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

The first digital ICs I used were Moto RTLs, packaged in a round black

MC7xx maybe.

John

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

Didn't Fairchild make those, that's what I used, IIRC.

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.

Tam

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

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

John

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.

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

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

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 flop.

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.

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.

RL