The Sinclair QL Forum

You are no doubt correct, but I'll verify by sbytes-ing a few bytes starting at 524,288!

I'm planning on making a similar mod - but replacing both logic chips on the right hand (processor) side of the PCB, and doing the same trick - three x 64K blocks - and the remaining socket switchable for either 128K ROM or RAM at the address designated for RAM expansion - for RAM to work - the cod...

That would certainly help with the C1 floppy interface as that takes 7.5K RAM meaning that the configuration programs can't load as they need BASIC and there's not enough memory left. Yes, that was the thing that inspired me to find a way to be able to open them and also any other large-ish BASIC p...

In the darkest depths of the internet I found an OPD Teledrive disk image that I haven't been able to get to work on my OPD yet, but browsing through the content of the image with a hex editor I found a couple of docs/references relating to putting ICL BASIC in ROM - which in my opinion is a mini ga...

Apparently the PCML TeleDrive interface could read C1 disks but would corrupt them if they were written to by it. They are supposed to be PC compatible, i.e. FAT12 with a PC boot sector and with the same geometry as a PC 720K as formatted by MSDOS. The PCML you see is in the DOS manufacturer field ...

Isn't a .IMA file merely a raw image which you can dd or rawwrite onto a 720K floppy? Yes, but it looks to my untrained eye like the .ima file was not originally a C1 OPD floppy disk. The files contain 'PCML' so they must have been disks made with the other interface. And changing those 2 rows of P...

I've just been experimenting with ImageDisk. With it, I was able to create an image file of my OPD formatted disk containing all the mdv wallet stuff. I was then able to write that image using DOS 6.22 (real hardware) to a fresh 720k disk and that seems to work fine in the OPD, so that's a start - I...

I think I may need a pointer or 2 regarding getting OPD images onto real disks! I found the .IMA image online (attached) and am trying to get that onto a real disk in such a way that the OPD can view the files etc. I note that Windows/DOS couldn't see any content on a disk I created with the OPD, th...

After some faffing today (dodgy FDD cable) I now have a working C1 clone floppy interface connected to my Merlin Tonto. A couple of useful observations: 1. It seems to work just as well with the slightly cheaper WD1770-PH controller chip as it does with a WD1772 variant. 2. It also had no issue with...

Success! My original m/b - the one with the boot loop - had some way out of spec electrolytic caps on it and my cheap Chinese tester also read high vloss (for what it's worth), mainly the blue 33uF ones, of which there are 5. Changed those and tried again, still had the boot loop but with a momentar...