2

The Wikipedia article on in-circuit emulators has no history section.

I didn't have much luck with Google searches either.

I'm wondering how far they date back. When was the first in-circuit emulator produced?

Here's a photo of what I gather is an early Intel ICE. Maybe they had been around for some years before this.

mds ice-80

ocrdu
  • 8,705
  • 21
  • 30
  • 42
hippietrail
  • 133
  • 5
  • I assume you mean microprocessor emulator. There are also PROM emulators, etc. – Mattman944 Sep 25 '22 at 07:25
  • 2
    They date back at least to the 1980's. I was using an ICE using a bond-out IC from Microchip by 1990/1991, I think. Still have the darned thing sitting above me on a shelf. (And Microchip still supports it, too.) I'm pretty sure it wasn't the first because I was already accustomed to the idea from earlier experiences (Intel 80286, memory serving -- huge blue boxy thing) when I bought it. I was very impressed by the ICE system Intel (massive cube of FPGAs) was using for its own P II development when I worked on the BX chipset, though, some years later. – jonk Sep 25 '22 at 09:30
  • 2
    you might have a more knowledgable audience on the Retrocomputing stack – Neil_UK Sep 25 '22 at 09:33
  • @Neil_UK: Ah I did not notice that the URL here says "electronics" but the site name is "electrical engineering". But there are other ICE questions here. The retro site can be very aggressive at closing questions that seem like a perfect fit so I'm hesitant to ask there. – hippietrail Sep 25 '22 at 09:52
  • @Mattman944 I don't know enough about the topic but from reading around it seems the original ones emulated at least one chip. I'm not sure if there were limited to microprocessors or sometimes did other chips or larger systems. [Apparently the term has since broadened](https://electronics.stackexchange.com/questions/288825) to devices for debugging using the CPU's built-in functionality rather than doing any actual emulation. I'm not asking about the latter kind. – hippietrail Sep 25 '22 at 09:56
  • Digital systems were debugged using logic analyzers, which recorded the values of signals over time. When single-chip microprocessors came along, there was the desire to record the values of internal signals, especially register values, that were not visible at the external pins of the chip. With the earliest MCUs, it wasn't hard to re-create their functionality using SSI/MSI parts; by far, the bulk of the ICE was devoted to the signal recording. – Dave Tweed Sep 25 '22 at 12:08
  • 1
    As the complexity and speed of MCUs started to grow, it became difficult to impossible to run the emulation in an external box through a long cable, so key parts of the ICE logic were built into the chip itself. External interfaces for this were proprietary at first (using special "bond-out" packages), but then were standardized to use JTAG, which is the current state of the art, along with other industry standards such as SWD (Single/Serial Wire Debug). – Dave Tweed Sep 25 '22 at 12:13
  • Really? History is based on opinion? There was no first ICE or its proven to be unknowable? That's quite amazing really. Why would facts and citations not work for this question? Is this standard for all history questions in electrical engineering? – hippietrail Sep 25 '22 at 14:19

1 Answers1

3

A partial answer: As far as I know the first commercially available in-circuit-emulator (=ICE) for microprocessors was one of the hardware options in Intel MDS 800 for their 8080. It was available in 1975. Unfortunately I do not know if someone had used the idea of ICE earlier without large scale marketing efforts.