[WHERE TO FIND]PROTEUS for ZX81

[kmurta]

kmurta: Let me tell that you are the ZX-81 man, dude!!!

You are genius! Thank you so much for help me to recover this forgotten piece of code. It means a lot for my.

Oh, that is an injustice , in this forum there are many zx81 men, do not forget the sirmorris, andy, bobs, dr beep and others. I'm just a humble disciple of these guys

I am very happy to have been able to help you recover this piece of software that means a lot to you.

Amazing! Well done Kelly! How did you manage the recovery?? I thought it would be near impossible with existing tools...

Indeed it was quite simple: first, using the editor Audacity, I applied a high-pass filter with cutoff frequency of 1500Hz. Then I normalize it and realized there was no drop's out, what led me to try to load it first in EightyOne, achieving success in the first attempt

[sirmorris]

Oh, that is an injustice , in this forum there are many zx81 men, do not forget the sirmorris, andy, bobs, dr beep and others. I'm just a humble disciple of these guys

Haha that may be true but one of the people in that list was far too clever for his own good I really thought it wouldn't work

Indeed it was quite simple: first, using the editor Audacity, I applied a high-pass filter with cutoff frequency of 1500Hz. Then I normalize it and realized there was no drop's out, what led me to try to load it first in EightyOne, achieving success in the first attempt

Wow - I shall be remembering this! Another cool filter in audacity is the leveller - if the original recording doesn't have much noise but has drop-outs then this can really help. If there is noise however, it amplifies this too

[DOAs_fan]

Dude, that's a really good game!!
...
Niiiiiiiiiiice.

Hi yerzmyey!

I am so glad It likes you! Hope you enjoy it!

An excellent game - would you mind if I add it to my ZX81 downloads page?

Hi RWAP!

Of course you can add to the download list.

My original idea was to restore and share it.

Only if it possible write the autor´s name like in this page:

http://zx81.eu5.org/msprog.htm

But it´s not mandatory.

...and don´t forget to send me the link

Oh, that is an injustice, in this forum there are many zx81 men, do not forget the sirmorris, andy, bobs, dr beep and others. I'm just a humble disciple of these guys
I am very happy to have been able to help you recover this piece of software that means a lot to you.

Sorry kmurta. I was too excited when I wrote this.

Was never my intention to forget sirmorris, andy, bobs, dr beep, yerzmyey, RWAP and everyone how was involved, directly or indirectly; in this restoring.

Sincere thanks to all!

In other hand: I don´t want to be out off topic but Is there any way to recover the assembler source code through the .p file?
Rather: Is there any way to recover the assembler source code?

Please, let me know if I have to open another topic for this issue.

Thanks

[sirmorris]

Unfortunately there is no way to recover the original source code. The compilation process translates the source into the machine code and the link between them is lost at that point. How was the program developed? On a ZX81 using one of the assembler packages or on another system - so called 'cross assembly'?

[1024MAK]

While what SirMorris says is true, for someone who knows what they are doing, it may be possible to disassemble the machine code back to assembly mnemonics.

However, how easy this is depends on if the machine code is self modifying, or other tricks were used.

No disassembly can generate the original source assembly code, like comments and meaningful labels, as none of this human readable information is needed by the CPU, so it is not included in the machine code...

Mark

[DOAs_fan]

Unfortunately there is no way to recover the original source code.
The compilation process translates the source into the machine code and the link between them is lost at that point.
How was the program developed? On a ZX81 using one of the assembler packages or on another system - so called 'cross assembly'?

mmmh, is a difficult question to answer.

I only remember that it was writen using the instruction set of Z80 microprocessor.

Do you need the name of the compiler used? I don´t know if I could find it but I will check all my old tapes for this quest.

While what SirMorris says is true, for someone who knows what they are doing, it may be possible to disassemble the machine code back to assembly mnemonics.

However, how easy this is depends on if the machine code is self modifying, or other tricks were used.

No disassembly can generate the original source assembly code, like comments and meaningful labels, as none of this human readable information is needed by the CPU,
so it is not included in the machine code...

If It is possible to recover a list of assembly mnemonics it is fine for me.

I do not care if the comments and name vars/labels are lost in the process.

Thanks!

[sirmorris]

Here's the assembly listing for the machine code portion of proteus.

I found a pretty good disassembler which is open source. This is useful as the non-standard ZX81 character set confuses most tools - I hacked modified it to output ZX character codes rather than ASCII in the comments. Eg:

Code: Select all

        ; --- START PROC L6412 ---
L6412:  LD      HL,(400Ch)
        INC     HL
        LD      DE,0175h
        ADD     HL,DE
        LD      (HL),3Ah        ; 'U'
        INC     HL
        LD      (HL),38h        ; 'S'
        INC     HL
        LD      (HL),39h        ; 'T'
        INC     HL
        LD      (HL),2Ah        ; 'E'
        INC     HL
        LD      (HL),29h        ; 'D'
        INC     HL
        LD      (HL),00h        ; ' '
        INC     HL
        LD      (HL),2Ch        ; 'G'
        INC     HL
        LD      (HL),26h        ; 'A'
        INC     HL
        LD      (HL),33h        ; 'N'
        INC     HL
        LD      (HL),26h        ; 'A'
        RET

... which is more meaningful I'm sure you'll agree.

I've enclosed the program as well as the text. It's fairly simple to drive but I found that you need to chop off the sysvars and display file in a hex editor before disassembly. It doesn't handle headers very well - you'll get a crash - and I'm too lazy to fix it.

[PokeMon]

I found a pretty good disassembler which is open source. This is useful as the non-standard ZX81 character set confuses most tools - I hacked modified it to output ZX character codes rather than ASCII in the comments. Eg:

I think it's not published as source ?!
I found only the executable with your link.
Did you just patch the character table ?

[sirmorris]

The source is available ... tomorrow

It's only a couple of lines of code and a character table which has changed. I don't know if the original project will need the changes I made.

C

[stefano]

In the meanwhile a have a hint to tune speed:
the constants for delay are stored in 19846 and 19848.
If your ZX81 runs too fast, try POKE 19846,2 to slow down the game a bit