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101090 discussions

Archived viruses, was Re: Reasonable price for a complete SOL-20 system?

by terry＠webweavers.co.nz

Here is some I wrote some time ago on my experiences with vintage viruses. Bear in mind it's a narrative (and hence somewhat long-winded and rambling) but anyway..here it is for anyone interested... http://www.classic-computers.org.nz/blog/2009-08-30-vintage-viruses.htm Terry (Tez)

9 years, 3 months

PDP-11 RL02 disk emulation

by scott.l.baker＠gmail.com

Hi Noel, >> Any chance it could be put into 'production'? Sure, if there is interest, I could make a run of boards. >> Also, what FPGA board are you using? I assume it's one that has an SD >> card socket or something, for actually storing the bits on? My project is just an interface board for an existing RL02 emulator project: www.pdp11gy.com There are a multiple project revisions listed on the pdp11gy.com site that use different Altera FPGA dev boards: DE0 Nano, DE0 Nano SOC, and BeMicro CV. I was planning to use a Terasic DE0 Nano dev board since these boards can be found on eBay from $50 to $100. The DE0 nano does not have an micro-SD card socket which is why there is a socket on my interface board. http://sierracircuitdesign.ddns.net/temp/RL02 The DE0 Nano SOC, and BeMicro CV dev boards have micro-SD card sockets, so if you used one of those, then you would not need to populate the micro-SD socket on the interface board. According to the author of the www.pdp11gy.com RL02 project, the 40-pin headers on DE0 Nano, DE0 Nano SOC, and BeMicro CV are compatible, so you could use my interface board with any of these boards. Regards, Scott

9 years, 3 months

Intel 8089A, 8089A-3, 8089-3 datasheet

by spacewar＠gmail.com

Does anyone have a datasheet for an Intel 8089A, 8089A-3, or 8089-3? The only datasheets I've found are for the "plain" 8089 with no "A" or numeric suffix. The component resellers show better availabiliity for with the "A" and/or "-3" suffix, though it's possible that those are in error. The 8089 is an I/O processor. The "-3" suffix is most likely a speed grade. The standard part without the "-3" is 5 MHz.

9 years, 3 months

RK8E Plessey Clone and Data Break Error

by marco＠familie-rauhut.eu

Hello all together, i restore a rk05 disk drive in combination with an Plessey RK8E clone controller. Now the drive itself is restored, and the connection cables are built. My problem is that the rk8e diskless controll test (dhrka) fails with an data break error. The diskless controlltest is running throug all register and also the databuffer test. But in the first data break routine it fails. Then i toggled in the Example program from the maintanence vol.III, Single Cycle Data Break Transfers (Write than Read). With this program the content of the SwitchRegister is written through the data buffer registers and read back to the memory. Afterwards it is compared to the original SR content. I found out that the routine is running if SR=7777. Deeper investigation results that the bits 0, 1, 4, 6 and 9 have to be one`s to run the routine. The other SR bits are switchable while running the program. Next thing i did is trying read data with futil. i could read data form the disk. But with many read errors. Because i do not know anything about the allignment between my diskpack and the drive, i formated the pack with the RK8E Formater (dhrkd). The write part of the format is running. In the disk checking part the formater fails. Anyway. Then i used futil and scanned the whole surface off the diskpack. On the whole disk are 5 bad blocks left. Now i am able to dump blocks from the disk. But it seems that no matter witch block i dump out, it is the same block all over the disk. Afterwards i tried to modifie some words in block 0. And this is working. When i write the modified block i see the modification also in every other block of the disk. Have anyone the lightning idea? On a Google search i found a post of Rick Bensene from 2014 on this list witch described a similiar problem. In this discussion where talked about an spike in the load signal of the current address register. I checked that and see that this was not my problem. Thanks in advance Marco Rauhut

9 years, 3 months

Unibus / Qbus

by shadoooo＠gmail.com

Hello, we are discussing on separate thread about doing an universal interface for PDP11. I'm taking all the relevant documentation about Unibus and Qbus busses, aiming to check the possibility of doing a board compatible, with some adjustments, with both worlds. I started to read the 1979 specifications, however it's not all clear to me, specially about Unibus. What I understood: - Qbus is complete on A and B connectors, so a dual card could be done. Some backplanes have a true serpentine, while some other has C and D with other signals, but those are of particular usage with dual-board interfaces. Basically both dual and quad boards can be done, with the latter using A and B and simply propagating grant on C and D, supposedly connected in standard serpentine. Unibus: the specifications are describing A and B, but backplanes are complicate than that, and can have Unibus, Modified Unibus, Extended Unibus, SPC... What for? If all the signals are in AB, why they are connected again in CDEF? There's some complete documentation about the different backplane types, and the standard approach for an Unibus board? Thanks Andrea

9 years, 3 months

DEC bus transceivers (was Re: Unibus disk controller with modern storage)

by jnc＠mercury.lcs.mit.edu

> From: David Bridgham > Just the bus interface takes over half the area of a dual-height board! In part because the level converters are SMD, and we had to mount them on (modified) wide DIP carriers to use them in a wire-wrap board. > I've played around with laying out what might be the production board > ... and I've got it down to a row of 8641 bus transceivers and a row or > two of the level-converter chips. > http://pdp10.froghouse.org/qsic/proto-pcb.jpg For those looking at that picture, it's not our current plan for 'producton' QSIC's; the one in the picture uses a daughter-card with an FPGA on it, but that makes the card to high to fit into a single slot. So the current plan is to do a card with an FPGA on it directly. Noel

9 years, 3 months

11/35 on eBait

by jnc＠mercury.lcs.mit.edu

> From: Glen Slick >> Went unsold at $3500. Relisted, this time at $5000. > there was a taker for that 11/35 at $5000 today.... Smack me with a wet halibut. They must not have seen the original listing? I can't come up with any other explanation why someone would pass up a chance to buy it for $3.5K, and pay $1.5 more for the priviledge... Noel

9 years, 3 months

11/35 on eBait

by jnc＠mercury.lcs.mit.edu

> Philipp Hachtmann wrote: > Was it really sold? I can't figure that out from here. Only "listing > has ended". And when I try to search for it, the website doesn't show > it :-( ??? If you go to the listing: http://www.ebay.com/itm/142146207101 the image has 'Sold' emblazoned across it. And if you click on that image, it takes you to the original listing, which says "Sold for: US$5,000". Noel

9 years, 3 months

Time to get rid of weird connected appliances! <<SKYNET MUST DIE>> check this

by COURYHOUSE＠aol.com

Time to get rid of weird connected appliances! <<SKYNET MUST DIE>> check this.... http://www.msn.com/en-us/news/technology/how-your-dvr-was-hijacked-to-help-…

9 years, 3 months

ASTEC 8151 PSU (TRS80, Osborne etc)

by witchy＠binarydinosaurs.co.uk

Hi folks, Now that the bouncing has calmed down I've got a question about this here triple output pretty ubiquitous power supply. This one had some burst caps so naturally wasn't working and was probably why the machine it came out of was taken out of use. I've replaced all of them because why not, along with the .1uF mains filtering cap that would also burst at some point and I still get low output on all rails. I've tested all the major components out of circuit and checked for shorts; in Apple ][ power supplies (also Astec, apart from the ones that aren't) low output is mostly caused by a feedback capacitor (C7) going out of spec, but these are all new and as close a match to the originals I could find. One thing I've not done is reflowed all connections so I'll do that later, but has anyone got experience of common failure modes with these things? Cheers -- Adrian/Witchy Binary Dinosaurs creator/curator Www.binarydinosaurs.co.uk - the UK's biggest private home computer collection?

9 years, 3 months

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