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Honest question -- why are they using PATA ribbon cables in the new NICAM codec box? Surely SATA would be more reliable and easier to administer.

by ihsw 11y ago

mseebach 11y ago
They most likely aren't ATA cables, as in, they aren't used to connect hard drives -- so it's not obvious that whatever purpose they serve could be served by a serial alternative. If you look at the photo of the back of the unit, you see a lot of very wide D-Sub sockets that these ribbon cables seem to connect to, so the unit is meant to connect to a bunch of other things. Actually, the need for these sockets seem to account for most of the size of the unit, the box appears pretty empty.
- logfromblammo 11y ago
  If you're designing your own boards with ribbon cables connecting them, I imagine that you could save a lot of money on parts by using 40-pin connectors with PATA cables--we're talking entire cents, for each of the 2 units. Also, I'm willing to bet a place like the BBC has boxes filled with spare PATA cables and 16MB SIMMs and 8 GB internal hard drives, and maybe even a room with a bunch of dusty 17" CRT monitors in it. And sometimes, rather than fill out a purchase order, one of the engineers descends into the hoard, returns with a cobbled-together frankenserver, and installs NetBSD on it. So they might actually be PATA cables using PATA connectors, but the signal between cards is not ATA.
  - pjc50 11y ago
    Exactly. And it has to connect to the same system as the original 1980s units, so whatever protocol it's using will be old. DB25-serial? SCSI? IEE-488? It would have been nice to have a few technical details on the system. Random BBC-related anecdote: the Cambridge University computer lab had, up to 1999, an info TV in the lobby driven by a 20 year old BBC micro in Teletext mode. This was apparently because it had an extremely powerful video output (more so than modern hardware) and the display was at the other end of 50m coaxial cable.
    - fanf2 11y ago
      The display was slaved via coax to, I think, four or five CRTs around the site. I don't know if there was a separate amplifier/splitter or not. It lasted a few years past 1999 - it was still in service for some time after I returned in 2002.
  - Sanddancer 11y ago
    If it was a scavenged system, I'd be apt to believe you, but a new build like this, you almost certainly would use new ribbon cables. In bulk, the ribbon is about fifty cents a foot, so reusing old parts wouldn't be worth the trouble of having to troubleshoot problems down the road.
    - logfromblammo 11y ago
      You may have missed my sarcasm. You can easily see from the pictures that the ribbon cables are different widths. It looks like every ribbon connects a PCB to a connector on the backplane, most of them D-subs. The photo of the backplanes as installed show that most of the connectors aren't even being used. By coincidence, the large-sized cables have 40 conductors. The medium ones have 25 or 26, and the small ones have 15 or 16. Those are all standard sizes for ribbon cable, and you can likely buy new cables of the correct sizes off the shelf for less than $10 each, or make them yourself at 20% the price or less. In comparison to the overall cost of engineering the box, the ribbon cables are just a drop in the well. Nevertheless, about 12 of the ribbon cables in the box could theoretically be replaced by old PATA cables and 35 million people would still never know. The potential problems would be that some ATA cables block pin 20 as a mechanical key, they would be longer than strictly necessary, and ribbon cables are obnoxiously effective antennas. The 40-pin ribbon cables as installed could almost certainly be used as very short PATA cable replacements, with a little mechanical modification of the connectors.
joezydeco 11y ago
Those look like custom digital connectors moving data to and from the codec boxes. They're not connecting hard drives here. If you had to connect 40 low-speed signal pins from one board to another, you'd do it as simply and cheaply as possible. Serializing them doesn't gain you much of anything, other than complexity.
jauer 11y ago
They aren't using PATA or SATA. They are using ribbon cables to connect boards to each other and to backplate connectors. Some of those ribbon cables could be carrying serial signaling on some lines but to get it all on one smaller cable with fewer signaling lines like SATA you'd need to mux/demux the data on each end which would add expensive chips to save money on cheap cables.
jmtd 11y ago
They almost certainly are not moving ATA commands over those ribbons, so SATA wouldn't be much use.

Honest question -- why are they using PATA ribbon cables in the new NICAM codec box? Surely SATA would be more reliable and easier to administer.

by ihsw 11y ago

Honest question -- why are they using PATA ribbon cables in the new NICAM codec box? Surely SATA would be more reliable and easier to administer.

mseebach 11y ago

They most likely aren't ATA cables, as in, they aren't used to connect hard drives -- so it's not obvious that whatever purpose they serve could be served by a serial alternative. If you look at the photo of the back of the unit, you see a lot of very wide D-Sub sockets that these ribbon cables seem to connect to, so the unit is meant to connect to a bunch of other things. Actually, the need for these sockets seem to account for most of the size of the unit, the box appears pretty empty.

logfromblammo 11y ago
If you're designing your own boards with ribbon cables connecting them, I imagine that you could save a lot of money on parts by using 40-pin connectors with PATA cables--we're talking entire cents, for each of the 2 units. Also, I'm willing to bet a place like the BBC has boxes filled with spare PATA cables and 16MB SIMMs and 8 GB internal hard drives, and maybe even a room with a bunch of dusty 17" CRT monitors in it. And sometimes, rather than fill out a purchase order, one of the engineers descends into the hoard, returns with a cobbled-together frankenserver, and installs NetBSD on it. So they might actually be PATA cables using PATA connectors, but the signal between cards is not ATA.
- pjc50 11y ago
  Exactly. And it has to connect to the same system as the original 1980s units, so whatever protocol it's using will be old. DB25-serial? SCSI? IEE-488? It would have been nice to have a few technical details on the system. Random BBC-related anecdote: the Cambridge University computer lab had, up to 1999, an info TV in the lobby driven by a 20 year old BBC micro in Teletext mode. This was apparently because it had an extremely powerful video output (more so than modern hardware) and the display was at the other end of 50m coaxial cable.
  - fanf2 11y ago
    The display was slaved via coax to, I think, four or five CRTs around the site. I don't know if there was a separate amplifier/splitter or not. It lasted a few years past 1999 - it was still in service for some time after I returned in 2002.
- Sanddancer 11y ago
  If it was a scavenged system, I'd be apt to believe you, but a new build like this, you almost certainly would use new ribbon cables. In bulk, the ribbon is about fifty cents a foot, so reusing old parts wouldn't be worth the trouble of having to troubleshoot problems down the road.
  - logfromblammo 11y ago
    You may have missed my sarcasm. You can easily see from the pictures that the ribbon cables are different widths. It looks like every ribbon connects a PCB to a connector on the backplane, most of them D-subs. The photo of the backplanes as installed show that most of the connectors aren't even being used. By coincidence, the large-sized cables have 40 conductors. The medium ones have 25 or 26, and the small ones have 15 or 16. Those are all standard sizes for ribbon cable, and you can likely buy new cables of the correct sizes off the shelf for less than $10 each, or make them yourself at 20% the price or less. In comparison to the overall cost of engineering the box, the ribbon cables are just a drop in the well. Nevertheless, about 12 of the ribbon cables in the box could theoretically be replaced by old PATA cables and 35 million people would still never know. The potential problems would be that some ATA cables block pin 20 as a mechanical key, they would be longer than strictly necessary, and ribbon cables are obnoxiously effective antennas. The 40-pin ribbon cables as installed could almost certainly be used as very short PATA cable replacements, with a little mechanical modification of the connectors.

joezydeco 11y ago

Those look like custom digital connectors moving data to and from the codec boxes. They're not connecting hard drives here. If you had to connect 40 low-speed signal pins from one board to another, you'd do it as simply and cheaply as possible. Serializing them doesn't gain you much of anything, other than complexity.

jauer 11y ago

They aren't using PATA or SATA. They are using ribbon cables to connect boards to each other and to backplate connectors. Some of those ribbon cables could be carrying serial signaling on some lines but to get it all on one smaller cable with fewer signaling lines like SATA you'd need to mux/demux the data on each end which would add expensive chips to save money on cheap cables.

jmtd 11y ago

They almost certainly are not moving ATA commands over those ribbons, so SATA wouldn't be much use.