these RTL or what?

On 6 Oct 2007 at 16:48, William Donzelli wrote: I remember getting the Adventure source tape and reading it in and saying "What the h*ll is this?" It didn't take too long before I figureed that I was dealing with 36-bit words with 5 7-bit ASCII characters packed into each. Of course, someone on a PDP-10 may have been equally puzzled to see 6- bit display code packed 10 characters per word, with an end-of-line being a 00 00 combination packed into the low-order 12 bits of a 60 bit word--otherwise, the meaning of 00 was a colon (:) character. The standard tape conversion/transfer utility for the Cyber 70's had no idea of how to deal with PDP-10 character representations. Most large mainframes excelled at I/O. The aforementioned Cyber 70s used 10 peripheral processors to transfer data between I/O devices and central memory. The standard I/O scheme was to use "circular buffering", so that it was possible to continously transfer data from one device to another by using two PPUs and having them chase buffer pointers. Disks were only somewhat faster than tapes. Deadstart involved reading a tape and copying files from it to disk. Much effort went into the deadstart routine that did this so that the tape could read non-stop. Cheers, Chuck