digital video on the coco?
What’s below isn’t intended as a full review. Just my opinioin of the functionality of the device, and ease of installation.
Almost a year ago, I had an accident and broke my ankle in three places. During the next three months while healing, I didn’t have anything else to do except read and watch TV, in between limited remote work assignments. Not exactly an awe inspiring time.
One day, while parsing thru YouTube sugestions, I stumbled across the video below:
Really? a CoCo 1 or coco 2 with HDMi and sprites? This device is created by AC Lovell, and the man is genius level smart. As you can see in the video, he’s in the process of recreating Pac-Man on a 16k CoCo 1. Some would accuse him of attempting the impossible – the previous versions of Pac-Man on the CoCo line were best on the CoCo 3 due to it’s improved architecture.
What’s a CoCoDV?
The cocodv is a small microcontroller that adds HDMI output ability to the CoCo 1 & 2 lines – it is not compatible with the CoCo 3. In addition to HDMI, it also adds sprites and SID type audio (as explained in AC’s video). In order to use the CoCoDV, you need to remove the 6847 from the CoCo, and place it in the socket on the cocodv board.
The CoCoDV then plugs into the original socket used by the 6847 – if it had one. If not, as is the case with MANY CoCo 2 models, you’ll need to de-solder the 6847 – carefully! – and solder in a socket. The dv board uses the 6847. Also, with a coco 2, if your’s has the T1 version of the 6847, it needs a different firmware. When discussing the possible purchase, be sure to be as specific as possible with AC, in order to get your CoCodv board correctly configured.
<warning>– if your coco 1 has the metal sheilding around the CPU, RAM, 6821s & 6847. that will need to be removed for proper clearance. Mine was already removed due to other work I had previously completed. </warning>
When installing the board, there are two installation options – cut or no cut…
cut – you need to remove the center post from your CoCo 1 in order for the cocodv board to be installed.
I removed the center post on mine with a small pair of side-cutters, with the CoCo 1 motherboard still in place. Which is why it looks like a hack job. It was easier than removing the motherboard and using a oscillating cutting tool – which would’ve made sense and looked better….
no cut – you use an offset board supplied by AC to clear the center post area.
To be transparent, I used this method at first – I didn’t like the double-stack approach. While the assembly seems stable at first, I didn’t find it to be particularly useful if the CoCo is moved a lot. On mine, I had to reseat the assembly several times as I was continually moving things around on my desk.
What’s included?
The cocodv board itself includes several other items not shown in this image:
- one flat flexi cable
- two sets of wire for sound and the control button on the hdmi board
- Offset board with extra sockets
- template
having installed two of these, I’d have to argue the most difficult part is cutting the CoCo case for the HDMI/audio header. On the first one, I used the template taped to the CoCo, and found it to not be at 100% scale – I’d say probably 98%, so I had to modify the holes. Took a while, but was doable. On the second one, I held the header up to the CoCo case and used a sharpie, starting with the hole for the audio jack, then HDMI port, buttons, and finally, the mounting holes. I’d also recommend orientating the board so the HDMI port is at the top. It’s easier to get the FFC installed, since that connector would be on the bottom – again, my experience speaking. YMMV…
The most important thing – take your time!!
There are two buttons on the the CoCoDV, and both can be connected to the header board as well. One is for selecting the artifact mode (remember the reset if the screen is blue?), which makes it easy to set the proper artifact color set. I used on the the 2-wire sets with IST connectors for this one.
The other is for development mode – I’ve left this disconnected for now, but there are two solder pads on the DV board, and two more IST pins on the HDMI header board.
Sound must be tapped from the motherboard – which I will likely do this weekend.
Just pictures
The pictures below are on a 55″ Hisense Roku TV – NOT a computer monitor of an appropriate size. While the image is the cleanest I’ve ever seen from a CoCo 1, the screen size makes it look blockier than it would otherwise be.
From what I’ve seen so far, the cocodv does exactly what AC says it’ll do – provide hdmi output to a TRS-80 color computer 1 or 2. For me, that alone warrants the price tag of $120. No need for multiple conversion methods – it just works.
As for the sprites and SID sound – and here’s the kicker – I doubt many people will ever use it. Sure, it’s a damn nice feature set to have, and bragging rights wise, CoCo owners can now say their coco 1 or 2 specs match (or exceed) the hardware of the vaunted C64. The one question here is this: will programmers EVER write software that takes full advantage of the new hardware features? This has been an ongoing problem in coco-land for quite some time – new hardware, new features. zero software to utilize it. The constant cries of ‘it’ll happen soon’ become barely heard echoes of the past as the software never materializes.
with the cocodv, however, it’s a slightly different situation. As more TV’s are made without composite input, and RF conversion boxes really no better than in 1980, the cocodv offers what I consider to be the cleanest video output on a CoCo 1 or 2 that I’ve ever seen. That alone is worth the price of admission. Hopefully, some coders will develop software, like AC is doing with his Pac-Man proof of concept.
Time will tell…
Links to AC’s videos:
upgraded coco video in an 8-bit color computer