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1. Foone🏳️‍⚧️ (foone@digipres.club)'s status on Saturday, 24-Dec-2022 02:25:11 UTC Foone🏳️‍⚧️

   in reply to

   And an MMR Output Converter, ASSY 70372.

   • Foone🏳️‍⚧️ (foone@digipres.club)'s status on Saturday, 24-Dec-2022 02:25:12 UTC Foone🏳️‍⚧️

     in reply to

     So it's got a separate power supply inside the case, plugged into a splitter on the power button line. (which, on an AT system, carries the full AC wall voltage)
     It provides ±18v at half an amp.

   • Foone🏳️‍⚧️ (foone@digipres.club)'s status on Saturday, 24-Dec-2022 02:25:12 UTC Foone🏳️‍⚧️

     in reply to

     Those power these two boards (with room for a third, missing on this model)
     This one is the MMR Input Converter, ASSY 70395. 8-channels.

   • Foone🏳️‍⚧️ (foone@digipres.club)'s status on Saturday, 24-Dec-2022 02:25:13 UTC Foone🏳️‍⚧️

     in reply to

     The front-panel display is a Optrex DMC-2026I display. 20x20 characters, each character being 5x8 pixels. This variant has a backlight, and it's built on the standard Hitachi HD44780 chip.

   • Foone🏳️‍⚧️ (foone@digipres.club)'s status on Saturday, 24-Dec-2022 02:25:13 UTC Foone🏳️‍⚧️

     in reply to

     The front panel is communicated with through this MMR FP/UIB Interface, Assy 70301.

     It's just a bunch of caps and resistors?

   • Foone🏳️‍⚧️ (foone@digipres.club)'s status on Saturday, 24-Dec-2022 02:25:13 UTC Foone🏳️‍⚧️

     in reply to

     and it's got three 32mb SDRAMs.
     So 96mb in total. That's a bunch for a Pentium 1!

   • Foone🏳️‍⚧️ (foone@digipres.club)'s status on Saturday, 24-Dec-2022 02:25:14 UTC Foone🏳️‍⚧️

     in reply to

     Then another of the same board, but this one is missing the receiver/transmitter chips. It's just got the RAM and FPGA.

   • Foone🏳️‍⚧️ (foone@digipres.club)'s status on Saturday, 24-Dec-2022 02:25:14 UTC Foone🏳️‍⚧️

     in reply to

     Then the final board is a Timeline PRX ASSY 70383.
     More SRAMs and lattice chips, and a PLX PCI9060 bus controller.
     So I suspect that many-pins backplane they use to connect all the boards may be a second PCI bus.

   • Foone🏳️‍⚧️ (foone@digipres.club)'s status on Saturday, 24-Dec-2022 02:25:14 UTC Foone🏳️‍⚧️

     in reply to

     It's also got a Motorola DSP56002PV80, a 24-bit DSP.

   • Foone🏳️‍⚧️ (foone@digipres.club)'s status on Saturday, 24-Dec-2022 02:25:15 UTC Foone🏳️‍⚧️

     in reply to

     It's got 4 of these CS8411-CS digital audio receivers, and then 4 of these CS8401-CS digital audio transmitters.

   • Foone🏳️‍⚧️ (foone@digipres.club)'s status on Saturday, 24-Dec-2022 02:25:15 UTC Foone🏳️‍⚧️

     in reply to

     And four of these IDT7132SA20J 2 kilobyte dual-ported static-ram chips. Probably for audio buffering/processing at super-low latency

   • Foone🏳️‍⚧️ (foone@digipres.club)'s status on Saturday, 24-Dec-2022 02:25:16 UTC Foone🏳️‍⚧️

     in reply to

     The first big custom board is this TimeLine Sync2 ASSY 70386.
     A bunch of FPGA chips, custom ASICs, and EEPROMs.
     It's 16-bit ISA, but it seems to talk to other boards through that big locking IDC connector on the top left, so that probably doesn't matter much.

   • Foone🏳️‍⚧️ (foone@digipres.club)'s status on Saturday, 24-Dec-2022 02:25:16 UTC Foone🏳️‍⚧️

     in reply to

     Then the MMR UIB, ASSY 70302.
     More FPGAs, ASICs, and EEPROMs.
     They integrated the serial port from the motherboard into this card, it seems.

   • Foone🏳️‍⚧️ (foone@digipres.club)'s status on Saturday, 24-Dec-2022 02:25:16 UTC Foone🏳️‍⚧️

     in reply to

     Then the 70384 DIO.
     Digital I/O, I suspect.

   • Foone🏳️‍⚧️ (foone@digipres.club)'s status on Saturday, 24-Dec-2022 02:25:17 UTC Foone🏳️‍⚧️

     in reply to

     Let's go through the boards.
     The smallest one is this MMR Biphase Option (BOB), ASSY 70303.
     Seems to have a bunch of RJ-?? plugs.

   • Foone🏳️‍⚧️ (foone@digipres.club)'s status on Saturday, 24-Dec-2022 02:25:17 UTC Foone🏳️‍⚧️

     in reply to

     Then a Symbios SYM8600SP SCSI board. Seems to be pretty standard, this is probably just an off the shelf component.

   • Foone🏳️‍⚧️ (foone@digipres.club)'s status on Saturday, 24-Dec-2022 02:25:18 UTC Foone🏳️‍⚧️

     And it turns out that CPU is a Pentium 133mhz, SY022.