ZX80 trouble shooting

[Paul]

Yes it recognizes it. 1 to 16 k are valid.
Kind regards Paul

[Lardo Boffin]

Yes it recognizes it. 1 to 16 k are valid.
Kind regards Paul

Thanks. How do I test that it is working? Ideally without trying to type in a really long program....
I’m used to the ZX81 taking extra time to show the K after startup which this isn’t doing. I’m new to the world of ZX80s.

[Moggy]

Here you go Lardo.

I'm almost sure this is courtesy of Mark.


Just tried on my own ZX80 to confirm that you should see 16384 for 16k and 1024 for 1k.

I tried it on a couple of (nameless) emulators and got stupid results so as said above tried on real kit for certainty.


LATE EDIT.

When used with the ZXpand it returns 16382 not 16384 so not sure what's going on there.

[Paul]

Searching for ZX80 ramtop with Google found
PRINT PEEK 16388 + 256 * PEEK 16389 NEW LINE

[Lardo Boffin]

Here you go Lardo.

I'm almost sure this is courtesy of Mark.


Just tried on my own ZX80 to confirm that you should see 16384 for 16k and 1024 for 1k.

I tried it on a couple of (nameless) emulators and got stupid results so as said above tried on real kit for certainty.


LATE EDIT.

When used with the ZXpand it returns 16382 not 16384 so not sure what's going on there.

Thanks Moggy - that does give 16384 on my ZX80.

[Lardo Boffin]

Searching for ZX80 ramtop with Google found
PRINT PEEK 16388 + 256 * PEEK 16389 NEW LINE

Thanks Paul - that also gave 16384 on my ZX80. But it took me a while to figure out how to get PEEK on the ZX80 though!

PRINT PEEK (16388) + 256 * PEEK(16389) NEW LINE

You actually have to type in PEEK not use a key combo. That really threw me.

Does the ZX80 not do a slow scan to determine how much RAM it has? On the 81 it takes a few seconds before the K appears with a RAM pack plugged in. On my 80 it is more or less instant.

[Moggy]

I can't say I know why this (my 80 is the same) I can only assume it 's because it doesn't use floating point for numbers only integer hence some basic programs run faster then the 81 even in fast mode.


Here's a link to the operating manual just in case you don't have it.

https://www.worldofspectrum.org/pub/sin ... Manual.pdf

[Lardo Boffin]

I can't say I know why this (my 80 is the same) I can only assume it 's because it doesn't use floating point for numbers only integer hence some basic programs run faster then the 81 even in fast mode.


Here's a link to the operating manual just in case you don't have it.

https://www.worldofspectrum.org/pub/sin ... Manual.pdf

Thanks. That would make sense about the integer maths.