test-drb June 2005

test-drb@ccmp.vtda.org

221 participants
681 discussions

by vcf＠siconic.com

I have some paper tapes that I'm trying to read and I have good reason to believe they are from a Wang machine of some type. They seem to hold some sort of document. The writing on the tape indicates a section number and "pages". The tape is 8-level. The 8th bit seems to be used as some sort of end-of-line or end-of-record marker. The 7th bit seems to be parity. So the actual symbol codes are likely 6-bit. I've read in the tapes and done some cryptanalysis but so far I haven't been able to see any patterns that would suggest groupings of letters at certain codes. At this point I'm confused. Does anyone know how Wang paper tapes were encoded, or does anyone know where there is technical documentation about this? So for my searches online have turned up empty. -- Sellam Ismail Vintage Computer Festival ------------------------------------------------------------------------------ International Man of Intrigue and Danger http://www.vintage.org [ Old computing resources for business || Buy/Sell/Trade Vintage Computers ] [ and academia at www.VintageTech.com || at http://marketplace.vintage.org ]

18 years, 9 months

yellowed murky plastic

by chrism3667＠yahoo.com

I would imagine this question has been asked hundreds of times, but what to do about it? Im guessing soaking it in bleachy water (50/50?). What say you? __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com

18 years, 9 months

Does anyone have a Radio Shack Electronics Learning Lab?

by ethan.dicks＠gmail.com

Hi, I picked up an ELL (RS 28-280) at the outlet store. It was cheap because all of the loose parts were missing. I have the base and the books. The PDF file on the RS web site doesn't list things in enough detail to be able to build a list of missing parts. I'm going through the books and trying to tally the required parts, but it's taking hours and I'm likely to make mistakes. Does anyone have one of these and might they have enough time to make a physical inventory? Even a digital picture of the parts spread out on a tabletop would be really helpful. Thanks, -ethan

18 years, 9 months

SASI device <-> PC ?

by julesrichardsonuk＠yahoo.co.uk

Has anyone here successfully interfaced a SASI device to a PC at the hardware level? I've got a few classic systems which use SASI (or not-quite-SCSI) controllers to talk to SASI-ST506 bridge boards and from there to ST506 type drives. As has been documented many times in the past here, an ST506 drive has a pretty tight relationship with its controller, and so hooking up the drive to a different controller (say MFM controller in a PC) causes all sorts of problems when it comes to backup. Hence driving the SASI side of things (and preserving the drive/bridge board relationship) would seem like a sensible move when it came to backing up data. In theory data could then be restored to a replacement drive if/when the original dies via the same method. Presumably inventing a simple SASI board to hang off a PC parallel port (say) is a lot easier than mucking around with the equivalent for floppy drives - or is the data rate still likely too low to cause timeout problems within the bridge board's firmware? I've got several Acorn, Torch and RML machines which use bridge boards and in most cases the tools needed to back up and restore data have long since vanished off the face of the earth (my RML fileserver's a particularly important one as it seems to be the only one left in the world) cheers Jules

18 years, 9 months

Any IBM Power / AIX fans out there?

by dwight.elvey＠amd.com

>From: "Jeff Davis" <jdaviscl2 at soupwizard.com> > >To pre-answer one question: no, I didn't get any operator keys for the boxes. > Are they difficult / expensive to find? If so, I'll go back on thursday and >dig thru the storage bins I found the machines in and look for a key... > >Jeff > Hi Take the lock to a locksmith. You might be surprised. I've not seen the one used on your unit but the local fellow here does them for $15 first key. Dwight

18 years, 9 months

Is this a PDP-8 card?

by rigdonj＠cfl.rr.com

I found a quad width card marked CESI VM816. It appears to be a memory card and has four rows of twelve IC sockets. The first row has 7 TMS4044-20NL ICs (4k x 1 SRAMs) in it and the second row is fully populated with the same ICs. The other rows are empty. There is an 8 position DIP switch as the end of each row of sockets. Does anyone any docs for this card or know anything about it? Joe

18 years, 9 months

SASI device <-> PC ?

by ajp166＠bellatlantic.net

> >Subject: Re: SASI device <-> PC ? > From: Jules Richardson <julesrichardsonuk at yahoo.co.uk> > Date: Thu, 30 Jun 2005 19:45:19 +0000 > To: cctalk at classiccmp.org > >On Thu, 2005-06-30 at 12:14 -0700, Lyle Bickley wrote: >> It's been a while since I used the controller, but IIRC it was an old ISA >> controller card like a WD7000 or Seagate ST-01/ST-02. Any early SCSI-1 >> controller should do - that was before SCSI became "smart" - and the >> messaging between the controller and the device (HDD) was minimal. A SASI >> device on such a controller will respond "well enough" to "look like" SCSI-1. >> >> As I said before - DO NOT mix a SASI device with a SCSI device on the same >> controller - or strange things can happen (don't ask). > >Yep - far as I remember, SASI's single target only, so I expect if you >have a SASI target on the same bus as a SCSI target all sorts of things >would happen! :-) > >Most classic SASI controllers seem to be little more than a handful of >buffer and latch ICs though (only about 6 chips total) - hence I was >wondering if someone had chucked together something to hang off a PC >parallel port (and just drive it all in software). Not especially >complex - my worry would be that the SASI target would timeout on >certain ops if the PC parallel port isn't quick enough though. > >cheers > >Jules The deal is that SASI is almost SCSI.. the differences are very small at the hardware level (interface). However the protocal and instruction set of the SASI bridge controllers is different from SCSI. That difference in instructions and protocal does not allow for mixing the two nor simple substitution of one for the other. SCSI was not standardized till the late 80s so there are a number of SASI/SCSI devices that predate the widespread acceptance of SCSI. There are a few systems that have a SCSI interface that were SASI or SCSI subset (DEC uVAX2000 for one). I've also done the reverse, used SCSI on older SASI machine but, it required a new bios to even talk to the SCSI disk. The later was due to the SCSI vs SASI bridge board (Xybec) instruction/protocal differences. Allison

18 years, 9 months

DEC M971??

by rigdonj＠cfl.rr.com

Anybody know what this is? It's a single width card with four resistors and a cable mounted on it. Joe

18 years, 9 months

DEC M912?

by rigdonj＠cfl.rr.com

Anybody know what this card is for? It's marked I/O Bus Conn Card. It's a double width card and has four rows of solder points and no handles> It's NIB. Joe

18 years, 9 months

Someone with an RML380Z....

by julesrichardsonuk＠yahoo.co.uk

If you have the original 40 column board, can you take a look inside and see if the 5th IC in from the right on the top row of chips (first one in after the DRAM) is a 74LS158? All the schematics show this as being a 74LS157 but it's got an LS158 on my board (which IIRC inverts the outputs). If the schematics are wrong I'll scribble a note on the copies that I have! (I'm trying to trace a fault on my board which is resulting in corrupted screen memory, and having the schematics disagree with the actual board is annoying! :-) cheers Jules

18 years, 9 months

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test-drb June 2005