RetroChallenge Winter Warm-Up 2014

Why change a .. ehrm, not winning concept? Just like last year, I'm entering the RetroChallenge Winter Warm-Up without any particular, ongoing task. Eventually I'll get preoccupied with one thing until I get stuck, and then I'll have to decide what to do instead...

Examples of tasks I am likely to spend my time on

• Rearrange my relatively small collection of (games) software. Lately I have seen dozens of vlogs featuring various collectors who have their stuff arranged nicely and kept together. I have stuff a little everywhere, including a few drawers full of boxes that just as well could be showcased in a shelf.
• Go through two huge boxes of 5.25" floppy disks that a friend donated in the fall of 2013. The vast majority are for the Atari 8-bit computers, but some appear to be of the C64/128 variety. At least I'll try to catalogue some of them to know what is worth keeping.
• A bit more programming here and there. I got stuck with VDP timing on my Creativision Reversi game last year, which I should've settled by now but haven't gotten around to do.
• My IBM RT hasn't been up to much action since I last powered it on, about January 7, 2013 as far as I can tell. I still need to see if I can get it to communicate with the rest of the world, e.g. through a dumb serial connection.
• Investigate why my Apple II to IBM PC joystick adapter doesn't register fire buttons. Actually I modified the design to accept auto-fire joysticks, which only caused the adapter to work even worse than before. Perhaps I used bad parts, wired them backwards or the design I found is not the correct one.
• Various other troubleshooting and fix projects. New candidate since last year is that my only working ZX Spectrum 48K no longer is working, after I tried to add a brand new joystick interface. I don't have a lot of hope that I'll be able to fix it within this time frame, but who knows?

Process log - Latest progress

December 30, 09:50 (GMT+1)

Project defined and early preparations.

January 5, 23:00 (GMT+1)

What a busy week! To this point, I got virtually nothing done on my RetroChallenge projects. I've measured some of my shelves, but not done any rearranging of those yet.

I brought up the two big boxes of floppy disks and just counted through those. With no intent to load anything yet, and as many of them already are documented what they should contain, I had a soft start just counting them. The total is that apart from my "own" collection of 5.25" floppy disks, a measly 100 or so, I'm now in possession of another 506 disks. The vast majority are home copied for the Atari 8-bit computers, but some appear to be for the C64 as well.

Actually there are a few original floppy disks in the lot as well, but only as loose disks with sleeve and some with instruction leaflet. This is the list, of which I don't think either are particularly rare ones. Unless otherwise specified, those are C64/128 disks:

• Breakout Construction Kit (*)
• Cauldron II
• Commodore 128 CP/M System Disk, CP/M Plus Version 3.0
• Commodore 1570/1571 Test/Demo
• DOS 2.5 (Atari Corp, might be more of those)
• Ferrari Formula One
• Fortress Underground (German edition)
• Giga Cad System (64'er)
• Glider Pilot
• Golden Games - Software made in Germany (Eckhart & Gehrmann Gbr)
• Grand Prix 500cc
• Monaco Super Fahrsimulator und weitere (*)
• Ninja Collection: Double Dragon
• Ninja Collection: Dragon Ninja
• Ninja Collection: Shadow Warriors
• Power Boat USA
• Pro Powerboat
• Saboteur (Elite Thrill Time, Gold vol. 2) - seems overwritten
• Savage
• Space Pilot Compendium (German edition)
• Starray (*)
• Teenage Mutant Hero Turtles
• Teenage Mutant Hero Turtles (different label)
• The Real Ghostbusters, Bit Star edition (*)
• Turrican II und weitere (*)
• Voyager (Rex Datentechnik)

The ones marked with an asterisk (*) are those I'm not certain they qualify as original disks, or just well made copies.

Apart from floppy disks, I also found one LensLok device and two Philips Professional digital cassettes, model LDB 4301 certified for 1600 FRI. I think those have stronger magnetizing than regular audio cassettes, but I haven't yet found out what the FRI acronym represents.

Oh well, perhaps the following week will make me reach more progress on the various small tasks. At least I should try to load some of those 500+ floppy disks, in particular those lacking a label with an index. I suppose I should try each disk first in a 1050, then a 1541 and finally a PC to see if either of them can read it.

January 12, 00:40 (GMT+1)

Not much happening here. The other night I tried to solder up a composite video cable for my Olivetti PC-1. While the pinout for the 8-pin DIN has been posted, it is unclear how the pins were numbered by the person who submitted the pinout. I tried all the obvious and less obvious combinations without much success. At one combination, I got a black screen with some pixels of garbage, which might be due to I combined sync and ground into a composite signal.

Currently I'm out of 8-pin DIN connectors to harvest, so I might have to order one from China. None of the local shops carry that kind of stuff and if I have to mail order, I might as well mail order at affordable prices.

The reason why I want composite video output instead of using the CGA output on the PC-1, is that I hope some of the games that use the NTSC composite video mode on the CGA will work on the Olivetti too, although it is not an US model. Perhaps I'm doing it in vain, time will tell.

Update: I found a domestic reseller with lower prices for small volumes than the sellers in far Asia, so I'm hopefully getting parts a bit sooner.

January 15, 01:05 (GMT+1)

So the items I ordered on the night to Sunday arrived on Tuesday, thanks to finding a domestic reseller.

My initial idea was to solder up some kind of jumper board, with one lead for each pin from the 8-pin DIN going to the middle of the jumper board, and then the outer rows joined to signal and ground respectively on a RCA connector.

While I managed to put it together, it was a rather tight fit, I was short on jumpers and the middle row after a while let go. Thus I reverted back to the terminal block solution, which is not as elegant but I often get to work.

After some fiddling, I found that the yellow lead must be the ground, and the white pin carries the composite video.

Yay! Now to figure out what yellow and white means in terms of pinout. It should be pointed out the connector actually is a 262 degree "horseshoe" connector, same as on the C64/128, Sega Genesis/Megadrive and others. I had not checked this prior to ordering connectors, but fortunately I ordered both the 262 and 270 degree variants, and in the end found that the 270 degree one kind of works if you carefully bend the two outer pins a bit outwards.

Anyway, the posted pinout looks like this:

Pin	Function	Connector
1	Blue video	Male
2	Green video
3	Red video
4	Ground
5	Sync	Female
6	Unknown
7	Composite video
8	Function switching

Now, my yellow lead (ground) is connected to pin 4 according to the graphic to the left, and the white lead (composite video) goes to pin 6. Apparently the given pinout does not match the standard numbering. At first I figured perhaps the numbering refers to the female connector, or male connector seen from the solder side but then it would be pins 5 + 7, not 4 + 7.

Perhaps I'll try an analog RGB connection as well, to sort the other pins, although composite video was my primary goal. As seen from the above pictures, my cable still is in a temporary state but that will be solved later on.

 

Update: It turns out this composite video is B&W. One could argue perhaps it outputs NTSC video and you're in PAL land, but this TV perfectly fine displays NTSC composite video in colour both from my Nintendo Famicom and an US VIC-20.

Oh well, perhaps I'll not have a lot of fun with it anyway, except for the satisfaction to figure out the pinout itself.