What does PUSHJ do?

[Allison]

>Subject: Re: What does PUSHJ do?
>   From: Johnny Billquist <bqt at Update.UU.SE>
>   Date: Sat, 21 May 2005 12:47:45 +0200 (CEST)
>     To: cctalk at classiccmp.org
>
>Ah! That explains it. :-)

I do have a PCdos compatable asm that is pretty neat but for little stuff
the eyeball does it fast enough. ;)

One day when time permits a RS08 equivelent will be made for the 8f
and I'll start running real software.

>> I've used one that did.  Might have been a hack.  The 6120 however does
>> and the DEC purchase spec is clear on that too. It's still done with IOTs.
>
>Must have been some additional hardware. One brain cell seems to think
>that DEC maybe sold some hardware to implement stacks on the pdp8, but it
>might have been the pdp-12 as well.
>But yes, the 6120 did have IOTs for that.
>
>I have several PDP-8/A systems around, but no 6120 systems...

I have no PDP-8a.  I do have three 6120 based systems, two DECmateIII
and a homebrew using the chip.  The 6120 is the second generation of the
6100 PDP-8 in CMOS.  It adds EMA and stacks via IOTs in hardware.  Runs 
OS/278 flavor of OS/8 well enough.


Allison