Old analog Gear, need manuals, etc.

[jeremyabel]

Do you have the pinouts for the cable? It's not wired completely pin-for-pin. From the technical guide:

Yeah, that's what I Googled for when I first found this thread, I saw it in the first page of posts. Currently kicking myself because I ordered a weird combination of cable pieces off Amazon in order to assemble this thing, and I just realized that if I had only taken 5 minutes to search on McMaster, I would have found the exact parts I needed at a fraction of the price...

At least I won't have to worry about the separate power supply; I only plan on the cable being 15 feet or so.

Thanks for all this info btw, I'm sure I'll have more questions once this thing gets up and running. You mentioned you have the user's manual, yeah? Is there like an introductory tutorial?

[jeremyabel]

Woo ok, I got my cable made up, keyboard looks like it's working fine! Video looks out of sync though... reading the previous posts, seems like I need to feed a black burst signal into REF LOCK.

[PID_Stop]

Thanks for all this info btw, I'm sure I'll have more questions once this thing gets up and running. You mentioned you have the user's manual, yeah? Is there like an introductory tutorial?

The operator's manual doesn't exactly have a tutorial so much as it is the tutorial. Once you get past the step of acquiring the channel, much of the operation is pretty intuitive. One of these days I really ought to scan the manual; unfortunately, the pages are a weird size, so I need to check whether the copier/scanner will handle them.

As far as questions go, bring them on!

Oh, and about the black burst reference: yes, I'm pretty sure the A51 won't run right without it. The analog-to-digital converter for the input does lock to the incoming video, but the memory addressing logic for reading the video to the output digital-to-analog converters expects to lock to the reference signal. Without a reference, the box free-runs on its internal oscillator; since it will never exactly match either the rate or phase of the input video, you will at best get periodic disturbances in the output video.

Jeff

[jeremyabel]

Oh, and about the black burst reference: yes, I'm pretty sure the A51 won't run right without it. The analog-to-digital converter for the input does lock to the incoming video, but the memory addressing logic for reading the video to the output digital-to-analog converters expects to lock to the reference signal. Without a reference, the box free-runs on its internal oscillator; since it will never exactly match either the rate or phase of the input video, you will at best get periodic disturbances in the output video.

After doing some research, I picked up a Horita BSG-50 Blackburst Generator for $30 off ebay, and a For.A FA-210 Time Base Corrector for a similar price. If I understand everything correctly, the blackburst generator would go into both the TBC and the A51, and my input video would go into the TBC and then get synced to the blackburst generator and fed into the A51. That makes sense in my head, but I've never fiddled with any of that stuff before.

As far as questions go, bring them on!

So, first question! Is there a way to change parameters in a more precise way than using the joystick? For instance, if I hit the Warp button and then the Shape softkey, I can scroll between all the warp shape options by moving the joystick left and right but unless I really feather the stick, it either scrolls through the list at speeds of "too fast" to "oh god way too fast". Is there a next / prev button sort of thing for this? Other parameters, like say the corner pin coordinates, have two parameters tied to left-right and up-down joystick movement. Is there a way I can enter numbers in for these parameters directly? Also, is there a way to clear these numbers back to zero?'

I'm really intrigued by the fact that I can apparently make a 10000-sided prism, and that there are warp shapes with great names like "pipe organ" and "shred"!

[PID_Stop]

After doing some research, I picked up a Horita BSG-50 Blackburst Generator for $30 off ebay, and a For.A FA-210 Time Base Corrector for a similar price. If I understand everything correctly, the blackburst generator would go into both the TBC and the A51, and my input video would go into the TBC and then get synced to the blackburst generator and fed into the A51. That makes sense in my head, but I've never fiddled with any of that stuff before.

Yes, that would work. If your original source has an external reference input, you can connect that to your black burst generator, and then you don't need the FA-210. If memory serves, I don't think the For-A had particularly good video processing, but I might be thinking of the DPS-235 (which definitely didn't).

So, first question! Is there a way to change parameters in a more precise way than using the joystick? For instance, if I hit the Warp button and then the Shape softkey, I can scroll between all the warp shape options by moving the joystick left and right but unless I really feather the stick, it either scrolls through the list at speeds of "too fast" to "oh god way too fast". Is there a next / prev button sort of thing for this? Other parameters, like say the corner pin coordinates, have two parameters tied to left-right and up-down joystick movement. Is there a way I can enter numbers in for these parameters directly? Also, is there a way to clear these numbers back to zero?'

Yes -- you can manually key in just about any parameters. I'll quote from the manual:

Using the Joystick
The joystick has three axes: H (deflecting it left/right), V (deflecting it up/down), and Z (rotating the joystick). To change a number, first highlight its softkey by pressing it, then deflect the joystick in the desired direction, based on the column that the number is in.

Using the Numeric Keypad
Like the joystick, the numeric keypad has three axes. To change a number, you must first highlight its softkey, and press either the H/7 button for an H axis entry, V/8 for a V axis entry, or Z/9 for a Z axis entry. Now select the desired number, using the decimal point and minus sign where needed, and press the ENTER button to enter it. Use the CLEAR button to abort this procedure if required.

I'm really intrigued by the fact that I can apparently make a 10000-sided prism, and that there are warp shapes with great names like "pipe organ" and "shred"!

The A51 is remarkably powerful, especially if you have the Warp option and more than one channel. At the time, it was a much less expensive alternative to the Ampex ADO; and it produced far superior video quality to the NEC E-Flex it replaced in our shop.

-- Jeff

[jeremyabel]

Yes, that would work. If your original source has an external reference input, you can connect that to your black burst generator, and then you don't need the FA-210. If memory serves, I don't think the For-A had particularly good video processing, but I might be thinking of the DPS-235 (which definitely didn't).

Hmm, right now I've just been planning on plugging stuff like VCRs and old video game consoles into it. I'd love an HDMI -> NTSC SD converter that would take blackburst, but something tells me that's not the sort of thing I'd be able to find on ebay for a $30 price tag .

Also, I managed to find the manuals and various other assorted documentation for the A53-D on the Abekas site: http://abekas.com/download/Legacy_Produ ... cts/A53-D/. Seems like it's similar to the A51 in operating principles, although the user interface is entirely different, but hopefully it'll provide me enough info to sort out the A51's finer points. Just reading the section on drawings solids is insane! Multiple passes just to get a cube on the screen! What sort of video recorders did people use for that sort of thing? I can't imagine using a consumer VCR for that sort of thing!

I imagine all the "3D" it's doing is fake 3D? Was there ever a system like this that could do realtime 3D broadcast effects without needing multiple passes? I know actual 3D graphics was in it's infancy in the early 90's, so was it the case that if you wanted anything more complicated / easier to work with than multipass recordings to build up a solid with the A51, you'd just go to one of the early SGI machines?

[PID_Stop]

Hmm, right now I've just been planning on plugging stuff like VCRs and old video game consoles into it. I'd love an HDMI -> NTSC SD converter that would take blackburst, but something tells me that's not the sort of thing I'd be able to find on ebay for a $30 price tag .

You will absolutely need time base correction for feeds from VCRs, so you're on the right track there. One thing you might encounter with older game devices is that many of them were not strictly NTSC-compliant: at least one that comes to mind actually produced 512 lines per frame instead of 525; televisions at the time didn't especially care, but a digital device like a TBC or a DVE might.

Also, I managed to find the manuals and various other assorted documentation for the A53-D on the Abekas site: http://abekas.com/download/Legacy_Produ ... cts/A53-D/. Seems like it's similar to the A51 in operating principles, although the user interface is entirely different, but hopefully it'll provide me enough info to sort out the A51's finer points.

The A51 (and the later A51+) were the replacement for the A53. I never figured out why they would be counting down instead of up. Many of the operating principles are very similar, though.

Just reading the section on drawings solids is insane! Multiple passes just to get a cube on the screen! What sort of video recorders did people use for that sort of thing? I can't imagine using a consumer VCR for that sort of thing! I imagine all the "3D" it's doing is fake 3D? Was there ever a system like this that could do realtime 3D broadcast effects without needing multiple passes? I know actual 3D graphics was in it's infancy in the early 90's, so was it the case that if you wanted anything more complicated / easier to work with than multipass recordings to build up a solid with the A51, you'd just go to one of the early SGI machines?

Back then, that sort of effect compositing typically used a one-inch VTR like a Sony BVH-2000 or Ampex VPR series. If you had a lot of money (and did a lot of animation), you could get a Sony BVH-2500, which used the same general scheme that other VTRs used for still-frame playback in order to do still-frame recording -- that is, hit the button and the machine would record a single frame of video, move the tape about 5/16", then stop and wait until you want to record the next frame. We had one of the earliest production models of this machine (the sixth one off the assembly line, by its serial number!), and it was a maintenance nightmare, needing constant adjustment. Sony redesigned the record trace system almost immediately. There was also a tapeless solution: the Abekas A-64 was an early digital video disk recorder that could be controlled like a tape machine, but stored the video on an array of hard drives. This was back in the late '80s, and if I remember correctly, it could hold up to about two minutes of video. I rebuilt a used A-64 for a local production house to use for animation, and while it was a remarkable device for the time, it was less than reliable.

Cost-effective real-time 3D effects finally became possible with the A51: add several channel frames, a keyboard combiner and a video combiner, and each channel becomes a live video portion of the overall effect. You can see a hint of this toward the end of their 1991 A51 demo video.

Jeff

[KPJL FM]

"Just reading the section on drawings solids is insane! Multiple passes just to get a cube on the screen! "

I remember having/using an early Chyron that took FOREVER to do a page with 6-7 lines of text.

Or maybe that was a dream. Or maybe I fell asleep waiting for the Chyron to finish.

[PID_Stop]

Yup. We used to have an early animation system that ran on a 386 with optional math co-processor chip. It would take about five minutes to render a frame; when it had finished, it readied up the BVH-2000, performed a one-frame insert edit, then took the VTR back out of standby... and the whole process would start all over for the next frame. Getting five seconds of animation would be an overnight project. When we got a BVH-2500 (the one that could record single frames without moving the tape), it at least reduced the tape wear from constant back-and-forth prerolling and editing.

Jeff

[jeremyabel]

Ok, so with the combined powers of a Horita BSG-50 blackburst generator, and For-A FA210 time base corrector, I can really do some wacky stuff to video! These warps are ridiculous and amazing, it's like the controls go from "oh, this is pretty subtle" to "huh, this has very little resemblance to the video I put into it!" I imagine there's a lot of secret engineering sauce that goes into how all that works in real-time.

Back then, that sort of effect compositing typically used a one-inch VTR like a Sony BVH-2000 or Ampex VPR series.

Do you have a general example of the workflow? Would that even be possible with a 1-channel system? The DPM-700 has a background video input, so I imagine the workflow there would be to animate a thing, record to tape, plug tape output to background input, repeat. But the A51 has no background input, so would you plug the key output into the video recorder and it'd mask off the area for recording? I imagine the most accessible tape recording solution would be a dvcam recorder, but I wonder if there's a way I can sync playback and capture via a modern computer using the RS424 output, hmm.

[PID_Stop]

Ok, so with the combined powers of a Horita BSG-50 blackburst generator, and For-A FA210 time base corrector, I can really do some wacky stuff to video! These warps are ridiculous and amazing, it's like the controls go from "oh, this is pretty subtle" to "huh, this has very little resemblance to the video I put into it!" I imagine there's a lot of secret engineering sauce that goes into how all that works in real-time.

Good for you!

Do you have a general example of the workflow? Would that even be possible with a 1-channel system?

If you're looking to animate a graphic that gets keyed over other video (as opposed to animating a full-screen graphic), there are two approaches. The first would be to animate the graphic with the background to a particular color (e.g., green or blue) and use chromakey to key it over your live video. This can work very well in an all-digital environment because SDI video is inherently component; in an analog composite system, it's not so good, and you usually end up with a colored fringe. A better solution in an analog world is to make the background "super black" -- that is, a signal where the luminance is at 0IRE (normal black is 7.5IRE). That allows you to do a luminance key to insert the animated graphic over live video, it avoids color fringing, and it means your graphic can include any color you wish to use. If I remember correctly, the A51 does pass super black (some devices clamp video to a minimum of 7.5 IRE). If you can't generate or record down to 0 IRE, you can use ordinary black as your background... but then you need to be mindful to keep all of the animated graphic that you want visible, enough above black so that the keyer can still distinguish between the graphic versus the background.

Jeff