Issue 2 Spectrum not loading software

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StephenM
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Issue 2 Spectrum not loading software

Post by StephenM » Wed Oct 09, 2019 11:36 am

Hi can anyone give me some ideas of what may be wrong with my Spectrum.

It's an issue 2 board and I'm using the PlayZX app on Android to try and load software. I have a mono cable and have tried various different volume levels to no avail.
The loading bars appear and I can get it to recognise the program, which it then continues to start displaying the title screen (sometimes this is corrupted other not) At this stage I get the tape loading error either 1:13 or 1:14.

The beeper works but I cannot hear the sound of the audio file loading. Is there something in the audio input circuit playing up and what can that be.

Any help will gratefully received
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Ast A. Moore
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Re: Issue 2 Spectrum not loading software

Post by Ast A. Moore » Wed Oct 09, 2019 1:14 pm

Provided you’re plugging the mono cable into the EAR socket (and not MIC), it’s likely that your audio source level is too low. If you are using a modern device for playback (such as a PC or a smartphone), then their output is usually not sufficient to drive a Spectrum’s audio input circuitry, especially that of the earlier models (Issue 1 and 2).

Try obtaining a small headphone amplifier and feed its output into the Spectrum.
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Every man should plant a tree, build a house, and write a ZX Spectrum game.

Author of A Yankee in Iraq, a 50 fps shoot-’em-up—the first game to utilize the floating bus on the +2A/+3,
and zasm Z80 Assembler syntax highlighter.

StephenM
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Re: Issue 2 Spectrum not loading software

Post by StephenM » Wed Oct 09, 2019 3:14 pm

Ast A. Moore wrote:
Wed Oct 09, 2019 1:14 pm
Try obtaining a small headphone amplifier and feed its output into the Spectrum.
Ok I'll try that thanks.
What is the minimum and maximum decibel limit that this issue 2 spectrum accept?
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Ast A. Moore
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Re: Issue 2 Spectrum not loading software

Post by Ast A. Moore » Wed Oct 09, 2019 10:39 pm

The Speccy is looking for something like 2–5V of the input signal’s amplitude. Most PCs and smartphones don’t produce a signal of more than 1V. Apple gear (both computers and iPhones/iPads, etc.) can put out up to 1.5V, and most Spectrums are okay with it (mine certainly are), but I’d say that’s the bare minimum.
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Every man should plant a tree, build a house, and write a ZX Spectrum game.

Author of A Yankee in Iraq, a 50 fps shoot-’em-up—the first game to utilize the floating bus on the +2A/+3,
and zasm Z80 Assembler syntax highlighter.

StephenM
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Re: Issue 2 Spectrum not loading software

Post by StephenM » Thu Oct 10, 2019 6:10 am

Hi,what do you think of these. Am I looking at the right thing? I don't want you to put your neck on the line but these are 3 different types of inline amps. Which vart would you think would more likely get the results I'm after?





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Ast A. Moore
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Re: Issue 2 Spectrum not loading software

Post by Ast A. Moore » Thu Oct 10, 2019 9:28 am

It’s hard to say with modern headphone amps, since most of them are designed to drive low-impedance loads (typically 16–32 Ohms). When the Spectrum was designed, it was meant to be used with tape recorders that expected loads in the hundred-ohm range. That said, the LIAM and DAAN looks like it will be capable of doing the job. I’m just guessing here, though. Don’t take my word as gospel.
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Every man should plant a tree, build a house, and write a ZX Spectrum game.

Author of A Yankee in Iraq, a 50 fps shoot-’em-up—the first game to utilize the floating bus on the +2A/+3,
and zasm Z80 Assembler syntax highlighter.

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1024MAK
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Re: Issue 2 Spectrum not loading software

Post by 1024MAK » Thu Oct 10, 2019 3:10 pm

I normally suggest some PC amplifier speakers like these.

Note the above is an example, I cannot vouch for that particular model. You will also have to buy suitable adapters / cables, as the speakers will be wired for stereo, but the ear socket on the ZX Spectrum will only work with a 3.5mm mono plug.

Mark
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StephenM
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Re: Issue 2 Spectrum not loading software

Post by StephenM » Fri Oct 11, 2019 7:48 pm

Success!

I bought the £30 inline amp from Amazon last night and it was delivered today , and it worked.

Thanks for the help.
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Ast A. Moore
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Re: Issue 2 Spectrum not loading software

Post by Ast A. Moore » Fri Oct 11, 2019 11:14 pm

Glad it all worked out for you.
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Every man should plant a tree, build a house, and write a ZX Spectrum game.

Author of A Yankee in Iraq, a 50 fps shoot-’em-up—the first game to utilize the floating bus on the +2A/+3,
and zasm Z80 Assembler syntax highlighter.

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