[Simh] ALTAIR thinko?

[Gregg Levine]

Hello!
Would the Octal reference for $FF be used because one of the authors
of emulator would be more familiar with those terms from working with
the one for the PDP-11?

I've seen the crowd courtesy the VCF and have a box here who's waiting
to be restored.

Oddly enough I came within a big something-else to own one (an Altair
or IMSAI or the Heathkit version) a long time ago.
-----
Gregg C Levine gregg.drwho8 at gmail.com
"This signature fought the Time Wars, time and again."


On Mon, Feb 2, 2015 at 10:40 AM, Clem Cole <clemc at ccc.com> wrote:
>
> On Mon, Feb 2, 2015 at 10:16 AM, Bailey, Scott <scott.bailey at hp.com> wrote:
>>
>> Non-existent memory.  On the 8080, reads to non-existent memory
>>       return 0377, and writes are ignored.
>
>
> That was definitely true and how the HW worked [although the comment should
> have been 0xFF or actually $FF in Intel syntax - since the 8080s were
> defined in hex not octal like PDP-11s).  There was no non-existent memory
> trap for the bus, so the HW read the data back as 0xFF because of TTL
> floating to high.
>
> I do miss the Altair and Imsai machines in a strange sort of way ;-)
>
> Clem
>
>
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