SpaceHobo
Experienced Member
So if I'm reading that right, it increments both the horizontal and vertical position; and you reset the one you're not advancing in order to either keep printing to the right, or do a CRLF kind of thing?
To my eye it seems dumber than that. It looks like X advances sensibly. Y, however, is jam-cleared to a multiple of the line height, then advanced by the character height. So you can leave that value in AC, and draw more characters advancing to the right. The low 4 or 5 bits would keep getting cleared, then set to the new value again. Meanwhile, of course, clogging up AC with gunk so you'd have to CLA to get anything else done.So if I'm reading that right, it increments both the horizontal and vertical position; and you reset the one you're not advancing in order to either keep printing to the right, or do a CRLF kind of thing?
Cool!Tried spcwr3. The PDP-12 build doesn't quite run on the SIMH out of the box. It exhibits the classic "no clock" symptom where the screen is only updated when a key is struck (causing an interrupt).
Rebuilding it to use the 8/E clock but the VC12 display works as expected. The interactive switch register kludge isn't there, so there's no controlling the ships, and they just fall into Z Polaris. The keyboard commands to change the ship types and other options do work as expected.
I so wish I had a student up to and interested in this challenge... or that I had a sabbatical.Anyone want to write clock and LINCtape support for SIMH?
Meanwhile, I wish an institution around here would let me do this as work toward a graduate degree!I so wish I had a student up to and interested in this challenge... or that I had a sabbatical.
And I've updated my avatar to celebrate!I punched in @SpaceHobo 's updated code and it works!
I was thinking about this while trying to brush up on LINC ASM a little. It seems like the LDA instructions and such make "noise" in AC less of an impediment than they do on the "TAD-only" 8.Maybe we are looking at it with our "young whippersnapper" eyes, and (as you suggest) it is just that AC got fiddled with in the process of drawing the half-character, and it wasn't important enough to add gating to change it.
Amazing work, @SpaceHobo !!!This thread now makes an appearance in the following video:
Up toward the top-right of the page should be a box containing the text "watch", or possibly "unwatch". That's the button to watch/unwatch the thread.I just realized I was out of the loop for this thread. I can't seem to find how to get email alerts when there are new postings. HELP;
The code is in https://svn.so-much-stuff.com/svn/trunk/pdp8/simh/. The PDP8 and PDP12 sub-directories should be more or less the same. There's example DECtape code there, but it's a little hard to comprehend it at first. You can write me with questions or for more info.I haven't dug into SIMH yet, but I'd be interested in working on the LINCtape emulation. I might need some hand-holding at first.