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Re: Difference between New rom and Old Rom

Posted: Fri Apr 05, 2019 8:27 am
by Lardo Boffin
Do you mean the ZX81 ROM with the math error?

I have sold a couple of these to people on this site - maybe they have the facility to dump them? I have a buggy ROM but no way to dump it.

Lardo

Re: Difference between New rom and Old Rom

Posted: Fri Apr 05, 2019 4:59 pm
by Moggy
Like Lardo I too have said ROM so will have a play around tonight by fitting it to my test zeddy and dumping its contents to the ZXpand, save it and post on here as a P file if that helps?

Re: Difference between New rom and Old Rom

Posted: Fri Apr 05, 2019 8:56 pm
by Moggy
As promised the old bugged ROM in P file format.

To view load into ZXspand at suitable address as per the manual (I chose 32767) or block load into Eighty One.

To turn this into something usable I leave to others as my learning doesn't stretch that far. :oops:

Re: Difference between New rom and Old Rom

Posted: Sat Apr 06, 2019 11:02 am
by RetroTechie
Thanks for your trouble Moggy! :)

Works as-is as ZX81 ROM (in emulators at least). Simply rename .p -> .rom or .bin as desired.

Re: Difference between New rom and Old Rom

Posted: Sat Apr 06, 2019 12:17 pm
by Moggy
No trouble RT glad to help will rename as you suggested and try it out in Eighty One. :D

EDIT.
Just realised this ROM already exits in the ROM folder of Eighty One!!!! :oops: :oops:

Re: Difference between New rom and Old Rom

Posted: Sun Apr 07, 2019 2:48 am
by Crayon21
Moggy wrote:
Sat Apr 06, 2019 12:17 pm
No trouble RT glad to help will rename as you suggested and try it out in Eighty One. :D

EDIT.
Just realised this ROM already exits in the ROM folder of Eighty One!!!! :oops: :oops:
someone slipped on the proverbial banana peel :lol:

Re: Difference between New rom and Old Rom

Posted: Sun Apr 07, 2019 9:21 am
by mrtinb
Crayon21 wrote:
Fri Apr 05, 2019 2:08 am
(sigh) is there an assembler for the zx81 already out there?
Many!
Someone also made a starting guide for cross compiling on a PC, if that's what you prefer.

Re: Difference between New rom and Old Rom

Posted: Sun Apr 07, 2019 1:29 pm
by Moggy
If you posses a ZXpand I can supply the EPROM code for the Memotech Z80 assembler interface which when loaded in the ZXpand to the address in the memory map this interface occupies allows the ZXpand to imitate the device.

The self running P file loaded from the memory card does all that is needed for this then just follow the manual which I can also supply.

Re: Difference between New rom and Old Rom

Posted: Sun Apr 07, 2019 2:05 pm
by mrtinb
Moggy wrote:
Sun Apr 07, 2019 1:29 pm
If you posses a ZXpand I can supply the EPROM code for the Memotech Z80 assembler interface which when loaded in the ZXpand to the address in the memory map this interface occupies allows the ZXpand to imitate the device.

The self running P file loaded from the memory card does all that is needed for this then just follow the manual which I can also supply.
You see, that’s something I would like to try.

Re: Difference between New rom and Old Rom

Posted: Sun Apr 07, 2019 8:47 pm
by Moggy
Here you are Martin.

In the folder are three files. ASSEMBLE.P ASMBIN.P and finally the text manual.

Making sure the two P files are in the same folder. Load the self running file ASSEMBLE.P which will then do two things.

1) It lowers ramtop down to the example shown in the manual. The two pokes in the listing for ASSEMBLE.P can be altered to what ever suits you, I used this setting only to illustrate the manuals example.

2) It will then load the ROM code (ASMBIN.P) to an address in the ZXpand identical to the one the original interface occupied(12288), the zeddy then resets leaving the code in place.

Once this is done just read the manual and away you go!!

The assembler listing is divided into three columns and to go from column one to column two/three you have to shift Z which is ok on original membrane keyboard but if using the Memotech Keyboard it sometimes leaps an extra space so you have to erase and start again which is a bit of a pain but much fun all the same.

Have fun!! :D