mbeck@ai.mit.edu (Mark Becker) (02/13/91)
Problems. My S-100 work has just come to an abrupt halt by the failure of both Shugart 851 8" floppy drives. One lost head #2 (the head that is on the head-load lever) some time ago, the other lost it two days ago. I find that if apply a light pressure on the heads then I can boot the system.. but this is obviously non-optimal. Questions: * I need references to repair places. Where have YOU sent 8" drives for repair? * Does anyone have a manual for this series drive that has a description of all the jumpers and what they do? Maybe an OEM manual with schematics? YOUR help is greatly appreciated. Mark mbeck@ai.mit.edu
donm@pnet07.cts.com (Don Maslin) (02/14/91)
mbeck@ai.mit.edu (Mark Becker) writes: >Problems. > >My S-100 work has just come to an abrupt halt by the failure of both >Shugart 851 8" floppy drives. One lost head #2 (the head that is on >the head-load lever) some time ago, the other lost it two days ago. > >I find that if apply a light pressure on the heads then I can boot the >system.. but this is obviously non-optimal. > Assuming that dirty heads are not the problem, have you lost the spring that loads the upper head? >Questions: > > * I need references to repair places. Where have YOU sent > 8" drives for repair? > Can't help you there. Likely you have a do-it-yourself project. > * Does anyone have a manual for this series drive that has a > description of all the jumpers and what they do? Maybe an > OEM manual with schematics? > Perhaps the following will be of some help. Customer Cut/Add Trace Options ___________________________________________________________________________ TRACE SHIPPED FROM FACTORY DESIGNATOR DESCRIPTION OPEN SHORT ------------------------------------------------------------------------- 5E Terminations for M'plxd Std Inputs H Plugged DS1 Drive Select 1 Input pin Plugged DS2,3,4 Drive Select 2,3,4 Input Pins X 1B,2B,3B,4B Side Select Option Using Drive Select X RR Radial Ready X RI Radial Index and Sector X R(SHUNT 4F) Option Shunt for Ready Output X 2S Two-Sided Status Output X 850/851 Sector Option Enable 850 851 I(SHUNT 4F) Index Outpur X S(SHUNT 4F) Sector Output X DC Disk Change Option X HL(SHUNT 4F) Stepper Power From Head Load X DS Stepper Power From Drive Select X WP Inhibit Write When Write Protected X NP Allow Write When Write Protected X D Alternate Input In Use X M MulZ:Z-Media Option Plugged DL Door Latch Option X A,B,X(SHUNT 4F) Radial Head Load X C Alternate Input Head Load X Z(SHUNT 4F) In Use From Drive Select X Y In Use From Head Load X HC*L&#xSide Select Option Using Direction Sel X S2 Standard Side Select Option Plugged S3 Side Select Option Using Drive Select X TS,FS Data Separation Option Select TS FS Plugged IW Write Current Switch Plugged RS Ready Standard Plugged RM Ready Modified X HLL Head Load Latch X IT In Use Terminator Plugged HI Head Load or In Use to the In Use Ckt X F (MLC10 only) Remove for MFM encoding. Instl for M2FM X AF(MLC11 only) Install for FM or MFM encoding Plugged NF(MLC11 only) Install for M2FM encoding X ------------------------------------------------------------------------- There is a DIP 'Shunt pack' at location 4F to select drive number and other options as indicated above. Also, at location 5E is a DIP socket for a terminating resistor pack. It appears to be simple 150 ohm per resistor type rather than a 220/330 ohm divider. -------------------------------KKK--------------------------------------- Keeper of the CP/M System Disk | UUCP: {nosc ucsd crash ncr-sd}!pnet07!donm Archives for the Dino(saur)SIG | ARPA: simasd!pnet07!donm@nosc.mil - San Diego Computer Society - | INET: donm@pnet07.cts.com