Tony Firshman wrote: > On Sun, 30 Mar 2003 at 09:17:48, wrote: > (ref: <[EMAIL PROTECTED]>) > >>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?? > > No - the Spectrum microdrives do not work on a QL, at least I have > never got one to work. > They certainly spin at a different rate, hence the really silly sector > figure. >
They can work, just not very reliably in some cases. I have frequently used a 4-mdv system (2 in the QL and 2 Spectrum ones on the cable) to run UCSD-Pascal. It runs better (much!) from floppies, but it does work. I always format cartridges on the QL drives then use them in the Spectrum drives. Oddly, given the problems that we have all experienced over the years with QL mdvs, using cartridges in the Spectrum drives on a Spectrum are very reliable, formatting to around 90Kb. I have hardly ever experienced the "bad medium" on the Spectrum, not so the QL ;-). I still have working cartridges for the Spectrum that were written getting on for 20 years ago. A friend who worked for Sinclair and ICL many years ago said that Sinclair reduced the speed of the drives in the QL to get to the magic 100 Kb, 200 sectors required by the designers. His opinion was that the speed requirement was too close to the mechanical tolerances for reliability. When ICL built the Tonto, etc., the mechanical parts were re-vamped and so they became much more relaiable. Peter S Tillier "Who needs perl when you can write dc, sokoban and an unlambda interpreter in sed?"
