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Old Motorola 3.6V chips - RTL? DTL? Anybody remember them?

Discussion in 'Electronic Design' started by Rich Grise, Jan 27, 2006.

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  1. Rich Grise

    Rich Grise Guest

    I was just sitting here whiling away a Friday afternoon, with the weather
    more amenable to having a picnic, and happened to think of some of the
    first integrated circuits (ICs) I ever heard of - they were from Motorola,
    and ran off 3.6Vdc Vcc, and they were either RTL or DTL, or maybe there
    isn't that much difference in those technologies.

    Oh, OK. I'm reminiscing. Sigh.

    Say, Jim Thompson - didn't you used to work at Motorola? I'm not going to
    say I think you worked there at the time, even though you are more than
    a year older than I am ;-), but I was just sort of wondering if you or
    anyone else remember those chips. Their part number was something like
    MC733 or MC312 or something like that - two letters to indicate "Motorola"
    and three digits.

    Anybody remember them, or have any stories about using them?

  2. John Larkin

    John Larkin Guest

    The first digital ICs I used were Moto RTLs, packaged in a round black
    8-pin glob-top with wire leads, like the old Fairchild transistors.
    Noisy, nasty, unreliable power hogs, as I recall. Noise immunity and
    fanout were both the pits.

    MC7xx maybe.

  3. Jim Thompson

    Jim Thompson Guest

    I was at Motorola SPD from 1962-1970.

    Besides all the analog stuff I did I was involved with ECL, RTL, DTL,
    TTL & PECL, but I really only remember the TTL and ECL/PECL numbers.

    RTL sucks for noise immunity EXCEPT when everything stays on-chip.
    I've done a number of analog chips with simple-minded RTL logic
    sections, but my preference is BiCMOS.

    ...Jim Thompson
  4. John Larkin wrote...
    Didn't Fairchild make those, that's what I used, IIRC.
  5. Tam/WB2TT

    Tam/WB2TT Guest

    Pretty sure the 3.6V parts were RTL. Max fanout was only 2 or 3 loads. I
    shouldn't have thrown out the old Moto manual.

  6. John  Larkin

    John Larkin Guest

    I used the Moto RTL stuff for a while, until DTL came out. Flirted
    with SUHL and Utilogic a bit, too, until TI/TTL finally won.

    I seem to recall (mists of time and all that) that the globtops were
    Motos, but they may well have been Fairchild. I posted a couple of
    pics to abse; this catalog, 1966, shows them in round metal cans, 8 or
    10 pins.

    Wow, just tripped across the datasheet for the MR1290, a 1000 amp
    silicon diode. It's water cooled!


  7. The Fairchild RTL I used was in a flatpak configuration. I also have
    (or had) some RTL with NASA markings for the 914 and 923 chips.

    Service to my country? Been there, Done that, and I've got my DD214 to
    prove it.
    Member of DAV #85.

    Michael A. Terrell
    Central Florida
  8. Joseph2k

    Joseph2k Guest

    If Fairchild made them the part numbers would be uL7XX not MC7XX.
  9. Barry Lennox

    Barry Lennox Guest

    Yes, I remember them well, grey ceramic/black epoxy blob things? built
    a scope timebase using one. Rushes to old semi junkbox,-- Thought I
    spotted one, but no it's a Fairchild SE6001. Right in between a CK722
    and several OC170s.

    Barry Lennox
  10. They were probably RTL. Really Terrrible Logic. Although at the time
    they just took your breath away. Two NAND gates in one little TO-5
    size package!! WowWee!! Even more impressive was the 923 J-K flip

    The outputs had a 400 ohm pull up IIRC, and the inputs had a 600 ohm
    input resistor. So you couldnt hook up too many inputs to an output
    before the logic swing went way down and the marginal noise immunity
    went to zero. And the flip-flop used a retarded charge-injection
    transfer scheme, so the clock had to have fast transition times, or the
    flip-flop wouldnt flip. Pretty sorry logic, but at the time there
    wasnt anything better at a reasonable price. DTL was available, but
    IIRC only at military part prices. Eventually Fairchild saw the light
    and started making DTL, then the price went down exponentially and the
    stuff caught on.
  11. legg

    legg Guest

    MC800-900 series were RTL in metal cans or ceramic flat-packs.
    MC700-800 series were RTL in 14pin DIP (TO-116)

    Tesed at 3V, rated for 12VCC surge, with +/- 4V input tolerance.

    The low fanout meant a lot of 'gate expanders' on offer.

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