|
Post by gsteemso on Oct 13, 2015 2:22:06 GMT
One of Hydro's other threads here reminded me of a big one that all projects of this nature should consider. Fixing the random number generator! The stock routine is just awful as far as producing evenly spread results, as you would expect if every output value were equally probable.
|
|
|
Post by gsteemso on Oct 13, 2015 2:16:52 GMT
As I understand it, the Commodore ROM random-number generator is horribly flawed. Some of the steps they have the machine perform actually make the result LESS random! I don't believe the discussion of this is still online (I'm pretty sure it was on C128 Alive!), but from what I remember they found when they disassembled it, whoever wrote it REALLY did not know enough about the problem domain. I am absolutely certain that better routines have been written and are in the public domain, though I'm not sure where you would look for the code. I always vaguely considered that I could go find it if I ever needed it and never really saved any of it.
I know even Commodore admitted that if you needed truly random data, the SID noise waveform and that register that lets you peek into the internal oscillator value is your best bet.
|
|
|
Post by gsteemso on Oct 13, 2015 2:06:30 GMT
If you set up a local http server ("web sharing" or the like), a Flyer can load programs or even entire disk images with a simple OPEN or LOAD command on the Commodore. I do not know if a Comet can do this as well, as I do not own one and have never investigated it.
|
|
|
Post by gsteemso on Oct 8, 2015 22:34:31 GMT
Well, I have specimens of two models here: the Cardco G-Wiz, and the Micro R&D Micrografix. They both come with a variety of DIP switches to adapt to different makes of printer and have small onboard print buffers. Physically, they are a little wider than a standard C64 cartridge and plug straight into the Centronics connector of an old-style PC printer, with a standard Commodore serial cable coming out of the other end. Not sure what else there is to say about them. They're pretty straightforward.
|
|
|
Post by gsteemso on Oct 3, 2015 7:03:18 GMT
Speaking as the owner of an older but still relatively newish office-grade multifunction printer which it would cost only half as much to REPLACE ENTIRELY as to buy replacement ink cartridges for, my big question is "what acceptably capable printer can you use with an 8-bit Commodore _that you can still get ink for_?"
If it helps, Commodore-serial-bus to Centronics adapters can't possibly be that unusual or hard to get; I myself have at least two of them here, neither of which I sought out. Presumably there are quite a few others floating around any given area that had a good installed Commodore base in the 1980s-1990s.
|
|
|
Post by gsteemso on Sept 25, 2015 18:45:23 GMT
I have a scart to HDMI adapter. Which model was it, how much was it and where do you get one? I've got one of those little passive adapters that runs composite/stereo into a SCART plug; I seem to recall reading that an RGB-to-SCART adapter is not much more complex.
|
|
|
Post by gsteemso on Sept 25, 2015 3:19:01 GMT
It will be very interesting indeed to see if the AD724 can handle funky video parameters. My thinking was that the ridiculous range of video timings the VDC can output would necessitate doing some sort of custom FPGA solution or the like, but someone (Mirkosoft?) mentioned in another thread that certain commercial units such as the Ambery AV-1 don't choke on, for example, Risen from Oblivion, so I'm probably over-thinking it. (I believe the AV-1 is a VGA encoder, so does not solve the S-Video problem, but it's still an interesting data point. Anybody out there who has one feel like cracking the case to see what chip(s) it uses?)
|
|
|
Post by gsteemso on Sept 21, 2015 22:09:04 GMT
There is a common chip now that does RGB to S-Video and Composite. What chip would that be? How does it react to custom scan rates and resolutions such as the VDC can output (e.g. the Risen from Oblivion demo)? If I were designing a solution to the C128 video problem, I’d probably make it output 720p or 1080i HDTV, filling in around the edges with the VDC border colour. That way you’d always have enough pixels to show everything, no matter how out of spec your program sets its video output. If I were going to really do it properly I’d include an option to do fancy processing to mimic CRT colour-blending effects on flat-panel TVs (which are most of them these days).
|
|
|
Post by gsteemso on Sept 21, 2015 21:56:00 GMT
While the reference to a “John Carlson” does sound vaguely familiar, I have no clue where from. Link please?
|
|
|
Post by gsteemso on Sept 19, 2015 6:41:59 GMT
"Homebrew"-ness is orthogonal to build quality. Your board looks very slick and professional -- and since you designed and built it yourself, therefore it is homebrewed.
I'll be interested to see if you can come up with an S-video converter that gives equally good results. As I understand it, Commodore didn't do that in the first place because it would have been prohibitively expensive to make a signal clear enough to be legible on a 1980s TV set in 80 columns. Obviously the technology is much better now, but at the same time, current development stopped being about SDTV video nearly a decade ago.
|
|