OSI 600D Superboard Build

[rubber_jonnie]

A largely positive day in terms of the build today, all the sockets are installed:

PXL_20240106_172652525.jpg

PXL_20240106_172705429.jpg

I would usually do the lowest components first, but some of them are taller than the sockets, so to ensure I got all the sockets level, and also to get the 'bulk' soldering out of the way, I opted to do the sockets first.

Note that all of the notches on the sockets point towards the keyboard end, which is considered 'South' with the power/video/cassette end being north in the build instructions.

This is contrary to the silkscreen, which on this particular reproduction board is 180 degrees out. The same is true for U41, whose notch faces east and not west. I've verified this with another builder and the build instructions from the original kit.

If you intend to build one of these, double check before fitting your sockets.

If all goes well I'll get the discrete parts soldered in tomorrow and If I'm really lucky, the key switches too. If I get all that done, then I'll hook up 5v after a 'short' test with the multimeter and do a quick smoke test before fitting any ICs.

I would say that it's a bit of a sod with not solder mask, as it's very easy to make unwanted solder bridges. My advice is clean them up as you make them, otherwise you may end up chasing them later.

I found an angled chisel tip was best for soldering, as the angle kept the rest of the tip away from other traces, but the point of the tip was very accurate for soldering and has a good thermal mass.

[stephen_usher]

Angled chisel with an oval cross section is my go-to tip for all soldering as it's many widths in one.

I guess that without the solder mask you have to make sure that you don't get too much solder on the socket leg otherwise you risk a bridge under the socket.

[rubber_jonnie]

Angled chisel with an oval cross section is my go-to tip for all soldering as it's many widths in one.

I guess that without the solder mask you have to make sure that you don't get too much solder on the socket leg otherwise you risk a bridge under the socket.

I mostly use an oval chisel, but it was too easy to get solder on other tracks and make bridges.

I've been very careful to not get too much solder through the board, luckily it's quite thick, and has decent vias so I'm hoping, though I'll check, that there are no bridges under the sockets.

[HigashiJun]

The OSI is starting to take shape !

:D

[HigashiJun]

Oh, and BTW, do you plan to fit the board in a case ?

[rubber_jonnie]

Oh, and BTW, do you plan to fit the board in a case ?

I'm undecided at this point, as I don't have the facilities/tools to easily make a case, but I may consider doing so at some point.

[rubber_jonnie]

The OSI is starting to take shape !

:D

It is indeed :)

I got some more done today:

PXL_20240107_162044630.jpg

However there are some component oddities around resistors and capacitors I need to clear up from the assembly guide, and there are parts I don't yet have, but yeah, it is starting to take shape and I'm pretty pleased.

I decided to fit just the one keyswitch as a trial, and I'm quite pleased , it's a great fit.

[HigashiJun]

I'm undecided at this point, as I don't have the facilities/tools to easily make a case, but I may consider doing so at some point.

Such a pity that a case kit doesn't exist...

:(

[HigashiJun]

It is indeed :)

I got some more done today:


PXL_20240107_162044630.jpg


However there are some component oddities around resistors and capacitors I need to clear up from the assembly guide, and there are parts I don't yet have, but yeah, it is starting to take shape and I'm pretty pleased.

I decided to fit just the one keyswitch as a trial, and I'm quite pleased , it's a great fit.

Can't wait to see the final result !

:D

[rubber_jonnie]

I'm undecided at this point, as I don't have the facilities/tools to easily make a case, but I may consider doing so at some point.

Such a pity that a case kit doesn't exist...

:(

I just looked at the assembly instructions and they are dated 1982, so very much the time when kit machines were in vogue, and building your own cases was a thing. I'll check the forum over at OSIweb to see what other people have done, though I think with the right tools I could certainly build something, so maybe further down the line.