Some time ago, Peter Graf kindly sent me a very early test version of QL-SD, designed to be used with the parallel port of a Super Gold Card. At the time, it had no real drivers and could only be used via a modified version of Jonathan Hudson’s Mtools software and a little front end I’d written for it, which was a bit clumsy.
Back in November, Peter sent me some new software to try out with it. This included a QL_BDI.BIN (the container QL filing system used by the current QL-SD drivers, called a Block Device Image – BDI) and a minimal set of software drivers. At the time I was unable to even find time to set up my Aurora/Super Gold Card system because of my partner Ann’s illness. It was only in the last few days that I got time to fetch out the system and find the parallel port version of QL-SD so carefully stashed away in the attic.
Peter had been careful to warn me that I had to use an SDHC card (not an old SD card) and it HAD to be freshly formatted in FAT32 format. Being as the 8GB SanDisk card was brand new, I foolishly copied the filing system file QL_BDI.BIN onto it, put the driver file on a floppy disk and wandered over to the Aurora. I LRESPRed the driver and waited until…
“Checking FAT…MOUNT failed! SD Card not found!” it said. Oh dear.
I duly reported this back to Peter, half expecting to be shouted at for taking this long to test the device with no positive outcome at the end of it. However, Peter merely reminded me it had to be a freshly formatted SDHC card, so that the QL_BDI.BIN file was contiguous on the card (not fragmented in different areas on the flash memory card). Having done this, I tried again and this time it worked. The card was recognised and I could copy files to it, list files, delete, create directories and so on. That will teach me to assume that a brand new SDHC card will be freshly formatted :o)
Then it all fell apart again. I used my copier program, called The Copier, from http://www.dilwyn.me.uk/files/index.html . I often use this program as, unlike most copiers, it can recreate the directory structure of an entire drive as well as copy the files. Sadly – bye bye SD card. Something went horribly wrong as it tried to make directories – it reported ‘Out Of Memory’ although there was 2MB free according to PRINT FREE_MEM. The QL_BDI.BIN image was no longer readable, even after resetting the computer. Back to the drawing board.
Reformatted the SDHC card, recopied the QL_BDI.BIN and this time did exactly the same thing running from SBASIC with manual MAKE_DIR, COPY and WCOPY commands. This time it worked. And worked well. At last I was able to send a positive report back to Peter that it worked, although one or two file handling programs seemed to cause problems. And I still have no idea what actually caused the problem with these programs, the only common feature is a QLib compiled MAKE_DIR command – The Copier works fine as long as you don’t tell it to recreate the directory structure.
When using the QL-SD with MTools I seem to remember file copying was slow. But copying using the new QL-SD drivers seemed much faster, although I didn’t have time to do detailed timings.
Like the better known version of QL-SD, this one uses the device name SDC1_, so to list files, for example, do DIR SDC1_ .
I now have a QL-SD manual and can experiment further with this device plus perhaps try out the BDI container files with QemuLator drivers which are supplied with QL-SD I believe – this would open up the possibility of using QemuLator to transfer files between Windows and my Aurora/SGC computer, which I’ll report back on later. I’ve read somewhere recently that Peter has made it possible for uQLx emulator to use the BDI filing system too.
So now we have another possible SD card interface to consider. While this will only work over a bidirectional parallel port like the Super Gold Card one, for people who don’t want to open up the QL to install a standard QL-SD.
Would there be interest in a parallel port version of QL-SD? If Peter gets feedback from users who would like to get this version, it might encourage him to arrange to get a few made.
It has to be said that this unit of mine is a VERY early prototype, and I remember him telling me a while back not to open it up to have a look as I’d probably never be able to put it all back together again (which sounds like early prototypes).