The Sinclair QL Forum

It's been a while since I last reported about OqtaDrive here. A lot has happened since then. An important change is that OqtaDrive has moved to a new home . The latest release is 0.3.4 . If you're using OqtaDrive but did not notice the move to CodeBerg, have a look at the latest feature additions . ...

Ah, got it, thanks. The 'chopping' off of the 1 due to the 16-bit register thing must have thrown me. Yes, when calculating this separately, you need to modulo the total sum (preset + bytes) with 0x1000, to get the actual checksum. Here's the function I have in OqtaDrive for this. Input is the sum ...

Ok, but that wasn't my calculation, that's what is always shown as the checksum at the end of a blank data block. I can never seem to get that result, I think I must be adding hex incorrectly. Ah, ok. Then let's calculate for a fresh data block: 0x0f0f + 0x100 * 0xaa + 0x100 * 0x55 = 0x10e0f That's...

Chr$ wrote:So e.g. for a blank sector it's just pairs of $AA and $55 and the check sum is always $0E0F.

That's the correct data block checksum after formatting. So your calculation is correct.

The QL Advanced user guide mentions a 2 byte checksum at the end of the sector header, but these don't seem to show within mdump .mdv files - the headers appear 14 bytes long and then immediately follows the file number etc. Is it simply not shown in the mdv file, just as the preambles are also omi...

Also doesn't work from Linux, using Firefox, Chrome, curl & wget. Really seems broken. I did download it last year, to use as reference when implementing QL support in OqtaDrive.

The QL Advanced User Guide is already available here, or are we talking about a different book or edition here?

Without the bridge, the drive daisy chain is broken, and nothing would work, be at OqtaDrive or an external real drive. For example, if you remove MDV1 from the QL and don't bridge pins 1 and 2 in its PCB socket, MDV2 will stop working.

Cool! Happy to see it working. I'll add a note to the project README, that points out the need to bridge the two pins when removing drives from a QL.

Hi Ernesto, could you run the OqtaDrive daemon with debug log level and do a dir mdv1_ or a load and post the log here or send via PM? Maybe we can infer something from that. And to clarify, you have OqtaDrive connected to the external connector, removed the internal drives, and bridged COMMS IN to ...