Re: PDP-12 Restoration at the RICM

On 06/05/2016 09:54 AM, Michael Thompson wrote: We fixed the RK05 disk this week. We replaced E3 (LM301A) and E1 (SN7404) on the G938 Servo Preamp module. The COUNT PULSE FWD H and the COUNT PULSE REV H signals from the G938 module are both working now. The drive will now seek correctly using

PDP-12 Restoration at the RICM

We fixed the RK05 disk this week. We replaced E3 (LM301A) and E1 (SN7404) on the G938 Servo Preamp module. The COUNT PULSE FWD H and the COUNT PULSE REV H signals from the G938 module are both working now. The drive will now seek correctly using the jumpers described in the Maintenance Manual or

PDP-12 Restoration at the RICM

We are now working on the RK8F controller and RK05 drive. The RK8F has special M7104 and M7105 boards so it will work in the DW8E Omnibus-Posibus chassis. The MAINDEC-08-DHRKA RK8E Diskless Control Test showed that a data-break to address worked, but did not work to address . After about

PDP-12 Restoration at the RICM

As a final diagnostic on the PDP-12 we tried to run FOCAL-69, but it started executing instructions in non existent memory. FOCAL initializes lots of peripherals and then tries different instructions to determine what processor it is running on. It executed what it thought was a TC01 DECtape IOT,

Re: PDP-12 Restoration at the RICM

On Tue, Dec 22, 2015 at 08:31:46PM -0500, Michael Thompson wrote: > the [paper tape] reader does not always step correctly and does not > read the tape correctly. Ah, then you have restored it to as-shipped condition :-) mcl

Re: PDP-12 Restoration at the RICM

On Thu, Dec 24, 2015 at 9:59 AM, Michael Thompson < michael.99.thomp...@gmail.com> wrote: > > Kyle's SerialDisk is here: https://github.com/drovak/os8diskserver I just pushed some changes earlier. Hopefully I didn't break too many things! :) The system handler now has support for FRTS. Still

Re: PDP-12 Restoration at the RICM

On 12/24/2015 01:22 PM, Jay Jaeger wrote: On 12/24/2015 9:59 AM, Michael Thompson wrote: We have been able to fix all types of broken flip-chips. Sourcing the components is sometimes a challenge. The Germanium transistors for the TU20 on the PDP-9 were hard to find. I remember replacing a

Re: PDP-12 Restoration at the RICM

On 12/24/2015 9:59 AM, Michael Thompson wrote: > > We have been able to fix all types of broken flip-chips. Sourcing the > components is sometimes a challenge. The Germanium transistors for the TU20 > on the PDP-9 were hard to find. > I remember replacing a germanium (at least I think it was)

Re: PDP-12 Restoration at the RICM

> > Date: Tue, 22 Dec 2015 20:56:51 -0600 > From: Jay Jaeger <cu...@charter.net> > Subject: Re: PDP-12 Restoration at the RICM > Message-ID: <567a0d73.2010...@charter.net> > Content-Type: text/plain; charset=utf-8 > > I have an image of MAINDEC-12-D8CD-PB, and

Re: PDP-12 Restoration at the RICM

I used my PDP-8/e at home to test the RX8E controller and the RX01 floppies that came with the PDP-12. Both worked OK. We found a bad SP380 on a M7102 board in the DW8E the Omnibus expansion chassis. This would not let the SKIP instructions work with the RX8E, RK05, or PC8E. Once we replaced the

Re: PDP-12 Restoration at the RICM (tony duell)

On Tue, Oct 13, 2015 at 08:32:49PM -0400, Michael Thompson wrote: > > What exactly do you mean by 'glitches'? Are these on a TTL level signal, > > an analogue > > output of the read amplifer, or what? > > > > You can see the logic analyzer trace of many of the TC12 signals here. >

Re: PDP-12 Restoration at the RICM

Did you ever speak with anyone at System Source (Bob) about their PDP 12? Maybe they'd be interested in collaborating. http://museum.syssrc.com/ On Tue, Oct 13, 2015 at 10:54 AM, Paul Koning wrote: > > > On Oct 12, 2015, at 9:16 PM, Rich Alderson >

Re: PDP-12 Restoration at the RICM

> On Oct 12, 2015, at 9:16 PM, Rich Alderson > wrote: > > ... > The M tracks are longitudinally encoded (6-bit values chosen such that they > read the same as NRZ backwards and forwards for DECtape, 4-bit values for > LINCtape) to predefine blocks (cf. disk

RE: PDP-12 Restoration at the RICM

From: Paul Koning Sent: Tuesday, October 13, 2015 7:55 AM >> On Oct 12, 2015, at 9:16 PM, Rich Alderson > >> wrote: >> ... >> The M tracks are longitudinally encoded (6-bit values chosen such that >> they read the same as NRZ backwards and forwards for DECtape,

RE: PDP-12 Restoration at the RICM (tony duell)

> > Date: Mon, 12 Oct 2015 18:29:11 + > From: tony duell <a...@p850ug1.demon.co.uk> > Subject: RE: PDP-12 Restoration at the RICM > > > We swapped the TU56 and TU55 drives between the PDP-12 and the PDP-8/I. > We > > Does the TU55 work correctly on the 8/I ?

Re: PDP-12 Restoration at the RICM (tony duell)

On 10/13/2015 07:32 PM, Michael Thompson wrote: Tracks 1 & 2 look fine. We swapped the probes for track 2 & 3 just to make sure that it wasn't a logic analyzer problem. A 'scope connected to the differential signals shows the same track 3 glitches. The glitches were present with the TU55 and

RE: PDP-12 Restoration at the RICM

> We swapped the TU56 and TU55 drives between the PDP-12 and the PDP-8/I. We Does the TU55 work correctly on the 8/I ? > The TU55 behaved a little better than the TU56, and sometimes would > actually boot OS/8. We continued chasing the issue and found glitches on > data channel 3. We have

Re: PDP-12 Restoration at the RICM

> > Date: Sun, 11 Oct 2015 18:44:54 -0500 > From: Jay Jaeger <cu...@charter.net> > Subject: Re: PDP-12 Restoration at the RICM > > Don't forget about the other more remote possibilities: cables, > backplane, bad wrap, supply voltages at the actual card(s) for the

RE: PDP-12 Restoration at the RICM

From: tony duell Sent: Monday, October 12, 2015 11:29 AM >> We swapped the TU56 and TU55 drives between the PDP-12 and the PDP-8/I. We > Does the TU55 work correctly on the 8/I ? >> The TU55 behaved a little better than the TU56, and sometimes would actually >> boot OS/8. We continued chasing

Re: PDP-12 Restoration at the RICM

We swapped the TU56 and TU55 drives between the PDP-12 and the PDP-8/I. We found that the TU56 uses a double-sided paddle card for the control signals and the TU55 uses a single-sided paddle-card. The TC12 tape controller in the PDP-12 will work with either tape drive if you have the right cable.

Re: PDP-12 Restoration at the RICM

On 11 October 2015 at 10:42, Michael Thompson wrote: > We are running out of things to try for debugging the TC12 controller in > the PDP-12. At this point we are really stumped as to why the TC12 doesn't > work correctly. We are going to try a few remaining ideas

Re: PDP-12 Restoration at the RICM

I have no constructive input to share - except the strong memory of the bloke who maintained my pdp-12s for 25 years before I collected them saying that the TC12 was an "absolute bugger" and the hardest part of the machine to troubleshoot! Good luck and don't feel bad about having a hard time with

PDP-12 Restoration at the RICM

The Maintenance Manual-II describes the procedures for checking and adjusting the TC12 timing. It needs a lot more notes about using the Auto Restart speed settings. This facility allows you to put the processor in Single Step and have the Continue button automatically pressed ad a controllable

Re: PDP-12 Restoration at the RICM

On 8/17/2015 1:51 PM, Rich Alderson wrote: From: Jay Jaeger Sent: Sunday, August 16, 2015 3:18 PM On 8/16/2015 9:00 AM, Michael Thompson wrote: We did a lot more debugging on the TC12 LINCtape controller. Second gut hunch is that it would be hard to see how the drive could cause this

RE: PDP-12 Restoration at the RICM

From: Jay Jaeger Sent: Sunday, August 16, 2015 3:18 PM On 8/16/2015 9:00 AM, Michael Thompson wrote: We did a lot more debugging on the TC12 LINCtape controller. Second gut hunch is that it would be hard to see how the drive could cause this UNLESS the TC12 uses one side of the redundant

Re: PDP-12 Restoration at the RICM

We did a lot more debugging on the TC12 LINCtape controller. We saw a 500ns glitch in the LMU MOTION signal that corresponded to a short slowdown in tape speed. We will investigate this next week. We entered the LINC instruction to check a single block (0707) in the left switches and a block

Re: PDP-12 Restoration at the RICM

On 8/16/2015 9:00 AM, Michael Thompson wrote: We did a lot more debugging on the TC12 LINCtape controller. We saw a 500ns glitch in the LMU MOTION signal that corresponded to a short slowdown in tape speed. We will investigate this next week. We entered the LINC instruction to check a

Re: PDP-12 Restoration at the RICM

When we first powered up the PDP-12 the main fuse for the VR12 display blew. A replacement fuse did the same. We thought that the brown goo in the bottom of the chassis had leaked from the high-voltage power supply, and the high-voltage power supply is directly connected to the input, so that was

RE: PDP-12 Restoration at the RICM

We reconnected the Variac to the input and with 10VAC the high-voltage power supply had a 1000VDC output. We put 10x 500kOhm resistors in series across the output and increased the Variac voltage. By measuring the voltage across one resistor we could see that the output was more than

RE: using new technology on old machines. Was: PDP-12 Restoration at the RICM

-Original Message- From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Chuck Guzis Sent: 15 June 2015 18:25 To: gene...@classiccmp.org; discuss...@classiccmp.org:On-Topic and Off- Topic Posts Subject: Re: using new technology on old machines. Was: PDP-12 Restoration

Re: using new technology on old machines. Was: PDP-12 Restoration at the RICM

Not all EE's have the same education with regard to how semiconductors function. When I was in school I took a class in semiconductor physics - an entire semester on how the wee beasties function - more than most EEs. The prof., Henry Guckel, told an interesting story about an advanced IBM

Re: PDP-12 Restoration at the RICM

We spent a few more hours on the PDP-12 today... With the machine just powered on the stack 0/1 regulator output was 20.04V. With tune3 running in field 1 and testing field 0 the stack 0/1 regulator output was 19.93. No memory errors were reported. When the voltage was adjust up to 22.5 and down

Re: PDP-12 Restoration at the RICM

The LINK indicator light on the front panel of the PDP-12 failed two weeks ago. The indicator light bulb failed, briefly shorted, and destroyed the transistor that turns the indicator on. An new transistor and bulb, and all is well. We have been chasing a transient problem in the PDP-12 core

Re: using new technology on old machines. Was: PDP-12 Restoration at the RICM

On Mon, Jun 15, 2015 at 10:53:33PM +0200, Pontus Pihlgren wrote: On Mon, Jun 15, 2015 at 04:53:01PM +, tony duell wrote: I also think it is in the spirit of the computer - using what is available to fix a problem at hand. I think the arduino was overkill when an attiny (smaller,

Re: using new technology on old machines. Was: PDP-12 Restoration at the RICM

(I would change the subject line, but I am not sure how to do it in my ISP's web mail client) As far as I know XH558 will be permanently stationed at Finningley after this year's flying season is completed. The full details are here: http://www.vulcantothesky.org/, including dates of flypasts and

Re: Windows and devices - was Re: using new technology on old machines. Was: PDP-12 Restoration at the RICM

On Jun 17, 2015, at 10:50 , Toby Thain t...@telegraphics.com.au wrote: Here's a cute gotcha I hit this week: - Have a running Windows 8.1 machine with PS/2 keyboard. - Shut it down, start up with only USB keyboard. - Shut down and boot again with PS/2 keyboard atached. - Windows ignores

Re: using new technology on old machines. Was: PDP-12 Restoration at the RICM

On Mon, Jun 15, 2015 at 10:14:18PM -0700, Mark J. Blair wrote: On Jun 15, 2015, at 21:59, tony duell a...@p850ug1.demon.co.uk wrote: Even though there are at least 4 different USB connectors Ok, you got me there! When I was working for a GPS startup, I used mini-B on everything I

Re: using new technology on old machines. Was: PDP-12 Restoration at the RICM

On Jun 16, 2015, at 06:46, tony duell a...@p850ug1.demon.co.uk wrote: Again, I wonder if the data retention time decreases as the number of bits per device increases. Intuitively it should. Mind you, any SD card is probably going to be more reliable than a real TU58 tape now :-) I think

RE: using new technology on old machines. Was: PDP-12 Restoration at the RICM

I am of course counting all the transistors inside that chip. Well, that was obvious. But it raises an interesting point, today you can cram a whole computer in the footprint of the simplest DIP carrier. For the same price point and same reliablity. Is it then overkill if you choose to

Re: using new technology on old machines. Was: PDP-12 Restoration at the RICM

Choosing the larger card is, IMO, the right answer because you don't actually waste the space, you extend the life significantly because the wear leveling will spread your 256K across the entire flash region. The larger that region, the less often you re-write the same cells, thereby extending

Re: using new technology on old machines. Was: PDP-12 Restoration at the RICM

On Jun 16, 2015, at 07:36, Chris Elmquist chr...@pobox.com wrote: So, now you have to use a Type A to Type A cable to connect this box to your computer. That is just really, really messed up and I honestly tried to make it right but it was like pushing a rope. I hope my friends will

Re: using new technology on old machines. Was: PDP-12 Restoration at the RICM

Again, I wonder if the data retention time decreases as the number of bits per device increases. Intuitively it should. Mind you, any SD card is probably going to be more reliable than a real TU58 tape now :-) I think that paper tape, used outdoors on a rainy day, is likely to be more reliable

Re: using new technology on old machines. Was: PDP-12 Restoration at the RICM

On Tuesday (06/16/2015 at 07:24AM -0700), Mark J. Blair wrote: On Jun 16, 2015, at 06:46, tony duell a...@p850ug1.demon.co.uk wrote: Again, I wonder if the data retention time decreases as the number of bits per device increases. Intuitively it should. Mind you, any SD card is

Re: using new technology on old machines. Was: PDP-12 Restoration at the RICM

On Tuesday (06/16/2015 at 07:43AM -0700), Mark J. Blair wrote: On Jun 16, 2015, at 07:36, Chris Elmquist chr...@pobox.com wrote: So, now you have to use a Type A to Type A cable to connect this box to your computer. That is just really, really messed up and I honestly tried to make it

Re: using new technology on old machines. Was: PDP-12 Restoration at the RICM

On Monday (06/15/2015 at 10:14PM -0700), Mark J. Blair wrote: On Jun 15, 2015, at 21:59, tony duell a...@p850ug1.demon.co.uk wrote: Even though there are at least 4 different USB connectors Ok, you got me there! When I was working for a GPS startup, I used mini-B on everything I

RE: using new technology on old machines. Was: PDP-12 Restoration at the RICM

On Tue, 16 Jun 2015, tony duell wrote: Actually, IIRC a USB A male-female cable violates the spec... The spec forbids extending the cable further? Or should the spec forbid absolutely any cable, with absolutely any USB connector on either end?

RE: PDP-12 Restoration at the RICM

Date: Mon, 15 Jun 2015 19:42:42 -0400 From: Michael Thompson michael.99.thomp...@gmail.com To: cctech cct...@classiccmp.org The M452 creates a 220 Hz clock for the TTY transmitter and a 880 Hz clock for the TTY receiver. The M405 for the DP12-B serial port generated a clock that is 16x the

RE: PDP-12 Restoration at the RICM

The M452 creates a 110 Hz clock for the TTY transmitter and a 880 Hz clock for the TTY receiver. Does it? The prints I have show the 2 outputs with a factor of 4 (not 8) in frequency. The M405 for the DP12-B serial port generated a clock that is 16x the baud rate which is then divided by

RE: PDP-12 Restoration at the RICM

Date: Mon, 15 Jun 2015 05:01:36 + From: tony duell a...@p850ug1.demon.co.uk Subject: RE: PDP-12 Restoration at the RICM (tony duell) Tony, thank you for your offer to supply replacement M452 Variable Clock modules for the console. We already have one jumpered for 110 baud

Re: using new technology on old machines. Was: PDP-12 Restoration at the RICM

On Tue, Jun 16, 2015 at 04:32:23AM +, tony duell wrote: Oh come on. You yourself said you are here to learn. This module is hardly complicatated. Well, you got me there :) /P

Re: using new technology on old machines. Was: PDP-12 Restoration at the RICM

On Tue, Jun 16, 2015 at 04:28:16AM +, tony duell wrote: I am of course counting all the transistors inside that chip. Well, that was obvious. But it raises an interesting point, today you can cram a whole computer in the footprint of the simplest DIP carrier. For the same price point and

Re: using new technology on old machines. Was: PDP-12 Restoration at the RICM

While I agree that as long as things can be restored it's not a real problem, I'm surprised that not more people consider it a serious overkill. We're talking about putting in a rather complex computer to generate a baud rate. Are people really that handicapped when it comes to building

Re: using new technology on old machines. Was: PDP-12 Restoration at the RICM

On Mon, Jun 15, 2015 at 11:52:28AM +0200, Johnny Billquist wrote: We're talking about putting in a rather complex computer to generate a baud rate. Are people really that handicapped when it comes to building hardware nowadays? Speaking for myself, yes. I have a Teensy 2.0 lying at my desk,

Re: PDP-12 Restoration at the RICM

On Jun 14, 2015, at 06:53, Michael Thompson michael.99.thomp...@gmail.com wrote: Dave Tumey sent us a new rubber hammer for the Teletype. This is the part that pushes the print drum against the ribbon and paper to print. These are newly molded parts that have not been available for

RE: PDP-12 Restoration at the RICM (tony duell)

Tony, thank you for your offer to supply replacement M452 Variable Clock modules for the console. We already have one jumpered for 110 baud for the Teletype. The other two M452 modules should be jumpered for 9600 baud and 38400 baud. The second serial port uses a M405 Crystal Clock module

Re: using new technology on old machines. Was: PDP-12 Restoration at the RICM

Indeed, you use what is at hand and what you are comfortable with. /P On Sun, Jun 14, 2015 at 09:41:42PM +0200, Simon Claessen wrote: as long as it is done in a way that it can be restored to its original, i have no problems in using newer technology in older machines. we have a alix sbc

using new technology on old machines. Was: PDP-12 Restoration at the RICM

as long as it is done in a way that it can be restored to its original, i have no problems in using newer technology in older machines. we have a alix sbc build into our tek 4002a for demonstrational purpouses, all done without damaging or altering the original machine. On 14-06-15 17:25, tony

Re: using new technology on old machines. Was: PDP-12 Restoration at the RICM

I also think it is in the spirit of the computer - using what is available to fix a problem at hand. I think the arduino was overkill when an attiny (smaller, easier to hide) would probably serve just as well. If you have the ttl logic bits lying around and know how to use them, fine. Still would

RE: PDP-12 Restoration at the RICM (tony duell)

Date: Sun, 14 Jun 2015 15:25:08 + From: tony duell a...@p850ug1.demon.co.uk To: General Discussion: On-Topic Posts cct...@classiccmp.org Subject: RE: PDP-12 Restoration at the RICM Warren made an Arduino based programmable baud rate generator that works for both serial ports. After

RE: using new technology on old machines. Was: PDP-12 Restoration at the RICM

] On Behalf Of Johnny Billquist Sent: 15 June 2015 10:52 To: cctalk@classiccmp.org Subject: Re: using new technology on old machines. Was: PDP-12 Restoration at the RICM While I agree that as long as things can be restored it's not a real problem, I'm surprised that not more people consider

Re: using new technology on old machines. Was: PDP-12 Restoration at the RICM

We're talking about putting in a rather complex computer to generate a baud rate. Are people really that handicapped when it comes to building hardware nowadays? Speaking as someone who didn't do that, but might well have - it's not a question of handicapped; it's a question of convenience,

Re: using new technology on old machines. Was: PDP-12 Restoration at the RICM

On Jun 15, 2015, at 3:06 AM, Pontus Pihlgren pon...@update.uu.se wrote: On Mon, Jun 15, 2015 at 11:52:28AM +0200, Johnny Billquist wrote: We're talking about putting in a rather complex computer to generate a baud rate. Are people really that handicapped when it comes to building hardware

RE: using new technology on old machines. Was: PDP-12 Restoration at the RICM

Why not do it properly first time? What is the rush in bringing up a classic computer? And for a test, use the TTL pulse generator you have on your bench. I don't have one. I have a lot of test equipment, but mostly for RF work. If I needed to generate TTL pulses, I'd probably pull

RE: using new technology on old machines. Was: PDP-12 Restoration at the RICM

I am very worried that people would rather use a microcontroller than change a couple of passives. Can't anyone read a schematic and think Nope. I didn't know this hobby required a degree in electrical engineering. Well it had better not. I don't have one By your criteria a lot of

Re: using new technology on old machines. Was: PDP-12 Restoration at the RICM

On Jun 15, 2015, at 21:28, tony duell a...@p850ug1.demon.co.uk wrote: As am I. I've learnt a heck of a lot since I started (there is a common myth that there is something magic about a processor. This hobby has taught me to understand quite a few at the gate level). And the day I stop

RE: using new technology on old machines. Was: PDP-12 Restoration at the RICM

Unfortunately I believe you. Use at least a thousand times more components than you need to. Actually it's just two, a Teensy and a usb cable. (Sorry, I couldn't resist). I am of course counting all the transistors inside that chip. How do you suggest I learn? I believe you had a

RE: using new technology on old machines. Was: PDP-12 Restoration at the RICM

I am very worried that people would rather use a microcontroller than change a couple of passives. Can't anyone read a schematic and think The exact same argument could be made for somebody using an NE555 instead of discrete transistors to blink an LED, or discrete transistors

Re: using new technology on old machines. Was: PDP-12 Restoration at the RICM

On Jun 15, 2015, at 21:59, tony duell a...@p850ug1.demon.co.uk wrote: Even though there are at least 4 different USB connectors Ok, you got me there! When I was working for a GPS startup, I used mini-B on everything I designed with USB (always devices, never hosts, and no need for USB

Re: using new technology on old machines. Was: PDP-12 Restoration at the RICM

On Jun 15, 2015, at 09:53 , tony duell a...@p850ug1.demon.co.uk wrote: I also think it is in the spirit of the computer - using what is available to fix a problem at hand. I think the arduino was overkill when an attiny (smaller, easier to hide) would probably serve just as well. Would

RE: using new technology on old machines. Was: PDP-12 Restoration at the RICM

Would you put plastic handles on a piecc of antique furniture? Would you make the seatboard for an antique longcase clock from MDF? Both are easily reversable, BTW. Sure! Temporarily and reversibly, of course, and I'd hope to replace them with proper stuff when possible. But to

RE: using new technology on old machines. Was: PDP-12 Restoration at the RICM

I also think it is in the spirit of the computer - using what is available to fix a problem at hand. I think the arduino was overkill when an attiny (smaller, easier to hide) would probably serve just as well. Would you put plastic handles on a piecc of antique furniture? Would you make the

RE: FPGA tricks - Re: using new technology on old machines. Was: PDP-12 Restoration at the RICM

-Original Message- From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of ben Sent: 15 June 2015 17:18 To: cctalk@classiccmp.org Subject: Re: FPGA tricks - Re: using new technology on old machines. Was: PDP-12 Restoration at the RICM On 6/15/2015 9:08 AM, Toby Thain

Re: FPGA tricks - Re: using new technology on old machines. Was: PDP-12 Restoration at the RICM

On 6/15/2015 10:57 AM, Dave G4UGM wrote: But alas the software does *not* support the older chips. How old is old? I managed to get a copy of ISE10.1 downloaded, installed and running without phoning, ringing or otherwise jumping through hoops. That supports the Spartan 2 which has been

RE: using new technology on old machines. Was: PDP-12 Restoration at the RICM

We're talking about putting in a rather complex computer to generate a baud rate. Are people really that handicapped when it comes to building hardware nowadays? Speaking for myself, yes. Unfortunately I believe you. Use at least a thousand times more components than you need to. Now,

Re: FPGA tricks - Re: using new technology on old machines. Was: PDP-12 Restoration at the RICM

On 6/15/2015 11:33 AM, Paul Koning wrote: On Jun 15, 2015, at 1:28 PM, ben bfranc...@jetnet.ab.ca wrote: On 6/15/2015 10:57 AM, Dave G4UGM wrote: But alas the software does *not* support the older chips. How old is old? I managed to get a copy of ISE10.1 downloaded, installed and running

Re: FPGA tricks - Re: using new technology on old machines. Was: PDP-12 Restoration at the RICM

On Jun 15, 2015, at 09:18, ben bfranc...@jetnet.ab.ca wrote: But alas the software does *not* support the older chips. You want to make a mod 5 years down the road, sorry we do not support that model any more. TTL needs to be stock piled now for the next +50 years. Good point. Just as TTL

Re: using new technology on old machines. Was: PDP-12 Restoration at the RICM

On Jun 15, 2015, at 11:54 , tony duell a...@p850ug1.demon.co.uk wrote: Why not do it properly first time? What is the rush in bringing up a classic computer? And for a test, use the TTL pulse generator you have on your bench. I don't have one. I have a lot of test equipment, but mostly for

Re: using new technology on old machines. Was: PDP-12 Restoration at the RICM

On Jun 15, 2015, at 12:15 , tony duell a...@p850ug1.demon.co.uk wrote: I am very worried that people would rather use a microcontroller than change a couple of passives. Can't anyone read a schematic and think The exact same argument could be made for somebody using an NE555 instead of

Re: using new technology on old machines. Was: PDP-12 Restoration at the RICM

On Mon, Jun 15, 2015 at 04:55:57PM +, tony duell wrote: Unfortunately I believe you. Use at least a thousand times more components than you need to. Actually it's just two, a Teensy and a usb cable. (Sorry, I couldn't resist). In general this worries me if you are restoring a

RE: using new technology on old machines. Was: PDP-12 Restoration at the RICM

We're talking about putting in a rather complex computer to generate a baud rate. Are people really that handicapped when it comes to building hardware nowadays? Are people aware how easy baud generators are? I've jsut turned up the M452 schematic. Has anyone else looked at it? It's a

RE: PDP-12 Restoration at the RICM (tony duell)

Tony, thank you for your offer to supply replacement M452 Variable Clock modules for the console. We already have one jumpered for 110 baud for the Teletype. The other two M452 modules should be jumpered for 9600 baud and 38400 baud. The second serial port uses a M405 Crystal Clock module

Re: using new technology on old machines. Was: PDP-12 Restoration at the RICM

On Mon, Jun 15, 2015 at 04:53:01PM +, tony duell wrote: I also think it is in the spirit of the computer - using what is available to fix a problem at hand. I think the arduino was overkill when an attiny (smaller, easier to hide) would probably serve just as well. Would you put

Re: using new technology on old machines. Was: PDP-12 Restoration at the RICM

On Mon, Jun 15, 2015 at 01:59:11PM -0700, Mark J. Blair wrote: Big. VERY big. :) And one more thing (until the next thing comes to mind): I consider this to be an enjoyable and level-headed debate, just in case anybody gets the mistaken impression that I'm trying to come down hard on Tony

Re: using new technology on old machines. Was: PDP-12 Restoration at the RICM

On Jun 15, 2015, at 14:56 , Dave G4UGM dave.g4...@gmail.com wrote: A friend of mine refused to buy modern SD Cards because there was no way he was going to fill them. Trouble is that although smaller SD cards were available they were way more expensive (being discontinued and therefore

RE: using new technology on old machines. Was: PDP-12 Restoration at the RICM

on old machines. Was: PDP-12 Restoration at the RICM On Jun 15, 2015, at 13:46 , Pontus Pihlgren pon...@update.uu.se wrote: On Mon, Jun 15, 2015 at 04:55:57PM +, tony duell wrote: Unfortunately I believe you. Use at least a thousand times more components than you need

Re: using new technology on old machines. Was: PDP-12 Restoration at the RICM

On Jun 15, 2015, at 14:27 , Robert Jarratt robert.jarr...@ntlworld.com wrote: This particular thread has all the hallmarks of one that *could* descend into a flame war. Thank you for avoiding that! I think we're doing ok. The same folks having a spirited debate in this thread are carrying

Re: PDP-12 Restoration at the RICM

I'll add that if the Rubber Renue treatment is ineffective, you can have your platen rebuilt by JJ Short: http://www.jjshort.com/typewriter-platen-repair.php --Chuck

Re: PDP-12 Restoration at the RICM

On 06/02/2015 05:09 AM, Michael Thompson wrote: I sent him an email and asked about the hammer, and a source for paper and ribbons. The platen is hard as a rock, so we will need to do something about that too. There's some stuff called Rubber Renue sold for just that purpose. Basically,

Re: PDP-12 Restoration at the RICM

I'll add that I've had several platens and power rolls rebuilt by JJ Short and the service was top notch. -C On Jun 4, 2015, at 5:07 PM, Chuck Guzis wrote: I'll add that if the Rubber Renue treatment is ineffective, you can have your platen rebuilt by JJ Short:

RE: PDP-12 Restoration at the RICM

Date: Mon, 1 Jun 2015 09:33:26 +0100 From: Robert Jarratt robert.jarr...@ntlworld.com Subject: RE: PDP-12 Restoration at the RICM Yes, the new rubber hammers are available from David Tumey. I think he wants about $7 for 10 of them. I have a supply of them here in the UK for anyone

Re: PDP-12 Restoration at the RICM

Michael, Sounds like you're making some real progress. Next time you're near the ASR33, check the rubber hammer for the print cylinder. These have a tendency to self destruct and in doing so, destroy the cylinder itself...and they can go at anytime. There's a fellow on the Greenkeys that has

Re: PDP-12 Restoration at the RICM

We spent some time on the console Teletype that came with the PDP-12. The platen was nearly impossible to move, so the Line Feed did not work. We removed the platen, and found that the plastic in the bearing area had swollen and was binding. We sanded, cleaned, and lubricate the bearing surface

Re: PDP-12 Restoration at the RICM

If you haven't yet found one, I have spares for the switch cover - I have an entire console and the backplanes (with the cards) whose machine was disassembled out from underneath them. JRJ On 5/10/2015 9:45 AM, Michael Thompson wrote: Sorry, I sent the message before I was finished. The CRT

Re: PDP-12 Restoration at the RICM

On 26/05/2015 03:02, Ethan Dicks wrote: On Mon, May 25, 2015 at 8:07 PM, Michael Thompson michael.99.thomp...@gmail.com wrote: Today we pulled all of the M113 flip-chips and tested them Do you have any writeups on Warren's FLIP-CHIP tester? I'd be very interested too, especially since I'm