New release of EightyOne available

[Spinnetti]

Awesome, making what IMO is the best emulator for me even better!

[kmurta]

A significant new version of EightyOne (v1.29) is now available. It can be found here:

Splendid! Congratulations for the excellent work!

The new version also includes support for the Improved Wait circuit functionality devised by Wilf Rigter to avoid the ZX81 needlessly running ~10% slower than it could have done.

Wow! Maybe it can also support clock doubler in a future version?

It's not a requirement, just an unassuming suggestion.

[jjp]

Great! thanks for accept my suggest! it works excelent!

Good to hear it works!

Other issue, the sources requiere a component named AnimTimer, but it is missing... anyway this component isn't used, but fail the compilation.

Thanks for bringing it to my attention. I'll sort that in the next release.

thanks!

[Paul]

Thank you very much for your efforts Paul!
I downloaded the 1.29 and it works perfectly for me!

[Elurdio]

Hi,

I have tried version 1.29 for Jupiter Ace emulation and using 48 K Ram Pack it does not work at all. With no Ram pack or 16K or 32 k rampacks it works fine, but with 48 k NO (the one I use).

The screen show artifacts and you can not write anything.

[Paul]

Ace with 16k and 48k works fine on my Eightyone 1.29

[Elurdio]

Hi,

After reading Paul's answer telling that for him it works fine with 48k I have made more tests.

I have found that it fails with 48k if you have allowed to overwrite ROM. If you start the emulator with this opiton allowed, it fails. If you start the emulator with this option deactivated and activate it, it works fine but when you do a hard reset to the emultor, it fails...

So it is a problem with 48k and the option "Protec ROM from Write" unchecked (that is, rom overwrite allowed).

[Fruitcake]

The Jupiter Ace ROM begins by testing the amount of RAM present. It starts at address $3C00 and progresses up the memory map writing value $FC to each location and reading it back to check if RAM exists there. When 48K RAM is selected and ROM protection is disabled then when the end of the Z80 address space is reached at $FFFF, things wrap back to address $0000 where the ROM resides and since the ROM is no longer protected then the ROM gets overwritten and hence crashes the computer.

Disabling the ROM protect option only makes sense if there is less than 48K of RAM present or if a custom ROM is used that does not perform the memory test employed by the standard ROM.

If you have run the emulator with 48K RAM and ROM protection disabled and hence corrupted the ROM contents, just re-enabling the ROM protection is not sufficient to recover things. You also need to perform a Hard Reset from the Control menu (or via Shift F2) which will re-instate the contents of the ROM.

[Fruitcake]

Wow! Maybe it can also support clock doubler in a future version?

Are there details somewhere of how this works as presumably something clever must be done to maintain the timing of the display output?

[Elurdio]

The Jupiter Ace ROM begins by testing the amount of RAM present. It starts at address $3C00 and progresses up the memory map writing value $FC to each location and reading it back to check if RAM exists there. When 48K RAM is selected and ROM protection is disabled then when the end of the Z80 address space is reached at $FFFF, things wrap back to address $0000 where the ROM resides and since the ROM is no longer protected then the ROM gets overwritten and hence crashes the computer.

Disabling the ROM protect option only makes sense if there is less than 48K of RAM present or if a custom ROM is used that does not perform the memory test employed by the standard ROM.

If you have run the emulator with 48K RAM and ROM protection disabled and hence corrupted the ROM contents, just re-enabling the ROM protection is not sufficient to recover things. You also need to perform a Hard Reset from the Control menu (or via Shift F2) which will re-instate the contents of the ROM.

Ok. Thanks.

So, wiht 48K (or 96k) I have to uncheck "Protect ROM from Writes" once the emulator has been started and check it before end session or reset it, isn't?
In other words, wiht 48k: Every time EightyOne starts or it is resetted it must have the "Protect ROM from Writes" checked.