Msx turbo-r fs-a1st motherboard versions?

Champion (420)

09-04-2020, 07:52

Have there been MSX turbo-r FS-A1ST versions with and without RF output? Or what is this motherboard without RF output at all?

By popolon_

Champion (420)

09-04-2020, 09:43

Added high res link.
https://msx.pics/image/Viqks

By dproldan

Resident (44)

09-04-2020, 10:26

That looks like a preproduction unit. There are many more changes compared to a standard A1ST, but the most interesting is the R800 IC in the bottom, on the left of the RAM. That kind of packaging is used during the development stages of new ICs.
Nice find!

By popolon_

Champion (420)

09-04-2020, 10:36

So if this is preproduction unit, is the 256K memory upgrade same as for normal unit? Or risk of damaging this unit? Anyway transformer change to 220v shuold not make harm?

By dproldan

Resident (44)

09-04-2020, 10:51

What you have is extremely rare. Companies only make 5-10 units of this kind during the development process and most of them are destroyed after the product goes into real production.
So, I wouldn't do any modification to it. Maybe the conversion to 220v if you're experienced with this stuff. The memory upgrade is a lot more delicate and invasive.
Try to dump the ROMs, as they are probably unique. Here are some instructions: https://www.msx.org/forum/msx-talk/emulation/dumpingreverse-engineering-msx

By Pac

Scribe (7104)

09-04-2020, 13:17

What's the S/N? Probably it will give us more clues... take a look:

https://www.msx.org/forum/msx-talk/hardware/how-many-turbo-r...

By popolon_

Champion (420)

09-04-2020, 13:47

There is no serial number at the back, just empty there.

By popolon_

Champion (420)

09-04-2020, 14:23

also the keyboard is not same as for production ?
https://msx.pics/image/Vi7CN

By meits

Scribe (6572)

09-04-2020, 15:24

That's an MSX2+ keyboard. They were there before the grey turbo R ones. So either the grey keyboards did not exist yet, or the previous owner did a swap.

By popolon_

Champion (420)

10-04-2020, 08:58

Here is closer pic link from nec and r800 chip. Also white rom socket can be seen barely.

https://msx.pics/image/Vibdd

By popolon_

Champion (420)

13-04-2020, 20:15

I dumped the tc574000D rom chip, and according to Nyyrikki, it was same as production version.