Over the last several months I have had problems with my hard disk. I have inquired here for advice several times as conditions changed and recieved help from several of you. Now the problem seems to be fully resolved so I thought I'd write out what happened and upload it as a file in case it might be of some help to someone. This informmation would have saved me a lot of trouble had I known it in the beginning. The basic trouble always seemed to be that sometimes the Hard Disk would not boot up. I could always boot from a floppy, but then could not access the hard disk. At first, this seemed solvable by opening the computer and reseating the HD cables at the controller card. Finally this no longer helped. On advice from several people, I blamed the controller ( a CHS from Suitable Solutions) So I replaced it with a used DEC controller. For several days after installing this, the problem seemed to be cured. Then it started in again--just like in a bad movie. Over a period of time, it got worse but for a while, I could get it to start by reseating the cables on the back of the drive. Someone had told me here that there was a place on the bottom of the drive where you could actually manually turn the shaft and and thereby start it turning. By this time I was aware that the drive was making a lot of noise when it did run, though it worked ok when it did run. That is, no errors. I realized that seating the cables on the back was not the direct problem--the movement of the whole drive (it had to be slid out and then back in again to do this) was enough of a jog to move the motor and/or disk enough to free it and allow it to start turning. Enough for a while. Then I had to resort to turning the bottom of the shaft. This always worked and still does. This disk drive is a Seagate ST 251 40 meg from Suitable Solutions so it had pretty good milage on it. I figured to get another one like it and started shopping around locally and then in Computer Shopper. There I found lots of them advertised new used and refurbished. Also the faster ST 251-1. I decided to go for new. After all, I already had a used one. I also found an ad for something bigger--a Microscience HH 1090 80 meg brand new. This is a half height MFM drive that I thought would format at about 65 meg on the Rainbow. It was a bit pricey but with all that extra space, I thought, go for it. Even though I had the infromation in Jerry Miller's article on page 4 of the June, 1988 issue of Rainbow News, I did not do the arithmetic so was dissapointed by about 10 meg. He gives the formula: (CYL * HEADS *8)/1024 = Approximate formatted capacity in megabites shere CYL must be less than or equal to 1024 and HEADS must be less than or equal to 8. Drives whose cylinders or heads exceed these values can only be formatted to the limit of either value. Note that these are approximations only. This drive has 7 heads and 1314 cylinders so it comes out around 55 meg. I'm still glad to have the extra space. There don't seem to be many MFM half height drives over 40 meg around. Half-height is the problem. The Rainbow must have MFM type drives which are not being made anymore and are getting scarce. Installation was easy. It fit right in where the Seagate was except I had to trim some rubber off of the DEC plugs that go to the back of the drive. No big deal. It is mounted under an Idrive--no problem. I bought it from jb TECHNOLOGIES of Moorpark CA. They were courtious and very fast in shipping. I paid 340.00 plus tax and shipping. Perhaps too much to spend on an old "Classic". I used WUTIL 3.2 for fomatting, partitioning, etc and even installed FASTBOOT. If you use FASTBOOT, be aware that if you have a CLIKCLOK it won' work in the autoexec.bat with the Turbow on. At the CLIKCLOK command I preceed it with "Turbow off" command and follow it with "Turbow on". That only eats about a half second of the time saved and the CLIKCLOK works like it's supposed to. I hope this helps someone with drive problems. Dick Hagen 72426,736