Search found 54 matches

by zx81user
Sun Apr 21, 2013 10:52 am
Forum: Hardware
Topic: ULA running hot
Replies: 19
Views: 9969

Re: ULA running hot

[quote="RetroTechie"Another approach would be to undervolt the ZX81... anyone tried that already?[/quote] I was also thinking about that, running it at a 10% lower voltage saves 20% dissipated heat, that is quite a lot! But I am not sure if the ULA & Z80 will still work reliably. I might try that wi...
by zx81user
Sun Apr 21, 2013 12:05 am
Forum: Hardware
Topic: ULA running hot
Replies: 19
Views: 9969

Re: ULA running hot

[quote="ksng36"This arrangement, though rather unsightly, does a good job preserving the life of the hardware from heat!Mark[/quote] I am not too worried about the temperature of the ROM & Z80. You could simply replace the Z80 with a CMOS type and preserve the original. Most chips do get warm, which...
by zx81user
Sat Apr 20, 2013 12:15 pm
Forum: Hardware
Topic: ULA running hot
Replies: 19
Views: 9969

Re: ULA running hot

Has anyone mentioned running the zeddy from a 7.5v supply? As long as you're at least 6.5v it should run cool. That would be a good alternative, but I don't think the 16k RAM packs will work anymore, isn't that right? They need the 9V supply for their DC/DC circuits, or will that still work fine on...
by zx81user
Sat Apr 20, 2013 1:12 am
Forum: Hardware
Topic: ULA running hot
Replies: 19
Views: 9969

Re: ULA running hot

because of the thermal resistance of the plastic package, the ULA 'chip' will probably still be fairly 'warm' even if you held the centre point of the ULA at 25C or so..!!!! It might not be as bad as you think, there is a lot of "metal" inside the DIP package, in fact, the center layer (where the d...
by zx81user
Fri Apr 19, 2013 1:46 pm
Forum: Hardware
Topic: ULA running hot
Replies: 19
Views: 9969

Re: ULA running hot

the thermal resistance from the ULA 'chip' itself to the heatsink will probably be quite high.. That's what I thought. It would actually be better to mount the ula on top of a heatsink rather than mounting a heatsink on top of a ula (or both :-) ). I don't know about that DIL40 heatsink, is that so...
by zx81user
Fri Apr 19, 2013 12:14 pm
Forum: Hardware
Topic: ULA running hot
Replies: 19
Views: 9969

Re: ULA running hot

That's really a funny idea. Most people use cooling parts in form of a DIL40 case. :shock: :lol: Yeah I had seen that, but I think the shape of the heat sink is not really important as you can hardly speak of air circulation inside the enclosure. It makes a big difference for sure, the DC/DC conver...
by zx81user
Fri Apr 19, 2013 1:51 am
Forum: Hardware
Topic: ULA running hot
Replies: 19
Views: 9969

ULA running hot

I read on a couple of pages that the ULA would get quite warm, so I thought I would check that out for myself and I was in for quite a shock! :!: I expected it to be warm but it was so hot that it is almost painful to touch! The 7805 heatsink was also warmer than I had expected. So I was in for an i...
by zx81user
Thu Apr 18, 2013 12:03 pm
Forum: Emulators
Topic: saving file as .p
Replies: 12
Views: 10450

Re: saving file as .p

Thanks! I knew it had to be something simple ;)

Michel
by zx81user
Thu Apr 18, 2013 2:10 am
Forum: Emulators
Topic: saving file as .p
Replies: 12
Views: 10450

saving file as .p

I wonder how I can save a file as .p in the EightyOne emulator. It seems I can only save to a "tape" file (tzx) but i'd like to load it as a .p into ZX-IDE and then transfer to the zeddy.

Michel
by zx81user
Wed Apr 17, 2013 12:02 am
Forum: Development
Topic: Working on game nr 20 in 1K Hires.
Replies: 24
Views: 9354

Re: Working on game nr 20 in 1K Hires.

It's really amazing what you can do in just 1k. I am working on an application myself that must fit in 1k (no hires game though) and I actually thought it would be an easy task as it isn't a very complicated application. However, 1k really is very small! I went back to have a look at your previous p...