Custom Rom

[eight088]

Hey everyone

A pet that I have (not the one I'm talking about in an already going repair thread) has a custom rom in it and just wondering if anyone knows what it might be based on what is written on it?

It has a bit of tape on it, with the writing "T/KIT XTRAM" on it.

The Pet is a 3016 with extra ram chips in it taking it to 32kb. Would an extra rom be needed to access this extra ram?

If anyone is keen, I should hopefully get my programmer next week, so should be able to read it and post it here for people to inspect.

Cheers

 

[Ruud]

I can only answer the question "Would an extra rom be needed to access this extra ram?": no.

The 3016 plus extra 16 KB of RAM makes it a 3032.

 

[daver2]

Get me a dump of it and I'll disassemble it and see what it does for you !

When I get home I will see what address UD4 starts at, and I'll give you a SYS command to try when you get your PET repaired...

Dave

 

[dave_m]

It's probably Toolkit that adds useful additional commands to BASIC. It usually goes into the D5 ($B000) socket but it looks like it is in the D4 ($A000) socket. There may be versions for that socket. See zimmers for more information: http://www.zimmers.net/anonftp/pub/cbm/firmware/computers/pet/other/

 

[dave_m]

Here's the manual for the D5 socket Toolkit. The modified D4 socket version may start with SYS 40960.
https://datassette.nyc3.cdn.digitaloceanspaces.com/livros/the_basic_programmers_toolkit_for_pet.pdf

 

[eight088]

Get me a dump of it and I'll disassemble it and see what it does for you !

When I get home I will see what address UD4 starts at, and I'll give you a SYS command to try when you get your PET repaired...

Dave

Hi Dave

I've tried to dump this rom... I'm not sure if it dumped properly or if the rom is corrupt but I can't get it to do anything. And I'm not really sure what I'm actually doing :|

I've just added .txt on the end to upload it.

Cheers

 

[Ruud]

I had a view at the BIN and my first impression is that it is a character ROM for video or printer: there are too much repetitions of codes or groups of code. And IMHO it isn't 6502 code: no $A5 = lda $xx, $AD = lda $xxxx or $A9 = lda #$xx to be found.

 

[eight088]

I had a view at the BIN and my first impression is that it is a character ROM for video or printer: there are too much repetitions of codes or groups of code. And IMHO it isn't 6502 code: no $A5 = lda $xx, $AD = lda $xxxx or $A9 = lda #$xx to be found.

Thanks for looking Ruud. I tried reading it again a few times, and I get different data (and checksum) each time, so the rom must be cooked.

Cheers

 

[Ruud]

Then it is time to throw this BIN holder in the bin.

 

[eight088]

Then it is time to throw this BIN holder in the bin.

Done! lol

 

[eight088]

So I just found a pin on the ic that was a bit dirty, so I tried giving it a little clean up and the leg snapped off... so I soldered a new leg on and I'm now getting consistent data reads from it. Here's the new file. I've noticed some A9 and A5s etc in it... When I put as a rom in $a000-$afff in vice(xpet) it gives me a illegal quantity error when I try to SYS 40690to it... Might still be corrupt but possibly looks a bit better?

ps, like the last one get rid of the .txt extension.

EDIT - I just compared this file to toolkit 4 $A000 over at zimmers, and at least the first 0000h to 00FFh look the same, so I'm concluding it's toolkit 4, but the rom is still corrupt.

Thanks

 

[daver2]

You were entering SYS 40960 weren't you, and not what you posted?

Dave

 

[eight088]

You were entering SYS 40960 weren't you, and not what you posted?

Dave

Oh crap I did type 40690! I just tried again and typed SYS 40960, and got some garbled text.

 

[daver2]

That probably indicates that the ROM is corrupt.

Dave