test-drb June 2007

test-drb@ccmp.vtda.org

224 participants
486 discussions

Telephony switches - is there anyone out there collecting these?

by classiccmp＠memory-alpha.org.uk

Hi, > How about early modems, anyone collect them? Not exactly early, but at one time I did collect various Hayes SmartModems and assorted other "interesting" modems....still have them, but lost interest in them LONG ago. TTFN - Pete.

18 years, 1 month

Old phone swittches

by pspan＠amerytel.net

Well, I can assure you that I do not have deep pockets, but I have 3,000 square feet of telephone switching equipment. Two main manufacturer's TRW Vidar and Stromberg Carlson DCO switches. I have been repairing these swithes for 25 years. The interesting thing about the DCO to this list is it was based on the DEC processors, 11/34 and 11//75. The DCO still incorporates the DEC Alpha CPU's, and at one time there were 1500 switches installed in the US. I know of 10 operating companies, including national carriers that are still using them. To the best of my knowedge, there is only one woking Vidar switch still operating in the US. With gov regs and technology pushing towards VoIP all of the companies will soon have the "suitcase" sized switches. Oh, and as you might guess, the MTBF is not engineered in years anymore, it is based on product life cycle.

18 years, 1 month

What didn't happen in the future

by aek＠bitsavers.org

> I wasn't aware the vinyl record had disappeared. It has for anyone under 30 Get over it.

18 years, 1 month

Modern external storage emulating RX02 (was Re: Most used toys, was Re: The late, great TRS-80)

by ajp166＠bellatlantic.net

> >Subject: Re: Modern external storage emulating RX02 (was Re: Most used toys,was Re: The late, great TRS-80) > From: Richard <legalize at xmission.com> > Date: Wed, 27 Jun 2007 12:54:41 -0600 > To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> > > >In article <468295F6.5050801 at nktelco.net>, > C H Dickman <chd_1 at nktelco.net> writes: > >> Ethan Dicks wrote: >> >> > and expansion options. An RX01/RX02-attached device, at least, will >> > work with OMNIBUS machines as well as the VT78 and DECmate I - overall >> > not a bad range to cover. >> >> I did that using a PC as the external storage and a PC parallel port as >> the interface. Lets me run my PDP-8/e and PDP-11/40. DECtape is cool, >> but a little slow. > >Do you have software/interface schematics? I have a DECmate I and no >RX0[12] drives. Easier to find an rx01. Allison >-- >"The Direct3D Graphics Pipeline" -- DirectX 9 draft available for download > <http://www.xmission.com/~legalize/book/download/index.html> > > Legalize Adulthood! <http://blogs.xmission.com/legalize/>

18 years, 1 month

Modern external storage emulating RX02 (was Re: Most used toys, was Re: The late, great TRS-80)

by ajp166＠bellatlantic.net

> >Subject: Re: Modern external storage emulating RX02 (was Re: Most used toys,was Re: The late, great TRS-80) > From: "Ethan Dicks" <ethan.dicks at gmail.com> > Date: Wed, 27 Jun 2007 16:02:14 -0400 > To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> > >On 6/27/07, Allison <ajp166 at bellatlantic.net> wrote: >> Using a Tu58 on an -8 is not a goot match and there are lots of gyrations. > >Agreed. > >> >If all PDP-8s had a spare serial port, it might make sense to have a >> >serially-attached modern mass storage peripheral. >> >> Adding a second serial is trivial as there were many differnt serial >> cards available. To make a TTY card RS232/432 passable is also not hard. > >It's trivial from the OMNIBUS days onward to add another serial port. >Not so trivial for a Straight-8, an -8/S, an -8/L or -8/i. One may >argue that machines that old don't matter so much, but I do happen to >have a BM08 on one --8/L (total of 12K) and would like to be able to >bring up OS/8 on it someday. I'd also like to expand my -8/i to have >8K of core (and perhaps a full 32K eventually) and bring OS/8 up on >that as well. If you have a parallel port or even an interface to read/write one bit with an IOT (less parts than parallelport or tty interface) there are possible interfaces even for 8s. >Changing out 20mA for RS-232 isn't hard at all with the older machines >- Vince Slyngstad made some EIA paddle cards for pre-OMNIBUS boxes. I >have at least two of his cards. Some day, I'll find the time to >assemble them, but for now, I'm fine with hanging a VT220 off of my >-8/L with a 20mA cable. 20ma works too. Though it's not hard to pick up the TTL or logic before 20ma conversion. >> What is possible now is a small micro and a big static ram of 512k are >> which fairly easy to find it's not unreasonable to simulate a RX02 >> using a micro at the end of a serial line (or parallel) and NOT use >> the protocal of TU58. > >Sure. There's no requirement to use the TU58 protocol, it's just >understood, is out there, and happens to work with a real device. If >you are going to write an OS/8 driver anyway, there's no reason to >stick with a protocol that's hard to use. I just dredged up an old >thread in my reading where someone suggested the TU-58 as the >"obvious" device for a diskless PDP-8. I was just heading that debate >off at the pass, since it was extensively investigated over 20 years >ago and determined to be difficult, technically. The need to buffer the tape data is the annoying part as well. >> The cpu/micro used does not have to be very high >> powered or fast as all it's doing is data transfer and PDP-8 PIO is >> usually slower than 30-40K words/sec. > >Certainly not if you are rolling your own interface. If you are >trying to make a plug-compatible RX02 emulator, there might be some >bit-level stuff that's timing critical, but the overall bandwidth is >rather low by modern standards. RX02 interface [RX8E] is fairly simple bit serial with clock. >> In the end what is used is more a matter of convenince than technology. > >Agreed. > >> I happen to be lucky(?) as my 8f has two serial cards but nothing >> else device wise. One of th cards is the usual console TTY but the >> other is a UART based M8652 that were often used for modem >> banks and serial data concentrators/switches made using PDP-8s. > >Nice. What I have is some Q or Ubus quad wide proto cards that could easily be used on Omnibus with a few cuts. Parallel IO is spelled out in the interface handbook. > >In amongst all the other recent PDP-8 discussions, I have to wonder >that if one was going to be spending $$$ on a 1 sq ft. PCB with edge >fingers and whatever line drivers, what would be a good choice of >peripheral options to stack on the same board. For example, the >DKC8AA has several independent devices on one hex-height card. In a DCKAA, have to look that one up. >quad-height form factor, one could easily stuff two RX8Es, and at >least one, if not two KL8Es, which should take care of a lot of >external I/O requirements. The RX8Es would use the standard OS/8 >driver, of course, simplifying that aspect of things, but then one >could attach that to either a real RX02 if you had one, with floppies >to read/write, or to an off-board RX02 emulator as we've been >discussing. Personally, I don't have even one RX8E per OMNIBUS >machine, so alternatives are an interesting direction for me. If the driver were developed for the device it could be anything. For example the device could be two parallel output and one input port. One output port sets the block address (128word block for 512kW) and the second is read/write to ram data with auto increment to the low block counter. That would be PIO, no micro and two 512k byte wide rams (4bits wasted) and 5 74LS161s as the ram address counter (modulus 128). There are existing pdp8 parallel IO cards that can do that. When it cools down and I get a few minutes that might be an easy board to try and build. I imagine patching OS/8 is not hard as the device page is locatable. Though the complete package would need a test program, formatter and a device driver for OS/8. Allison > >-ethan

18 years, 1 month

nice but OT (HP/Apollo workstation)

by classiccmp＠memory-alpha.org.uk

Hi, >>....I though they'd dropped that after the 400 series? > > No. Yeah, I've just had a rummage around "hpmuseum.net". It seems the "HP-Apollo" name was used up until the end of the 700 series, in fact the 712 (the last of the 700 series) was the first machine to be branded "HP" alone. Learn summat new every day. :-) > http://www.debian.org/ports/hppa/ > > I've installed it on C110 and possibly HP "Apollo 715" systems >a few years ago... Thanks for the info. I did a reasonable amount of "googling" when I picked up this 712, but didn't find that port. Only OpenBSD and NetBSD appeared to have PA-RISC ports. I don't currently have any intention of switching away from HP-UX, but it's nice to have the option.... TTFN - Pete.

18 years, 1 month

Modern external storage emulating RX02 (was Re: Most used toys, was Re: The late, great TRS-80)

by ethan.dicks＠gmail.com

On 6/26/07, Dave McGuire <mcguire at neurotica.com> wrote: > > Serially connecting would rot though... > > Yeah, kinda. I was just reading some old list threads about PDP-8s and TU58s and emulators - transfer speed aside, the real problem was that most pre-OMNIBUS PDP-8s didn't have a spare serial port (just the console TTY), and that the serial hardware needs to be able to send a Break to the TU-58 to properly initialize and reset the controller in the TU-58, and unmodified PDP-8 hardware can't do that. I did run across a bunch of old 12-bit SIG newsletters from when the TU-58 was new, and all the gyrations folks went through to be able to use them, since at the time, they were about the cheapest mass storage you could get from DEC. One entire aspect of the project was how to mod M706/M707 or KL8E serial interfaces to generate a break. Another aspect was trying to wedge a driver into a couple of pages of code. If all PDP-8s had a spare serial port, it might make sense to have a serially-attached modern mass storage peripheral. Since that's nowhere near universal, it frequently comes down to deciding on which models to support. One of the few disadvantages of the PDP-8 spanning 1965 to 1994 (PDP-8 to DECmate III) is that there's a huge variety of hardware that all runs the same instruction set (give or take a couple instructions), but with an equally huge variety of default peripherals and expansion options. An RX01/RX02-attached device, at least, will work with OMNIBUS machines as well as the VT78 and DECmate I - overall not a bad range to cover. -ethan

18 years, 1 month

Modern external storage emulating RX02 (was Re: Most used toys, was Re: The late, great TRS-80)

by ajp166＠bellatlantic.net

> >Subject: Modern external storage emulating RX02 (was Re: Most used toys,was Re: The late, great TRS-80) > From: "Ethan Dicks" <ethan.dicks at gmail.com> > Date: Wed, 27 Jun 2007 11:14:19 -0400 > To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> > >On 6/26/07, Dave McGuire <mcguire at neurotica.com> wrote: >> > Serially connecting would rot though... >> >> Yeah, kinda. > >I was just reading some old list threads about PDP-8s and TU58s and >emulators - transfer speed aside, the real problem was that most >pre-OMNIBUS PDP-8s didn't have a spare serial port (just the console >TTY), and that the serial hardware needs to be able to send a Break to >the TU-58 to properly initialize and reset the controller in the >TU-58, and unmodified PDP-8 hardware can't do that. I did run across >a bunch of old 12-bit SIG newsletters from when the TU-58 was new, and >all the gyrations folks went through to be able to use them, since at >the time, they were about the cheapest mass storage you could get from >DEC. One entire aspect of the project was how to mod M706/M707 or >KL8E serial interfaces to generate a break. Another aspect was trying >to wedge a driver into a couple of pages of code. Using a Tu58 on an -8 is not a goot match and there are lots of gyrations. > >If all PDP-8s had a spare serial port, it might make sense to have a >serially-attached modern mass storage peripheral. Adding a second serial is trivial as there were many differnt serial cards available. To make a TTY card RS232/432 passable is also not hard. > Since that's >nowhere near universal, it frequently comes down to deciding on which >models to support. One of the few disadvantages of the PDP-8 spanning >1965 to 1994 (PDP-8 to DECmate III) is that there's a huge variety of >hardware that all runs the same instruction set (give or take a couple >instructions), but with an equally huge variety of default peripherals >and expansion options. An RX01/RX02-attached device, at least, will >work with OMNIBUS machines as well as the VT78 and DECmate I - overall >not a bad range to cover. > >-ethan What is possible now is a small micro and a big static ram of 512k are which fairly easy to find it's not unreasonable to simulate a RX02 using a micro at the end of a serial line (or parallel) and NOT use the protocal of TU58. The cpu/micro used does not have to be very high powered or fast as all it's doing is data transfer and PDP-8 PIO is usually slower than 30-40K words/sec. In the end what is used is more a matter of convenince than technology. I happen to be lucky(?) as my 8f has two serial cards but nothing else device wise. One of th cards is the usual console TTY but the other is a UART based M8652 that were often used for modem banks and serial data concentrators/switches made using PDP-8s. Allison

18 years, 1 month

Emulating an RX02 via parallel port (was Re: Most used toys, was Re: The late, great TRS-80)

by ethan.dicks＠gmail.com

On 6/27/07, Allison <ajp166 at bellatlantic.net> wrote: > For PDP-8 ops, even 10mb is a "large" disk I'm sure so even a 1mb ram > could work well as a "ramdisk". Sure... since OS/8 uses 12-bit block pointers, 10MB works out to 5 "devices". 1MB of RAM for a RAM disk isn't tiny, either. -ethan

18 years, 1 month

Telephony switches - is there anyone out there collecting these?

by aek＠bitsavers.org

> Are there people out there, on the list or otherwise, that are actively > collecting these machines? Absolutely. There are private collectors with operational CO's. These are serious deep-pockets people who are buying surplussed microwave relay stations and putting museums into them. There are two I know of in San Jose and the central valley in private hands. The telephony collectors have many decades of head start on us computer types.

18 years, 1 month

← Newer
1
...
8
9
10
11
12
13
14
...
49
Older →

Jump to page:

2025

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

2009

2008

2007

2006

2005

2004

2003

2002

2001

2000

1999

1998

1997

test-drb June 2007