The Sinclair QL Forum

Thanks allot!

Hi,

I would like to know the default parameters for the QL windows, i.e. the red, white and command window so I can restore them at the end of program that changes the window size / mode.
Or maybe a command that can restore them into their original sizes etc?

Thanks,

Antonis

Eventualy I found the problem. It was with the checksum of the file info block. It seems it is wrong in most of the MDV you can find on the net. After fixing the checksums it worked!

Hi Martyn,

Here are some screen dumps from the oscilloscope.

Sector timings and gaps.
sector timing.jpg

Gap between header and data record.
gap between header data.jpg

Data start. Track 1 is yellow.
data start 3 - track1 yellow.jpg

Data end. Track 1 is yellow.
data end 2 - track1 yellow ...

Hi,
I'm trying to make a microdrive emulator for the Sinclair QL using a raspberry pico. I have already built an oqtadrive but actually I prefer something simpler.
I'm using the pico, an SD card reader and a 74LS125 quad buffer that I use to interface with the track lines. For the rest of the lines ...

Hi,

I just checked again my connections. I have

TRACK1 data-> Nano A4-> 2.2K Resistor -> EDGE CONNECTOR TOP.1
TRACK2 data-> Nano A0-> 2.2K Resistor -> EDGE CONNECTOR BOTTOM.1

which I believe is correct. After the problems I had I copied this design from oqtadrive but it did not seem to help.

I ...

Here you can see the test board and more details of the data on the tracks.

Hi and thanks for the help!

Yellow is track1, green track2.

I prepared a few screen shots from the oscilloscope:
1. a few sectors
2. one sector
3. a header
4. a header's data in more detail
5. bit_timing : shows the bit timing in 1μs scale

The power source is from the QL 9V pin through a traco ...

Hi,
I'm trying to port gertk's microdrive emulator to arduino nano + esp32. I intend to use the nano as the interface with the QL, since it supports 5V pins with enough current and use the ESP32 as an interface to the SD card and WiFi access - web server to upload MDV files and manage them.
Although ...

I had a ZX Spectrum and always wanted to get a QL. In 1984 instead of a QL I got a PC as it offered better work perspectives (and I wasn't the one with the money making the choice). I work in the software industry and also with embedded systems. Now, 38 years after I managed to obtain a working QL ...