Logbook

11/29/03=20: Drew a schematic of all the TTY connections, similar to = "Figure=20 5-7", but with more detail and as many parts values as I = currently know.=20 Still need to know the resistance of the reader-run relay to be = able to=20 design a reliable replacement.
11/28/03=20: Tried to fix my second M706. Replaced the first FF in the = divider=20 chain, but the clocking is still dead. Guess I'll have to = replace the=20 second, too.; Found out why my TTY printer is dead. The "Carriage Rear = Rail" has=20 fallen off of it's mounting screws.; Filled up my JameCo shopping cart with parts for the M452 = and W076=20 replacements. Always a shock when so many little bitty items add = up to=20 real money.
11/25/03=20: Fiddled with a new design for reader-run. I still haven't = figured=20 out a way to supply the needed drive, keep the component count = down, and=20 not add load to the reader-run line.
11/25/03=20: Just to prove I could do it, I downloaded Focal '69 at 19200 = baud.=20 It took 6 seconds, and gave a zero checksum. Wish my 8L worked = well=20 enough to actually *run* Focal '69. Guess now I can download and = run=20 some diagnostics to figure out what is wrong, though.
11/24/03=20: Checked out the RS-232 side of the W076X -- it works. = Shortened the=20 pulse length of the one-shot in the M452X and that got the input = side=20 working at 110 baud (output worked before). Tried setting 19200 = baud,=20 but it didn't work. Eventually discovered I had swapped the = wiring for=20 19200 baud and 4800 baud. It works fine now at all the speeds = (up to=20 19200) that I can set with Hypterterm. So nice to use reliable = RS-232=20 stuff instead of my half-dead TTY.; My cable for the LA36 finally arrived. Idiot seller sent it = media=20 rate. Since when is a cable media?? Two months to get it here.
11/23/03=20: Spent a bunch of time converting this stuff into web pages = so others=20 can see it.; Started this log. Typed up a "To Do" list, indicating what = needs to=20 be done for the major hardware pieces in the collection.
11/22/03=20: Tracked the problem with the W076X to the BC05M cable I = built, which=20 is now fixed. TTY input works. TTY is in such bad shape that I = can=92t see=20 the echo, but the print mechanism is activated correctly. Will = have to=20 switch to LA36 when connectors get here. Still no ability to = test=20 reader-run in real use.; Spent some time writing a documentation-sheet for the W076X = to match=20 the one for the M452X.; Spent some time getting the W076 board description ready for = the=20 board fabricator.
11/21/03=20: Built BC05M equivalent cable for testing W076X. W076X = isn=92t working=20 =96 only 2ma is available at the transmit loop, instead of 20ma. = Odd,=20 since everything checks out when I measure it at the chips on = the W076X.
11/20/03=20: Convinced myself to stop fiddling with the M452X for now and = work on=20 the W076X. Still need to check frequencies against my M410s, and = to=20 decide whether or not to rework the monostable to match DEC=92s = design.

=
		*My PDP-8 Stuff* *11/03*



	Home \| = 03/04 = \|=20 02/04 = \|=20 01/04 = \|=20 12/03 = \|=20 11/03 \|=20 Pictures \|=20 To=20 Do \| Bulb Page =


		Here is where I ramble about what I am up to, where the = PDP-8s are=20 concerned.



		11/29/03=20 Drew a schematic of all the TTY connections, similar to = "Figure=20 5-7", but with more detail and as many parts values as I = currently know.=20 Still need to know the resistance of the reader-run relay to be = able to=20 design a reliable replacement. 11/28/03=20 Tried to fix my second M706. Replaced the first FF in the = divider=20 chain, but the clocking is still dead. Guess I'll have to = replace the=20 second, too. Found out why my TTY printer is dead. The "Carriage Rear = Rail" has=20 fallen off of it's mounting screws. Filled up my JameCo shopping cart with parts for the M452 = and W076=20 replacements. Always a shock when so many little bitty items add = up to=20 real money. 11/25/03=20 Fiddled with a new design for reader-run. I still haven't = figured=20 out a way to supply the needed drive, keep the component count = down, and=20 not add load to the reader-run line. 11/25/03=20 Just to prove I could do it, I downloaded Focal '69 at 19200 = baud.=20 It took 6 seconds, and gave a zero checksum. Wish my 8L worked = well=20 enough to actually run Focal '69. Guess now I can download and = run=20 some diagnostics to figure out what is wrong, though. 11/24/03=20 Checked out the RS-232 side of the W076X -- it works. = Shortened the=20 pulse length of the one-shot in the M452X and that got the input = side=20 working at 110 baud (output worked before). Tried setting 19200 = baud,=20 but it didn't work. Eventually discovered I had swapped the = wiring for=20 19200 baud and 4800 baud. It works fine now at all the speeds = (up to=20 19200) that I can set with Hypterterm. So nice to use reliable = RS-232=20 stuff instead of my half-dead TTY. My cable for the LA36 finally arrived. Idiot seller sent it = media=20 rate. Since when is a cable media?? Two months to get it here. 11/23/03=20 Spent a bunch of time converting this stuff into web pages = so others=20 can see it. Started this log. Typed up a "To Do" list, indicating what = needs to=20 be done for the major hardware pieces in the collection. 11/22/03=20 Tracked the problem with the W076X to the BC05M cable I = built, which=20 is now fixed. TTY input works. TTY is in such bad shape that I = can=92t see=20 the echo, but the print mechanism is activated correctly. Will = have to=20 switch to LA36 when connectors get here. Still no ability to = test=20 reader-run in real use. Spent some time writing a documentation-sheet for the W076X = to match=20 the one for the M452X. Spent some time getting the W076 board description ready for = the=20 board fabricator. 11/21/03=20 Built BC05M equivalent cable for testing W076X. W076X = isn=92t working=20 =96 only 2ma is available at the transmit loop, instead of 20ma. = Odd,=20 since everything checks out when I measure it at the chips on = the W076X. 11/20/03=20 Convinced myself to stop fiddling with the M452X for now and = work on=20 the W076X. Still need to check frequencies against my M410s, and = to=20 decide whether or not to rework the monostable to match DEC=92s = design.



		Last=20 updated on My PDP-8 Stuff


		=0A= =0A= *My PDP-8 Stuff* =0A= =0A=



	=0A= =0A= Home \| 03/04 \| = 02/04 \| = 01/04 \| = 12/03 \| = 11/03 \| = Pictures = \| To Do \| = Bulb Page=0A= =0A= =0A=