DEC Paper Tape Punch/Reader Pricing

[Nevets01]

Very cool picture.

Is that a standard 19" rack? If so, then it is possible to get racks larger than 48U( think 52 off the shelf?). Of course then weight becomes a serious issue, and honestly that thing looks cooler in 2 racks anyway.

At home I put a 32U rack on top of a custom-made cabinet because I don't like to bend over.

Thank you!
Yes, they're standard 19" racks, but I wouldn't want to put it in different ones, since these are the original DEC racks it was installed in. They're not H960s, but they are DEC-made. They're similar to the racks used with the PDP-5, but painted black instead of blue.
(My PDP-8 was almost certainly installed in the same lab as a PDP-5, which is likely why it has PDP-5-like trim)

 

[hunterjwizzard]

Ahhh, yeah that is a very fair point. Heck if someone handed me a set of 4 post DEC racks tomorrow I'd probably swap out my current ones for them. A friend of mine has this hideous vintage orange 4 post rack I want desperately. Yeah I can totally get the value of keeping it in original DEC racks.

 

[ftcnet]

I have a spare functional Rk05 doing nothing. I'm currently moving to another home and I'm going to study next year. So a bit busy but I like the idea. I'm wondering, did Vince start with a cpld/fpga version of the RK8E? That could be a single board instead of three boards. The TTL TD8E version is also on my todo/wish list.

If someone is serious about creating an Omnibus RK05 drive controller/interface, please consider doing the RK8L (2 quad boards). It includes support for 8 drives and 1-4096 word transfers. The 1-4096 word count feature simplifies TSS/8 support. DEC has supplied 'official' RK8L diagnostics so that part is already done. The M8372 schematics are available, but I've yet to find any similar documentation for the M8371. I know someone who claims to have a RK8L board set so it might be possible to 'reverse engineer' enough of a M8371 schematic that way.

Re: re-doing a TTL TD8E controller. Please consider Charles Lasner's claim "... that DEC did implement a TC8E Omnibus DECtape controller to the prototype stage, but never sold it. It was totally compatible with the TC01/08 ...". Wouldn't a TC8E Omnibus DECtape controller be far more desireable since diagnostics and software already exist for it?

 

[NF6X]

Speaking of an unreleased Omnibus DECtape controller, has anybody made an Omnibus DECtape emulator yet? I think something like that would be desirable to folks like me who have Omnibus systems but have not managed to acquire real DECtape hardware.

 

[antiquekid3]

I got through about 80% of the software design for a DECtape emulator and mentally worked through the hardware design. If someone wants to work with me to finish that up, I think that would be very helpful for those with controllers but only one or two transports. It would be very nice to have the reproduction TD8E and certainly a TC8E someday as well.

 

[DougIngraham]

Speaking of an unreleased Omnibus DECtape controller, has anybody made an Omnibus DECtape emulator yet? I think something like that would be desirable to folks like me who have Omnibus systems but have not managed to acquire real DECtape hardware.

I am not clear what you are desiring.

There are three ways to have DECtape on an omnibus machine (that I can think of).

1. TD8E with all its issues. Does not make a good system/boot device without lots of other stuff.
2. TC08 operating off of a Posibus converter (M8350) and data break interface (M8360) board sets.
3. TC01 operating off of a Posibus converter and data break interface with the addition of a Posi to Negi converter.

My CSD (Console Serial Disk) program can mount simh style DECtape images if something like that was what you wanted. I don't see how this is really different from an emulator from a use standpoint. DECtape is pretty much the same as a small disk image when emulated.

So exactly what part of this are you talking about emulating?

And I just realized we have hijacked the thread.

To get back on topic, I sold a PC04 reader/punch a couple of years ago for a little over a thousand dollars. It needed a little cleanup but I think it was in reasonably good shape. With the way things seem to be now I think it would sell for twice as much on Ebay.

 

[NF6X]

I was inquiring about whether somebody has already made hardware for fully software compatible (from the PDP-8 CPU's perspective; not using real DECtape media) emulation of a DECtape subsystem. From what you've noted plus Charles Lasner's discussion linked above, I'd want it to emulate a TC01/TC08, or perhaps the unreleased Omnibus interface Charles described.

A general purpose Omnibus "emulator for all of the hardware I wish I had, but don't" like the Unibone/Qbone card would be convenient to have. I wonder if anybody has gotten around to making one yet? I've daydreamed off and on about how I might implement one.

I have a real PDP-8/M in the middle of repair/restoration, but I have no real peripherals for it other than an ASR33 which I plan to convert to be equivalent to DEC's "LT33" configuration. I have an M8357 RX8E controller card on the way from eBay which I hope to mate with an RX02 drive I have sitting on the shelf, so I'll have some sort of random-access storage on my PDP-8/M eventually. But what I'd really like is any or all of the less easily obtained peripherals such as the high speed punch/reader, RK05 subsystem, and/or DECtape subsystem. Until I find such peripherals which are both available and affordable at the same time, I'm open to considering hardware emulation to tide me over.

I don't care at all about considerations such as whether paper tape was practical to use vs. a hard drive; this is just fun hobby stuff, and practicality has nothing to do with it.

 

[DougIngraham]

I was inquiring about whether somebody has already made hardware for fully software compatible (from the PDP-8 CPU's perspective; not using real DECtape media) emulation of a DECtape subsystem. From what you've noted plus Charles Lasner's discussion linked above, I'd want it to emulate a TC01/TC08, or perhaps the unreleased Omnibus interface Charles described.

Not to my knowledge. Kyle mentioned above that he has thought about a drive emulator. But controllers are quite rare as well. RX8E is a lot more common and more capable but not as much fun.

A general purpose Omnibus "emulator for all of the hardware I wish I had, but don't" like the Unibone/Qbone card would be convenient to have. I wonder if anybody has gotten around to making one yet? I've daydreamed off and on about how I might implement one.

This is more difficult on the 8 than the 11 due to the fact that the 11 uses memory mapped I/O and on the 8 you would need to be able to handle the IOT's and talk to memory from your magic device. Not impossible but certainly not as straightforward as the 11.

I have a real PDP-8/M in the middle of repair/restoration, but I have no real peripherals for it other than an ASR33 which I plan to convert to be equivalent to DEC's "LT33" configuration. I have an M8357 RX8E controller card on the way from eBay which I hope to mate with an RX02 drive I have sitting on the shelf, so I'll have some sort of random-access storage on my PDP-8/M eventually. But what I'd really like is any or all of the less easily obtained peripherals such as the high speed punch/reader, RK05 subsystem, and/or DECtape subsystem. Until I find such peripherals which are both available and affordable at the same time, I'm open to considering hardware emulation to tide me over.

If you are going to emulate a mass storage device it might as well be the RK05 or RX01. And both of those exist although you need to have a controller. Which you have in the case of the RX01 or RX02. An emulated DECtape doesn't make much sense to me. You would need to have a screen on the front which would show the tape reels spinning in order to distinguish it from an RX01 emulation.

I don't care at all about considerations such as whether paper tape was practical to use vs. a hard drive; this is just fun hobby stuff, and practicality has nothing to do with it.

Oh yes. If a computationally intensive task was started on a PDP-8 in 1965 and somehow the machine was still working on that task today it would take only about half an hour for the same program run on modern server hardware to catch up. It is all for fun. Practicality has nothing to do with it!

 

[NF6X]

A screen showing the spinning emulated tape reels would be neat, and I understand that there’s software to do exactly that which I’ll play with once I build my PiDP-8 kit. But that seems a bit too two-dimensional to me for a peripheral hardware emulation on a real PDP-8 system. Why not have the emulator spin model reels with motors on a model tape drive?

 

[AK6DN]

... I have an M8357 RX8E controller card on the way from eBay which I hope to mate with an RX02 drive I have sitting on the shelf, so I'll have some sort of random-access storage on my PDP-8/M eventually ....

I still have lots of assembled and tested RX01/02 emulators available. See my signature below for info. Plugs in in place of an RX0n drive into the PDP8/PDP11 controller.
Just add your own Arduino Mega2560 controller board. Ref: https://github.com/AK6DN/rx02_emulator

 

[NF6X]

That sounds like a useful tool. I'll probably get one.