Talent DPC-200 Power Supply Failure

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By Jipe

Paragon (1374)

Jipe's picture

07-03-2018, 16:15

make the 3nd schematic with 2 IC 74HCT32 and HCT00
is more easy to find Smile

By tsMKG

Resident (48)

tsMKG's picture

07-03-2018, 16:52

Heh, by the time you answered, I have already made the one based on the first schematic ^^'

Using this library: http://msx.hansotten.com/do-it-yourself/

I made this PCB: https://mega.nz/#F!wjAHiBoQ!WezCN6JGCsSkRV-UJDbY0Q
Is my PCB alright? And how do you build PCB's with such small tracks? I gave the tracks a width of 0.02 inches and it's still small (for me at least).

also had to change the small signal transistors library because the latest EAGLE update of that library has a breaking bug in which most component did not work, so there's the small signal transistor library i used there too ^^'

By tsMKG

Resident (48)

tsMKG's picture

10-03-2018, 18:39

I think I might drop the idea of making a RAM expansion cartridge because why not use the EXPANSION BUS instead?

There are too many things in the way of making a RAM cartridge so I might just do the RAM expansion through the bus, but that leaves me with two questions:

1) Is it valid? I mean, will having RAM on the EXPANSION BUS work?

2) What is each of the pins in the EXPANSION BUS?

EDIT: BTW, this is the expansion bus of my machine Smile

By rderooy

Paladin (682)

rderooy's picture

10-03-2018, 23:44

The expansion bus in this case is almost certainly just be a MSX cartridge port with a non-standard connector.

By tsMKG

Resident (48)

tsMKG's picture

11-03-2018, 04:29

Ugh! This expansion bus seems to have TWO polarizer keys instead of the COMMON ONE and even it's hard to find connectors without polarizer key at all because the COMMON IS ONE Evil

Well, aside from that fact, I need to find a way to connect this EB Shocked!

(The connector is an IDC one, right?)

EDIT: Oh I get it, I get it, it's an IDC. Now, how does one remove the polarizer key from the IDC50F connector? And if I want to build my own IDC50F connector, how should I do it? Because the way I'm used to is to pins of the same column be the same. But here, pins on a same column but in a different row differ. And I'm quite confused at this point Question But is 12:28 AM here and I should sleep.

By Grauw

Ascended (8735)

Grauw's picture

11-03-2018, 04:35

Well, if you want one without notch, you can just file or cut it off, right? Smile

By tsMKG

Resident (48)

tsMKG's picture

15-03-2018, 00:38

I'm just coming here another more time to ask if the 74HCT32 on the ram expansion diagram is replaceable with another quad-OR gate IC in case I don't get it.

Also I'm getting troubles to even get a standard 50 pins (2x25) cable, is THAT RARE the cable? I don't think that shouldn't be the case specially when we still have XP machines on some homes here.

(Also all i found in my house near to a 50 pin cable was a 34 pin cable Sad )

By Jipe

Paragon (1374)

Jipe's picture

15-03-2018, 15:55

you can take a 74LS32 , 50 pins cable it's for old SCSI interface
https://www.ebay.fr/itm/Internal-SCSI-Ribbon-Cable-6-x-50-wa...

By tsMKG

Resident (48)

tsMKG's picture

31-03-2018, 02:39

So it turns out that I'm not very good at making PCBs Tongue
Specially single-sided PCBs

I make the new PCB single sided because it's easier to produce one than producing the RAM cart which is double sided (and there aren't board houses nowhere near my home, not even futher)

I mean, I'm literally making a lot of flying wires because on how the diagram set ups the data and the address pins. And I'm not done with the PBC yet oO

Can anyone give me a hand on this?

(BTW the connector I'm using is an IDC 50 and I've checked the pin numbering as it should be these) :)

By gdx

Prophet (3316)

gdx's picture

31-03-2018, 10:13

You have reversed the odd and even pins! The pinout must be like this:

1 3  ~  47 49
o o  ~   o o
o o  ~   o o
2 4  ~  48 50

Look your picture of the PCB here, the pins 41 and 43 are connected to GND as described in the wiki. Pins 42 and 44 can not be connected together.

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