Chuck(G)
25k Member
...including people who sit at them.Modern computers don't have much of this.
...including people who sit at them.Modern computers don't have much of this.
This must be an interesting question for the store employees. "Hello. I am wondering if this ribbon would work to replace the DEC paper tape in a PDP-8?"I keep thinking there must be some 1" wide ribbons and I look for this in craft stores.
Ha! I will have to try asking like that sometime just to see the response.This must be an interesting question for the store employees. "Hello. I am wondering if this ribbon would work to replace the DEC paper tape in a PDP-8?"
I assume you meant a PC05 for your PDP11?Just to give you an idea on pricing, I bought a fully serviced, restored and working PC04 with controller (PDP11) for 1500 EUR + shipping a couple of years ago.
RK05 is 203 tracks, 2 surfaces, 16 sectors per track, 256 words per sector(Edit: Backing up a RK05 disk to the PTP: would take 30 days assuming you can keep the punch fed with paper tape. Read time for restore however would only be a mere 6 days reading 24*7.)
Well, that makes it almost seem reasonable with compression. Between 3 and 4 hours. Restore would then be somewhere between 26 and 34 minutes.RK05 is 203 tracks, 2 surfaces, 16 sectors per track, 256 words per sector
203*2*16*256 = 1662976 words or 2494464 bytes
Punch is 50 characters per second
2494464/50 = 49889 seconds
49889/60/60 = 13.86 hours. Still not going to try.
Didn't find how long a box of tape was in a quick search to see how many boxes that would be.
Wow, I really screwed up my math somehow. My error. Ah I'll bet I calced it at 50 chars per minute, not second. Or maybe I was thinking an RM80....RK05 is 203 tracks, 2 surfaces, 16 sectors per track, 256 words per sector
203*2*16*256 = 1662976 words or 2494464 bytes
Punch is 50 characters per second
2494464/50 = 49889 seconds
49889/60/60 = 13.86 hours. Still not going to try.
Didn't find how long a box of tape was in a quick search to see how many boxes that would be.
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I've made clones of the RX8E controllers a while back. ...
The RK05 controller is a three board set and these are not easy to find. RK05 drives can be found, but suitable 16 sector disk packs is another story.
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Regards, Roland
Hi Roland, there is shortage of RK8E controllers. With George Wiley's nice RK05 emulator there is an increased demand for these controllers. You have cloned a number of other Omnibus controllers. Would you be able and willing to do a RK8E clone? Vince Slyngstad has recreated the original PCBs but some of the parts have become unavailable, so a build is difficult if not impossible. Unfortunately I don't have the KiCAD or Eagle skills to do this myself.
I did start a design like that, but ran into a problem that the boards have a lot of top connector and other pins, so the pin counts exceeded those available for the CPLD by a good margin. This is also worsened by the thing being a DMA device, which is inherently more complicated and pin intensive than polled I/O.Good idea, 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.
Regards, Roland
I'm also curious to the complete setup from Schroeders PDP8/e.Any chance we can get a distance shot of the whole machine? I've never had a good visual of what a full PDP looks like.
Any chance we can get a distance shot of the whole machine? I've never had a good visual of what a full PDP looks like.
I'm also curious to the complete setup from Schroeders PDP8/e.
But it really depends on the options you have for your machine. [...]
Would it help to setup a crowd funding scheme like Kickstarter to fund the development of an RK8E controller clone?Good idea, 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.
Regards, Roland
It seems to me that the critical constraint is the lack of a developer ... not the cost of materials. Unless you're proposing to hire a developer?Would it help to setup a crowd funding scheme like Kickstarter to fund the development of an RK8E controller clone?
No, for me the fun is enoughWould it help to setup a crowd funding scheme like Kickstarter to fund the development of an RK8E controller clone?
Since a CPLD version of the RK8E looks like a pile of work, I'm thinking a shorter path might be simple TTL replacements for the old DEC chips. As mentioned earlier, the DEC board layouts are generally available in CAD tools, and there is probably demand for 8266 replacements and such. Perhaps JLC or similar would be able to build the replacements affordably.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.
Very cool picture.I have thought about taking the TC01 and the TU55 out, and putting them in the same rack as the 8/I, but there's two problems with that, one being the interesting other stuff in the rack (those extra panels were added by those who used the machine) and two being the fact that while one TU55 will fit in the same rack as the CPU, two will not, and I am still holding out hope for a second.
(if anyone knows where I could get a second TU55 to fill that empty slot, let me know, heh)