>
>Subject: Re: Paper tape Utilities/Images
> From: "Dave Dunfield" <dave06a dunfield.com>
> Date: Thu, 28 Sep 2006 05:49:15 -0500
> To: "General Discussion: On-Topic and
Off-Topic Posts" <cctalkclassiccmp.org>
>
>> Dave wrote.....
>> > I have posted the utilities I created to read
paper tapes to my site in
>> > the Software/Images section (near the bottom
of the main page):
>> ...snip... PTR/PTC ...snip...
>>
>> Dave.... have you considered supporting serially
attached paper tape
>> reader/punches instead of just parallel devices?
>
>Hi Jay,
>
>I'd be happy to ... but I don't have a serial reader, so
I need info on
>the details of the interface (does it just send the raw
serial stream as
>read from the tape or is there some protocol around it).
Dave,
Most of the serial PTR/PTP I used were not unlike the ASR33,
The only
protocal was the usual; start and stop bits of serial comms.
So for
every byte read by the reader you got a byte in serial form.
It's just
a stream of chars (7 or 8bit) as punched on the tape.
Reminder,
leader on most of those will be read as zeros so the average
tape will
have a long line of zeros preceeding the content.
There was one I'd used (deep memory test ca1977) that used
the CTS
line on the serial output to a corospnding line on the
serial input
(both for punch and reader) as hardware flow control (their
manual
called it hardware restraint). For that case CTS gated
read(send bytes)
no read and for the punch case CTS gated the hosts ability
to send the
next byte until the punch was ready for the next character.
This was
only needed for slow (read case) hosts that could not accept
the 300cps
read or a fast (relative) host that could over run the 75cps
punch. Oddly
enough the unit (punch reader was Remex with custom third
party board)
only had 4800 baud serial rate! Only saw one like it and the
closest
Remex model was parallel only.
That's the hardware.. The tapes them selves could be Intel
hex format, Moto
S records, binary, ASCI text or some vendors format
(relocatable binary
or hex in some cases). Never minding DEC BIN and RIM
formats. The oddest
and is old Intel BNPF!
FYI: for those not familiar that was a ROM submission format
and Xasm
output format. Each byte was recorded on Ptape as example:
11000011 C3h BPPNNNNPPF (yes 10 chars on tape!)
00000000 00h BNNNNNNNNF
00010000 10h BNNNPNNNNF
The small advanatage is human readable. It was self
cehcking at the char level
as anything other than BNPF was invalid. I was wasy to do a
simple reader
needed only to sense three holes (sprocket and two bits) to
discern if
the character was B,N,P or F making it very easy to
serialize. I had
to do that back in '74 as a lab EE for a controller (8008
based) project.
Allison
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