pahp
Experienced Member
Whoa, 765! That's a new number. Can you post this in PDP-12 Roll Call? We should update the Wikipedia page on the '12 because this information is better attested and different.
Done and done!Whoa, 765! That's a new number. Can you post this in PDP-12 Roll Call? We should update the Wikipedia page on the '12 because this information is better attested and different.
Well, I'm sort of unclear about that. There's a plaque on the lower backplane that saysI've been waiting for him to post the serial number of his 12.
Our label is in the top left of the cabinet if you're looking in towards the tape drives. It is stamped PDP12 as in the picture above. Ours also has an M36 stamp.Where should I be looking?
Found it. Mine says:Our label is in the top left of the cabinet if you're looking in towards the tape drives.
If you wanted your code to run everywhere, you'd avoid those features. There was a concept called "Family of Eight", which had to do with writing code compatible across the line (well, except for the 8/S, which was so lame that no-one cared to code for it).
Right. I think of it more as avoiding the incompatible corners. For instance, no pre-Omnibus machine has IOTs 6XX0 -- they just don't do anything on a Negibus or Posibus machine. That's where the later os8diskserver/SerialDisk versions ran into issues. Earlier versions also used BSW.This is the compatible set of instructions you use on the PDP side for os8diskserver, right?
One of my long term projects is to write a program that looks at a PAL program and gives warnings for constructs that will not run on all machines. It will be impossible to do this perfectly because there is self modifying code found a lot of places. The biggest issues are that the Operate micro instructions combine in different ways on different machines.This is the compatible set of instructions you use on the PDP side for os8diskserver, right?
The EAE is a seperate issue, as what was later called "mode A" exists as an option for the older machines (except the 8/L). EAE is also not available for the 8/A or DECmate, though they do have an MQ register. I still avoid it generally as not needed by most programs. Space War doesn't need the speed or the space, for instance.
As I posted this I realized that I am responding off topic again.Richard Larry tells it that after the VAX team had settled down a bit, he went to the PDP-8 team and said "You guys should make an address extension model to use more RAM, too!" and then the PDP-10 team, and so on. Earlier in the interview he talks a bit about how product teams focused on relative cost of RAM vs other parts in their product sales, and tried to keep a balance that helped both functionality and profits, so that may have helped produce the 8A and the K*-10 units that could address multiple "mobies" of RAM.
But he calls it a "VAX for the Eight" in this interview.