MZ-700 Blank Key.

Doz
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Re: MZ-700 Blank Key.

Post by Doz »

Been while, real paying work and a broken ZX Spectrum got in the way.

I've set the tape speed (using 8KHz) and the azimuth (using 4KHz , don't have a 3K tape)

Scoping up pin 8 of the cassette recorder interface, shows nice data is arriving, and yet I still get intermittant reading of the header, and never a sucessful load.
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Doz
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Joined: Thu Jun 03, 2021 9:38 pm
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Re: MZ-700 Blank Key.

Post by Doz »

Data is arriving on Pin 12 of the 8255...
Doz
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Joined: Thu Jun 03, 2021 9:38 pm
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Re: MZ-700 Blank Key.

Post by Doz »

... although it's junk ...

Looking at the timing from the data on the tape, it's clear something's not right with the alignment. Listening back to the Basic tape vs the wav on a known good cassette deck, it appears the tape is recorded at the wrong speed. Checking my 8K speed alignment tape against the known good deck, shows that to be OK.

I've jumpered pins 2 & 8 on the cassette deck connector and grounded pin 5, and fed the wav in from my ancient MP3 player ... bingo.

Re-recording the wav on the known good deck, and it all now works :)

@ psmart, is that offer of a blank key and stem still available?
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Doz
Posts: 18
Joined: Thu Jun 03, 2021 9:38 pm
Location: Gloucestershire
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Re: MZ-700 Blank Key.

Post by Doz »

Just a little write up on the 'ole blog.

https://andydoz.blogspot.com/2021/08/sh ... s-and.html

Thanks for listening to my ramblings, and helping me out.
psmart
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Re: MZ-700 Blank Key.

Post by psmart »

Sure, just PM me an address and will post it to you.

I wrote an extension to my monitor program TZFS which allows me to read/write all the MZ format cassettes on the MZ-700 data corder. I needed this for the MZ-80B/2000/800 as they use different speeds/specs and it showed how sensitive the tape speed is. I have a few tapes which where obviously written with worn drive belts as they are not readable after calibration!!!

Well done though, another restored machine - as they say on the X68K forum - 'Keep the scene alive' .
Sharp MZ/X Series Projects and FPGA Emulator
engineers@work : https://eaw.app/sharpmz-series/
Doz
Posts: 18
Joined: Thu Jun 03, 2021 9:38 pm
Location: Gloucestershire
Contact:

Re: MZ-700 Blank Key.

Post by Doz »

Key now replaced. Left it out in the sun for a bit, which is slowly bleaching the case.
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