Tape level indicator

[blackdalek]

I'll vote for battery powered too. And pre-built

[Bryce]

There's actually no difference between the 5V and 9V versions, so I think I'll just supply them all with the 9V battery version with the comment "This can be powered fropm the CPC 5V intead if required".

I did a quick layout last night and I'll make a prototype (excuse to play with my newly built CNC PCB router ) as soon as I have time.

Bryce.

[remax]

Any news ?

[Bryce]

I've been away for ages and have a huge backlog of repairs to get through, so no, nothing further has been done at the moment.

Bryce.

[remax]

I've been away for ages and have a huge backlog of repairs to get through, so no, nothing further has been done at the moment.

Bryce.

No problem, i just wanted to have news 

[LambdaMikel]

How is this one doing btw?

[Bryce]

It's not, but as soon as I have finished building the Joystick testers I'll get back to it.

Bryce.

[remax]

Now that i finally found the time to hook up my external tape player, this would come very handy !

[Bryce]

Now that I'm stuck at home, it may be a good time to actually do this project

Bryce.

[protek]

Would the level indicator work in the case of recording a file from the PC soundcard to tape?

[Bryce]

It would work with any sound source connected to the CPCs Tape input socket.

Bryce.

[protek]

It would work with any sound source connected to the CPCs Tape input socket.

Well then, count me in for one as well, if you're still taking interests.

[RetroCPC]

Bryce,

My first post here - I've just purchased a non working CPC6128 from EBay - Hopefully it should arrive sometime next week.

More years ago then I care to remember I owned a "fully loaded" CPC464 with green screen monitor. I dont recall any tape loading errors with the CPC464 internal tape drive - how sensitive / fussy is the CPC6128's tape interface circuit? I recall my first "computer" a ZX81 being a real hit or miss affair - yes lost so many hours having to retype code after a failed save to tape...

As your going to so much effort to design / building / testing / shipping PCB's I wonder if it would not be beneficial to add a couple of band-pass filters to improve the robustness of the tape interface circuit - not sure what coding format Amstrad used on the tape interface, but suspect its some form of FSK modulation... I would imagine a coupe of bandpass filters set around the 1 / 0 tones would make a huge difference to the reliability of the interface... I would be happy to help with the schematic / PCB layout if you wanted... we could added the level meter after the bandpass filters to give a really decent indication of level...

The PCB could be powered from the 5V or 12V... inserted in the power leads from the monitor...

Is there any decent information on the CPC's Tape interface / modulation scheme? What would be great is test software that generates test tones over the tape interface.. it really should not be that hard to do... the tape port seems to be connected directly to the 8255... this does leave many possibility to improve the interface.

When my unit arrives I can investigate the interface - but I don't currently even own a tape cassette player / cassette tapes...


I'll also purchase a CPC464 when I clean unit comes up to probe its internal tape section - it will be strange to own one again after so many years...

[Bryce]

A bandpass filter would improve the reliability, I even have it on my list of trials. However, the volume seems to be the thing that most people battle with, which is why I looked at making a level indicator in the first place. The 464 doesn't have this issue as the tapedeck has fixed volume.

As far as schematics / layouts are concerned, I think I already had them finished when I (temporarily) abandoned this project. My plan was to power it all from a 9V battery for several reasons: It doesn't  need to be permanently powered, a battery introduces no additional noise to the signal and there are already many other CPC expansions taking power from the 5V rail.

If you think the ZX81 was hit and miss, try loading a tape on an Oric 1

Bryce.

[RetroCPC]

Now your just being flash I was too poor to own an Oric1   - you really have to ask yourself HOW anything could have a worst tape interface then the ZX81!!!

[Bryce]

They managed it by messing up the firmware, if you install the Oric Atmos Firmware it's almost as reliable as a ZX81

I like the Avatar pic, is that to compliment my Max Headroom theme?


Bryce.

[RetroCPC]

Arh yes - Dear Amanda Payes - my first "Love" the reason I watched Max Headroom  - wonder how the series has fared the test of time!

I used to digitize the video image with my CPC video digitizer card (was it from John Morrison? - then upgraded to a Romco or some such)... Max actually came out quite well - maybe due to his limited palette and resolution...


You can have Max, I'll keep Amanda!

[VintageAdvantage]

A TAPE LEVEL INDICATOR? 
Wow, you guys are really developing HIGHTECH here, aren't you? 
No wonder development of this kind of sophisticated equipment takes YEARS!

[tjohnson]

A TAPE LEVEL INDICATOR? 
Wow, you guys are really developing HIGHTECH here, aren't you? 
No wonder development of this kind of sophisticated equipment takes YEARS!

Wow I think someone thinks they can do better?  Go ahead make my day

[VintageAdvantage]

Wow I think someone thinks they can do better?  Go ahead make my day

Hold your johnson uhmm horses - all cool 

[tjohnson]

Hold your johnson uhmm horses - all cool 

Cheers Uncle Sam, horses held.

[RetroCPC]

A TAPE LEVEL INDICATOR? 
Wow, you guys are really developing HIGHTECH here, aren't you? 

Indeed, we have our CPC's arranged in a Mini CPC super Cluster with custom developed node to node RS232 networking maxed out at 19200 baud to power the simulation tools...

No wonder development of this kind of sophisticated equipment takes YEARS!

Something of very great concern to the whole team, we have been exploring the possibility of overclock our CPU's to 8MHz to reduce the simulation times... we might need to resort to water cooling - we are however concerned about the upper clock limit of the CPC's ASIC... working at the forefront of technology is just so fraught with challenges!!!

We are dedicating the full engineering mindset of the collective, but have no fear - a working level meter is near!

[Bryce]

A TAPE LEVEL INDICATOR? 
Wow, you guys are really developing HIGHTECH here, aren't you? 
No wonder development of this kind of sophisticated equipment takes YEARS!

Why does it have to be something High-Tech? Lo-Tech things can be extremely useful to users too. Should we stop making spoons because they are not sophisticated enough?

Bryce.

[RetroCPC]

Why does it have to be something High-Tech? Lo-Tech things can be extremely useful to users too. Should we stop making spoons because they are not sophisticated enough?

Bryce.

I took the original post from VintageAdvantage as just jest no negative intent..

BTW - this level meter from EBay looks interesting, could be powered from the Monitor 12V output.

https://www.ebay.com/itm/New-32-LED-Level-Indicator-VU-Meter-Music-Sound-Audio-Display-Analyzer/382481146148?

[Bryce]

Yeah, but I'd prefer my own single PCB layout with the sockets and other components together. Also, it has way too many LED's. The device only needs maybe 7 LED's: 3x Red, one green in the middle and 3x Red on the other side. So you know where to hit. The entire device can be much smaller than that.

Bryce.