[HECnet] RSX or RSTS

[Robert Armstrong]

> Johnny Billquist <bqt at softjar.se> wrote:
>I think the 11/53 commonly ran at 15 MHz, while the 11/73 could be found 
>with 18 MHz. But otherwise yes, same basic system, really.
>Not a speed demon. Upgrading to an 11/83 does make a noticeable difference.

  The big win for the 11/83 was the PMI bus, not the clock speed.  That's entirely different hardware, though, and not much I can do about that.  PMI memory wouldn't be a problem in the BA123, but I don't believe there was ever an 11/83 board made with S-box handles.  Actually, I think the 11/53 and 53+ were the only S-Box PDP-11s made (at least they're the only ones I remember).

  The M8190-AB (I think) 11/73 board was 15MHz and the M8190-AE 11/73 was 18MHz.  And you're right - the 11/53 was 15MHz.  Again, I don't think DEC ever made a 18Mhz 11/53.

Bob