Sinclair ZX80 / ZX81 / Z88 Forums

As I understand it you must make the part of RAM from 8 to 16 KB readonly in the EightyOne emulator. Is this because SPONZY overwrites it? Could one change the ROM so that it doesn't overwrite the RAM? I have a real ZX81 with 56 KB RAM and 8 KB RAM in the ordinary ROM address space that can be filled with data and then write-protected, but I can't easily write-protect the first 8 KB of the ordinary RAM.

Hi,
In EO you have to select at least 16K of RAM, then load the SPONZY.ROM (16K!).

MOB-i-L wrote:I have a real ZX81 with 56 KB RAM...
...but I can't easily write-protect the first 8 KB of the ordinary RAM.

As far as I know, the SPONZY does not want to write the second 8K ($2000-$3FFF) area.
Zsolt

Hi everybody.

I have been testing Sponzy ROM on my emulator ZEsarUX
http://sourceforge.net/projects/zesarux/

This is not a normal 8KB rom (it's 16kb length) so to use in my emulator you have to enable some things before. I updated the FAQ file on the snapshot version of my emulator with the following information (which you can use to run Sponzy on ZEsarUX 3.0 or previous versions):

Q: I tried to run the ZX81 Sponzy ROM on the emulator but it doesn't work
A: You will probably have set "Custom machine" from the menu. But the sponzy rom is 16KB long and the emulator loads only 8KB rom by default.
To be able to use this rom, you must enable RAM on addresses 2000h-3fffh. So:

1) Set normal ZX81 machine. Go to menu hardware->"ZX80/81 8K RAM in 2000H" and enable it
2) Machine Selection->Custom machine. Select sponzy rom and machine type ZX81. It will load only the first 8 KB of ROM. It will hang the ZX81 and
the display will show "trash", also the "Real Video" setting is auto-enabled.
3) The trick here is to load the rest of the ROM on addresses 2000h-3fffh. To do that, go to menu Debugging-> Load binary block. Select the same
sponzy rom file, set address to 0, and set lenght to 0 (to load the whole file). The emulator will load the whole file, but addresses 0000-1fffh are
write protected, but it is not a problem so these addresses are already loaded since pass 2. Addresses 2000h-3fffh will be written (so we enabled RAM here) with the rest of the Sponzy ROM
4) Go to menu debugging->Reset
5) The rom is working now but you will probably see only a white display. So, Sponzy rom uses WRX display mode. You must enable it on menu Display Settings->WRX


Cheers
Cesar

Will Sponzy require M1NOT mod for 16k program? These would fit below the M1NOT limit. Or does Sponzy require M1NOT mod for all software?

Hi,
The real 16K programs do not require M1NOT mod (it enables program execution in $8000-$BFFF range).
Most of those softwares, which run on 16K Speccy, wiil work with SPONZY.
Regards,
Zsolt

I'm not able to get this to work with EightyOne emulator, what I am I doing wrong?

Thanks,

Shaun.

Shaun_B wrote: ↑Sun Mar 04, 2018 12:38 pm I'm not able to get this to work with EightyOne emulator, what I am I doing wrong?

Hi Shaun,
Using Options/Hardware menu, you have to enable the hi-res displaying (WRX) and then select the sponzy.rom.
HTH,
Zsolt

Thanks I've got it working.

Regards,

Shaun.

Is there any way to implement this on the ZXMore (as that has WRK and lots of RAM available).

Thanks,

Shaun.

Sorry Shaun,
I don't have ZXMORE - PokeMon will surely write the correct answer.
Regards,
Zsolt