Is Microdrive Speed sufficient?

[Paul]

Hi,
I was discussing an Idea with some friends in the german QL forum and the Question rose wether an SD-Card Adapter (that would replace a Microdrive) giving the original speed of a microdrive (because it's a hardware replacement for this that would also be usable on a Spectrums Interface1) would be accepteable?
It would need no drivers and would be 100% compatible (at least that is where we would like to get) as it is a replacement just without the reliability issue and, using an SD card, available and affordable storage.
It would be one Hardware that could be mounted in a original Microdrive case, using the same cables, emulating up to eight microdrives that could be mounted or unmounted from a list of images on the SD-Card. Speedup would be impossibe if we want to keep the original ULAs of QL and Spectrum.

The question here is just if the speed would be acceptable given the good compatibilty and no port being used except the Microdriveconnector (are there any addons using this connector except from microdrives?)
I hope I find some people who answer to this.
Greetings from Germanys west end
Regards Paul

[vanpeebles]

The speed is fine for me, just the reliability that causes problems. This does sound like an existing project mentioned in the hardware thread? Maybe someone could make an electronic microdrive cartridge?

[tofro]

All,
my concern would be not so much speed (which, on an original QL shouldn't be a problem), but much more capacity. An emulated microdrive could (if 100% emulation) not hold much more than the typical 100 sectors worth of data of a tape. That is (at least in my opinion) not enough for modern software. You'd be forced to distribute your files across a lot of virtual drives, or you would need to content yourself with "retro" software.

Cheers,
Tobias

[tofro]

And another one - off topic:

What's the "german QL forum"? Did I miss something here?

Tobias

[Paul]

As requested:
http://forum.tlienhard.com/phpBB3/
I was not shure if I was allowed to post the link.
Most entries there are in German. Translations make them more or less readble.
If you consider posting there and are not good in the german language, english posts are welcome and understood better by most users than the translated equivalent in german.

@vanspeebles:
coud you post a link so its easier to find for me what you were hinting to?

[vanpeebles]

Posting a link to another forum is fine but be sure to tell them about us too The other thread is here:

http://www.theqlforum.com/viewtopic.php? ... 8bdbe07bc1

[Paul]

Posting a link to another forum is fine but be sure to tell them about us too The other thread is here:

http://www.theqlforum.com/viewtopic.php? ... 8bdbe07bc1

I get a "The requested topic does not exist."

[vanpeebles]

Hmm could be with the DNS still updating. If you go to the hardware section it's the top thread called QL SD Card.

[Paul]

All,
my concern would be not so much speed (which, on an original QL shouldn't be a problem), but much more capacity. An emulated microdrive could (if 100% emulation) not hold much more than the typical 100 sectors worth of data of a tape. That is (at least in my opinion) not enough for modern software. You'd be forced to distribute your files across a lot of virtual drives, or you would need to content yourself with "retro" software.

Cheers,
Tobias

Exactly. That's why I ask. If size is not enough we need not think any further. If we make a own driver (having many compatibility issues) we can have larger images in this concept, but then the given speed is a bad joke.
The speed matches the original size of 100k, so files can be read in acceptable time.
The speed is limited by the ula which only generates "fixed frequencies" (I know they vary, but cannot be changed by users) making it impossible to get the bits much shorter. Only the Gaps could be shorter, as on real cartriges. But that doesn't really help.

It was just a question as we thought that adding the spectrum users to the buyers list would be helpful. And a device without any soldering/opening of the QL/Spectrum would be nice to have.
So I wait and see what happens. Maybe there will be a QL-SD for the ROMPORT, otherwise there is someone in the spectrum forum (of tlienhard) connecting a vdrive2 (scottish USB-Port for FAT32 disks like USB-Sticks and hard drives) to a serial port of the spectrum. As the QL also has a serial port this might also be usable on the QL. But the driver needs to be loaded before and uses RAM, which is very limited on an original QL. There is loads of experience with vdrive2 and ZX81 in the german ZX81 Forum. If speed is an issue, there is also a vdip1 device that can be accessed parallel and could be placed on a ROMPORT card - if anyone would develop this!