test-drb

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101090 discussions

by cclist＠sydex.com

I've been reading William Blair's 1807 article on cryptography, called "Ciper": http://www.jdege.us/crypto/blair-cipher.pdf Around PDF page 16, near the bottom of the first column, he proposes a code that represents letters of the alphabet, using the symbols a and b. What's interesting is that this is nothing more than a binary code, with A being aaaaa, H being aabbb and so on to Z being babbb. Is this the first mention of using a binary code to represent letters of the (Roman) alphabet? For the time, a remarkable document. --Chuck

15 years, 5 months

VAX 11/750 and Pyramid Technologies machine available in Brisbane, Australia

by sellam＠vintagetech.com

Hello All! See below. Please respond to original sender. Reply-to: <zzpeter at inbox.com> ---------- Forwarded message ---------- Date: Mon, 29 Nov 2010 05:20:22 -0800 From: peter ... <zzpeter at inbox.com> To: donate at vintage.org Subject: Re: old computers available Hi, I have a pyramid technologies computer, and also a Vax 11/750 (with many manuals, spare circuit boards, cables , monitors, tapes and misc parts)... which sadly I am unable to keep in storage any longer. Hence I am looking for a person or organisation to donate them to... The catch... I am in Brisbane (Australia), do you have a branch in Australia, or know of any group, or person in Australia that would be interested in taking care of these machines? Regards, Peter --- EOM -- 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 ]

15 years, 5 months

SCSI to IDE

by jlobocki＠gmail.com

Ok, so I have been doing research, and this affects everyone here who collects SGI, apple, and anything using scsi. in the near future, the supply of smaller SCSI drives will eventually dry up, due to failure from age and lack of supply, as I believe they are no longer manufactured, unless for the industrial/server market. I could be wrong on that part, but I take it as such because my searching for them brings up nothing new. what does that mean for collectors? it means that your neat little apple or SGI or etc will run, until the scsi disk dies, then we will be left cannibalizing machines for disks, paying ridiculous prices for leftover scsi disks, which will skyrocket because of the small supply. So what is our option? I have seen SCSI to IDE adapters around, but they go up into the $100's to $200's, say you have a minimum 10 machines, that leaves you somewhere between $1,000 and $2,000 total, before the disk or devices. If we could design a simple SCSI to IDE interface, we could be set for a good long while on storage for these devices for a decent amount of time. There are all sorts of adapters to IDE, there is CF to IDE, SD to IDE, SD to CF which could be placed in a CF to IDE adapter if need be, i'm sure one could also rig up a USB drive to SCSI if one tried, but I could be wrong. Having said that, I know nothing about programming microcontrollers or simple processors, but I have seen people on the board who do. I'm sure if we can find a chip capable, and lay out a schematic, source code, and possibly a board layout, members could source their own boards and components to build their own devices at home (given they have a chip programmer), so no one person has to take on the responsibility of supplying parts, kits, finished devices unless they so choose to. This is just an idea, if nothing becomes of it, no big deal, just putting it out there.... -Joe

15 years, 5 months

Deleted partition recovery

by Hollandia＠ccountry.net

A primary partition on C drive of one of my computers is gone. FDISK says that there is no partition on that drive. Is there any way to undo this without losing the information on that drive? I will of course need to do this from DOS...

15 years, 5 months

Sac State 8008 dumps online...comments welcome!

by bdamer＠digitalspace.com

CC-folks, What may be the earliest substantial surviving intel 8008 code (circa 1972) has been rescued from eight 1702 PROMs (thanks Dwight Elvey) and disassembled (thanks James Markevitch) and is now online for comment at: http://www.digibarn.com/stories/bill-pentz-story/8008-listing.html The team working on this is making their best guess that this was the particular code that controlled the Tektronix 4023 color raster display which in turn had boards in a card cage that controlled the other peripherals. Original SacState project initiator and leader Bill Pentz donated the surviving version of this system (consisting of boards and some documentation) a couple of years ago. One board contained the 1702s and we had no idea if there was anything still left in them. Surprise surprise there was! The full system and its story is described at: http://www.digibarn.com/stories/bill-pentz-story/index.html with a 3D graphical reconstruction of what it might have looked like (it drove a Diablo hard disk pack, ASR-33, serial interface, keyboard, Tek 4023). The history, the claims... So far with many folks weighing in, this might indeed be the "first" complete microcomputer system, with peripherals, a primitive OS, language and etc. It was built by Cal State Sacramento working with Tektronix and Intel, starting in the spring of '72 and getting stuff operational over the summer and fall of that year. As best as project leader Bill Pentz can recollect this system was processing 50,000 patient medical records and plotting color charts on the Tek by spring of '73. It also ran IBM BAL (370 mainframe assembly language programs) in emulation. We are still looking for someone who can peruse their backs issues of Popular Electronics from '73 and '74 to look for a brief mention of this project (anyone got a set?). So feel free to comment on the code. Note that for one eROMs there was either a bent pin or bad line -> bit 5 missing so its guesswork there. bruce

15 years, 5 months

IBM transistors and SMS cards

by wdonzelli＠gmail.com

I was cleaning up the estate of an MIT prof, and came across some Philco transistors with odd markings that I suspect were made for IBM. Generally, TI made the transistors for IBM, but I have seen a few SMS cards with Philcos on them. Philco transistors look a bit like bullets - about 1/2 inch long, and maybe 3/16 inch diameter, metal with a rounded top. Often the leads are insulated, as the spacing is very tight. I do not have any SMS cards with Philco transistors. Does anyone (CHM 1401 crowd?) have any they could inspect for me? I would like to know the numbers printed on the case. -- Will

15 years, 5 months

SCSI to IDE.htm

by lynchaj＠yahoo.com

SCSI to IDE joe lobocki jlobocki <mailto:cctalk%40classiccmp.org?Subject=Re%3A%20SCSI%20to%20IDE&In-Reply-To= %3CAANLkTinO5OZGqmp_tiokWNnqYD_e7AAwKDE7ALoG2_8%2B%40mail.gmail.com%3E> at gmail.com Fri Nov 26 10:48:01 CST 2010 * Previous message: AT <http://classiccmp.org/pipermail/cctalk/2010-November/294377.html> &T 3B1 Unix PC Boot ROMs * Next message: SCSI to IDE <http://classiccmp.org/pipermail/cctalk/2010-November/294385.html> * Messages sorted by: [ date ] <http://classiccmp.org/pipermail/cctalk/2010-November/date.html#294382> [ thread ] <http://classiccmp.org/pipermail/cctalk/2010-November/thread.html#294382> [ <http://classiccmp.org/pipermail/cctalk/2010-November/subject.html#294382> subject ] [ author ] <http://classiccmp.org/pipermail/cctalk/2010-November/author.html#294382> _____ Ok, so I have been doing research, and this affects everyone here who collects SGI, apple, and anything using scsi. in the near future, the supply of smaller SCSI drives will eventually dry up, due to failure from age and lack of supply, as I believe they are no longer manufactured, unless for the industrial/server market. I could be wrong on that part, but I take it as such because my searching for them brings up nothing new. what does that mean for collectors? it means that your neat little apple or SGI or etc will run, until the scsi disk dies, then we will be left cannibalizing machines for disks, paying ridiculous prices for leftover scsi disks, which will skyrocket because of the small supply. So what is our option? I have seen SCSI to IDE adapters around, but they go up into the $100's to $200's, say you have a minimum 10 machines, that leaves you somewhere between $1,000 and $2,000 total, before the disk or devices. If we could design a simple SCSI to IDE interface, we could be set for a good long while on storage for these devices for a decent amount of time. There are all sorts of adapters to IDE, there is CF to IDE, SD to IDE, SD to CF which could be placed in a CF to IDE adapter if need be, i'm sure one could also rig up a USB drive to SCSI if one tried, but I could be wrong. Having said that, I know nothing about programming microcontrollers or simple processors, but I have seen people on the board who do. I'm sure if we can find a chip capable, and lay out a schematic, source code, and possibly a board layout, members could source their own boards and components to build their own devices at home (given they have a chip programmer), so no one person has to take on the responsibility of supplying parts, kits, finished devices unless they so choose to. This is just an idea, if nothing becomes of it, no big deal, just putting it out there.... -Joe _____ * Previous message: AT <http://classiccmp.org/pipermail/cctalk/2010-November/294377.html> &T 3B1 Unix PC Boot ROMs * Next message: SCSI to IDE <http://classiccmp.org/pipermail/cctalk/2010-November/294385.html> * Messages sorted by: [ date ] <http://classiccmp.org/pipermail/cctalk/2010-November/date.html#294382> [ thread ] <http://classiccmp.org/pipermail/cctalk/2010-November/thread.html#294382> [ <http://classiccmp.org/pipermail/cctalk/2010-November/subject.html#294382> subject ] [ author ] <http://classiccmp.org/pipermail/cctalk/2010-November/author.html#294382> _____ More information <http://www.classiccmp.org/mailman/listinfo/cctalk> about the cctalk mailing list _____ -----REPLY----- Hi! I am willing to make a PCB and offer it as part of the N8VEM home brew computer project. If someone would send me a design I will be glad to make a schematic, PCB layout, and get a small number of prototype boards. This could be a simple circuit comprised of a Z80 with three 8255 PPIs, RAM and ROM (one 8255 for IDE, two 8255s for SCSI-2) or a more complex microcontroller scheme. Please contact me if interested. Thanks and have a nice day! Andrew Lynch

15 years, 5 months

cctalk Digest, Vol 87, Issue 54

by shawn.t.rutledge＠gmail.com

> So what is the Z80 card for? Apparently for running CP/M on a PC. http://books.google.com/books?id=gD4EAAAAMBAJ&pg=PA1 http://books.google.com/books?id=NjAEAAAAMBAJ&pg=PA1 http://pctimeline.info/ibmpc/index.htm 1982 March Xedex introduces the Baby Blue card (a Z80B processor on a plug-in card), allowing the IBM PC to run standard CP/M programs. Price: US$600. [346.92] [396.10] (April [9]) (Vendex company[346.93])

15 years, 5 months

Update on Epoxy Potting Removal

by scanning.cc＠gmail.com

Now that I have access to the main unit the plot thickens. All of the outputs of the potted brick go to full-wave bridge rectifiers in the main unit such that you get a plus and minus voltage reference to the CT ( center tap ). That big potted POS is nothing more than a big friggin transformer ! The main output leads ( 1 2 and 3 ) have 28 VAC coming out of them. I put a Variac on the " transformer " and turned it up very slowly. At not much voltage it gets very HOT ( I suspect shorted windings or a whole shorted primary on the input side. The 28 VAC output figure came from estimating proportionally what the output voltage would be with a full 115 VAC on the input primary. I own this puppy now !! Best regards, Steven

15 years, 5 months

MEK6800D2 restoration

by wim＠hackbox.be

> As somebody elase said, I think you have to read the data regiater too. Ok, I improved my test program to read the data reg and also give some visual feedback: LDAA #$10 ; like in JBUG STAA $8008 ; ACIA control STAA $8022 ; enable 1 digit leds LOOP LDAA #$7F STAA $8020 ; clear display READ LDAA $8008 ; ACIA status ASRA BCC READ ; data ready? LDAB $8009 ; ACIA data STAA $8020 ; display status LDX #$0100 ; delay DELAY DEX BNE DELAY CMPB #'G ; EOT? BNE LOOP SWI The idea is to light a digit for a brief period when a byte is read and have the segments show the status register. Also it should exit if it received the "G". Ok, the G may be *in* a data block but I hardly ever found a G anyway. At least it allows me to tune the volume until I receive something. But it looks random and looking at the leds, like half of the bytes read are framing errors. Obviously, I varied what I could think of (delay, "G", ...) used several recorders (2PCs with audacity, a real cassette deck and two audio cables) > I assume you have the manual for this evaluation kit. It's on bitsavers > if you don't. It explains how the cassette interface circuitry works in > some detail, and is well worth reading. Yes, I have the manual and read it through. > I asusme you intiialising the 6850 correctly, and that you're settign > that 4053 analoge switch properly,. If not, it can never work. I'm initialising it by writing $10 in the control reg, which I copied from the JBUG listing. I don't find any reference of a "4053" or similar in the docs of the kit. > Do you have a (real [1]) tape recorder? If so, try saving something. > Listen to the recording, does it sound like the typical 'burble'? And try > loading it. Point being if there's something wrong with how you're playing > the audio files you could have problems. Yes, dug up my Realistic cassette recorder that came with my TRS-80 but it didn't help. The samples I'm trying to load are recorded with the kit itself. They sound typical and I was able to decode them to binary. As a test, I decoded the jbug rom and compared it to the file from bitsavers. It matched! (except for 4 bytes near the end which are zero on bitsavers an are actually different on my rom). That made me conclude that the 'punch' function is working and the samples I'm using are good. I would like to test with a known-good audio file but I can't find any... I must point out that the kit is expanded and I haven't figured out what it is exactly. The wirewrap area on the processor board has two extra ACIAs and a crystal. I understand the original was a 614.4, this seemed to be replaced by 1MHz and the 614.4 used for the other ACIAs. Anyway, I already swapped them (which did make me type less double characters since I guess the keyboard scan delay is chosen for the original clock speed). The kit came with a Philips Mini-DCR and the cables seem to be made to connect that on the J1 I/O connector. I could go the route of restoring that, but it seems more challenging and it wouldn't allow me to transfer data with the outside world. But I'd like to get at least to the point that I can load and run a program without having to type it in... I also read that the kit allows to connect RS-232, that would be ideal but I don't see how that's possible without adding components and wiring. Wim.

15 years, 5 months

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