29 Jan
2014
29 Jan
'14
8:20 p.m.
On Wed, Jan 29, 2014 at 1:51 PM, Johnny Billquist <bqt at update.uu.se> wrote:
Eh? What? There was an option for 8-bit clean communication in the ASR33,
as well as other parity choices. But by default an ASR33 have *MARK* parity.
And all older PDP-8 software that I've ever seen also assumes MARK parity.
If you try running older PDP-8 software with your terminal set to even
parity, it will not work.
If you are ever near an ASR33 with a paper punch, you can easily verify
that it is doing mark parity by just enabling the punch, and check what
codes you get there as you type, with the ASR33 in local mode.
Johnny
I punched this tape on a Model 33 ASR in local mode and it seems to have
even parity. Bonus points for deciphering it! :)
http://i.imgur.com/R3GPWIS.jpg
I'll try some more software with mark parity, but I believe CHECKMO II (the
chess game) really wants even parity.
Kyle
