NEC PC-TV151

I’ve got so many computers that either require or look best over digital RGB but only one monitor that supports it. If anything happens to that monitor, I can’t (optimally) use many of these machines. I decided to mitigate the risk by replacing one of my other monitors with this one. Nice and crisp text output, although photos come out slightly blurry due to the front glass cover.

The NEC PC-TV151 supports digital RGB, JP21, and composite. This is an excellent combination as I have a few systems that output over JP21 as well. But this one supports digital RGB using 15 colors, as opposed to the 8 colors that most digital RGB monitors support. Of course, supporting 15 colors is useless unless the computer also supports 15 colors, but that is indeed the case with the PC-6001mkIISR.

I don’t know how many games take advantage of the 15 colors, but one such game is Dig Dug. Here is a side-by-side comparison of 15 color more on the PC-TV151 and 8 colors on the PC-TV455.

The title and high score screens have some noticeable differences, for example the 8-color mode completely lacks orange, and the 15-color mode has differently mapped shades of blue, and although it came out a bit subtle in the photo, two shades of green (the 3rd and 4th high scores). But the major difference is in gameplay. The colors in 15-color mode are more natural because 8-color mode doesn’t output brown. The 15-color mode matches the colors output over composite on the PC-6001mkII (non-SR version).

Sharp PC-3100S

In addition to the X1 and the MZ series of computers, Sharp had another line of 8-bit computers. This would have been released around the time of the NEC PC-8001, and could probably be considered its peer, but did not achieve a fraction of the notoriety that the PC-8001 did. Information on this system appears scant.

Kudos to the Japanese couriers for the way they treat packages. One of the stickers on each box reads “do not crush box; putting heavy items on this box is forbidden.” Indeed, they arrived in good shape, for being approximately 40-year-old cardboard boxes. I opened up the boxes and laid out the components.

The machine and matching monitor are in amazing condition! This is all pre-cleaning but the worst thing I can see was done intentionally – the tape to hold the function-keys guide in place. But now the big test… does it work? If either one of these pieces doesn’t work, I’m up a creek, at least for a while, because I would need to bug someone to make me a custom cable for either the monitor or the system to be able to test them separately.

But luckily, they fired right up! I breathe a sigh of relief every time I see these ancient beasts still beat their electronic hearts. Okay, I see we are dumped into BASIC, as is customary for most of these computers, although now that I think about it, both the MZ and X1 series don’t, so I was pretty pleased that the PC series does, as I wouldn’t be able to do much without it. BASIC, though, I can do something with. Or can I? The most basic of BASIC commands, PRINT, is recognized but doesn’t do what one would expect it to.

First, when you make an error, the PC-3100S *really* wants you to stop and think about what you’ve done. It beeps three times, displays your error at the bottom, and doesn’t give you your cursor back! Never seen anything like it. As far as I can tell, you have two options for proceeding, up-arrow to get your line back and fix it, or CL to erase the line and start over. DISP seems to work the same as PRINT in standard BASIC. Perhaps in this BASIC, PRINT is for interacting with a printer? This is far from the only difference in BASIC. From the one and only source of informationI could find about this system, which also isn’t terribly detailed, this BASIC is similar to Sharp’s pocket computer BASIC. So that might be a source of information, too.

Let’s take a closer look at the aesthetics and connections of this machine. First is the main system itself. It has a decidedly unique keyboard. The first thing I noticed quickly was that there is no shift key. You instead go from mode to mode using the dedicated keys. You start in alphanumeric mode, and you can switch to katakana mode or punctuation mode. And although it’s not a mode per se, you can also enter another set of characters and graphic symbols by holding down control. Parts of this system resemble the MZ-700, although the MZ-700 does also have a shift key. The directional arrow keys surrounding the home key is also unusual. But really, aside from having a QWERTY layout, they made this different in almost every way.

And the monitor. You can adjust the viewing angle and the height by pivoting or sliding it along the rails on the side. That’s pretty cool! It’s also much lighter than most, I guess because it’s monochrome and doesn’t need all of the extra electronics to process and generate color. And another first for me, there’s no plug for the video source of any sort, you screw in three wires for video, sync, and ground. I’m not sure if mixing these would produce disastrous results or not, but I’m certainly glad they left the cable attached!

I do believe there is a problem with the system. It largely appears to work, but the way it stores code and displays it seems problematic. I’m trying to figure out the pattern and will post more soon, but I think there’s probably something wrong with a RAM chip. There are many other quirks, which may just be standard system behavior or may be glitches. This system is so unlike anything I’ve used before, I’m not able to clearly determine.

CZ-600D Innards

Some games that run at 15kHz (Syvalion is the only one that comes to mind right now; most 15kHz games didn’t have this problem) were too wide on my monitor. The edges of the game were not visible. I thought I would just adjust the horizontal size, but of the kajillion buttons under the front panel, not one of them adjusts horizontal size. So I took it apart (something I loathe doing with CRTs because of the risk of death if you’re not careful, and frankly I’m not always careful, although I suspect I’m more careful than usual with an open CRT) and looked for the horizontal size pot on the inside.

Well, I can’t say with certainty that it wasn’t there, because there are a kajillion billion more pots on the inside. But the clearly labeled ones were not related to horizontal size. They are all for controlling color – if you look at the pots from the front (brown side of the board), left to right, there’s red bias, green bias, blue bias, red drive, and blue drive. That info was handy later as I needed to adjust something a bit on a different monitor, but in the end I couldn’t adjust the horizontal size.

While I had it apart, though, I took the opportunity to give the big outer shell a shower. I didn’t think about potential damage to the sticker, but fortunately it wasn’t especially problematic.

Dried it off and it’s back in action, beautiful as always!

Video Mode Comparisons

First, let me preface this by saying it’s not a tremendously scientific experiment. Although I made sure my major camera settings didn’t change, there are a lot of factors on the monitors themselves that I’m not sure how to control or don’t have the ability to compensate for, and some results I can’t interpret in terms of what is causing what I see as differences and shortcomings. Also, I’ve made the images quite large, larger than usual, because it can be hard to discern the detail when they are small.

And nothing new or unexpected is happening here. This is just a light comparison in how much improvement can be achieved by using the best output mode. Anyway, here’s what I did.

First I put my MZ-700 up to the task. I connected it by both composite video (to my NEC PC-TV455) and by digital RGB (to my Sharp CZ-600DB) and then loaded the game “Ottotto”. First with lights on:

Then with the lights out:

The digital RGB is of course much clearer. I kind of feel that composite should have been better than it appears to be, though. But I’ve tried the composite output on another monitor, and it’s about the same. I wonder if something is not working quite right in the composite output circuitry.

Next I changed everything. The computer for this round is the Sony HB-F1XD (MSX2). The monitors are the same, but this time their functions are swapped – the PC-TV455 gets analog RGB and the CZ-600DB gets the composite. I shot it with both BASIC and the game Last Armageddon. Again, lights on:

And same scenes with the lights off.

And again, the analog RGB looks much nicer. It’s also noticeable on the MZ-700, but especially on the MSZ2, which displays kanji, the big difference is in the clarity of the text. Although my Sharp X1 Turbo Z in high-resolution mode by far provides the clearest text, upgrading from composite to RGB is still tremendously helpful in terms of clarity. Also, the color palette is surprisingly different, and some of it may be down to settings on the monitors, but at least to some extent, the color differences exist even if used on the same monitor.

Umm, also, if anyone knows how to remove that gigantic “P.”, I’d be really grateful! I think it requires the remote, which I don’t have.

Sharp CZ-600DB

I saw an auction for a (nother) Sharp X1 Turbo Z and this monitor – a Sharp CZ-600DB. Usually this stuff goes on Yahoo Auctions with the standard auction format, and it gets bid way expensive and finishes arbitrarily high. But I happened to catch this one with a fixed price – first to buy it gets it. The price was very reasonable for these items. The catch? It was untested. It was a toss of the dice that I couldn’t pass up.

As you can see, it was designed with the same aesthetics as the Sharp X1 Turbo Z. They look very handsome together, although I believe officially this is supposed to be a monitor for the X68000.

So I bought it and it was delivered to me and having these things shipped just makes me so gosh-darned nervous because even when they’re tested working, there’s a chance it will suddenly die from being used again after so long, or there was some internal damage during shipping, or the seller’s testing didn’t uncover some problems. Not even knowing if it’s *supposed* to work makes me all the more anxious! I opened it up and after removing some sticker residue, it looks quite nice.

But when I turned it on it looked pretty bad. Through composite, it had a very faded image and slanted horizontal lines running the whole screen. I switched to digital RGB and it got worse. I could barely discern that the monitor was receiving the signal at all, nearly nothing but those horizontal lines.

And then I left it alone. I let it sit for about an hour. When I came back to it, the picture had cleared up 100%. It was beautiful!

Turning off and right back on had no negative effect. But when I left it off for about an hour, it took about 10 seconds to reach the correct black level. When I finished for the night, I left it unplugged for about 18 hours. Upon plugging it back in, the horizontal lines were back. Nowhere near as strong as the day before, and it cleared up in about one minute. I guess it’s a capacitor problem.

Like my NEC PC-TV455, the CZ-600DB is a tri-sync monitor (15kHz, 24kHz, and 31kHz) and it incorporates a TV tuner. The CZ-600DB lacks a couple of connections that the PC-TV455 has, but it still has some pretty good hookups. It’s also a 15″ screen instead of 14″.

And plenty of controls to get just the right picture.

It came with the original factory stickers in place. I’ll be the first to admit, if it were me and I received this new at the time, I’d probably rip them right off and throw them in the trash. But they’ve been attached for 30 years now, so I think I’m just going to keep it that way!

I don’t know if it will surpass my PC-TV455 as my primary monitor in the long run, but right now I am enjoying looking at this lovely item perched above my own X1 Turbo Z.

Here it is displaying text and DoorDoor over analog RGB, and Haja no Fuuin on my PC-8801mk2 over digital RGB.