I seem to recall the following information from many years ago: 1) cabling has to be reversed, i.e. using standard leads, the microdrives end up facing away from you. (you probably knew this already if you've actually got 2 of them working)
2) there is a slight speed difference between QL and ZX microdrives, but usually does not matter too much, but may show up in format operations or reading 'marginal' cartridges. IIRC, there was a recommendation that you did not format QL cartridges using ZX microdrives on a QL, not sure if this was due to speed variations or what. 3) the format of ZX, QL and OPD/Tonto cartridges are different 4) presumably you have tried these drives on a Spectrum to check that they do actually work on a spectrum system? Dilwyn Jones Rich Mellor wrote: > Here's a little oddity... > > I have got 3 ZX microdrives which supposedly work with the Spectrum (and > Interface 1). However, I have tested them by adding them to the QL's > microdrive expansion port and using FORMAT ram1_mdv3 (thanks Miracle) with > the following results: > > 1) All 3 plugged in together, give format failed on mdv3 to mdv5 > 2) I tried the middle ZX Microdrive on its own - that gave format failed.. > 3) I tried each of the other two ZX Microdrive units on their own - both give > 255/255 sectors (ie. all sectors on the cartridge are copied across). > 4) I tried these 2 working ZX Microdrive units together - both now allow the > format command to copy the microdrive cartridge, but they only give 248/255 > sectors and 221/255 sectors > > Hmm - is there a loss of signal when using more than one add-on ZX Microdrive > ?? I seem to recall that these units were not up to the same standard as the > built -in QL microdrives - am I correct??
