Built mine Minestrel ZX80 Clone, but

Discussions about Sinclair ZX80 and ZX81 Hardware
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nihirash
Posts: 22
Joined: Sat Jul 28, 2018 8:00 pm

Built mine Minestrel ZX80 Clone, but

Post by nihirash » Sat Aug 04, 2018 2:57 pm

Inverse characters are inversed or stable by half or sometimes "noisy" filled second part.

Tape loading always failed(tried from notebook via audio output, wav file made by FASM-ZX IDE).

Does anybody know what may be reason of this issues? "Hello, worlds" from basic works correctly.

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1024MAK
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Joined: Mon Sep 26, 2011 10:56 am
Location: Looking forward to summer in Somerset, UK...

Re: Built mine Minestrel ZX80 Clone, but

Post by 1024MAK » Sat Aug 04, 2018 3:16 pm

I don't have one of these, so can only give general guidance.

For your inverse character issue, could you post up a photo of the screen image please.

I don't know about the tape cassette circuitry on this clone, but all original Sinclair computers were designed with the 'shoe box' style mono-cassette decks in mind. They could output a reasonable amount of voltage on their earphone output jacks. In comparison, on most modern audio devices/outputs, the output from the headphone sockets are limited, and often are unable to produce sufficient signal, so when used with the original Sinclair computers, the computer can't hear the signal. So you will often find advice to use an audio amplifier (with headphone output) to help.

Secondly, it's actually rather tricky getting the volume setting correct for the ZX80 and ZX81. And some LCD's just don't like the strange signal that the computer produces during loading and saving, which does not help.

Mark

nihirash
Posts: 22
Joined: Sat Jul 28, 2018 8:00 pm

Re: Built mine Minestrel ZX80 Clone, but

Post by nihirash » Sat Aug 04, 2018 9:19 pm

Hello!

I've swaped Z80 with mine ZX-Speccy and cursor stable now.
Now basic works ok.

But when I tried to load mazgos(for ZX-80 with 8K rom) - it crashing mine Zedddy. For test I created "test tape" with

10 PRINT "HELLO, WORLD"

This loads ok. 3K Invaiders crashes too.

RAMTOP points to 32768
Is there ramtests for ZX-81 or ZX-80 with 16K RAM?

nihirash
Posts: 22
Joined: Sat Jul 28, 2018 8:00 pm

Re: Built mine Minestrel ZX80 Clone, but

Post by nihirash » Sat Aug 04, 2018 10:34 pm

I corrected volume and all was loaded fine!

Now I'm real member of Zeddy-fan community :D

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1024MAK
Posts: 2151
Joined: Mon Sep 26, 2011 10:56 am
Location: Looking forward to summer in Somerset, UK...

Re: Built mine Minestrel ZX80 Clone, but

Post by 1024MAK » Sat Aug 04, 2018 10:45 pm

Well done :D

Have fun ;)

Mark

nihirash
Posts: 22
Joined: Sat Jul 28, 2018 8:00 pm

Re: Built mine Minestrel ZX80 Clone, but

Post by nihirash » Sun Aug 12, 2018 4:14 pm

Photo of mine self-built zeddy.

Image

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