Paper tape Utilities/Images

[Allison]

>
>Subject: Re: Paper tape Utilities/Images
>   From: "Dave Dunfield" <dave06a at dunfield.com>
>   Date: Thu, 28 Sep 2006 05:49:15 -0500
>     To: "General Discussion: On-Topic and Off-Topic Posts"	<cctalk at classiccmp.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