Type 64 line printer added

[Bill E]

New IOT 45, the line printer. Needed a way to get stuff out, and a line printer is it. Puts the output in a file as ascii text. I had trouble finding the documentation, so the implementation is from what I could find plus what the Type 62 printer did. It does do my best guess at timing.

My documentation and the program that produced the above included.

As usual, this is a dynamically loaded IOT.

Bill

[Bill E]

As usual, if it's worth doing, it's worth overdoing. It appears that the Type 62 printer was used for all the early -1's, not sure when the switch was made to the Type 64, possibly only for -1C's or even -1D's.

Therefore, I'm supporting both with a mode switch. The Type 62 is well documented with timings, so I can reproduce that accurately.

Of course, DEC couldn't use the same IOT subcodes in IOT 45 for the same thing, so the bits are different, and the printers don't work exactly the same way. Moral - if you're going to use it, pick one and stick with it.

The Type 62 is twice as fast as the Type 64, 600 lines per minute. 

Hmm, maybe the 64 was cheaper? Targeted for the -4?

Another feature common to both was a 'spacing tape' in the printer that customers could change. This specified the number of lines each spacing selection value in the IOT subfield was used.

Ok, I'll support that in the config file, why not? Give me a day.

Bill

[Clem Cole]

On Sat, Mar 21, 2026 at 4:19 PM Bill E <wjegr...@gmail.com> wrote:

Another feature common to both was a 'spacing tape' in the printer that customers could change. This specified the number of lines each spacing selection value in the IOT subfield was used.

Ok, I'll support that in the config file, why not? Give me a day.

That was standard in all early printers.  It was often called "carriage control tape" [https://en.wikipedia.org/wiki/Carriage_control_tape ] or also sometimes the "Vertical Format Tape."   The idea was developed before computers and was originally used very late in the 1940s in the IBM 407 [https://web.archive.org/web/20100809095516/http://www.bitsavers.org/pdf/ibm/cardProc/22-5765-7_407oper_1953.pdf] and 402 accounting systems, as a feature that businesses/accounting folks exploited to print the first computer forms. 

The DEC Type 62 is based on the Anelex Series 5 https://museum.cs.rptu.de/Rechner/Zuse/Allgemeine%20Peripheriegeraete/Schnelldrucker/Anelex-5/Dokumente/Instruction%20Manual%20for%20the%20ANELEX%20Series%205%20Printer%20System.pdf 

I personally first saw carriage control tape in the late 1960s in the IBM 1403.

Everything DEC's sold up to and including the 1970 release of the LP10 and LP08 (which were the Data Products 2400 series printers, released in 1968, under the covers), both of which had the by-then industry-standard 12-channel carriage-control tape base system internally.   As I understand it, in 1970, IBM released the 3211, which had what they called a "Vertical Format Buffer" (VFB), an electronic storage area within the printer's control unit that held the page-skipping and formatting instructions.    Some time after 1970, a  VFB option was available from Data Products for the 2400 series (i.e., after IBM).  So DEC could not have begun supporting a printer with a VFB until that time.  What I don't know is when it became an option from DEC directly and my google search foo has not helped me answer that.

But the point of all this is that any of the systems DEC shipped with a printer until sometime in the early 1970s had to include a printer control unit that used a carriage control tape.

[Bill E]

Great info. So, the Type 62 and 64 will be modern with vfbs now. :)

Bil

[Bill E]

Type 62 and 64 now working, and they have vfbs. :)

Bill