Saturday, 20 February 2021

 Dk'TRONICS 64K MEMORY / SILICON DISC MODIFICATIONS FOR AMSTRAD CPC SERIES


Dk'TRONICS 64K RAM / SILICON DISC PACKS

  


Full 256K RAM Upgrade Complete

 
Modification: Conversion to Silicon Disc
 
Fitting: Memory <-> Silicon Disc Mini SPDT Toggle switch

Dk'TRONICS 64K RAM / SILICON DISC PACKS

  White labels Modifications
1 Dk'TRONICS 64K MEMORY
DIP-16 Socket: Yes x 8
74LS153: Yes + 1x DIP-16
74LS74: Yes + 1x DIP-14
256k Chips: Yes x 8 – HM50256P-15
Fit: Memory <-> Silicon Disc mini SPDT toggle switch
2 Dk'TRONICS 64K MEMORY
DIP-16 Socket: Yes x 8 + 1
74LS153: Yes + 1x DIP-16
74LS74: Yes + 1x DIP-14
256k Chips: Yes x 8 – 41256-15 F1288
Fit: Memory <-> Silicon Disc mini SPDT toggle switch

 
3 Dk'TRONICS 64K MEMORY
DIP-16 Socket: Yes x 8 + 1
74LS153: Yes + 1x DIP-16
74LS74: Yes + 1x DIP-14
256k Chips: Yes x 8 – NEC D41256C-15
Fit: Memory <-> Silicon Disc mini SPDT toggle switch
4 Dk'TRONICS 64K MEMORY
DIP-16 Socket: Yes x 8
74LS153: No - No 1x DIP-16
74LS74: No - No 1x DIP-14
256k Chips: Yes x 8 – KM41256AP-15
Modification: Conversion to Silicon Disc
5 Dk'TRONICS 64K MEMORY
DIP-16 Socket: Yes x 8
74LS153: No - No 1x DIP-16
74LS74: No - No 1x DIP-14
256k Chips: Yes x 8 – KM41256AP-15
Modification: Conversion to Silicon Disc
6 Dk'TRONICS 64K MEMORY
DIP-16 Socket: No – requires x 8
74LS153: No - No 1x DIP-16
74LS74: No - No 1x DIP-14
256k Chips: No - requires x 8
Missing: 25x2P 50P 2.54mm 0.1" Card Edge Slot Socket Connector - 50 Way Card Edge expansion Connector at the back of RAM pack
  • Add 8 x DIP-16 Socket + 8 x 256k RAM chips
  • Add 1 x DIP-16 Socket + 1 x 74LS153
  • Add 1 x DIP-14 Socket + 1 x 74LS74
  • Add 1 x 50 Way Card Edge expansion Connector at the back of RAM pack
  • Make sure it's Fully 256K RAM Upgrade Completed with 2 small wire loops jumper settings changed to points horizontally
  • Modification: Conversion to Silicon Disc
7 Dk'TRONICS 64K MEMORY
DIP-16 Socket: No – requires x 8
74LS153: No - No 1x DIP-16
74LS74: No - No 1x DIP-14
256k Chips: No - requires x 8
8 Dk'TRONICS 64K MEMORY
DIP-16 Socket: Yes x 8
74LS153: No - No 1x DIP-16
74LS74: No - No 1x DIP-14
256k Chips: Yes x 8 – NEC D41256C-15 x 6 & NEC D41257C-15 x 2
9 Dk'TRONICS 64K MEMORY
DIP-16 Socket: Yes x 8
74LS153: Yes - No 1x DIP-16
74LS74: Yes - No 1x DIP-14
256k Chips: Yes x 8 – KM41256P-15H x 7 & NEC D41256C-15 x 1
Modification: Add / change 2 wire loops jumper settings to points horizontally
9a Dk'TRONICS SILICON DISC
DIP-16 Socket: Yes x 8
74LS153: Yes - No 1x DIP-16
74LS74: Yes - No 1x DIP-14
256k Chips: Yes x 8 – NEC D41256C-15
Fit: Memory <-> Silicon Disc mini SPDT toggle switch
10 Dk'TRONICS 64K MEMORY
DIP-16 Socket: Yes & No - x 6 - Need 2 more
74LS74: Yes + 1x DIP-14
74LS153: Yes + 1x DIP-16
256k Chips: No x 8
Fit: Memory <-> Silicon Disc mini SPDT toggle switch

 

Notes:

  • These white self adhesive labels are used as a guide, basically just do the tasks that are marked in red X's e.g. RAM pack No. 10 will need to solder in 6 more 16-pin sockets, fit mini SPDT switch & de-solder existing 64K RAM chips & replace it with 256K RAM chips
     

  • Please have a quick check / give it a once over on the back of the RAM packs to see if it needs some de-soldering / re-soldering on bad soldering / no contact with lack of solder / loose connection. I really appreciate it if you check on all of them, thanks.
     

  • As for adding some small metal wire for the horizontally wire loops jumper settings. You can use the remainder of spare capacitors to snip of both metal legs and use them as wire loops jumper settings and use them as part of Modification: Conversion to Silicon Disc as well, if its long enough.
     

  • As for RAM Pack No. 6, I'm not sure which is the right way for soldering the 25x2P 50P (50 way) 2.54mm 0.1" Card Edge Slot Socket expansion Connector onto the back of RAM pack as there is no key way / gap between 23 & 21 for CPC Expansion Port - https://cutt.ly/xxRKNFc. See the pic of CPC 464 motherboard - https://cutt.ly/MxRLdHM for the Expansion port on the right (PL1) to see what I mean. Again, just letting you know in advance but don't worry, just take in your own time at your own pace
     

  • As for RAM Pack No. 7 can Fit: Memory <-> Silicon Disc mini SPDT toggle switch as it has two link holes at the bottom for fitting a switch.
     

  • As for fitting the switch, you can use already modified Silicon Disk with after market switch fitted which is together with 64K Memory Pack No. 10 to give you an idea how it is done or you can use this link: https://cutt.ly/RxEpDq7 as reference, if you get struck.

PC-186 Winchester Drive Controller Upgrade for PN 12865


Here are a few examples of the following fully populated PC-186 Controller cards as shown below:
 

 

PN 12865 Issue 3 HDD SCSI Controller Card from
RM Nimbus X10

PN 12865 Issue 3 HDD SCSI Controller Card from
RM Nimbus PC-186 PC2 (1985)

 
 

PN 23731 Issue 1 FDD/HDD SCSI (SASI) Drive
Controller card from Slimline PC-186

PN 23731 Issue 1 FDD/HDD SCSI (SASI) Drive
Controller card from RM Nimbus website

 

Here are the following missing components that are needed to be added onto half populated card:

 

Location(s)

Component

Qty

IC11, IC25 & IC26

SN74ALS74AN - DIP-14

3

IC12

SN74ALS244AN - DIP-20

1

IC13

SN74ALS374AN - DIP-20

1

IC14

SN74ALS638A - DIP-20

1

IC17

SN74ALS08N - DIP-14

1

IC18

SN74LS173AN - DIP-16

1

IC19

SN74ALS02N - DIP-14

1

IC20

SN7438N - DIP-14

1

IC22

SN74ALS21N - DIP-14

1

IC23

SN74LS221N - DIP-16

1

IC24

SN74ALS32N - DIP-14

1

IC28

SN74LS14N - DIP-14

1

C19, C20, C23, C25 & C31

220pF 100V Capacitor

5

C24 & C27 

10UF/10V Tantalum Bead Capacitor

2

RN2

4114R-2-151 - Replacement: 4114R-2-221LF

1

R8

4.7k ohm resistor - Resistor color code

1

R9

39k ohm resistor - Resistor color code

1

R10

330 ohm resistor - Resistor color code

1

J4

34 Pin IDC Box Header - 2.54mm

1

D2, D3 & D4

1N4001 1A Diode

3

C26

104 e52 100nf - Ceramic Disc Capacitor (104) 50V

1

C29

47UF/16V Tantalum Bead Capacitor

1

 

Extras:

 

Location(s) Component Qty
IC11, IC17, IC19, IC20, IC22, IC24, IC25, IC26, IC28 & RN2 DIP-14 IC Sockets 10
IC18 & IC23 DIP-16 IC Sockets 2
IC12, IC13 & IC14 DIP-20 IC Sockets 3

 

PN 12865 Issue 4 Controller Card from RM Nimbus PC-186 PC2: 1987 (half populated to FDD only) - Before pics


I think the best thing is de-soldier and re-soldier the following items onto this controller card:

 

 

Location(s)

Component

Qty

 Key

IC11, IC17, IC19, IC20, IC22, IC24, IC25, IC26, IC28 & RN2

DIP-14 IC Sockets

10

 Blue Crosses & Red 5 points Star

IC18 & IC23

DIP-16 IC Sockets

2

 Red Crosses

IC12, IC13 & IC14

DIP-20 IC Sockets

3

 Green Crosses

C19, C20, C23, C25 & C31

220pF 100V Capacitor

5

 Blue Circles

C24 & C27 

10UF/10V Tantalum Bead Capacitor

2

 Red Circles

R8

4.7k ohm resistor - Resistor color code

1

 Blue Capsule

R9

39k ohm resistor - Resistor color code

1

 Blue Capsule

R10

330 ohm resistor - Resistor color code

1

 Blue Capsule

J4

34 Pin IDC Box Header - 2.54mm

1

 Gold 5 points Star

D2, D3 & D4

1N4001 1A Diode

3

 Red Capsules

C26

104 e52 100nf - Ceramic Disc Capacitor (104) 50V

1

 Yellow Cross

C29

47UF/16V Tantalum Bead Capacitor

1

 Green Circle
at

No comments:

Post a Comment

Subscribe to: Post Comments (Atom)

  Dk'TRONICS 64K MEMORY / SILICON DISC MODIFICATIONS FOR AMSTRAD CPC SERIES Dk...

  • (no title)
      Dk'TRONICS 64K MEMORY / SILICON DISC MODIFICATIONS FOR AMSTRAD CPC SERIES Dk...