Search found 2035 matches

by Moggy
Sat Jul 11, 2020 10:56 pm
Forum: Hardware
Topic: ZX81 ROM burning
Replies: 6
Views: 167

Re: ZX81 ROM burning

I don't see why they shouldn't work from an electrical point of view if they are designed to make the 2764 replace the original chip, the one point to consider is will the cases go back together with the adaptor fitted as there is not much clearance between the ROM chip and the top case and any adap...
by Moggy
Sat Jul 11, 2020 10:50 pm
Forum: Hardware
Topic: ZX81 ROM burning
Replies: 6
Views: 167

Re: ZX81 ROM burning

You may also find this useful, a double speed BASIC, ROM image found here...

https://www.sinclairzxworld.com/viewtop ... lit=zx81x2
by Moggy
Sat Jul 11, 2020 10:45 pm
Forum: Hardware
Topic: ZX81 ROM burning
Replies: 6
Views: 167

Re: ZX81 ROM burning

I use quite a few 2764's in my zeddies but was guilty of using an over elaborate rewiring system for the chip until i was educated by the forum member found here.. https://www.sinclairzxworld.com/viewtopic.php?f=22&t=3725 I think you will find his first post most illuminating with a very easy quick ...
by Moggy
Fri Jul 10, 2020 12:57 pm
Forum: Development
Topic: ZX81 Assembly on OSX
Replies: 15
Views: 324

Re: ZX81 Assembly on OSX

Some common ROM routines, their address in hex, new or old ROM and register use. If there is any interest I can also scan the accompanying text to these routines taken from the book mentioned below, other wise the meanings should be clear enough. In nearly every one the full register set is used so ...
by Moggy
Wed Jul 08, 2020 12:11 pm
Forum: Hardware
Topic: Differentuating a different logic states/pulses on oscilloscope
Replies: 14
Views: 705

Re: Differentuating a different logic states/pulses on oscilloscope

Can I add my personal thanks too Mark for this most enlightening,informative series of posts? This should definitely be placed somewhere prominently for people new to the zeddy to use as a go-to and for those like myself who are less technically minded to refer to now and then. Excellent just excell...
by Moggy
Sun Jun 28, 2020 2:06 pm
Forum: Welcome Area
Topic: Found a ZX81 and fixed it
Replies: 14
Views: 996

Re: Found a ZX81 and fixed it

Superb news, another one back on the road. Well done Sir!! :D
by Moggy
Thu Jun 25, 2020 9:11 pm
Forum: SALES
Topic: Lardo buys another zeddy
Replies: 82
Views: 18583

Re: Lardo buys another zeddy

Do you have the coloured screen overlays?
by Moggy
Thu Jun 25, 2020 8:32 pm
Forum: SALES
Topic: Lardo buys another zeddy
Replies: 82
Views: 18583

Re: Lardo buys another zeddy

Sensible thinking. I hope Karl can make some more of his boards soon because the home made thing is ok but you need the later back porch ULA and I find they never work well on modern LCD TV's. Just as a side issue. When using those video boards I recently thought I'd try them with a switch wired in ...
by Moggy
Thu Jun 25, 2020 8:19 pm
Forum: SALES
Topic: Lardo buys another zeddy
Replies: 82
Views: 18583

Re: Lardo buys another zeddy

Hee hee !

Why are you replacing that ULA Lardo? I always liked the look of those later Ferranti jobbies.

The Vectrex now there's a strange beast. I have it on Pi emulation but cannot get to grips with it at all.


Moggy furiously scribbles letter to Mrs Lardo