSE GPL LINK * by Doug Warren/Craig Miller * GPLLNK DATA GLNKWS DATA GLINK1 RTNAD DATA XMLRTN GXMLAD DATA >176C DATA >50 GLNKWS EQU $->18 BSS >08 GLINK1 MOV *R11,@GR4 MOV *R14+,@GR6 MOV @XTAB27,R12 MOV R9,@XTAB27 LWPI GPLWS BL *R4 MOV @GXMLAD,@>8302(R4) INCT @STKPNT B @LDGADD XMLRTN MOV @GETSTK,R4 BL *R4 LWPI GLNKWS MOV R12,@XTAB27 RTWP * * DATA SECTION * WS BSS 32 OUR REGISTERS AMS DATA 0 PAGES BEYOND 15 NOSTR BYTE 19 TEXT 'NO AMS CARD PRESENT' PGSTR BYTE 14 TEXT 'PAGES FOUND = ' FRMSTR BYTE 9 TEXT 'FRAMES = ' ANYKEY BYTE >20 END * * END OF COMPLETE PROGRAM * * PART TWO OF SIDEBAR - A "SNIPPET" * * SUBROUTINE SETFRM (FROM AMS VIDEO TITLER) * ON ENTRY, R3 CONTAINS THE CURRENT FRAME NUMBER (1 THRU XX) * WHERE XX CAN BE 9 (128K CARD), 20 (256K CARD), OR 41 (512K CARD) * PAGE NUMBERS START WITH 0, SO FOR EXAMPLE ON A 256K CARD, PAGES * ARE NUMBERS 0 THRU 63, FOR A TOTAL OF 64 PAGES * * THE PROGRAM "KNOWS" HOW MANY FRAMES ARE AVAILABLE, AND * WON'T USE THIS SUBROUTINE BEYOND THE AVAILABLE FRAMES. * SETFRM MOV R3,R1 COPY CURRENT FRAME # TO R1 MPY @THREE,R3 MULTIPLY R3 BY 3 INC R4 ADD 1 TO PRODUCT IN R4 (PAGE NUMBER ON AMS = 4 THRU YY) * YY IS THE HIGHEST PAGE -2 SWPB R4 SWAP TO LEFT BYTE COC @ONEWD,R1 CHECK CURRENT FRAME FOR ODD/EVEN JNE SETEVN IF NOT 1 IN LSB, EVEN SETODD LI R8,>4014 MAP FOR >A000 LI R1,>A000 SET R1=>A000 JMP SETPGS JUMP SETEVN LI R8,>401A MAP FOR >D000 LI R1,>D000 SET R1=>D000 SETPGS LI R12,>1E00 AMS CRU ADDR SBO 0 TURN ON CARD SBO 1 TURN ON MAPPER LI R5,3 THREE WRITES TO MAKE (3 PAGES PER FRAME) SETLP MOV R4,*R8+ SET CURRENT PAGE AND INCT R8 AI R4,>100 NEXT PAGE DEC R5 DEC COUNT JNE SETLP RPT IF NOT 0 SBZ 0 TURN OFF CARD MEMORY (>4000) * THE MAPPER STAYS ON RT RETURN * UPON RETURN, R1 IS USED TO DETERMINE WHERE THE FRAME IS SENT OR GOTTEN FROM * DEPENDING WHETHER WE'RE WRITING OR READING A FRAME * * END OF PART 2 OF SIDEBAR 3 Quote Link to comment Share on other sites More sharing options...
+Lee Stewart Posted August 29, 2014 Share Posted August 29, 2014 (edited) @Willsy's TurboForth can use it. TF auto-detects SAMS and initializes it if it is found. TF has a >MAP word for managing SAMS memory. It requires on the stack a bank number and an address on a 4K boundary in 32K RAM space to map it to. ...lee PS: I may lift @Willsy's code into fbForth. He gave me permission—I just don't have the hardware, so I didn't really think much about it. I know I can test it under emulation...so...maybe. Edited August 29, 2014 by Lee Stewart 1 Quote Link to comment Share on other sites More sharing options...
+InsaneMultitasker Posted August 29, 2014 Share Posted August 29, 2014 The memory, as I understand, is accessed through 8k pages. The SAMS is cool, but kind of a PITA. That's why I dig the Geneve so much - no faffing with paged memory. Both used paged memory. The Geneve pages memory using an 8-byte mapper, where each byte represents 8K of a 64K window. SAMS differs in the window size (4k) and the mapping (CRU based). I'm not sure where the big PITA comes from, it's pretty simple really. 1 Quote Link to comment Share on other sites More sharing options...
RobertLM78 Posted August 29, 2014 Share Posted August 29, 2014 (edited) I'm honestly not sure how memory works under the hood on the Geneve. What I do know is I was able to do what I wanted with Myarc BASIC without moving stuff around in memory like I would have had to do with SAMS and RXB. Edited August 29, 2014 by RobertLM78 Quote Link to comment Share on other sites More sharing options...
+InsaneMultitasker Posted August 29, 2014 Share Posted August 29, 2014 I'm honestly not sure how memory works under the hood on the Geneve. What I do know is I was able to do what I wanted with Myarc BASIC without moving stuff around in memory like I would have had to do with SAMS and RXB. Ah, yes, gotcha. Myarc BASIC for the Geneve takes away the memory management pain in that regard 1 Quote Link to comment Share on other sites More sharing options...
RXB Posted August 29, 2014 Share Posted August 29, 2014 (edited) Thanks, Rich. To be honest, rather than knowing how the RXB user makes use of the SAMS, I'm much more interested in how RXB itself makes use of it. Is there a memory manager present that keeps track of pages under the hood? What kind of memory structure do you use to store this data? When RXB sees the command: CALL AMSINIT or 100 CALL AMSINIT ! Can be used in a program or command mode. CALL AMSINIT tells RXB to find the SAMS card and sets the memory from top of what ever SAMS size top to bottom with the values of (top page) 255 to (bottom page) 0 for each 4K page of SAMS memory. RXB turns off interrupts first then sets the memory pages then puts the SAMS card into MAP MODE and returns to XB. This is a cut and paste from the RXB 2012 documents: In MAP mode the mapper register setup is equivalent to: EXAMPLE1 mapper address mapper page num address range -------------- ------ -------- ------------- HEX Dec HEX Dec memory area --- --- --- --- ----------- >4004 = 16388 is MR02 = >10 = 16 points to >2000 - >2FFF range >4006 = 16390 is MR03 = >11 = 17 points to >3000 - >3FFF range >4014 = 16404 is MR10 = >12 = 18 points to >A000 - >AFFF range >4016 = 16406 is MR11 = >13 = 19 points to >B000 - >BFFF range >4018 = 16408 is MR12 = >14 = 20 points to >C000 - >CFFF range >401A = 16410 is MR13 = >15 = 21 points to >D000 - >DFFF range >401C = 16412 is MR14 = >16 = 22 points to >E000 - >EFFF range >401E = 16414 is MR15 = >17 = 23 points to >F000 - >FFFF range (MR=Mapper Register) In RXB presently SAMS 4K pages 0,1,2,3,4,5,6,7 are reserved (32K) for future use in RXB (I have some ideas not fully written yet) watch for future expansions of RXB. But 240 pages of 4K are for use in RXB SAMS to the user. So 960K is available to any user depending on size of the SAMS card you use. Now RXB includes the same commands originally created by Joe Delekto and Paul Schippnick. (Depending on what year you talk about.) These commands are CALL AMSON ! Turns on the SAMS mapper registers write access. CALL AMSOFF ! Turns off the SAMS mapper registers write access. CALL AMSPASS ! Turns on the SAMS pass mode so it acts like a normal TI 32K. CALL AMSMAP ! Turns on the SAMS map mode so pages can be changed, but CALL AMSON must be turned on first. Lastly the real meat of RXB SAMS support is CALL AMSBANK(low page,high page) Here is a page from RXB docs on AMSBANK: The AMSBANK command will only work with a AMS memory card. AMSBANK turns on the read/write lines of AMS mapper registers stores the first value into the mapper register that sets low half of lower 8K, then stores the second value into the mapper register that sets high half of lower 8K. If the page-number is less then 0 or larger than 239 a BAD VALUE error results. If page-number is larger than the AMS card size allows * AMS BANK NUMBER ERROR * results. Neither error will affect previously loaded pages. No lock-up will result. AMSBANK breaks the lower 8K into two halves of 4K. The lower 4K is Hex >2000 to >2FFF and the upper is Hex >3000 to >3FFF so switching lower 8K requires two 4K pages to be used. This is the only disadvantage to AMSBANK, but flexibility does result. Less wasted pages results in more memory available. The formula is: AMS SIZE/4-16=pages. EXAMPLE: 256/4-16 is 48 pages. In other words 0 to 15 pages would be 16 pages for use. The odd ball numbering scheme of AMSBANK results from pages 0 to 15 not being used in MAP mode. AMSBANK creates it's own numbers of pages 0 to 239 by starting actually at page 16 of the AMS. That would be page 0 of AMSBANK. This lay out leaves open 8 4K pages for PASS mode, and 8 4K pages for future use. The reason I did not require single 8K pages is you can put the same SAMS bank in both the lower and upper page at same time and when you write to either it writes to both at same time. EXAMPLE: 100 CALL AMSINIT ! INITIALIZE LOWER 8K SAMS MEMORY 110 CALL AMSBANK(5,5) ! AMS PAGES IS IN LOWER 8K IN BOTTOM >2000 AND UPPER >3000 AT SAME TIME 120 CALL LOAD(8192,128,255) ! PUT HEX >80 AND >FF AT >2000 IN LOWER 8K 130 CALL PEEK(12288,X,Y) ! GET VALUES AT HEX >3000 AND PUT INTO X AND Y VARIABLES 140 CALL PEEK(8192,A,B) ! GET VALUES AT HEX >2000 AND PUT INTO A AND B VARIABLES 150 PRINT A;B,X;Y run this program and you get: 128 255 128 255 This much faster then variables or VDP access as it writes two places at same time. All kinds of ideas for this come to mind for search or compare in XB. Maybe I need to make some more videos. P.S. RXB uses the SAMS for ASSEMBLY or extra memory that the user decides what to use it for unlike Myarc XB you are basically stuck with one way to use it. That makes it easy but limited. Edited August 29, 2014 by RXB 1 Quote Link to comment Share on other sites More sharing options...
jacquesg Posted August 30, 2014 Share Posted August 30, 2014 You can find the 3 disks that accompanied the SAMS card when released by the SW99er group on the Yahoo site named SWPB under the Files section. These disks contain a number of archived files containing Art Green's SAM's program including, a SAMS macro assembler, linker and library manager, with explanatory manuals. Joe Delekto's c99 for use with the SAMS card is also included. This was used to create the TI-NOPOLY program. Art also included a menu program to run SAMS and non-SAMS programs. There are other SAMS related items on this Yahoo site. If you have trouble accessing this site write to me privately. Regards, Jacques Quote Link to comment Share on other sites More sharing options...
Willsy Posted August 30, 2014 Share Posted August 30, 2014 http://turboforth.net/source/Bank1/1-04-Memory.html t's easy to select banks in the SAMS card. See the above page for some source. Look for >MAP (as in "to memory mapper"). Quote Link to comment Share on other sites More sharing options...
gregallenwarner Posted August 30, 2014 Author Share Posted August 30, 2014 Rich, Forgive me if my question doesn't make a lot of sense, but how does RXB keep the program memory safe when remapping banks with CALL AMSBANK? In other words, if I've got an RXB program loaded into memory, if I want to map new page into a memory bank, how does it avoid the situation where the current page of memory where the current line of code is being executed gets paged out for a different one, making the next line of code for execution unavailable? Or is this an impossible scenario? For example, if I've got program code loaded at >2000, and the instruction at >2000 instructs the SAMS to swap out bank >2 with a new page, all of a sudden, the memory at >2000 changes, so when the program counter increments to the next instruction at >2002, the memory appearing at that location is now different from a new bank being paged in, and my program is corrupted. Does RXB have a way to detect this or prevent it? I'm just trying to develop good strategies for using the SAMS so I avoid any pitfalls like this as I'm experimenting with it. Quote Link to comment Share on other sites More sharing options...
RXB Posted August 31, 2014 Share Posted August 31, 2014 (edited) Rich, Forgive me if my question doesn't make a lot of sense, but how does RXB keep the program memory safe when remapping banks with CALL AMSBANK? In other words, if I've got an RXB program loaded into memory, if I want to map new page into a memory bank, how does it avoid the situation where the current page of memory where the current line of code is being executed gets paged out for a different one, making the next line of code for execution unavailable? Or is this an impossible scenario? For example, if I've got program code loaded at >2000, and the instruction at >2000 instructs the SAMS to swap out bank >2 with a new page, all of a sudden, the memory at >2000 changes, so when the program counter increments to the next instruction at >2002, the memory appearing at that location is now different from a new bank being paged in, and my program is corrupted. Does RXB have a way to detect this or prevent it? I'm just trying to develop good strategies for using the SAMS so I avoid any pitfalls like this as I'm experimenting with it. Impossible as the SAMS support for RXB only swtiches the lower 8K used for Assembly, but can also be used for many more functions if you watch the demos of loading graphics or games or Assembly. First off why would you load code to swap SAMS banks when RXB has that feature built in and management is handled for you by CALL AMSBANK(low page,high page) ????? Now say you load an Assembly program and want to load another and use both at once from RXB. 100 CALL AMSINIT ! Must proceed any use of AMSBANK or the pages will be out of order and unknown result will happen. ....... program.... 500 CALL AMSBANK(0,1) ! Page 0 and 1 are used for lower 8K in two 4K pages of page 0 is >2000 to >2FFF and page 1 is >3000 to >3FFF 510 ! Your Assembly program is loaded here.... 520 CALL AMSBANK(2,3) ! Page 2 and 3 are used for lower 8K in two 4K pages of page 2 is >2000 to >2FFF and page 3 is >3000 to >3FFF 530 ! Your other Assembly program is loaded here.... .... program.... 800 CALL AMSBANK(low page,high page) ! Put either 0,1 or 2,3 depending on which Assembly program you want to use. So do you see you have 240 pages in RXB to use for 4K pages in lower and higher page? Now only pitfall is you must write your program so you do not over write your own code, but that is no different then using the same variable and not saving it. In other words like doing this: 100 A(X,Y)=10 ... program ... 340 A(X,Y)=50 But you did not change X,Y so you just over wrote the value in A(X,Y) with 50 instead of the 10 it was before. You see not changing X,Y resulted in a bad value. Thus the same goes for CALL AMSBANK(0,1) or CALL AMSBANK(2,3) as you just need to keep the correct pages in lower 8K per what you are doing. By the way CALL AMSBANK(X,Y) is equally valid as hard coded numbers like CALL AMSBANK(44,66) Additionally RXB has a way to load faster then any other way for the SAMS memory. Example loader: RXB SAMS LOADER EXAMPLE 100 ! RXB AMS LOADER DEMO 110 ! NO ASSEMBLY USED 120 CALL AMSINIT 130 FOR A=1 TO 20 140 CALL AMSBANK(A,A+20) 150 CALL BLOAD("DSK1.SCRN"&STR$(A)) ! This line could just as easily load Assembly programs saved with CALL BSAVE that creates these files. 160 CALL MOVES("RV",2079,8192,0) 170 NEXT A 180 FOR A=1 TO 20 190 CALL AMSBANK(A,A+20) 200 CALL MOVES("RV",2079,8192,0) 210 NEXT A 220 GOTO 180 Watch the video demos as it shows this working. And works with Assembly or in the above example loads LOWER 8K with a copy of video memory. Edited August 31, 2014 by RXB Quote Link to comment Share on other sites More sharing options...
RXB Posted September 1, 2014 Share Posted September 1, 2014 (edited) I forgot to mention that RXB command CALL AMSINIT will not delete anything out of the SAMS or will it change any data in the SAMS or will it affect any programs in memory. CALL AMSINIT just loads the SAMS memory mapper with the values of each page from lowest to highest. So what every page you were on is still the same you loaded. Edited September 1, 2014 by RXB Quote Link to comment Share on other sites More sharing options...
+Vorticon Posted September 1, 2014 Share Posted September 1, 2014 I know there is/was documentation out there, perhaps part of the RAG assembler package and the AMS package. The process is not overly difficult to map pages in and out. I believe the following information comes from an article in Micropendium written by Bruce Harrison. Do you happen to know which issue this was published in by any chance? Quote Link to comment Share on other sites More sharing options...
+Lee Stewart Posted September 1, 2014 Share Posted September 1, 2014 Do you happen to know which issue this was published in by any chance? Walid, here's an excerpt from the list of articles for Micropendium: Article Date Page ----------------------------------- -------- ---- AMS CARD TAKING ADVANTAGE OF MEMORY 9/1/1996 22 AMS COPY REV 9/1/1995 24 AMS CUSTOMIZING YOUR AMS CARD 7/1/1995 14 AMS REV 7/1/1995 20 AMS SCHEMATICS BECOME PUBLIC DOM 3/1/1994 23 AMS SLIDESHOW REV 1/1/1997 34 AMS UPDATE TO THE AMS AND SCSI 7/1/1995 20 AMS VIDEO TITLER REV 11/1/1996 35 ...lee Quote Link to comment Share on other sites More sharing options...
+Vorticon Posted September 1, 2014 Share Posted September 1, 2014 Thanks Lee! I have had a SAMS card for quite some time but I still have to do anything with it. All I use it for is as a glorified 32K RAM expansion which is ignominious when you think of it, and I'm hoping to re-familiarize myself with its use in the hope that the gods of inspiration will perhaps bestow on me a good project idea fit for its technical greatness 2 Quote Link to comment Share on other sites More sharing options...
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