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As far as I'm concerned there is only one model of the Intel 8089 (the D8089A-3). I am not able to find any information on this. While the 8086,8088 and 8087 use the scheme of the last number (-3 in this case) being -2 on 8MHz versions and (seemingly very rare) -1 for 10MHz versions, the -3 for me seems out of place.

Also what clock is it using? I found info about it being 5MHz or 6MHz. But didn't find any 8088 CPU (for example) that used 6MHz.

So is the 8089 just so rare that only this version exists, and where can you find info on different versions? Where there 8MHz versions that would work with the 8088-2 or the 8086-2?

One theory that I have is that this processor simply is capable of running on all clock speeds mentioned here.

Sorry for my English and thanks in advance. I'm asking this cause we're maybe going to build an IAPX-88/21 system on breadboard. (as in the IAPX-88 manual there isn't much info on building a system only with the 8088 and 8087)

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    It's very likely this chip never made it over its initial 5MHz version - Simply because IBM decided not to include it in their PC architecture (and used the 8237 instead).
    – tofro
    Jan 29 at 17:16
  • i thought that too, but the "revision number" 3 irritated me so i had no clue if it actually was this
    – juffma
    Jan 29 at 17:32
  • Wikipedia seems to think along the same lines: en.wikipedia.org/wiki/Intel_8089
    – tofro
    Jan 29 at 17:58
  • Youre right, it seems to be like that. That numebr still confuses me tho. propably thats just something about energy usage.
    – juffma
    Jan 29 at 18:24

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[...] scheme of the last number being -2 on 8mhz versions -1 for 10mhz versions [...]

  1. They are not versions but speed grades.
  2. Versions are donated by letters after the base number.
  3. There is no fixed relation between speed grade and grade marker.
  4. The number is just to make it being different.
  5. What timing goes with what grade is to be looked up at the data sheets.
  6. No suffix simply means base grade

Also what clock is it using? i found info about it being 5mhz or 6mhz. But didn't find any 8088 cpu (for example) that used 6mhz.

There is no relation between the speed grade suffixes used for different devices.

One theory that i have is that this processor simply is capable of running on all clock speeds mentioned here.

Rather unlikely. Speed grades develop over time with improved production yield. No device comes at highest speed grade first.

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