Commodore Plus/4 and Yamaha CX-11

So, these two arrived fairly recently.

The Plus/4 was bought "sold as seen" on eBay and doesn't produce any video output. So, I'll need to work on fixing it. It needs a good clean both inside and out.

The Yamaha CX-11 was sold as working. It powers up fine, and "call music" goes into the Yamaha ROM, allowing playing around with voices and apparently control via MIDI.

Other than a basic test, I've not had time to play with it. It also needs a good clean.

I've not been able to find out much info on the CX-11. It seems like a slight variant on the much more common CX-5M. It has the SFG-05 unit, instead of SFG-01, RGB out, two normal MSX 50 pin slots as well as the Yamaha 60-pin side-slot with the SFG-05 fitted. Apart from this, it seems very similar to the CX-5M and YIS-503, but looks like the CX-5M II. It's a standard MSX (not MSX2), with 32K RAM and 16K VRAM. I've not popped it open to see what's inside yet. I have the CX-5M and YIS-503 service manuals, and they should be handy for comparison. I also recently received the MegaFlashROM SCC+ SD (with 512K RAM). With this, I should be able to load ROMs for the original Yamaha software and play around with this.



The SFG-05 uses the YM2164 (OPP) chip, which is apparently pretty much identical to the YM2151 (OPM).

I also bought a few Y8950 chips. This audio chip was used for the MSX-Audio FM synth standard, as available in some expansion cartridges. According to Wikipedia, it is similar to the YM3526 (OPL/OPL1), with added ADPCM sample and playback. I might build an MSX-Audio board, or hook them up more directly, perhaps to some homebrew kit too.

There is also MSX-Music, which is based on the YM2413 chip (OPLL, stripped down OPL2).  Most MSX2+ machines had MSX-Music, including my Sony HB-FX1DJ. From what I understand, this should be a slightly more capable FM synth, but lacks ADPCM.

Oita trip - part 1

Short note.

Usually I keep track on Yahoo Auction in Japan for astronomy related stuff, especially rare optics, something I'm sure my wife wishes I would stop. However, this time I decided on getting a retro computer. Originally I was considering a SORD M5, but didn't like the mad prices. I initially decided on a Toshiba HX-10 - a pretty canonical MSX.

However, I went on a bit of an MSX frenzy.

First I got a Toshiba HX-20, with broken video output. I suspect it's most likely the video RAM, but it could potentially be the ROM holding the character set (unlikely, as the thing boots), the video chip itself, or (hopefully not) some custom logic chip. I liked the idea of fixing this up, and also getting an extra slot over the HX-10. I'll probably replace all the caps, and maybe some of the regulators with more modern versions that spew out less heat. It also needs a good clean.

Then I decided I wanted a higher end machine, too, an MSX2+. I ended up getting into a bidding war on a very nicely restored Sony HB-F1XDJ. It's been re-capped and very well cleaned. I avoided the Sanyo and Panasonic kit as they were extremely ugly (even if some of the specs were better).

The guy who restored it has a thing for old computers, and has a blog. Amusingly, he got a couple of keys out of place when he put the keyboard back together, so I'll have to fix those. Those who like boxed, pristine computers will not like the fact that I'm going to remove that fugly sticker, and also most likely hack the internals to add more RAM. This thing is about the size of an Amiga A500, maybe a little smaller.

The keyboards on both of these machines are pretty nice mechanical keyboards. Not something you can say for many 80's home computers.

These both arrived before I left Japan, so I was able to bring them back with me. I also bought a Yamaha CX-11, which arrived the day after I left and will be sent on.

Note: the Sharp X-68000 series is way cool. I must resist.

I took my Vixen Sphinx SXW mount with me. I've only used this a few times in the past couple of years, the most memorable time being at a public outreach event with TASOS. I've tried selling it before, but found it hard to get a decent price locally, and it's kind of heavy and not high-end enough to ship internationally. So, having previously purchased the GINJI 200FN, which is over the limit for my Vixen GP, both kept at my in-laws in Japan, I decided to take the SXW and leave it there. No need for a tripod as the tripod I have for the GP works for the SXW, and the half-pillar, which I also took.

In the photo above, there are various Borg bits in the focusser. I must have been faffing about with the Baader MPCC or something, as no extension tubes are needed to get focus with the Pentax XW20.

There will be a separate post about my experiences with this mount.