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02-07-88/T\SWR01
This website contains an archive of files for the Acorn Electron, BBC Micro, Acorn Archimedes, Commodore 16 and Commodore 64 computers, which Dominic Ford has rescued from his private collection of floppy disks and cassettes.
Some of these files were originally commercial releases in the 1980s and 1990s, but they are now widely available online. I assume that copyright over them is no longer being asserted. If you own the copyright and would like files to be removed, please contact me.
| Tape/disk: | Home » CEEFAX disks » telesoftware8.adl |
| Filename: | 02-07-88/T\SWR01 |
| Read OK: | ✔ |
| File size: | 4789 bytes |
| Load address: | 0000 |
| Exec address: | FFFFFFFF |
Duplicates
There is 1 duplicate copy of this file in the archive:
- CEEFAX disks » telesoftware3.adl » 23_10_87/T\SWR01
- CEEFAX disks » telesoftware8.adl » 02-07-88/T\SWR01
File contents
Mastering Sideways ROM & RAM - Module 01 - Introduction
-------------------------------------------------------
It is possible to write sideways ram software on a BBC B or B+ 64k
without sideways ram but, if you use one of these machines, it will
save you a great deal of time blowing and erasing eproms if SWR is
available to test the software as it is being developed.
Adding SWR to the BBC B+ 64k is very straightforward as Acorn
produce a 64k SWR upgrade which can be fitted by Acorn dealers. Don't
attempt to fit it yourself unless you are absolutely sure you have the
skill needed to complete the job.
Fitting an SWR upgrade to the BBC B is a job most users can attempt
without incuring a dealer's service charge. There are many sideways
ram and rom boards available which can be fitted without soldering any
components. You should look carefully at the facilities offered by the
various manufacturers of SWR boards and choose the board that best
suits your needs. I recommend that you consider the following points
when you look for a SWR board.
1. A mimimum of 16k of sideways ram is required. 32k or 64k is useful
but not essential. Most boards which use static rams do so because the
design is much simpler. There is an old designer's joke that the
difference between static and dynamic ram is that static ram works.
Don't let this nonsense prevent you buying a dynamic ram board.
2. Physical switching for read and write protection of the SWR is
highly desirable. Read protection will be used to switch out the
offending memory when you load an invalid rom image which causes the
computer to hang up. Write protection is useful if you want to develop
rom images that are protected against running in SWR. Software
switching of read and write protection is a poor substitute for real
switches that click.
3. Look carefully at the way in which flying leads are attached to
the main computer circuit board. Compare the different methods
manufacturers use. Some boards use quite unprofessional design
techniques.
4. Battery backup of SWR is useful, but not essential.
5. Many SWR boards have sockets for extra roms. The BBC B MOS will
support up to sixteen sideways rom or ram banks. The main circuit
board has only four sideways rom sockets, two of which are taken up
with BASIC and the DFS. The extra sockets on a sideways ram/rom board
will be useful if you have more roms than rom sockets.
There are a number of manufacturers who produce boards which meet
these requirements to a greater or lesser extent. Which manufacturer
you choose is up to you. You can be sure that all the boards produced
by reputable companies will perform adequately but it is not possible
to recommend one board as better in every respect than any other.
When you have fitted the upgrade board into your computer you might
want to store the programs contained in your roms on disc or tape and
then load and run the rom images in SWR. All Acorn supported languages
will run in unprotected SWR and most rom images will run in write
protected SWR.
Where the copyright of the software contained in a rom is not owned
by Acorn, specific permission must be obtained from the owner of the
copyright before copying it onto disc or tape.
In Acorn's User Guide (Part no. 408000, Issue no. 2, March 1984,
page 20) it states "... you can keep a library of paged roms on disc,
which can be called up in the same way as roms installed inside the
BBC Microcomputer. However, in using this facility you must ensure
that you do not infringe the rights of the owner of the copyright of
the program contained in the rom".
As long as you do not infringe the rights of the owner of the
copyright of the program, roms can be saved onto a library disc and
run in ram. Some software producers take a less enlightened view than
Acorn take to running their roms in SWR and attempt to protect them
against it. Most of this protection does little to deter professional
software pirates but it should be taken as an indicator of the
copyright owner's unwillingness to allow his or her work to be used in
SWR.
If you want to ensure that your own work will only run in eproms and
not in SWR there are a number of techniques you can try. An 8k rom
image is duplicated from &A000 and one of the methods of protecting 8k
rom images is to add &2000 to the subroutine and jump addresses.
Another, far less common, method is to prevent the rom image running
in socket &0F. This socket is commonly used for SWR on rom boards and
the only way to get these rom images to run in socket &0F is to
disassemble and modify them. When you have completed this course you
will certainly know what to look for in a rom disassembly if you
wanted to do this but it is quite a good way of detering most amateur
rom pilferers.
I will now begin to explore the programming techniques needed to use
SWR. There are a number of MOS subroutines, memory locations and
registers associated with SWR. Rather than examine them all now I will
consider the calls and locations as they arise throughout the course.
In this module I will look at the paged rom select register at &FE30,
the paged memory select register at &FE34, the MOS subroutine Osrdrm,
and Osbytes &72 and &AA.
There are differences in the way in which the paged rom select
register and the paged memory select register are used in the BBC B,
the BBC B+ and the Master computers. The reason for the differences
can be seen by examining the memory maps of these machines (figures
1.1, 1.2 and 1.3).
&FFFF +-------+ &FFFF
! !
! MOS !
! !
&BFFF --+-------+-------+-------+-------+ &C000
! ROM &C! ROM &D! ROM &E! ROM &F!
! ! ! ! !
! ! ! DFS ! BASIC !
&8000 --+-------+-------+-------+-------+ &7FFF
Up to 16 sideways rom/ram banks ! !
! User !
! memory!
! !
! !
&1900 +-------+ Oshwm
! !
&0000 +-------+ &0000
Figure 1.1 Memory map of the BBC B
----------------------------------
The BBC B MOS supports up to sixteen paged roms although an
expansion board is required if more than four roms are to be used. The
paged rom select register at &FE30 is a 4 bit write only register
which determines which of the 16 roms is switched into the main memory
map. If you want to read the contents of this register you should read
the zero page copy of it at &F4. The most significant nybble of the
paged rom select register is not used on the BBC B.
&FFFF +-------+ &FFFF
! !
! MOS !
! !
&BFFF --+-------+-------+-------+-------+ &C000
! ROM &C! ROM &D! ROM &E! ROM &F+-------+ &AFFF
! ! ! ! ! Paged !
! ! ! DFS ! BASIC ! memory!
&8000 --+-------+-------+-------+-------+-------+ &8000
Up to 16 sideways rom/ram banks ! ! !
! User ! Shadow!
! memory! ram !
! ! !
! +-------+ &3000
&1900 +-------+ Oshwm
! !
&0000 +-------+ &0000
Figure 1.2 Memory map of the BBC B+
-----------------------------------
The BBC B+ has a similar memory map to the BBC B but in addition to
the paged roms it also supports paged or shadow memory. The paged
memory (shadow ram) select register at &FE34 is used to determine
whether or not the shadow ram is used as screen memory. This register
should only be altered using Osbyte &72 (*FX114) or the command
*SHADOW. The BBC B+ has a "spare" 12k of paged memory from &8000 to
&AFFF. This can be switched in or out of the main memory map using the
most significant bit of the paged rom select register at &FE30.
Setting the most significant bit of the paged rom select register has
no effect on the BBC B but on the BBC B+ it switches the paged memory
from &8000 to &AFFF into the main memory map. BBC Telesoftware has
broadcast a program that uses this technique to allow BBC B+ 64k
computer users to load and run 8k service roms in this area of paged
memory.
The Master computer uses a slightly different memory map to the B
series. The "spare" 12k of paged memory has now been split into two
areas, one from &8000 to &8FFF and the other from &C000 to &DFFF. The
paged ram from &8000 to &8FFF is used by the MOS as a soft key buffer,
character font, and VDU workspace. The paged ram from &C000 to &DCFF
is available as paged rom workspace and the paged ram from &DD00 to
&DFFF is used as MOS workspace.
&FFFF +-------+ &FFFF
! !
! MOS +-------+ &DFFF
! !Wkspace!
&BFFF --+-------+-------+-------+-------+-------+ &C000
! ROM &C! ROM &D! ROM &E! ROM &F!
! ! ! ! !
! BASIC ! ADFS ! View ! Term. +-------+ &8FFF
&8000 --+-------+-------+-------+-------+-------+ &8000
Up to 16 Sideways rom/ram banks ! ! !
! User ! Shadow!
! memory! ram !
! ! !
! +-------+ &3000
! !
&0E00 +-------+ Oshwm
&0000 +-------+ &0000
Figure 1.3 Memory map of the BBC Master
---------------------------------------
Paged rom workspace on the BBC B and B+ is just below the user
memory. The BBC B DFS claims 2.75k of workspace from &0E00 to &1900.
This workspace can be in paged memory on the Master series allowing
Oshwm to stay at &0E00 with all filing systems. Bit 3 of the paged
memory select register at &FE34 is used to overlay the paged rom
workspace onto the Master MOS so that it appears above the paged rom
using it. Bit 3 of the paged memory select register can be toggled
directly but you must not directly alter any other bit in this
register. This topic will be covered in more detail in modules 11 and
12 which deal with paged rom workspace.
The use of the least significant nybble of the paged rom select
register at is common to all BBC micros. The operating system uses
this register, and the zero page copy of it at &F4, to keep track of
which paged rom is being used at any time. If you want to alter this
register directly you can only do so from machine code. If you alter
it from BASIC or any other language rom you will cause the computer to
hang up.
The order in which the paged rom select register and its copy at &F4
are altered is important. You must store the same number in both
locations and alter &F4 first. Immediatly after altering &F4 you must
store the same value in &FE30. For example:
LDA #&0A
STA &F4
STA &FE30
This code will switch bank &0A into the main memory map. If you
reverse the order of the last two instructions you will find that 99%
of the time everything works properly but, sooner or later, an
interupt occuring between the two store instructions will cause to
computer to hang up. Switching a paged rom into the main memory map in
this way can be quite useful if you want to transfer the contents of a
rom into user memory or transfer the contents of user memory into a
particular sideways ram.
There is an official way to read a byte of memory from any paged
rom. This uses the operating system call Osrdrm at &FFB9 with the
relevant paged rom number in the Y register and the address of the
byte in the paged rom in locations &F6 and &F7 (the paged rom
pointers). The value of the byte read by Osrdrm is returned in the
accumulator. The X, Y and status registers will be undefined after the
call.
Both these techniques are demonstrated in the program READROM. When
the program is running it uses Osrdrm to read the title string in
every rom socket that has an active rom image and then prompts the
user to choose which rom number, from 0-15, to switch into the main
memory map. The chosen rom is switched in and copied from &8000 to
&3C00 and then switched back out again. The rom image can then be
examined and, if required, saved to the currently active filing
system. Although some of the program is in BASIC the switching and
copying can only be done in machine code.
The program uses Osbyte &AA to find the start of the rom information
table. This call returns the origin of a 16 byte table containing one
byte per paged rom. Each byte contains the rom type byte contained in
location &8006 of the rom or contains zero if an active rom is not
present. Rom type bytes are an important part of the rom header and
will be dealt with in more detail when rom headers are considered in
module 2.
Chain the program READROM and satisfy yourself that it works
properly. It must run in the I/O processor and will not work in a
second processor.
There are two machine code routines used in the program. The first
(lines 200-430) is called once for each possible rom number from 0 to
15. It looks up the address of the start of the rom information table
with Osbyte &AA (lines 210-240) and then uses the number of the rom as
an offset in the Y register to see if there is a valid rom in the
socket being considered (line 280). If there is a valid rom image
present the routine reads the title of the rom using Osrdrm and
displays it on the screen (lines 340-430). The rom title always starts
at &8009 in a valid rom image and always ends with a binary zero.
The second machine code routine is in lines 440-700. This stores the
current rom number (lines 450-460) before switching the chosen rom
into the main memory map (lines 470-490). It then copies the chosen
rom image into user memory (lines 500-660), and finally switches the
original rom back into the main memory map (lines 670-690).
The BASIC part of the program is mainly concerned with displaying
the copy of the rom image on the screen (lines 860-990) and, if
required, with saving a copy of the rom image onto disc or tape
(PROCsave, lines 1000-1190). Before it makes a copy of the rom image
onto disc the program compares the first &100 bytes of the image with
&100 bytes 8k higher in memory (lines 1090-1110). If every pair of
&100 bytes is identical the rom is recognised as an 8k image and only
the first &2000 bytes are saved.
The program READROM, as well as illustrating the techniques
described above, will be useful in later modules when you will want to
examine or save the contents of sideways ram banks. The program can be
modified to produce another program to load rom images into any
sideways ram bank, including the paged memory bank of the BBC B+. This
has been left as an exercise for you to complete.
10 REM: READROM
20 MODE7
30 HIMEM=&3C00
40 DIM mcode &100
50 select=&FE30
60 osrdrm=&FFB9
70 osasci=&FFE3
80 osbyte=&FFF4
90 oscli=&FFF7
100 copy=&70
110 temp=&71
120 read=&72
130 write=&74
140 romnumber=&F4
150 rompoint=&F6
160 ON ERROR PRINT : END
170 FOR pass=0 TO 2 STEP 2
180 P%=mcode
190 [ OPT pass
200 .number
210 LDA #&AA
220 LDX #0
230 LDY #&FF
240 JSR osbyte \ Find rom table
250 STX read
260 STY read+1
270 LDY copy
280 LDA (read),Y
290 BEQ finish
300 LDA #8
310 STA rompoint
320 LDA #&80
330 STA rompoint+1
340 .readname
350 INC rompoint
360 LDY copy
370 JSR osrdrm
380 CMP #ASC(" ")
390 BCC finish
400 JSR osasci
410 JMP readname
420 .finish
430 RTS
440 .move
450 LDA romnumber
460 STA temp
470 LDA copy
480 STA romnumber
490 STA select
500 LDA #&80
510 STA read+1
520 LDA #&3C
530 STA write+1
540 LDY #0
550 STY read
560 STY write
570 .relocate
580 LDA (read),Y
590 STA (write),Y
600 INY
610 BNE relocate
620 INC read+1
630 INC write+1
640 LDA read+1
650 CMP #&C0
660 BNE relocate
670 LDA temp
680 STA romnumber
690 STA select
700 RTS
710 ]
720 NEXT
730 FOR socket=0 TO 15
740 ?copy=socket
750 IF socket<10 PRINT;" ";
760 PRINT;socket;" ";
770 CALL number
780 PRINT
790 NEXT
800 VDU14
810 REPEAT
820 INPUT'"Which ROM &(0-15) "socket
830 UNTIL socket >= 0 AND socket < 16
840 ?copy=socket
850 CALL move
860 PRINT'"<SHIFT> to scroll, <ESCAPE> to exit"
870 ON ERROR PROCsave
880 FOR block=&3C00 TO &7BFF STEP 8
890 PRINT';~block+&4400;" ";
900 FOR memory=0 TO 7
910 byte=block?memory
920 IF byte<16 VDU48
930 PRINT;~byte;" ";
940 NEXT
950 FOR memory=0 TO 7
960 byte=memory?block
970 IF byte>31 AND byte<127 VDUbyte ELSE VDU46
980 NEXT
990 NEXT
1000 PROCsave
1010 END
1020 DEFPROCsave
1030 ON ERROR PRINT : END
1040 VDU15
1050 INPUT''"Save ROM? (Y/N) "yes$
1060 REPEAT
1070 IF yes$="Y" INPUT"Filename? : "filename$ ELSE INPUT"An
other? (Y/N) "yes$ : IF yes$<>"Y" END ELSE RUN
1080 size=FALSE
1090 FOR block=&3C00 TO &3D00
1100 IF ?block <> ?(block+&2000) size= TRUE
1110 NEXT
1120 IF size=TRUE size=&4000 ELSE size=&2000
1130 $mcode="SAVE "+filename$+" 3C00+"+STR$~(size)+" FFFF80
00 FFFF8000"
1140 X%=mcode MOD 256
1150 Y%=mcode DIV 256
1160 CALL oscli
1170 yes$=""
1180 UNTIL FALSE
1190 ENDPROC
00000000 4d 61 73 74 65 72 69 6e 67 20 53 69 64 65 77 61 |Mastering Sidewa|
00000010 79 73 20 52 4f 4d 20 26 20 52 41 4d 20 2d 20 4d |ys ROM & RAM - M|
00000020 6f 64 75 6c 65 20 30 31 20 2d 20 49 6e 74 72 6f |odule 01 - Intro|
00000030 64 75 63 74 69 6f 6e 0d 2d 2d 2d 2d 2d 2d 2d 2d |duction.--------|
00000040 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d |----------------|
*
00000060 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 0d |---------------.|
00000070 0d 20 20 49 74 20 69 73 20 70 6f 73 73 69 62 6c |. It is possibl|
00000080 65 20 74 6f 20 77 72 69 74 65 20 73 69 64 65 77 |e to write sidew|
00000090 61 79 73 20 72 61 6d 20 73 6f 66 74 77 61 72 65 |ays ram software|
000000a0 20 6f 6e 20 61 20 42 42 43 20 42 20 6f 72 20 42 | on a BBC B or B|
000000b0 2b 20 36 34 6b 0d 77 69 74 68 6f 75 74 20 73 69 |+ 64k.without si|
000000c0 64 65 77 61 79 73 20 72 61 6d 20 62 75 74 2c 20 |deways ram but, |
000000d0 69 66 20 79 6f 75 20 75 73 65 20 6f 6e 65 20 6f |if you use one o|
000000e0 66 20 74 68 65 73 65 20 6d 61 63 68 69 6e 65 73 |f these machines|
000000f0 2c 20 69 74 20 77 69 6c 6c 0d 73 61 76 65 20 79 |, it will.save y|
00000100 6f 75 20 61 20 67 72 65 61 74 20 64 65 61 6c 20 |ou a great deal |
00000110 6f 66 20 74 69 6d 65 20 62 6c 6f 77 69 6e 67 20 |of time blowing |
00000120 61 6e 64 20 65 72 61 73 69 6e 67 20 65 70 72 6f |and erasing epro|
00000130 6d 73 20 69 66 20 53 57 52 20 69 73 0d 61 76 61 |ms if SWR is.ava|
00000140 69 6c 61 62 6c 65 20 74 6f 20 74 65 73 74 20 74 |ilable to test t|
00000150 68 65 20 73 6f 66 74 77 61 72 65 20 61 73 20 69 |he software as i|
00000160 74 20 69 73 20 62 65 69 6e 67 20 64 65 76 65 6c |t is being devel|
00000170 6f 70 65 64 2e 0d 0d 20 20 41 64 64 69 6e 67 20 |oped... Adding |
00000180 53 57 52 20 74 6f 20 74 68 65 20 42 42 43 20 42 |SWR to the BBC B|
00000190 2b 20 36 34 6b 20 69 73 20 76 65 72 79 20 73 74 |+ 64k is very st|
000001a0 72 61 69 67 68 74 66 6f 72 77 61 72 64 20 61 73 |raightforward as|
000001b0 20 41 63 6f 72 6e 0d 70 72 6f 64 75 63 65 20 61 | Acorn.produce a|
000001c0 20 36 34 6b 20 53 57 52 20 75 70 67 72 61 64 65 | 64k SWR upgrade|
000001d0 20 77 68 69 63 68 20 63 61 6e 20 62 65 20 66 69 | which can be fi|
000001e0 74 74 65 64 20 62 79 20 41 63 6f 72 6e 20 64 65 |tted by Acorn de|
000001f0 61 6c 65 72 73 2e 20 44 6f 6e 27 74 0d 61 74 74 |alers. Don't.att|
00000200 65 6d 70 74 20 74 6f 20 66 69 74 20 69 74 20 79 |empt to fit it y|
00000210 6f 75 72 73 65 6c 66 20 75 6e 6c 65 73 73 20 79 |ourself unless y|
00000220 6f 75 20 61 72 65 20 61 62 73 6f 6c 75 74 65 6c |ou are absolutel|
00000230 79 20 73 75 72 65 20 79 6f 75 20 68 61 76 65 20 |y sure you have |
00000240 74 68 65 0d 73 6b 69 6c 6c 20 6e 65 65 64 65 64 |the.skill needed|
00000250 20 74 6f 20 63 6f 6d 70 6c 65 74 65 20 74 68 65 | to complete the|
00000260 20 6a 6f 62 2e 0d 0d 20 20 46 69 74 74 69 6e 67 | job... Fitting|
00000270 20 61 6e 20 53 57 52 20 75 70 67 72 61 64 65 20 | an SWR upgrade |
00000280 74 6f 20 74 68 65 20 42 42 43 20 42 20 69 73 20 |to the BBC B is |
00000290 61 20 6a 6f 62 20 6d 6f 73 74 20 75 73 65 72 73 |a job most users|
000002a0 20 63 61 6e 20 61 74 74 65 6d 70 74 0d 77 69 74 | can attempt.wit|
000002b0 68 6f 75 74 20 69 6e 63 75 72 69 6e 67 20 61 20 |hout incuring a |
000002c0 64 65 61 6c 65 72 27 73 20 73 65 72 76 69 63 65 |dealer's service|
000002d0 20 63 68 61 72 67 65 2e 20 54 68 65 72 65 20 61 | charge. There a|
000002e0 72 65 20 6d 61 6e 79 20 73 69 64 65 77 61 79 73 |re many sideways|
000002f0 0d 72 61 6d 20 61 6e 64 20 72 6f 6d 20 62 6f 61 |.ram and rom boa|
00000300 72 64 73 20 61 76 61 69 6c 61 62 6c 65 20 77 68 |rds available wh|
00000310 69 63 68 20 63 61 6e 20 62 65 20 66 69 74 74 65 |ich can be fitte|
00000320 64 20 77 69 74 68 6f 75 74 20 73 6f 6c 64 65 72 |d without solder|
00000330 69 6e 67 20 61 6e 79 0d 63 6f 6d 70 6f 6e 65 6e |ing any.componen|
00000340 74 73 2e 20 59 6f 75 20 73 68 6f 75 6c 64 20 6c |ts. You should l|
00000350 6f 6f 6b 20 63 61 72 65 66 75 6c 6c 79 20 61 74 |ook carefully at|
00000360 20 74 68 65 20 66 61 63 69 6c 69 74 69 65 73 20 | the facilities |
00000370 6f 66 66 65 72 65 64 20 62 79 20 74 68 65 0d 76 |offered by the.v|
00000380 61 72 69 6f 75 73 20 6d 61 6e 75 66 61 63 74 75 |arious manufactu|
00000390 72 65 72 73 20 6f 66 20 53 57 52 20 62 6f 61 72 |rers of SWR boar|
000003a0 64 73 20 61 6e 64 20 63 68 6f 6f 73 65 20 74 68 |ds and choose th|
000003b0 65 20 62 6f 61 72 64 20 74 68 61 74 20 62 65 73 |e board that bes|
000003c0 74 0d 73 75 69 74 73 20 79 6f 75 72 20 6e 65 65 |t.suits your nee|
000003d0 64 73 2e 20 49 20 72 65 63 6f 6d 6d 65 6e 64 20 |ds. I recommend |
000003e0 74 68 61 74 20 79 6f 75 20 63 6f 6e 73 69 64 65 |that you conside|
000003f0 72 20 74 68 65 20 66 6f 6c 6c 6f 77 69 6e 67 20 |r the following |
00000400 70 6f 69 6e 74 73 0d 77 68 65 6e 20 79 6f 75 20 |points.when you |
00000410 6c 6f 6f 6b 20 66 6f 72 20 61 20 53 57 52 20 62 |look for a SWR b|
00000420 6f 61 72 64 2e 0d 0d 31 2e 20 20 41 20 6d 69 6d |oard...1. A mim|
00000430 69 6d 75 6d 20 6f 66 20 31 36 6b 20 6f 66 20 73 |imum of 16k of s|
00000440 69 64 65 77 61 79 73 20 72 61 6d 20 69 73 20 72 |ideways ram is r|
00000450 65 71 75 69 72 65 64 2e 20 33 32 6b 20 6f 72 20 |equired. 32k or |
00000460 36 34 6b 20 69 73 20 75 73 65 66 75 6c 0d 62 75 |64k is useful.bu|
00000470 74 20 6e 6f 74 20 65 73 73 65 6e 74 69 61 6c 2e |t not essential.|
00000480 20 4d 6f 73 74 20 62 6f 61 72 64 73 20 77 68 69 | Most boards whi|
00000490 63 68 20 75 73 65 20 73 74 61 74 69 63 20 72 61 |ch use static ra|
000004a0 6d 73 20 64 6f 20 73 6f 20 62 65 63 61 75 73 65 |ms do so because|
000004b0 20 74 68 65 0d 64 65 73 69 67 6e 20 69 73 20 6d | the.design is m|
000004c0 75 63 68 20 73 69 6d 70 6c 65 72 2e 20 54 68 65 |uch simpler. The|
000004d0 72 65 20 69 73 20 61 6e 20 6f 6c 64 20 64 65 73 |re is an old des|
000004e0 69 67 6e 65 72 27 73 20 6a 6f 6b 65 20 74 68 61 |igner's joke tha|
000004f0 74 20 74 68 65 0d 64 69 66 66 65 72 65 6e 63 65 |t the.difference|
00000500 20 62 65 74 77 65 65 6e 20 73 74 61 74 69 63 20 | between static |
00000510 61 6e 64 20 64 79 6e 61 6d 69 63 20 72 61 6d 20 |and dynamic ram |
00000520 69 73 20 74 68 61 74 20 73 74 61 74 69 63 20 72 |is that static r|
00000530 61 6d 20 77 6f 72 6b 73 2e 0d 44 6f 6e 27 74 20 |am works..Don't |
00000540 6c 65 74 20 74 68 69 73 20 6e 6f 6e 73 65 6e 73 |let this nonsens|
00000550 65 20 70 72 65 76 65 6e 74 20 79 6f 75 20 62 75 |e prevent you bu|
00000560 79 69 6e 67 20 61 20 64 79 6e 61 6d 69 63 20 72 |ying a dynamic r|
00000570 61 6d 20 62 6f 61 72 64 2e 0d 0d 32 2e 20 20 50 |am board...2. P|
00000580 68 79 73 69 63 61 6c 20 73 77 69 74 63 68 69 6e |hysical switchin|
00000590 67 20 66 6f 72 20 72 65 61 64 20 61 6e 64 20 77 |g for read and w|
000005a0 72 69 74 65 20 70 72 6f 74 65 63 74 69 6f 6e 20 |rite protection |
000005b0 6f 66 20 74 68 65 20 53 57 52 20 69 73 0d 68 69 |of the SWR is.hi|
000005c0 67 68 6c 79 20 64 65 73 69 72 61 62 6c 65 2e 20 |ghly desirable. |
000005d0 52 65 61 64 20 70 72 6f 74 65 63 74 69 6f 6e 20 |Read protection |
000005e0 77 69 6c 6c 20 62 65 20 75 73 65 64 20 74 6f 20 |will be used to |
000005f0 73 77 69 74 63 68 20 6f 75 74 20 74 68 65 0d 6f |switch out the.o|
00000600 66 66 65 6e 64 69 6e 67 20 6d 65 6d 6f 72 79 20 |ffending memory |
00000610 77 68 65 6e 20 79 6f 75 20 6c 6f 61 64 20 61 6e |when you load an|
00000620 20 69 6e 76 61 6c 69 64 20 72 6f 6d 20 69 6d 61 | invalid rom ima|
00000630 67 65 20 77 68 69 63 68 20 63 61 75 73 65 73 20 |ge which causes |
00000640 74 68 65 0d 63 6f 6d 70 75 74 65 72 20 74 6f 20 |the.computer to |
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00003a10 63 20 74 68 65 20 70 72 6f 67 72 61 6d 20 63 6f |c the program co|
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00003ae0 20 26 32 30 30 30 20 62 79 74 65 73 20 61 72 65 | &2000 bytes are|
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00003b10 61 73 20 77 65 6c 6c 20 61 73 20 69 6c 6c 75 73 |as well as illus|
00003b20 74 72 61 74 69 6e 67 20 74 68 65 20 74 65 63 68 |trating the tech|
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00003b50 75 73 65 66 75 6c 20 69 6e 20 6c 61 74 65 72 20 |useful in later |
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00003ba0 64 65 77 61 79 73 20 72 61 6d 20 62 61 6e 6b 73 |deways ram banks|
00003bb0 2e 20 54 68 65 20 70 72 6f 67 72 61 6d 20 63 61 |. The program ca|
00003bc0 6e 20 62 65 0d 6d 6f 64 69 66 69 65 64 20 74 6f |n be.modified to|
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00003be0 20 70 72 6f 67 72 61 6d 20 74 6f 20 6c 6f 61 64 | program to load|
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00003c50 62 65 65 6e 20 6c 65 66 74 20 61 73 20 61 6e 20 |been left as an |
00003c60 65 78 65 72 63 69 73 65 20 66 6f 72 20 79 6f 75 |exercise for you|
00003c70 20 74 6f 20 63 6f 6d 70 6c 65 74 65 2e 0d 0d 0d | to complete....|
00003c80 0d 20 20 20 31 30 20 52 45 4d 3a 20 52 45 41 44 |. 10 REM: READ|
00003c90 52 4f 4d 0d 20 20 20 32 30 20 4d 4f 44 45 37 0d |ROM. 20 MODE7.|
00003ca0 20 20 20 33 30 20 48 49 4d 45 4d 3d 26 33 43 30 | 30 HIMEM=&3C0|
00003cb0 30 0d 20 20 20 34 30 20 44 49 4d 20 6d 63 6f 64 |0. 40 DIM mcod|
00003cc0 65 20 26 31 30 30 0d 20 20 20 35 30 20 73 65 6c |e &100. 50 sel|
00003cd0 65 63 74 3d 26 46 45 33 30 0d 20 20 20 36 30 20 |ect=&FE30. 60 |
00003ce0 6f 73 72 64 72 6d 3d 26 46 46 42 39 0d 20 20 20 |osrdrm=&FFB9. |
00003cf0 37 30 20 6f 73 61 73 63 69 3d 26 46 46 45 33 0d |70 osasci=&FFE3.|
00003d00 20 20 20 38 30 20 6f 73 62 79 74 65 3d 26 46 46 | 80 osbyte=&FF|
00003d10 46 34 0d 20 20 20 39 30 20 6f 73 63 6c 69 3d 26 |F4. 90 oscli=&|
00003d20 46 46 46 37 0d 20 20 31 30 30 20 63 6f 70 79 3d |FFF7. 100 copy=|
00003d30 26 37 30 0d 20 20 31 31 30 20 74 65 6d 70 3d 26 |&70. 110 temp=&|
00003d40 37 31 0d 20 20 31 32 30 20 72 65 61 64 3d 26 37 |71. 120 read=&7|
00003d50 32 0d 20 20 31 33 30 20 77 72 69 74 65 3d 26 37 |2. 130 write=&7|
00003d60 34 0d 20 20 31 34 30 20 72 6f 6d 6e 75 6d 62 65 |4. 140 romnumbe|
00003d70 72 3d 26 46 34 0d 20 20 31 35 30 20 72 6f 6d 70 |r=&F4. 150 romp|
00003d80 6f 69 6e 74 3d 26 46 36 0d 20 20 31 36 30 20 4f |oint=&F6. 160 O|
00003d90 4e 20 45 52 52 4f 52 20 50 52 49 4e 54 20 3a 20 |N ERROR PRINT : |
00003da0 45 4e 44 0d 20 20 31 37 30 20 46 4f 52 20 70 61 |END. 170 FOR pa|
00003db0 73 73 3d 30 20 54 4f 20 32 20 53 54 45 50 20 32 |ss=0 TO 2 STEP 2|
00003dc0 0d 20 20 31 38 30 20 50 25 3d 6d 63 6f 64 65 0d |. 180 P%=mcode.|
00003dd0 20 20 31 39 30 20 5b 20 20 20 20 20 20 20 4f 50 | 190 [ OP|
00003de0 54 20 70 61 73 73 0d 20 20 32 30 30 20 2e 6e 75 |T pass. 200 .nu|
00003df0 6d 62 65 72 0d 20 20 32 31 30 20 20 20 20 20 20 |mber. 210 |
00003e00 20 20 20 4c 44 41 20 23 26 41 41 0d 20 20 32 32 | LDA #&AA. 22|
00003e10 30 20 20 20 20 20 20 20 20 20 4c 44 58 20 23 30 |0 LDX #0|
00003e20 0d 20 20 32 33 30 20 20 20 20 20 20 20 20 20 4c |. 230 L|
00003e30 44 59 20 23 26 46 46 0d 20 20 32 34 30 20 20 20 |DY #&FF. 240 |
00003e40 20 20 20 20 20 20 4a 53 52 20 6f 73 62 79 74 65 | JSR osbyte|
00003e50 20 20 20 20 5c 20 46 69 6e 64 20 72 6f 6d 20 74 | \ Find rom t|
00003e60 61 62 6c 65 0d 20 20 32 35 30 20 20 20 20 20 20 |able. 250 |
00003e70 20 20 20 53 54 58 20 72 65 61 64 0d 20 20 32 36 | STX read. 26|
00003e80 30 20 20 20 20 20 20 20 20 20 53 54 59 20 72 65 |0 STY re|
00003e90 61 64 2b 31 0d 20 20 32 37 30 20 20 20 20 20 20 |ad+1. 270 |
00003ea0 20 20 20 4c 44 59 20 63 6f 70 79 0d 20 20 32 38 | LDY copy. 28|
00003eb0 30 20 20 20 20 20 20 20 20 20 4c 44 41 20 28 72 |0 LDA (r|
00003ec0 65 61 64 29 2c 59 0d 20 20 32 39 30 20 20 20 20 |ead),Y. 290 |
00003ed0 20 20 20 20 20 42 45 51 20 66 69 6e 69 73 68 0d | BEQ finish.|
00003ee0 20 20 33 30 30 20 20 20 20 20 20 20 20 20 4c 44 | 300 LD|
00003ef0 41 20 23 38 0d 20 20 33 31 30 20 20 20 20 20 20 |A #8. 310 |
00003f00 20 20 20 53 54 41 20 72 6f 6d 70 6f 69 6e 74 0d | STA rompoint.|
00003f10 20 20 33 32 30 20 20 20 20 20 20 20 20 20 4c 44 | 320 LD|
00003f20 41 20 23 26 38 30 0d 20 20 33 33 30 20 20 20 20 |A #&80. 330 |
00003f30 20 20 20 20 20 53 54 41 20 72 6f 6d 70 6f 69 6e | STA rompoin|
00003f40 74 2b 31 0d 20 20 33 34 30 20 2e 72 65 61 64 6e |t+1. 340 .readn|
00003f50 61 6d 65 0d 20 20 33 35 30 20 20 20 20 20 20 20 |ame. 350 |
00003f60 20 20 49 4e 43 20 72 6f 6d 70 6f 69 6e 74 0d 20 | INC rompoint. |
00003f70 20 33 36 30 20 20 20 20 20 20 20 20 20 4c 44 59 | 360 LDY|
00003f80 20 63 6f 70 79 0d 20 20 33 37 30 20 20 20 20 20 | copy. 370 |
00003f90 20 20 20 20 4a 53 52 20 6f 73 72 64 72 6d 0d 20 | JSR osrdrm. |
00003fa0 20 33 38 30 20 20 20 20 20 20 20 20 20 43 4d 50 | 380 CMP|
00003fb0 20 23 41 53 43 28 22 20 22 29 0d 20 20 33 39 30 | #ASC(" "). 390|
00003fc0 20 20 20 20 20 20 20 20 20 42 43 43 20 66 69 6e | BCC fin|
00003fd0 69 73 68 0d 20 20 34 30 30 20 20 20 20 20 20 20 |ish. 400 |
00003fe0 20 20 4a 53 52 20 6f 73 61 73 63 69 0d 20 20 34 | JSR osasci. 4|
00003ff0 31 30 20 20 20 20 20 20 20 20 20 4a 4d 50 20 72 |10 JMP r|
00004000 65 61 64 6e 61 6d 65 0d 20 20 34 32 30 20 2e 66 |eadname. 420 .f|
00004010 69 6e 69 73 68 0d 20 20 34 33 30 20 20 20 20 20 |inish. 430 |
00004020 20 20 20 20 52 54 53 0d 20 20 34 34 30 20 2e 6d | RTS. 440 .m|
00004030 6f 76 65 0d 20 20 34 35 30 20 20 20 20 20 20 20 |ove. 450 |
00004040 20 20 4c 44 41 20 72 6f 6d 6e 75 6d 62 65 72 0d | LDA romnumber.|
00004050 20 20 34 36 30 20 20 20 20 20 20 20 20 20 53 54 | 460 ST|
00004060 41 20 74 65 6d 70 0d 20 20 34 37 30 20 20 20 20 |A temp. 470 |
00004070 20 20 20 20 20 4c 44 41 20 63 6f 70 79 0d 20 20 | LDA copy. |
00004080 34 38 30 20 20 20 20 20 20 20 20 20 53 54 41 20 |480 STA |
00004090 72 6f 6d 6e 75 6d 62 65 72 0d 20 20 34 39 30 20 |romnumber. 490 |
000040a0 20 20 20 20 20 20 20 20 53 54 41 20 73 65 6c 65 | STA sele|
000040b0 63 74 0d 20 20 35 30 30 20 20 20 20 20 20 20 20 |ct. 500 |
000040c0 20 4c 44 41 20 23 26 38 30 0d 20 20 35 31 30 20 | LDA #&80. 510 |
000040d0 20 20 20 20 20 20 20 20 53 54 41 20 72 65 61 64 | STA read|
000040e0 2b 31 0d 20 20 35 32 30 20 20 20 20 20 20 20 20 |+1. 520 |
000040f0 20 4c 44 41 20 23 26 33 43 0d 20 20 35 33 30 20 | LDA #&3C. 530 |
00004100 20 20 20 20 20 20 20 20 53 54 41 20 77 72 69 74 | STA writ|
00004110 65 2b 31 0d 20 20 35 34 30 20 20 20 20 20 20 20 |e+1. 540 |
00004120 20 20 4c 44 59 20 23 30 0d 20 20 35 35 30 20 20 | LDY #0. 550 |
00004130 20 20 20 20 20 20 20 53 54 59 20 72 65 61 64 0d | STY read.|
00004140 20 20 35 36 30 20 20 20 20 20 20 20 20 20 53 54 | 560 ST|
00004150 59 20 77 72 69 74 65 0d 20 20 35 37 30 20 2e 72 |Y write. 570 .r|
00004160 65 6c 6f 63 61 74 65 0d 20 20 35 38 30 20 20 20 |elocate. 580 |
00004170 20 20 20 20 20 20 4c 44 41 20 28 72 65 61 64 29 | LDA (read)|
00004180 2c 59 0d 20 20 35 39 30 20 20 20 20 20 20 20 20 |,Y. 590 |
00004190 20 53 54 41 20 28 77 72 69 74 65 29 2c 59 0d 20 | STA (write),Y. |
000041a0 20 36 30 30 20 20 20 20 20 20 20 20 20 49 4e 59 | 600 INY|
000041b0 0d 20 20 36 31 30 20 20 20 20 20 20 20 20 20 42 |. 610 B|
000041c0 4e 45 20 72 65 6c 6f 63 61 74 65 0d 20 20 36 32 |NE relocate. 62|
000041d0 30 20 20 20 20 20 20 20 20 20 49 4e 43 20 72 65 |0 INC re|
000041e0 61 64 2b 31 0d 20 20 36 33 30 20 20 20 20 20 20 |ad+1. 630 |
000041f0 20 20 20 49 4e 43 20 77 72 69 74 65 2b 31 0d 20 | INC write+1. |
00004200 20 36 34 30 20 20 20 20 20 20 20 20 20 4c 44 41 | 640 LDA|
00004210 20 72 65 61 64 2b 31 0d 20 20 36 35 30 20 20 20 | read+1. 650 |
00004220 20 20 20 20 20 20 43 4d 50 20 23 26 43 30 0d 20 | CMP #&C0. |
00004230 20 36 36 30 20 20 20 20 20 20 20 20 20 42 4e 45 | 660 BNE|
00004240 20 72 65 6c 6f 63 61 74 65 0d 20 20 36 37 30 20 | relocate. 670 |
00004250 20 20 20 20 20 20 20 20 4c 44 41 20 74 65 6d 70 | LDA temp|
00004260 0d 20 20 36 38 30 20 20 20 20 20 20 20 20 20 53 |. 680 S|
00004270 54 41 20 72 6f 6d 6e 75 6d 62 65 72 0d 20 20 36 |TA romnumber. 6|
00004280 39 30 20 20 20 20 20 20 20 20 20 53 54 41 20 73 |90 STA s|
00004290 65 6c 65 63 74 0d 20 20 37 30 30 20 20 20 20 20 |elect. 700 |
000042a0 20 20 20 20 52 54 53 0d 20 20 37 31 30 20 5d 0d | RTS. 710 ].|
000042b0 20 20 37 32 30 20 4e 45 58 54 0d 20 20 37 33 30 | 720 NEXT. 730|
000042c0 20 46 4f 52 20 73 6f 63 6b 65 74 3d 30 20 54 4f | FOR socket=0 TO|
000042d0 20 31 35 0d 20 20 37 34 30 20 3f 63 6f 70 79 3d | 15. 740 ?copy=|
000042e0 73 6f 63 6b 65 74 0d 20 20 37 35 30 20 49 46 20 |socket. 750 IF |
000042f0 73 6f 63 6b 65 74 3c 31 30 20 50 52 49 4e 54 3b |socket<10 PRINT;|
00004300 22 20 22 3b 0d 20 20 37 36 30 20 50 52 49 4e 54 |" ";. 760 PRINT|
00004310 3b 73 6f 63 6b 65 74 3b 22 20 22 3b 0d 20 20 37 |;socket;" ";. 7|
00004320 37 30 20 43 41 4c 4c 20 6e 75 6d 62 65 72 0d 20 |70 CALL number. |
00004330 20 37 38 30 20 50 52 49 4e 54 0d 20 20 37 39 30 | 780 PRINT. 790|
00004340 20 4e 45 58 54 0d 20 20 38 30 30 20 56 44 55 31 | NEXT. 800 VDU1|
00004350 34 0d 20 20 38 31 30 20 52 45 50 45 41 54 0d 20 |4. 810 REPEAT. |
00004360 20 38 32 30 20 49 4e 50 55 54 27 22 57 68 69 63 | 820 INPUT'"Whic|
00004370 68 20 52 4f 4d 20 26 28 30 2d 31 35 29 20 22 73 |h ROM &(0-15) "s|
00004380 6f 63 6b 65 74 0d 20 20 38 33 30 20 55 4e 54 49 |ocket. 830 UNTI|
00004390 4c 20 73 6f 63 6b 65 74 20 3e 3d 20 30 20 41 4e |L socket >= 0 AN|
000043a0 44 20 73 6f 63 6b 65 74 20 3c 20 31 36 0d 20 20 |D socket < 16. |
000043b0 38 34 30 20 3f 63 6f 70 79 3d 73 6f 63 6b 65 74 |840 ?copy=socket|
000043c0 0d 20 20 38 35 30 20 43 41 4c 4c 20 6d 6f 76 65 |. 850 CALL move|
000043d0 0d 20 20 38 36 30 20 50 52 49 4e 54 27 22 3c 53 |. 860 PRINT'"<S|
000043e0 48 49 46 54 3e 20 74 6f 20 73 63 72 6f 6c 6c 2c |HIFT> to scroll,|
000043f0 20 3c 45 53 43 41 50 45 3e 20 74 6f 20 65 78 69 | <ESCAPE> to exi|
00004400 74 22 0d 20 20 38 37 30 20 4f 4e 20 45 52 52 4f |t". 870 ON ERRO|
00004410 52 20 50 52 4f 43 73 61 76 65 0d 20 20 38 38 30 |R PROCsave. 880|
00004420 20 46 4f 52 20 62 6c 6f 63 6b 3d 26 33 43 30 30 | FOR block=&3C00|
00004430 20 54 4f 20 26 37 42 46 46 20 53 54 45 50 20 38 | TO &7BFF STEP 8|
00004440 0d 20 20 38 39 30 20 50 52 49 4e 54 27 3b 7e 62 |. 890 PRINT';~b|
00004450 6c 6f 63 6b 2b 26 34 34 30 30 3b 22 20 20 22 3b |lock+&4400;" ";|
00004460 0d 20 20 39 30 30 20 46 4f 52 20 6d 65 6d 6f 72 |. 900 FOR memor|
00004470 79 3d 30 20 54 4f 20 37 0d 20 20 39 31 30 20 62 |y=0 TO 7. 910 b|
00004480 79 74 65 3d 62 6c 6f 63 6b 3f 6d 65 6d 6f 72 79 |yte=block?memory|
00004490 0d 20 20 39 32 30 20 49 46 20 62 79 74 65 3c 31 |. 920 IF byte<1|
000044a0 36 20 56 44 55 34 38 0d 20 20 39 33 30 20 50 52 |6 VDU48. 930 PR|
000044b0 49 4e 54 3b 7e 62 79 74 65 3b 22 20 22 3b 0d 20 |INT;~byte;" ";. |
000044c0 20 39 34 30 20 4e 45 58 54 0d 20 20 39 35 30 20 | 940 NEXT. 950 |
000044d0 46 4f 52 20 6d 65 6d 6f 72 79 3d 30 20 54 4f 20 |FOR memory=0 TO |
000044e0 37 0d 20 20 39 36 30 20 62 79 74 65 3d 6d 65 6d |7. 960 byte=mem|
000044f0 6f 72 79 3f 62 6c 6f 63 6b 0d 20 20 39 37 30 20 |ory?block. 970 |
00004500 49 46 20 62 79 74 65 3e 33 31 20 41 4e 44 20 62 |IF byte>31 AND b|
00004510 79 74 65 3c 31 32 37 20 56 44 55 62 79 74 65 20 |yte<127 VDUbyte |
00004520 45 4c 53 45 20 56 44 55 34 36 0d 20 20 39 38 30 |ELSE VDU46. 980|
00004530 20 4e 45 58 54 0d 20 20 39 39 30 20 4e 45 58 54 | NEXT. 990 NEXT|
00004540 0d 20 31 30 30 30 20 50 52 4f 43 73 61 76 65 0d |. 1000 PROCsave.|
00004550 20 31 30 31 30 20 45 4e 44 0d 20 31 30 32 30 20 | 1010 END. 1020 |
00004560 44 45 46 50 52 4f 43 73 61 76 65 0d 20 31 30 33 |DEFPROCsave. 103|
00004570 30 20 4f 4e 20 45 52 52 4f 52 20 50 52 49 4e 54 |0 ON ERROR PRINT|
00004580 20 3a 20 45 4e 44 0d 20 31 30 34 30 20 56 44 55 | : END. 1040 VDU|
00004590 31 35 0d 20 31 30 35 30 20 49 4e 50 55 54 27 27 |15. 1050 INPUT''|
000045a0 22 53 61 76 65 20 52 4f 4d 3f 20 28 59 2f 4e 29 |"Save ROM? (Y/N)|
000045b0 20 22 79 65 73 24 0d 20 31 30 36 30 20 52 45 50 | "yes$. 1060 REP|
000045c0 45 41 54 0d 20 31 30 37 30 20 49 46 20 79 65 73 |EAT. 1070 IF yes|
000045d0 24 3d 22 59 22 20 49 4e 50 55 54 22 46 69 6c 65 |$="Y" INPUT"File|
000045e0 6e 61 6d 65 3f 20 3a 20 22 66 69 6c 65 6e 61 6d |name? : "filenam|
000045f0 65 24 20 45 4c 53 45 20 49 4e 50 55 54 22 41 6e |e$ ELSE INPUT"An|
00004600 0d 20 20 20 20 20 20 6f 74 68 65 72 3f 20 28 59 |. other? (Y|
00004610 2f 4e 29 20 22 79 65 73 24 20 3a 20 49 46 20 79 |/N) "yes$ : IF y|
00004620 65 73 24 3c 3e 22 59 22 20 45 4e 44 20 45 4c 53 |es$<>"Y" END ELS|
00004630 45 20 52 55 4e 0d 20 31 30 38 30 20 73 69 7a 65 |E RUN. 1080 size|
00004640 3d 46 41 4c 53 45 0d 20 31 30 39 30 20 46 4f 52 |=FALSE. 1090 FOR|
00004650 20 62 6c 6f 63 6b 3d 26 33 43 30 30 20 54 4f 20 | block=&3C00 TO |
00004660 26 33 44 30 30 0d 20 31 31 30 30 20 49 46 20 3f |&3D00. 1100 IF ?|
00004670 62 6c 6f 63 6b 20 3c 3e 20 3f 28 62 6c 6f 63 6b |block <> ?(block|
00004680 2b 26 32 30 30 30 29 20 73 69 7a 65 3d 20 54 52 |+&2000) size= TR|
00004690 55 45 0d 20 31 31 31 30 20 4e 45 58 54 0d 20 31 |UE. 1110 NEXT. 1|
000046a0 31 32 30 20 49 46 20 73 69 7a 65 3d 54 52 55 45 |120 IF size=TRUE|
000046b0 20 73 69 7a 65 3d 26 34 30 30 30 20 45 4c 53 45 | size=&4000 ELSE|
000046c0 20 73 69 7a 65 3d 26 32 30 30 30 0d 20 31 31 33 | size=&2000. 113|
000046d0 30 20 24 6d 63 6f 64 65 3d 22 53 41 56 45 20 22 |0 $mcode="SAVE "|
000046e0 2b 66 69 6c 65 6e 61 6d 65 24 2b 22 20 33 43 30 |+filename$+" 3C0|
000046f0 30 2b 22 2b 53 54 52 24 7e 28 73 69 7a 65 29 2b |0+"+STR$~(size)+|
00004700 22 20 46 46 46 46 38 30 0d 20 20 20 20 20 20 30 |" FFFF80. 0|
00004710 30 20 46 46 46 46 38 30 30 30 22 0d 20 31 31 34 |0 FFFF8000". 114|
00004720 30 20 58 25 3d 6d 63 6f 64 65 20 4d 4f 44 20 32 |0 X%=mcode MOD 2|
00004730 35 36 0d 20 31 31 35 30 20 59 25 3d 6d 63 6f 64 |56. 1150 Y%=mcod|
00004740 65 20 44 49 56 20 32 35 36 0d 20 31 31 36 30 20 |e DIV 256. 1160 |
00004750 43 41 4c 4c 20 6f 73 63 6c 69 0d 20 31 31 37 30 |CALL oscli. 1170|
00004760 20 79 65 73 24 3d 22 22 0d 20 31 31 38 30 20 55 | yes$="". 1180 U|
00004770 4e 54 49 4c 20 46 41 4c 53 45 0d 20 31 31 39 30 |NTIL FALSE. 1190|
00004780 20 45 4e 44 50 52 4f 43 0d | ENDPROC.|
00004789 
02-07-88/T\SWR01.m0
02-07-88/T\SWR01.m1
02-07-88/T\SWR01.m2
02-07-88/T\SWR01.m4
02-07-88/T\SWR01.m5
.