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The cool chips! — Parallax Forums

The cool chips!

markaericmarkaeric Posts: 282
edited 2012-09-13 10:46 in General Discussion
I imagine that just about everyone on this forum once in a while comes across an IC (digital/analog/both) that they've never seen before and thinks to themselves "This is cool!" For me, the Propeller is definitely one of them.


What have you come across that you thought was cool?


I knew quad port SRAM is commonly used in the cores of processors, what I did didn't know was that there were manufacturers that made these in external memory form:
http://www.cypress.com/?id=117
It would definitely be cool sitting between four Propellers, or even as an interface between different processors.

If that's a bit excessive, then how about dual-port?
http://www.cypress.com/?id=82

Comments

  • Cluso99Cluso99 Posts: 18,069
    edited 2012-09-11 18:55
    I used Dual Port memory more than 20 years ago in a commercial design for comms between dual processors on the pcb. I used a Xilinx FPGA for the interface to the motherboard of the mini-computer that these pcbs were used in. While they were expensive at the time, they were nothing compared to the pcb selling price due to the initial R&D costs.
  • kwinnkwinn Posts: 8,697
    edited 2012-09-11 18:57
    Yes, that would be cool, and only a cool $462.50 for the quad port. Now the dual port chip at $20-30 would make a nice buffer for a logic analyzer or digital scope.
  • Cluso99Cluso99 Posts: 18,069
    edited 2012-09-11 19:03
    What we need is a single cog chip (without hub, but with I/O pins - say 16). Then we could build our own prop monster using discrete memory and multiple cog chips. Something like a 200+MHz cog, low power, perhaps 20 pins narrow SIOC20 or TSSOP20, and cheap! - internal trimmed/trimmable oscillator and ~$1.00 in quantity.

    Just imagine what we could do with this! Unfortunately, while hobbyists would use a load of them (if in DIP), I don't really see the commercial quantities for Parallax because of all the other chips out there that would compete.
  • LawsonLawson Posts: 870
    edited 2012-09-11 19:30
    Yea the Propeller is top of my "This is cool" list. The MCP6541 and it's op-amp relatives are a close second. (available in DIP packages too!) Before I found them I never figured I could get analog circuits to run on a few microamps.

    Lawson
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2012-09-11 19:55
    The Propeller is easily the coolest chip I've ever worked with. Between Spin and PASM, rapid (or is that "rabid" ?) application development (RAD) is a breeze. On a much lower plane, the ATTiny13 is pretty amazing, given its size and cost, but it's not the easiest thing to program in assembly. (I don't do C.) Going down another few notches, how about the 555? That thing can do so much for so little!

    Going down still more levels, some of the least appreciated chips, IMO, but ones which I find quite useful, are three-terminal voltage detectors (also known as "supervisors"). They can be used for much more than just brown-out detectors and power-on reset controllers.

    -Phil
  • CircuitsoftCircuitsoft Posts: 1,166
    edited 2012-09-11 22:32
    The LM3909 is actually one of those chips for me. The internal circuitry is so simple (far simpler than a 555), yet it can perform many functions.
  • Cluso99Cluso99 Posts: 18,069
    edited 2012-09-11 22:55
    Phil etc:
    I find the ATTiny84A (SOIC14) and ATTiny87(SOIC20 & TSSOP20) nice pricepoint devices. But yeah, what a pain to setup all those registers.
    So much simpler to grab an object and load it into a cog ;)
  • Heater.Heater. Posts: 21,230
    edited 2012-09-11 23:06
    Cool chips?

    Well, as a young teenager in the 1971 or so I discovered our local amateur radio club. On my first visit to a meeting there a guy was giving a talk about this new fangled digital logic to all the old HAMs, AND, OR, XOR, counters. adders etc. I was toatally mesmerized and awestruck by the possibilities. The humble SN7400 quad NAND was cool. The SN7490 was incredible. Soon I assembled this calculator http://www.vintagecalculators.com/html/advance_wireless_world.html and get this, ALL the logic was in a single chip! A Texas Instruments TMS1802. Then came the micro-processors, oh my God....
  • Cluso99Cluso99 Posts: 18,069
    edited 2012-09-12 03:41
    My first "big" chip design in 72-73 (well I did the pcb design and I built it for my TO2) was a single chip 40pin ceramic UART. Previously the receiver and transmitter sections wer in different 28 in chips. But I cut my teeth on reject 74xx chips labelled BP1, etc. Some of the gates worked in the package and sometimes they had an internal tie to another gate. But they were cheap - about 1 pound (yes they came from a company in the UK). Fancy paying a pound for a reject 7400 today!!!
  • LeonLeon Posts: 7,620
    edited 2012-09-12 03:58
    That was a company called Bi-Pak. They seemed to disappear and were replaced by a similar outfit called Bi-Pre-Pak.

    Before those surplus TTL chips became available I played with some RTL parts made by Fairchild, and started building a digital counter using them.
  • Heater.Heater. Posts: 21,230
    edited 2012-09-12 04:22
    Jeez, now we are going back. A school friend and I spent an afternoon sifting out all the RTL chips we could find from a huge box of old electronic parts when a surplus dealer had a clean out. Numbers were 9xx if I remeber correctly. Never did anything with them.

    74 series I would get from Henrys Radio on the Edgeware Road. There still seems to be a Henrys their but not much sign of radio.
  • LeonLeon Posts: 7,620
    edited 2012-09-12 06:22
    The 914 was a NAND/NOR gate, and the 923 a JK flip-flop. My counter used four 923s and a 914 (IIRC) per decade, with four lamps (no LEDS then) displaying the output for each decade in BCD. I think I had four decades.

    The Marconi Myriad computer was built in the 1960s using RTL. It used to be popular for air-traffic control.
  • Cluso99Cluso99 Posts: 18,069
    edited 2012-09-12 06:53
    yes, it is hard to remember a time without leds. i remember when they first became available. i just could not believe how they worked.
  • Heater.Heater. Posts: 21,230
    edited 2012-09-12 07:17
    Same here, older guy had a LED and a battery he was showing off around school, never seen one before, "What you mean it's a diode as well?!!"
  • LeonLeon Posts: 7,620
    edited 2012-09-12 07:23
    I bought some as soon as they became available, from HP. They were expensive and came in a metal case with a little red window and weren't very bright.
  • blittledblittled Posts: 681
    edited 2012-09-12 07:33
    My first exposure to computers was an article on the COSMAC 1802 ELF computer. I was fascinated with the 1802 chip but never had the pocket change as a teenager to get the kit. I was thrilled to find one at the freebie table at UPENE! Now to I need the hex display driver chips and the 1862 Video chip.... hmmm I wonder if a Propeller can be interfaced to it :)
  • LeonLeon Posts: 7,620
    edited 2012-09-12 07:45
    Here is a COSMAC ELF 1802 system implemented in an FPGA:

    http://www.youtube.com/watch?v=4IhDMDVBYio
  • Martin HodgeMartin Hodge Posts: 1,246
    edited 2012-09-12 07:47
    I came into it much later. For me it was the MC68705P3 SoC. Not too long after that, the BS2.
  • markaericmarkaeric Posts: 282
    edited 2012-09-12 14:15
    @Phil

    I definitely agree with the 555. The 555 competition that was held a little while back proved this. I was in total awe over some of the "hacks".


    Having to build a processor from discrete logic sounds tedious, but definitely cool. One thing that's a bummer is how many good components have become obsolete. While searching online, I've come across many components that would have worked great in a project, but were no longer made and had no equivalents.

    @Heater
    That calculator is awesome! I particularly enjoy the power supply - no fancy switching wall wart here - just some good ol' fashioned iron, and a few beefy caps :D
  • PublisonPublison Posts: 12,366
    edited 2012-09-12 15:32
    My cool chip was the Intersil 8038 VCO. I was into synthesizers back in the 70's and 80's and built a few with this chip(s).

    They still command a respectable price on ebay, except for the Chinese knockoffs that can't get the logo correct.

    Still have five that need to go on a test bed to check out.
  • Tracy AllenTracy Allen Posts: 6,664
    edited 2012-09-12 16:07
    LM10 op-amp + 0.2V reference. 1978 design by Bob Widlar,National app-note AN-211 New Op Amp Ideas.
  • NWCCTVNWCCTV Posts: 3,629
    edited 2012-09-12 16:53
    Any of the chips in this post look familiar to anyone?

    http://forums.parallax.com/showthread.php?142263-IC-Assistance-needed.
  • kwinnkwinn Posts: 8,697
    edited 2012-09-12 17:37
    NWCCTV wrote: »
    Any of the chips in this post look familiar to anyone?

    http://forums.parallax.com/showthread.php?142263-IC-Assistance-needed.

    Used or replaced almost every chip on the list in some piece of equipment at one time or another.
  • Cluso99Cluso99 Posts: 18,069
    edited 2012-09-12 18:25
    Martin Hodge wrote: »
    I came into it much later. For me it was the MC68705P3 SoC. Not too long after that, the BS2.
    Oh memories... I was shipping these in a commercial design of mine (replaced 4 logic boards of ICs) before the official release that was withheld because of a bug (IIRC in the oscillator circuit) that did not affect my design. Had a pair of 68705P3S and not much else. Motorola agreed to supply me with the final protos so I could release my product. At $150 per chip they were a steal at the time but later I was buying them for <$8 per chip.
  • Mark_TMark_T Posts: 1,981
    edited 2012-09-13 06:18
    I suppose way back it would have been the Z80A microprocessor, a full 2.5MHz of 8-bit wonder!

    More recently perhaps one of the transceivers-on-a-chip (nRF24L01+ comes to mind) or direct digital synthesis chips like the AD9912 (1 GHz sample rate, 14bit DAC, upto 400MHz output)
  • davejamesdavejames Posts: 4,047
    edited 2012-09-13 09:15
    The LM and LMF series of switch-capacitor filters from National Semi, way back when.

    And more recently, the muxing chips from Analog Devices.
  • Heater.Heater. Posts: 21,230
    edited 2012-09-13 09:36
    Now a days I kind of impressed by class D audio amplifier chips. I have one here from MPS on a demo board that I have been meaning to power up for a while. I tried building a class D amp from discreet components in technical school but could never stop the thing from committing suicide, the distortion was terrible anyway so I guess it did the honourable thing:)
  • blittledblittled Posts: 681
    edited 2012-09-13 09:53
    @Mart_T, I have 14 Z80A's in my junk box. Maybe I should build a multicore Z80 computer :)
  • davejamesdavejames Posts: 4,047
    edited 2012-09-13 10:46
    Heater. wrote: »
    Now a days I kind of impressed by class D audio amplifier chips.

    ...yeah - they are peaking my interest also.

    I like the efficiency aspect, which can translate to less heat-sinking requirements. Couple that with a switch-mode power supply and you wind up with lotsa power w/o lotsa weight.
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