Thursday, 8 May 2014


Here are some of my very first experiences with QL-SD card reader for Sinclair QL, the Most Interesting Computer in the World. This is a recent solution, designed by Peter Graf and manufactured by Paul Veltjens. It allows to bypass the dreadful Microdrive and gives a larger capacity drive image for loading and saving files.

The device is very straightforward and it's also really simple to install. Although it is a kind of a prototype, the device appears quite well thought out and clean. No soldering or messing with the QL: You only need to open the QL and replace a couple of chips.

Lazy man's install. The card reader is intended to replace one of the Microdrives.

The manual is extremely well written and helpful, but I'll summarize the process anyway.

  • Backup the files that already exist on the SD to your PC/Mac/Linux. From the included folder, unpack a suitable sized drive image (Such as QL_128K_BDI.BIN if you have unexpanded QL) and rename it to QL_BDI.BIN. Copy it on the card top directory, overwriting the previous file. Put the card back in the reader.
  • Open the QL case (leave in the two screws below the microdrives, and oh, be careful with your keyboard membranes).
  • Remove the two ROM chips from the QL and insert the QL-SD ROM chip. I found the chip somewhat tight to insert. The pins are a bit short, so make sure the chip is firmly in place.
  • It's possible to replace the physical microdrive with the reader so that the card sticks out neatly from the existing drive opening. The circuit board has ready-made holes for this.

What you should see after a succesful installation.
Then, off you go. Turning on the QL brings up the Minerva logo, and you have a possibility to bypass the reader. Minerva is one of those improved ROM thingies, which holds overall enhancements over the original QL ROMs. The default setup also boots to the Toolkit II extension, which longtime QL users swear is "absolutely necessary". The TK2 helps with directory structures, networking, multitasking and offers a plethora of handy new commands. But if you need to make the boot slightly faster and save some memory, the Toolkit can be made optional.

A bit sad thing here is that the unexpanded QL can only really handle 3MB drive images. This can't be helped. But let's not despair, that's still more than 35 microdrive cartridges! (And from what I get modern memory expansion options are soon arriving.) But anyway, it all depends what you want to do with your QL. For now, I'm quite happy to mess around with the SuperBASIC and fiddling with the boot file.
Toolkit II loaded, listing multitasking jobs
As I have two QLs, I'm interested in the possibilities for using the second QL as a "pure" vanilla machine, connected to the QL-SD boosted computer. So far, I had no luck in using the Toolkit II FSERVE command for setting up a file server, which would have been cool. I did load and run the Toolkit via LBYTES to the second QL, though. The network loading seems to quit altogether after I activate the Toolkit II. This may be due to memory, Toolkit II or it's just something I don't yet understand about the syntax. It's probably nothing to do with the QL-SD per se as the network works fine without the TK2.

The QL-SD appears a very good solution for SD card reading, something I've been waiting to happen for QL for some time. I can only hope these will be available in the future too.


  1. Kewl! I'll try mine soon. Hopefully it'll create some interest in QL coding again.

  2. Tero,
    the reason why FSERVE breaks on your second QL is that TK2 does all the network timing using tight loops - Trose run at different speed (about half as fast) if the Toolkit is loaded in lower (unexpanded) RAM (due to concurrency with the video chip). If you want to use the QL network, you should either have a 0 wait state RAM extension or run TK2 from ROM - ideally from an expansion board, as QL-SD already occupies the ROM slot memory area.