The Sinclair QL Forum

From breadboard to prototype.. small_2013-09-15 14.59.37.jpg small_2013-09-15 15.00.01.jpg small_2013-09-15 15.00.19.jpg I used a Recom 7805 replacement R-785.0-1.0 (switching type regulator) to reduce the voltage from the QL (9 Volts) to 5 Volts before feeding it into the mbed. Theoretically it wou...

Gert, the problem with the existing driver is that basically everything is laid out for no more than 255 sectors. (The sector maps, the file and block # to be transferred to a write vectored routine, basically everything is byte-sized). I doubt this can be tricked to work with larger virtual tapes....

Given the limitations of microdrives, if you're replacing the hardware that sits in the microdrive bays ANYWAY, why not use a floppy driver-based system? Given the extra simplicity and reliability, and roughly equal cost, it's an easier development path. This is a cool project though. You don not h...

Yes - this looks good work - the main issue going forward is going to be to try and get around the 255 sector limit. I would also aim to have this as a replacement which could fit in either the QL's microdrive slots, or a ZX Spectrum microdrive unit - that would open it to the widest possible marke...

Connection to the SD card made, reading and writing works at the moment to a .MDV image file in the main directory of the (micro)SD card !

Very impressive! Will you be able to make some kind of virtual microdrive that could replace the original one inside the QL? That is the idea, using a small and cheap microcontroller. Maybe the new LPC812 connected to a (micro)SDcard and a simple linear voltage stabilizer to create 3,3 Volt from th...

Well, result! Yes... My first directory generated by the mbed and recognized by the QL.. :D dir_mdv3.jpg After some more fiddling the QL now can start and stop the virtual Microdrive and thus read in any sector it wants. The mbed MD emulator keeps track of the current sector and just cycles around a...

dex wrote:I think, that Spectrum Microdrive format and QL Microdrive format are too different, and the book will not help.

Indeed, I found much more relevant information in the QL Advanced User Guide.
Pages 302-310 have been very helpful in getting the timing right.

I know this is an old thread but has anyone of you got any further investigating the microdrive emulation ? On this forum and on the tlienhard.com forum I started threads about my emulation effort with an mbed http://mbed.org as slave device to the QL emulating a microdrive. So far I have succeeded ...

If the timing is no problem, overlapping memory will just work. When a byte is written it is written into both memory chips, when read it should be the same too.. Not pretty but no disaster either. What is possible is to detect if the DMSCL line is pulled externally and than disable the internal mem...