[Coco] Color Forth Help Request
Stephen H. Fischer
SFischer1 at Mindspring.com
Sat Feb 21 17:00:01 EST 2015
Hi,
Jeff's and John's MSDOS CoCo3 emulators both allow breakpoints and other commands in addition to saving your state.
Here is the text from Jeff's CoCo3 6809 Emulator.
Jeff appears to had added some things to his CoCo3 6809 Emulator.
John placed his 6309 version on RTSI and left.
-----------------------------------------------
8. THE DEBUGGER
---------------
The debugger halts the emulator, displaying the current state of all the
registers in the "6809" CPU, and also includes a 128-byte memory map and
a disassembly of current instructions. In the lower-left corner, the first
few entries on the U and S stacks are shown. Several commands are available
to you, as summarised in the box on the lower-right: (These commands are
probably best understood through experimentation. [ESC] will cancel any
option except [E]DIT, which is immediate.)
[B] Sets a BREAKPOINT address. The emulator will resume normal execution
until the breakpoint is hit, at which time the debugger reappears. Only
one breakpoint can be set at a time. The breakpoint is cleared the next
the the debugger or another menu is displayed.
[C] CONTINUE emulation. The breakpoint is cleared and the program returns
to normal emulation.
[D] Change the start address of DISASSEMBLY. A register or hexidecimal
address can be specified. If a register is given, the start address of
the disassembly will always follow whatever is in that register. The
default for this prompt is the next byte after the last instruction
displayed on the current disassembly.
[E] EDIT memory. Places a cursor on the memory map with which you can
directly modify memory. Arrows, PG UP and PG DN work. ROM and memory-
mapped device addresses behave as in the genuine machine. ESC or ENTER
when done.
[F] Change the 6809 FLAG registers. Press the letter of the flag to toggle
its true (1) or false (0) value. ESC to abort, ENTER to keep changes
and return to main debugger options.
[L] LOCATE WORD. Enter a 16-bit word and the debugger will search the
current 6809 address space (i.e. only memory banks currently switched
in by the MMU) for that word. The search starts at the current memory
address in the memory dump window.
[H] HEXIDECIMAL CALCULATOR. Enter a hex number or register to start. You
then enter one of the following operations:
[+], [-], [*], [/], [A]nd, [O]r, [X]or, [N]eg, [S]hift, [R]ot, [D]ecimal
The first seven of these will prompt for a second number or register to
operate with. [N] will NEGate the current result. [S] or [R] followed
by the left or right arrows will shift or rotate the bit positions of
the result as appropriate ([ESC] to return to calculator options). [D]
will display the decimal equivalent and/or allow you to enter a decimal
value. [ESC] will return to the main debugger options.
[M] Change the MEMORY DUMP start address. Enter either a hex address or a
register. If a register is used, the start address of the memory dump
will always follow that register's contents.
[O] STEP OVER. Same as "SINGLE STEP" below, except if a JSR or BSR is
encountered, the emulator will instead run until it reaches the return
address (i.e. the address immediately following the JSR or BSR
instruction).
[Q] QUIT EMULATOR. Exits back to MS-DOS. You must confirm this choice with
a "Y". An other reply will return to the main debugger options.
[R] Change REGISTER contents. Select a register using the arrow keys
followed by [ENTER], or by pressing its letter. Then type a new hex
value for its contents, or the name of another register to copy that
register's contents to the currently selected register.
[S] SINGLE STEP. Execute one 6809 instruction and return to the debugger.
[V] VIEW VIDEO. Display the current CoCo screen and wait for a key to be
pressed. Pressing any key will return you to the debugger's main
options.
Register names are just there 6809 names, without brackets, except for the
D register. D is entered as "A/B" to distinguish it from the hex numbers
000D, 000A, 000B, and 00AB.
-----------------------------------------------
I have never MESSed around so I cannot speak for that Emulator.
If you are running W7 Professional or higher I recommend using the free XP Virtual Machine adding Windows 98 SE as it allows Windows type operations and a true MSDOS environment.
VCC offers nothing AFAIK.
SHF
----- Original Message -----
From: "Arthur Flexser" <flexser at fiu.edu>
To: "CoCoList for Color Computer Enthusiasts" <coco at maltedmedia.com>
Sent: Saturday, February 21, 2015 10:39 AM
Subject: Re: [Coco] Color Forth Help Request
> I'd suggest acquiring a programming tool that allows you to set breakpoints
> and single step, which would have quickly turned up the location of the
> error. Perhaps VCC allows this as an option?
>
> Art
>
> On Sat, Feb 21, 2015 at 12:20 PM, Stephen Pereira <spereira1952 at comcast.net>
> wrote:
>
>> Art & Darren:
>>
>> Thank you both so very much for your attention and assistance with my
>> problem!
>>
>> As I said in a previous note, I am a good 8080 assembly language
>> programmer, but I’m a rank beginner with the 6809. I am not surprised that
>> I made this error, but I am surprised that the assembler did not catch it.
>>
>> I am using the EDTASM6309 that I purchased from Robert Gault. I’ll bet
>> he’ll be interested to hear about this.
>>
>> This would have taken me quite a bit of time to figure out on my own, to
>> say the least. I probably would have gone ahead and plugged in a 6809 back
>> into my computer in order to be using one machine for all my projects,
>> rather than splitting between two different machines.
>>
>> Thanka a million, guys! I greatly appreciate your help with this!
>>
>> smp
>> --
>> Stephen M. Pereira
>> Bedford, NH 03110
>> KB1SXE
>>
>>
>> > On Feb 20, 2015, at 8:16 PM, Darren A <mechacoco at gmail.com> wrote:
>> >
>> > On Fri, Feb 20, 2015 at 4:20 PM, Stephen Pereira <
>> spereira1952 at comcast.net>
>> > wrote:
>> >
>> >> Here is my code:
>> >>
>> >> *
>> >> * BRUTE FORCE ROUTINE TO LOAD SCREENS 1 THRU 8
>> >> * USING THE DECB LOADM ROUTINE
>> >> * JAN 2015, SMP
>> >> * ERROR CHECK & ADVICE FROM BRETT GORDON
>> >> *
>> >> FCB $84,'L,'S,'C,'R+$80
>> >> FDB SSCR-7
>> >> LSCR FDB *+2
>> >> PSHS CC,A,B,DP,X,Y,U SAVE ALL JUST IN CASE
>> >> LDX #$094C CLEAR FILE NAME LOCATION
>> >> LDA #32
>> >> L3 STA ,X+
>> >> CMPX #$0954
>> >> BNE L3
>> >> LDX #$094C FILE NAME LOCATION
>> >> L4 JSR $A1B1 GET KEY IN A
>> >> TFR A,B SAVE KEY IN B
>> >> PSHS B,X,Y
>> >> JSR [$A002] ECHO KEY
>> >> PULS Y,X,B
>> >> TFR B,A GET KEY IN A
>> >> CMPA #13 CR?
>> >> BEQ NXT2 CR ENDS LOOP
>> >> STA ,X+ STORE KEY IN FILE NAME
>> >> CMPX #$0954 DONE IF 8 KEYS
>> >> BNE L4
>> >> NXT2 LDX #$0954 FILE EXTENSION LOCATION
>> >> LDA #$42 B
>> >> STA ,X+
>> >> LDA #$49 I
>> >> STA ,X+
>> >> LDA #$4E N
>> >> STA ,X
>> >> LDD #$0200 FILE TYPE = 2, ASCII FLAG = 0
>> >> STD $0957
>> >> LDX #$0000
>> >> STX #$00D3 OFFSET = 0
>> >> JSR $CA07 OPEN NEXT AVAIL FILE FOR INPUT
>> >> LDD #RET2 RETURN ADDR FOR LOADM RTS
>> >> PSHS D
>> >> JMP $CFE3 LOADM
>> >> RET2 PULS U,Y,X,DP,B,A,CC RESTORE ALL
>> >> JMP NEXT RETURN TO FORTH
>> >>
>> >> This code works fine on a stock CoCo 3, as well as in VCC with a 6809
>> >> CPU. It is not elegant, and I don’t think I tried any fancy stuff.
>> Don’t
>> >> worry about the first few lines of code - they are for linking into
>> Color
>> >> Forth, and that seem to be fine.
>> >>
>> >> As far as I can tell, this code does not initiate any disk activity when
>> >> the CPU is a 6309, the machine simply goes off into never-never-land.
>> >>
>> >> Thanks, in advance, for whatever observations or advice you may have to
>> >> offer.
>> >>
>> >
>> >
>> > The code listing above contains an illegal instruction. In particular:
>> >
>> > STX #$00D3 OFFSET = 0
>> >
>> > You can't use an immediate operand with STX. If that is how it actually
>> > appears in your source code then it should be fixed. I would be
>> surprised
>> > that an assembler accepts that without an error or warning.
>> >
>> > - Darren
>> >
>> > --
>> > Coco mailing list
>> > Coco at maltedmedia.com
>> > https://pairlist5.pair.net/mailman/listinfo/coco
>>
>>
>> --
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>> https://pairlist5.pair.net/mailman/listinfo/coco
>>
>
> --
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>
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