Search found 171 matches

by rune
Mon Aug 21, 2017 2:45 pm
Forum: Development
Topic: ZXmore - questions and answers (FAQ)
Replies: 131
Views: 32726

Re: ZXmore - questions and answers (FAQ)

Hi, Im getting the parts together for my ZX More. One chip I cant seem to get is a 74HCT85

Farnell dont stock them. eBay sellers want around 4.50 for one. What is the chip used for and can anyone advise where I can get one at a sensible price?
by rune
Sat Jul 15, 2017 7:36 pm
Forum: Hardware
Topic: ZX81 case screws
Replies: 11
Views: 2459

Re: ZX81 case screws

and here is my alternative, black one is original...

Image

Couple of quid for 200. If anyone needs any, PM and we can work something out for the price of p&p.
by rune
Wed Jul 12, 2017 8:58 pm
Forum: Hardware
Topic: ZX81 case screws
Replies: 11
Views: 2459

Re: ZX81 case screws

Well 3mm dont work. The heads are too tight in the recessed holes.
by rune
Wed Jul 12, 2017 5:05 pm
Forum: Hardware
Topic: ZX81 case screws
Replies: 11
Views: 2459

Re: ZX81 case screws

Thanks for the help, Looks like diameter is 2.2 and 9.5 or 6.5.

It those I got are too big, I'll look around the web for some.
by rune
Wed Jul 12, 2017 1:54 pm
Forum: Hardware
Topic: ZX81 case screws
Replies: 11
Views: 2459

Re: ZX81 case screws

They are called plastite screws. I think they are 3 x 12 mm. Got a pile of them from the scrap bin at work. I'll try them tonight and post if they work or not.
by rune
Wed Jul 12, 2017 1:34 pm
Forum: Hardware
Topic: ZX81 case screws
Replies: 11
Views: 2459

Re: ZX81 case screws

Thanks for the link. While I like Sell My Retro, 6.49 inc post for 7 tiny screws is crazy.

If I can get the size(s) its usually possible to buy them a lot cheaper...
by rune
Tue Jul 11, 2017 5:32 pm
Forum: Hardware
Topic: ZX81 case screws
Replies: 11
Views: 2459

ZX81 case screws

Every time I open a ZX81 I lose 1 or 2 screws. Can anyone tell me what type/size of screws to buy?

Thanks

Dave
by rune
Sat Jun 10, 2017 7:56 am
Forum: Hardware
Topic: Create ULA for €5?
Replies: 84
Views: 17430

Re: Create ULA for €5?

I'd like one too Paul and am happy to prepay.
by rune
Fri May 26, 2017 10:50 pm
Forum: Hardware
Topic: Resurrecting a ZX81 - Step by step help appreciated.
Replies: 26
Views: 5448

Re: Resurrecting a ZX81 - Step by step help appreciated.

Hi Mark, Im going to post a couple of pics to make sure I know what pulse/rapid pulse etc looks like: http://www.weegieboard.co.uk/Images/Pulse.jpg normal pulse eg Z80 Pin 16 .5us 5V http://www.weegieboard.co.uk/Images/Rapid.jpg rapid pulse eg Z80 Pin 19 .5us 5V http://www.weegieboard.co.uk/Images/A...
by rune
Thu May 25, 2017 10:19 pm
Forum: Hardware
Topic: Resurrecting a ZX81 - Step by step help appreciated.
Replies: 26
Views: 5448

Re: Resurrecting a ZX81 - Step by step help appreciated.

A little more work, replacing "equivalent" transistors with the correct ZTX313s and finding a short now means I have three boards all showing good signals at ULA P14, TR2 and Z80 P6. Also got decent back porch at ULA p16. On the three boards I think I have one with a good CCB Composite board, one I ...