----------------------------------------------------------------------- MODIFICATION LEVEL SUMMARY Product Code P/N 520-0115-1 Product Type C10 P31 Page of Date Issued Revision F ======================================================================= Mod Level 0 Reference # 2.908 Date Released 01/24/85 ----------------------------------------------------------------------- Change: 1) Release 520-0115-1 to production On Bill of Material 520-0115-1: Delete : 007-0026 5A 10uH inductor L1,2,3,4,8,9 Add : 007-0022 5A 10uH inductor L1,2,3,4,8,9 2) Release 520-0153-1 to production - identical to Rev. E1 except: Delete: 001-0026 Resistor 5.6K R28 007-0026 5A 10uH inductor radial, L4,8,9 Add : 001-0025 Resistor 5.1K, R28 007-0022 5A 10uH inductor-axial, L4,8,9 017-0262 PC board tab (amp) , J8 Ref. description R41 to 001-0006(to description) 3) Release 520-0115-2/0153-2 per attached mark-ups. 4) Jumper pad below the "C" in C14 to the pad below the "4" in L14 (component side), see artwork. 5) Jumper IC34 pin 2 to IC30 pin 14. (component side) 6) Cut trace above IC31 pin 1 solder side. 7) Cut trace that runs between pins 3 and 5 of J4 solder side. 8) Jumper IC12 pin 15 to the lower lead of the .047 bypass capacitor near IC12 pin 13. (solder side) Reason: 1-3) Bill of Material corrections. 4) +12V is not connected to IC's 41 and 42. 5-6) D4 is connected to select. 7) +12V is shorted to GND. 8) GND is not connected to IC's 1,2 and 12. ----------------------------------------------------------------------- Mod Level 1 Reference # 2.980 Date Released 02/08/85 ----------------------------------------------------------------------- Change: 1) Install a 74s00 at location IC26 with pin 4 bent up. 2) Cut trace coming from IC26 pin 5 component side (between IC20 and IC26). 3) Cut trace coming from IC26 pin 6 component side (before plate-thru above "IC52") 4) Cut trace coming from the plate-thru above IC43 pin 20 component side. 5) Cut trace coming from the plate-thru below and to the right of Q11, component side. 6) Jumper plate-thru above IC43 pin 20 to IC26 pin 6, component side. 7) Jumper plate-thru between IC52 pins 5 and 10 to plate- thru above "IC52", solder side. 8) On the component side, jumper IC26 pin 4 pad to IC52 pin 11. 9) On the component side, jumper plate-thru below and to the right of Q11 to IC26 pin 4. 10) On the solder side, jumper IC18 pin 32 to IC26 pin 5. Reason: This modification adds one additional wait state when doing I/O to the 1793 disk controller in order to meet the maximum data access from RE* specification. This specification is now being violated on 6MHZ C10's. It also disables the C10 from being able to use vectored interupts, which are not currently used anyway. ----------------------------------------------------------------------- Mod Level 2 Reference # Date Released ----------------------------------------------------------------------- Jumped mod level 2. ----------------------------------------------------------------------- Mod Level 3 Reference # Date Released ----------------------------------------------------------------------- Jumped mod level 3. ----------------------------------------------------------------------- Mod Level 4 Reference # 3.042 Date Released 02/26/85 ----------------------------------------------------------------------- Change: On Bill of Material, 520-0115-1/0153-1, Rev E, Add: 1) 001-0202 10 Meg ohm 1/2 watt 20% resistor, R42 2) Add R42 to component side per page 2 and page 3. 3) On 520-0115-1 and 520-0153-1 Rev. F install R42 on the component side, per page 4 and 5. 4) Mod level of 520-0115-2 and 520-0153-2 Rev. F are rolled Reason: 1&2) Need to add bleeder resistor between capacitor C14 (D.C. ground and A.C. ground) to protect serial port drivers and receivers on Rev. E boards also. ECO 3033 included Rev. F on A.T.E. boards test cannot performed if resistor is on the solder side of PCB per rework instructions on ECO 3033. 3) Loaded board test (ATE) can not be performed with components on the solder side of the board. 4) To correct Rev. Mod. level list. ----------------------------------------------------------------------- Mod Level 5 Reference # 3.069 Date Released 03/07/85 ----------------------------------------------------------------------- Change: 1) This ECO will obsolete deviations 138 and 139, and support mod level roll up referenced by deviation authorizations. 2) On PCB assemblies 520-0115-1 Rev. E1 and F and 520-0153-1 Rev. E1 and F, cut jumper as per attached redlined drawing. Correct schematic (040-0115) per attached redlined drawing. Reason: A large number of CKBC keyboards failed with C5 and C10 Rev. E1 and F boards. The reason was due to low input voltage (12v) to the CKBC board. Inductors in series with the 12v supply, have excessive voltage drops. At the CKBC end, the supply voltage is as low as 6.5 volts. The mod on the C5 and C10 assemblies bypasses the 100uH inductor L7, which was in series with the CKBC 12v 22uH inductors. However, this did not fix the problem completely since the voltage drop across 22uH inductors was still quite high and, some percentage of CKBC keyboards may still fail. Jumpering the inductors L1 and L2 in CKBC assembly is a temporary fix. Subsequent ECO will provide permanent fix. ----------------------------------------------------------------------- Mod Level 6 Reference # 3.073 Date Released 03/12/85 ----------------------------------------------------------------------- Change: 1) On Bill of Material, change: 007-0000 22uH inductor 140 ma, Qty 7 > 4, L6,10,11,12 On Bill of Material, Add: 007-0049 22uH inductor 290ma, Qty 3, L13,14,15 2) Remove jumpers on L1 and L2 as shown on ECO 3069, P/N 520-0142, when installing new inductor. Reason: A large number of CKBC keyboards failed with C5 and C10 Rev. E1 and Rev. F boards. The reason was due to low input voltage (12v) to the CKBC board. Inductors in series with the 12v supply, have excessive voltage drops. At the CKBC end, the supply voltage is as low as 6.5 volts. Deviation 138 did not fix the problem completely. Voltage drop across 22uH inductors (part no. 007-0000) in series with the CKBC 12v supply is quite high. Deviation 139 was a temporary fix, this ECO will resolve the problem. ----------------------------------------------------------------------- Mod Level 7 Reference # 3.109 Date Released 03/22/85 ----------------------------------------------------------------------- Change: 1) Remove 10uH axial inductors at L4 and L8, install radial inductors (P/N 007-0026) 10uH at locations L4 and L8. 2) Add a jumper from the cathode of D2 to L4 pad near J5. 3) Add a jumper from IC1 pin 8 to IC12 pin 8. Reason: The axial inductors drop too much voltage to be used at L4 and L8. A bad ground return on IC12 and IC1 was causing write problems on some floppy drives. ----------------------------------------------------------------------- Mod Level 8 Reference # 3.124 Date Released 03/27/85 ----------------------------------------------------------------------- Change: Remove R40 (P/N 001-0000) 10 ohm resistor and jumper the two pads of R40 with a insulated jumper wire (component side). Reason: To minimize the DC ground potential difference between the floppy drives and the C10 logic board. ----------------------------------------------------------------------- Mod Level 9 Reference # 3.185 Date Released 04/19/85 Change: Delete C21 and C14 (P/N 004-0161) .0068uF capacitor. Reason: To avoid burning out the serial driver IC's. ----------------------------------------------------------------------- Mod Level 10 Reference # 3.176 Date Released 04/19/85 ----------------------------------------------------------------------- Change: On the Bill of Material, Add: 001-0012, resistor 330 ohm, Qty 2, R39 and R40. 1) Cut trace on solder side between IC41 pin 3 and J3 pin 3. 2) Cut trace on solder side between IC41 pin 6 and J3 pin 7. 3) On the component solder one side of R39 to IC41 pin 3, solder jumper wire to other side of R39. Remove solder from feed-thru hole, run jumper wire through to solder side of board, and solder J3 pin 3. 4) Repeat step 3 for R40 between IC41 pin 6 and J3 pin 7. Reason: C5 driver will be blown out by ground loop current and for static. By adding a resistor to the driver's output, the transient current will be limited and the chance of blowing out the driver will be reduced. ----------------------------------------------------------------------- Mod Level 11 Reference # 3.242 Date Released 05/15/85 ----------------------------------------------------------------------- Change: On the above Bill of Material, Add: 008-0002, IN4148 diode, Qty 1 Solder a IN4148 diode across R32 with the cathode end towards the designator "R32". Reason: To improve the performance of the reset circuit. ----------------------------------------------------------------------- Mod Level 12 Reference # 3.544 Date Released 11/15/85 ----------------------------------------------------------------------- Change: 1) Cut trace coming from IC37 pin 10 component side. 2) Solder one lead of a 330 ohm resistor to pin 10 of IC37 and the other lead to the plate-thru hole near IC41 pin 13. Reason: To provide a current limiting resistor at the RxD input of the serial port, IC37 pin 10. ----------------------------------------------------------------------- Mod Level 13 Reference # 3.555 Date Released ----------------------------------------------------------------------- Change: 1) Replace R100 the 10 Meg ground isolation resistor with a 100K ohm resistor. Reason: To suppress electro-static noise.