Wednesday, April 12, 2017

Hunting for a display solution for my Commodore 64

My plan when getting the C64 was all along to make use of my old Eizo E67T VGA CRT that I kept lugging along throughout all my apartment moves for the last 15 plus years. It wouldn't be much nostalgia to slap on an LCD screen after all.
The problem was, the set I bought only came with an RF cable, the lowest quality solution to get video out of the C64. The AV port, though, has pins for both composite video and s-video with s-video obviously being the preferred option:



There's a ton of guides online on how to construct your own s-video cable with just about everyone suggesting to add a resistor on the Chroma line since the signal is apparently not up to specs, too strong, and modern displays would have trouble handling it correctly. I was going to order the parts from China and the guide linked above to make my own cable, but patience got the better of me and I ended up ordering a proper one off of a guy our Commodore Facebook group crowd suggested.
He used high-end connectors and even slapped on a ferrite core to cut out interference. You can generally find good options for $15~20 when searching for "c64 s-video cable" on eBay.

That was step one. The Eizo unfortunately doesn't have an S-Video in, though. Besides the standard VGA plug it has RGBHV BNC connectors but can't handle the 15kHz PAL signal and being in NTSC land here in Japan I had to stick with my Eizo. So I needed to get an upscaler. The online community apparently had mixed results with devices like the one to the right. An "svideo to vga" search on Amazon reveals a whole slew of these things, always the same case, always different branding and ranging from like 12 to 40 bucks.

I decided to go for one somewhere in the middle of the price range hoping it'd heighten my chances for success. It said to handle both PAL and NTSC and came with an OSD to select several different output resolutions/frequencies from 800x600 up to 1280x1024.

 That all didn't help and the result was horrible and completely unusable as you can see on the right. No colors as if it couldn't detect the PAL signal correctly and the still picture here doesn't do the brain shattering flickering it put out any justice either. So I returned it and went for the fancy 40 bucks option, a device produced in Japan with similar features but it certainly looked more high-end and didn't come in the same old casing like all the many other Chinese versions.
Being made in Japan, though, had absolutely no influence and the result was unfortunately exactly as useless as with the other. So back to the drawing board.

 Even though the seller assured me that the unit was tested working, it dawned on me that I never actually saw a correct picture coming from this breadbox. Could it be that the upscalers worked properly all along and that there is a problem with the VIC-II chip or some other issue with the machine itself?

Time for some proper testing then. Unfortunately, the cable I ordered only has an S-Video lead and all the LCD screens and TVs I have lying around the house only have the typical yellow RCA connector for composite video input. This requires some outside the box thinking...
Pin-out diagram shows composite on pin 4 and ground on pin 2. So, some alligator clips, 2 Arduino starter kit jumper wires and an RCA cable later and I had the Frankenstein construction ready to the left here. Then, lo and behold, on my huge LG TV via composite-in finally the nostalgic blue on light blue start screen I've so dearly missed:

Tuesday, April 11, 2017

Commodore 64 arrives, finding modern PSU replacements...




Thanks to my awesome friends and their generous baggage allowance on their trip to Japan, I'm now finally united with my auction purchase and more excited than a little kiddo on Christmas to finally be in possession of my breadbin 64!

Time for some unpacking and testing. The seller ensured me that he powered it up and all was still working fine, so hopefully there won't be any nasty surprises like the dreaded black screen of death welcoming me. Everyone online warned me about the danger of using the original power supply, though, and how it could fry your RAM chips and more. But Japan being on 100V while this PAL box came with a 220V PSU, I didn't have any use for it anyway. I purchased this Y-cable instead that lets you plug in a 9V AC and a 5V DC adapter separately. I already had plenty 5V DC adapters lying around and just ordered a 9V AC adapter from Rakuten.

To power the 1541-II floppy drive was a bit trickier, but fortunately people pointed out that you could get both 5V and 12V DC from old ATX PC case power supplies. I ended up ordered this AC adapter meant to power old IDE disk and CD drives. Sourcing the right 4 pin DIN plug that goes into the floppy drive proved a bit tougher, but some extensive Aliexpress searching revealed the right one eventually too.

That sorts out all the power needs, but getting the video to display in any meaningful manner will be a whole other story, so stay tuned for that...

Monday, March 20, 2017

Building a batch of RetroVGA scanlines generators


While anxiously waiting to get my hands on the recently acquired "real" Commodore 64 before it finally finds its way over to me to Tokyo, I was forced to still make due with emulation. For that I've slapped RetroPie on my aging Raspberry Pi 1 Model B and filled up the SD card with the latest GameBase64 collection which included all the classics I grew up with.

This certainly got me my game fix, but one thing glaringly missing from this retro experience were the distinct scanlines a proper CRT with PAL resolution would display. The games just wouldn't look the same as I remembered.

If you've got some time to spare, read thru this now classic blog post here: Scanlines Demystified

Now, the RetroPie distro comes with all kinds of shaders that try to emulate the picture a real CRT screen would put out and I've played with all of them but the outcome was never good enough. Also, it certainly didn't help that this kind of emulation is very CPU heavy and almost brought my trusty old RPi to its knees every time I turned any of these effects on.

Scouring the interwebs further for a better solution I came across Bruno's excellent blog post: RetroVGA Scanlines Generator. Here he describes a device that does exactly what I want, in hardware, with some cheap TTL logic chips. And he generously released the schematics under the Creative Commons license to boot!

So I downloaded his files and fetched myself a free copy of Autodesk's PCB design software Eagle to view the files, make whatever necessary adjustment and then export the gerber files that PCB manufacturers normally need in order to produce your boards.

To get my boards made a buddy from back home pointed me to DirtyPCBs.com, a very easy to use, cheap, no-nonsense online store that doesn't even require you to export gerber files and directly accepts the Eagle .brd file for uploading. Minimum order is 10 boards and the total with postage to Japan came to $23, not bad at all. Production and shipping was said to take 1-8 weeks but in reality the package arrived after 2 weeks, well within my patience limit :)

This gave me time to also source the rest of the necessary components from AliExpress. Took me quite a while to find the correct parts, so I've created a wishlist to bookmark them. Have at it if you want to build your own device.

Once everything arrived it was time to break out the soldering iron and get cracking:
 


The results where fantastic, scanlines like I remembered them! The 3 potentiometers let you regulate the intensity for each color channel (red, green & blue) and there are toggle switches to turn the scanlines off altogether, to switch from narrow to wide scanlines (draw double scanlines), to flip between drawing them on either even or odd lines and to invert the VSYNC signal, which I never needed to use but Bruno explains that this might be necessary for resolutions other than 640x480@60Hz.


What a happy little project... got me back into using my soldering skills and let me build something that's actually going to be useful.
Of course I won't need all 10 boards, so I ended up keeping 2 for myself. On one I fit on a male VGA plug on the input side so could plug it directly into any VGA graphics card and skip having to plug in an extra cable on this side, but it had to be mounted on the underside of the board for the pins to align. 2 or 3 I gave to buddies of mine who I know are into retro gaming and would appreciate it. And the rest of them I put up on eBay to recuperate some of the expenses.

I threw in free shipping world wide, so I didn't really make any money off of it, but I made some good friends in Australia, German, Finland, etc... seems everyone was happy with this little device and what it can do.


Tuesday, March 7, 2017

Proud new owner of a Breadbin C64 for the first time

The original C64, lovingly referred to as breadbin due to its shape, has always held a special place in my heart. Although I grew up with a C128, I really wanted to own a C64 just for the colorway and shape of the chassis alone. There's something so distinct 80s about it. But also for the older 6851 SID chip, which in my eyes always sounded better.

After months of browsing eBay hoping to get a lucky break and  finding a working C64 for a price I could actually agree with, I had to realize that that won't be a viable option to get my hands on some real Commodore hardware again. Most listings were for "untested" unit, speak broken ones. And the recent retro explosion sure didn't help with the prices either.

Additionally, shipping cost to Japan would normally make even the cheap finds an unfeasible option and most listings where from the states, meaning for NTSC machines. To avoid compatibility issues I really wanted to find a PAL machine like I was used to from my childhood, though.

So, new plan then. Over to Ricardo.ch, the Swiss auction website where people generally go pick up their winnings in person. This would give me some peace of mind, plus I'd avoid the shipping cost... if I can convince my dad back home to actually go pick up the machine I'd bet on and hopefully win.

Sure enough I came across a great listing including a breadbin C64, tested working even, a 1541-II floppy drive, a Quickshot II Turbo and a Quickjoy III joystick, a Final Cartridge III, manuals and a box full of floppies for 180 bucks swiss... not cheap, but in my eyes a great deal no less.

So I've put my bid in, kept my fingers crossed for like 3 days until the auction ran out that nobody would overbid me and sure enough I was the only guy interested in it. And now I'm the proud new owner of a working breadbin Commodore 64 for the first time in my life!

Monday, February 27, 2017

Embarking on a journey to the past


As the proud owner of a  Commodore 128D back in the 80s, I still can't quite fathom how I ever manage to part with this amazing machine and give it away.

Well, I didn't quite give it away. I "lent" it to my little cusin. Or so I'm telling myself to this day.

In any case, due to school and work I moved on the the world of x86 compatible machines and kind of forgot about my beloved Commodore box. Only to find out that, year's later when I wanted to check up on it's state, it apparently broke some while back, got stored in my uncle attic for years and eventually had to be tossed out to make room. Quite the expected faith, actually, and truly my own fault for not showing I still had interest in it and checking up on it sooner.

To be fair, though, at that time I probably wouldn't have had the patience or knowledge to get it in working order again anyway. So I've let it be and moved on. But I never totally lost interest in the Commodore world and always had an emulator handy on most of my machines of the day for a trip down nostalgia lane with a quick play of The Great Giana Sisters or The Last Ninja, two of my all time favorite games.


With the retro computing boom in full effect lately and me recently discovering and joining the awesome Commodore 64/128 Facebook group, where I found lots of like minded geeks... all of them about the same age as me, haha... I'm now positively encouraged to embark on some eBay browsing and getting myself back into the C64 scene.

Wish me luck!