test-drb

test-drb@ccmp.vtda.org

101090 discussions

by dm561＠torfree.net

-------------Original Message: Date: Mon, 18 Feb 2008 18:47:10 -0500 From: "Andrew Lynch" <lynchaj at yahoo.com> Subject: secondary FDC on PC with MS-DOS? Hi, I am building a test station using an old 486 ISA only computer to test floppy disk drives and old ST-506/ST-412 style hard disk drives. The computer seems to work OK and has a Western Digital ST-506 MFM hard disk controller with a FDC on the card (IO address $1F0). To help with testing floppy drives, I thought I would add a secondary FDC however that is turning out to be much more difficult than I planned. It seems there are drivers required to make floppy drives attached to the secondary controller appear as drive letters under MS-DOS. I searched around a bit and found SDRIVE.SYS which refuses to acknowledge any of the other FDCs I place in the computer at the secondary address (IO address $170). There are some references to a DC2.SYS program but I cannot find it anywhere online. http://www.seasip.info/VintagePC/floppies.html Does anyone know how to add multiple FDCs to a PC so I can have multiple floppy disk drives? Of course, the Compaticard IV would be nice but those are very expensive and almost unobtainable these days. I have a Compaticard I which "sort of" works but the drive gives errors every other time I access it. Thanks in advance for any help -- especially if someone could send me or tell me where I could find the DC2.SYS files. Andrew Lynch ------------------ You could also look for a 4-drive FDC with its own BIOS; I'll dig through the pile & see if I've got one to spare. Meanwhile, try asking on the Vintage Computer forums; there were some mentioned there recently. mike

18 years, 1 month

secondary FDC on PC with MS-DOS

by lynchaj＠yahoo.com

>From Andrew Lynch: > I searched around a bit and found SDRIVE.SYS which refuses to > acknowledge any of the other FDCs I place in the computer at the > secondary address (IO address $170). I/O port 0170H refers to the secondary *hard drive* address (the primary being 01f0H). The secondary FDC address is 037xH (the primary is 03FxH). Let me look around--I've got several old MS-DOS secondary port drivers kicking around here. A word of warning, however. For a secondary controller using the same DMA and IRQ (2 and 6) as the primary, the primary needs to have implemented the "enable" bit at I/O port 03F2H so it can float its own DMA and IRQ lines when the secondary controller is active. Not all controllers will do this, even though it's documented as part of the standard PC architecture. If you want to check out the operation of your secondary controller, hook a drive to it and find copy of FORMATQM or COPYQM (or 22DISK...) and set up a DISKETTE.CFG file for it to use. In the meantime, I'll look for a good driver. Cheers, Chuck -----REPLY----- Hi Chuck! Thanks to you and Mike S too for replying. I accidentally said $170 for the address but I really meant $3F0 and $370. I had been staring at these IO cards for a while and got confused. Sorry! The primary FDC am using ($3F0) is on a Western Digital ST-506/ST-412/FDC controller combo board. I have been using a variety of Multi IO boards trying to get the secondary FDC to work ($370). My plan is to share the DMA and IRQ lines which *should* work since I won't be using the drives at the same time. If you can find a driver which will let me access the drive from MS-DOS, that'd certainly be helpful. It is possible that the primary FDC is interfering with the enable bit but I will try the 22disk approach and see if that helps. I am kind of surprised this aspect of the project has been as much trouble as it has been. I would have thought the secondary FDC from DOS would have been well explored but there is practically nothing on the internet on the subject. This is easy in CP/M and seems like it would be in Linux too. I learn something everyday! Thanks for your help! Much appreciated! Andrew Lynch PS, I tried the 22disk approach and it worked like a charm. I think SDRIVE.SYS might be the problem. I was able to write a custom DISKETTE.CFG and format the disk in a CP/M format, copy files to it, and get a directory >from the drive attached to the secondary FDC. At least we know the hardware is basically good

18 years, 1 month

Does anyone have a high-res pic/scan of a Hayes Chronograph display?

by ethan.dicks＠usap.gov

Hi, all, I was digging through my Hayes Chronograph docs again, and was wondering if anyone out there has ever taken a high-res (1 megapixel or better) photo or stuck the display of their chronograph on a flatbed scanner. I've found several low-res pictures, but nothing hi-res enough to show the alarm and low-bat icons above the shorter digits. Thanks for any pointers, -ethan -- Ethan Dicks, A-333-S Current South Pole Weather at 19-Feb-2008 at 04:20 Z South Pole Station PSC 468 Box 400 Temp -38.6 F (-39.2 C) Windchill -69.6 F (-56.5 C) APO AP 96598 Wind 13.9 kts Grid 40 Barometer 675.8 mb (10787 ft) Ethan.Dicks at usap.gov http://penguincentral.com/penguincentral.html

18 years, 1 month

RFC: Floppy reader/writer project

by classiccmp＠philpem.me.uk

Hi guys, The USB floppy reader project is back on track as of about an hour ago. I've found a distributor who has a couple of Altera FPGAs in stock, and although it'll take a few days for them to arrive from Belgium, they were quite happy to sell me just five of them. For anyone that wants to look up the datasheet, they're Altera Cyclone II devices, p/n EP2C8T144C8N. Cost was ?11.58 +VAT. This nifty device also has a pair of onboard PLLs - which means I can put a relatively low-speed oscillator on the board, then boost the clock up to whatever the acquisition clock needs to be, and generate the 32MHz clock for the data separator / sync detector with the second PLL. Very cool. A quick does-this-work-or-not test build of the code I was using on the Xilinx chip clocked in at 5% utilisation of the Cyclone -- that means the final version will more than likely use a smaller chip (likely an EP2C5; the entry-level Cyclone 2). I'm still using the "time the length of the time between RD_DATA pulses" method for acquiring the data, but I'm increasing the acquisition clock so that the reader can measure the timing down to an accuracy of 50ns minimum (25ns with the 40MHz clock option). The counter is now 15-bit with an INDEX (index pulse was high at data bit leading edge) bit for every counter word. This gives a maximum counter period of 1.6384ms at 50ns, or 0.8192ms at 25ns... or a minimum bit rate of 610 or 1220 bits per second respectively. Maximum data rate is likely to be around 5-10Mbps. From what I've been told, the Trace disc duplicators had an accuracy of 50ns, which is where the base clock for the floppy reader came from (the SPS have based most of their data analysis on Trace duplicators, so the clock rates need to be close-or-identical). I've also scrapped the SRAM storage in favour of SDRAM. For the ?5 unit cost of the 256K*16 Cypress SRAM, I've managed to get a 4M*16 PC133 SDRAM chip. This gives a maximum track length of 4*1024*1024 (4194304) magnetic transitions; probably far more than any floppy disc ever made. Like I said before - the aim isn't to get an image with the intent of only decoding it (although the hardware can be rigged to do that). The aim is to be able to get as much information off a disc to be able to state that: - The data is accurate - The data is original (timing will differ between two drives -- if e.g. a high score table has been modified on a factory-written disc, the modification will be at a very slightly different data rate). Also, if you've only got one chance at reading a potentially-defective disc, you want to get as much information from that disc as you possibly can in the time you have. This is what I consider to be the spec at this moment in time: CPU: Microchip PIC18F4550 USB MCU at 40MHz (10MIPS peak) with Altera FPGA coprocessor / DAQ controller RAM: Micron Technology 4M*16 SDRAM Interfacing: USB Full Speed (12Mbps), RS232 as a jumper selectable option (115200 baud). Power: 5V DC from USB port, external supply required for drives Features: - Open-collector outputs, high-voltage (30V) tolerant - Over-voltage protected TTL level inputs with pull up resistors - Standard 34-pin drive interface, with 6 User I/O pins - Acquisition start/stop methods: - Both leading and trailing edge event triggers available (trigger-at and trigger-after) - Event Counters for all events -- wait for event to occur N times before triggering - Instant On (starts as soon as START bit is set, not valid for STOP) - Stops when memory full (always enabled) - MFM Sync word detector -- detects a 16-bit MFM word (e.g. Sync A1) - Index pulse -- typically start on leading edge, stop on trailing - Hard-sector track mark detector -- detects the double-pulse track marker and triggers from the index line - Fully reprogrammable -- boot-block protected Flash on PIC, 8Mbit Atmel DataFlash to configure FPGA. - Two user-selectable FPGA microcode blocks -- store standard FPGA code in one half of the DataFlash, and customised code in the other. - Fully open-sourced design -- hardware, software and HDL code -- basically under the "Wisp628 licence": - The design is open, so you can tweak, modify and play with it as you see fit - What you aren't allowed to do is sell kits, or pre-built units for profit. So if someone asks you to build one for them from scratch (i.e. not >from a kit), you can do so, as long as you only charge for the components you used to build it. - Software is GPL2 without the "or any later version" clause, plain and simple. So the inevitable questions from me: - Am I too late with this? Is it worth continuing and finishing the project? - If I said one of these boxes would cost ?75 (around the same as a Catweasel), would you buy one? - Are there any features you guys think I should add? - Does the licence sound too restrictive? I've put around ?300 into the project thus far, not counting time. I know I've got basically no chance of recouping all of it, but it would be nice to make at least some of that money back. Like the subject line says - this is a Request For Comments - I know I'm not going to please everyone, but I'd like to get as close as I can :) I've set up a mailing list at <http://mail.philpem.me.uk/mailman/listinfo/floppy-reader_philpem.me.uk> to carry announcements and discussions about the project -- saves cluttering up classiccmp with it (unless people would rather discuss it here?) Thanks, -- Phil. | (\_/) This is Bunny. Copy and paste Bunny classiccmp at philpem.me.uk | (='.'=) into your signature to help him gain http://www.philpem.me.uk/ | (")_(") world domination.

18 years, 1 month

Bubble memory devices

by dm561＠torfree.net

-----------Original Message: Date: Tue, 19 Feb 2008 00:13:18 -0500 From: Dave McGuire <mcguire at neurotica.com> Subject: Re: Bubble memory devices To: "General Discussion: On-Topic Posts Only" <cctech at classiccmp.org> <snip> I've always been a fan of bubble memory, although I have no functional bubble subsystems here. I've seen S-100 and Q-bus bubble memory boards (the latter I missed on eBay by a few dollars maybe a year ago), and there's at least one piece of test equipment made by Fluke (I don't recall which one) that uses bubble memory cartridges. I also have some brand new Sharp CE-100B cartridges, but no machine to use them in. -Dave --------------Reply: I've got the machine; want to get rid of one or two? mike

18 years, 1 month

Apple // europlus

by roger.holmes＠microspot.co.uk

On 19 Feb, 2008, at 18:00, cctalk-request at classiccmp.org wrote: > From: Tim Riker <Tim at Rikers.org> > > I'm not sure what a europlus version of the machine is though. The euro means 110/240 volt switchable power supply. I don't think there was any other change, though it was common to have a colour card (in slot 7?) which took the NTSC signal, decoded it and re-coded into PAL. I guess there was a corresponding SECAM card for France. As you probably know, the plus mean floating point Basic.

18 years, 1 month

Help identifying Mystery CDC Terminal

by cclist＠sydex.com

> From: Josh Dersch I actually used one of those at CDC ca. 1974-75. You got the good version--there was a version with a reduced linecount on it (8?). At Sunnyvale ops, we had a roomful of them connected to the STAR-100 Cyber frontend in Arden Hills. At the time, department policy wouldn't allow a terminal to reside on one's desk, so we had a "terminal room". I think we ran them at 300 bps from a 9600 bps link. I wrote the Star OGNATE text editor to operate with one of these--and to see how creative I could get with all of those great STAR string and vector instructions. Much to my horror, I found the editor still in use at ETA in 1985. (OGNATE, BTW, stands for "Oh G-d, not another text editor"). IIRC, the terminal was very "dumb". At the time, I was also project manager for the STAR remote MCU. The thing that I best recall was that the engineer at the Arden Hills end took forever to design his own UART from SSI. It ran at some oddball speed, like 1800 bps. Cheers, Chuck

18 years, 1 month

secondary FDC on PC with MS-DOS?

by cclist＠sydex.com

18 years, 1 month

TU10 tape drive restoration

by wacarder＠earthlink.net

>I am working on restoring a DEC TU10 tape drive for my PDP-8/E and want to >see if anybody has experience repairing them before I do too much to it. ...snip... >David Gesswein >http://www.pdp8online.com/ -- Run an old computer with blinkenlights I'm interested in following this restoration project. I have two TU10 tape drives. One is somewhat dismantled, but complete, and was used with a PDP-11/45. The other one is in the rack connected to an 11/40. Do you plan to keep some type of online log on your web site? Thanks, Ashley http://www.woffordwitch.com

18 years, 1 month

Seeking Mouse Systems driver MOUSESYS.COM

by sellam＠vintagetech.com

Does anyone have the Mouse Systems driver MOUSESYS.COM? This is for their early PC optical mice. If you've got it, can you please contact me directly? Thanks! -- 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, 1 month

Help identifying Mystery CDC Terminal...

by derschjo＠msu.edu

Hey all -- Picked up an old dumb terminal (and I feel secure in calling this one "old") today at Re-PC in Tukwila, WA (I'm starting to really dig this place...). It's a CDC, labeled on the back as a "Display Terminal" (go figure), Equip. Id #CC5A5-A, Series Code 2, Part #15551800. I haven't been able to find any information on this beast at all on the 'net. I've put up some pictures here: http://yahozna.dyndns.org/computers/cdcterminal/ (Haven't had a chance to clean it up yet, so it's kinda smudgy...) My favorite thing about this terminal is the huge, backlit buttons on the front for Power, etc... very cool :). I've powered it up after giving it a check-out, and it appears to work fine. I haven't hooked it up to a serial line yet, but that's coming... maybe Linux has a termcap entry for this thing? :) Opening it up reveals repair tags with dates in 1974. There are four PCBs mounted inside, connected by a ton of ribbon connectors (there's no backplane to speak of). Looks like it's all TTL, though I haven't taken the boards out to investigate. Not sure I want to disturb them :). Anyone know anything about this thing? What's it capable of? What was it originally connected to? Thanks! Josh

18 years, 1 month

Bubble memory devices

by aliensrcooluk＠yahoo.co.uk

Hi, Whilst waiting for a video to download (I'm still on dial-up) I decided to have a flick through an issue of 80 Microcomputing. It's issue 10 (October 1980) and inlcudes an article about the row about whether the US government and/or patent office should honour copyrights for computer software. Anyway, on page 46 I stumbled across an interesting article (called "A Slow Road To Bubble Memories") about bubble memory. The main bubble memory manufacturers of the time were Intel Corp., Texas Instruments and Rockwell Int. The article also mentions that Rockwell had a bubble system, a 256K bit board, available for $1,800. Meanwhile Intel had a bubble system in kit form - 7110-1 Magnetic Memory board came with all control and support circuitry - and sold for $2,000. What happened to bubble memory? Did it die out due to the costs, or did people prefer to use cassettes, disks etc. instead? Regards, Andrew B aliensrcooluk at yahoo.co.uk

18 years, 1 month

secondary FDC on PC with MS-DOS?

by lynchaj＠yahoo.com

Hi, I am building a test station using an old 486 ISA only computer to test floppy disk drives and old ST-506/ST-412 style hard disk drives. The computer seems to work OK and has a Western Digital ST-506 MFM hard disk controller with a FDC on the card (IO address $1F0). To help with testing floppy drives, I thought I would add a secondary FDC however that is turning out to be much more difficult than I planned. It seems there are drivers required to make floppy drives attached to the secondary controller appear as drive letters under MS-DOS. I searched around a bit and found SDRIVE.SYS which refuses to acknowledge any of the other FDCs I place in the computer at the secondary address (IO address $170). There are some references to a DC2.SYS program but I cannot find it anywhere online. http://www.seasip.info/VintagePC/floppies.html Does anyone know how to add multiple FDCs to a PC so I can have multiple floppy disk drives? Of course, the Compaticard IV would be nice but those are very expensive and almost unobtainable these days. I have a Compaticard I which "sort of" works but the drive gives errors every other time I access it. Thanks in advance for any help -- especially if someone could send me or tell me where I could find the DC2.SYS files. Andrew Lynch

18 years, 1 month

Bubble memory devices

by ajp166＠bellatlantic.net

> >Subject: Re: Bubble memory devices > From: ard at p850ug1.demon.co.uk (Tony Duell) > Date: Mon, 18 Feb 2008 22:52:51 +0000 (GMT) > To: cctalk at classiccmp.org > >> Anyway, on page 46 I stumbled across an interesting article (called "A >> Slow Road To Bubble Memories") about bubble memory. The main bubble >> memory manufacturers of the time were Intel Corp., Texas Instruments >> and Rockwell Int. The article also mentions that Rockwell had a bubble >> system, a 256K bit board, available for $1,800. Meanwhile Intel had a >> bubble system in kit form - 7110-1 Magnetic Memory board came with all >> control and support circuitry - and sold for $2,000. >> >> What happened to bubble memory? Did it die out due to the costs, or >> did people prefer to use cassettes, disks etc. instead? > >I think it pretty much died out due to cost and limited capacity. IIRC, >that Intel chipset was 1Mbit, or 128K bytes. And it was hardly cheap. >Bubble memory did get used in some portables, for example, since with no >moving parts it's pretty rugged. So the claimed. It was small, 128kb and largest was 512kb. It wasn't energy frugal the 128k board was something like 12W! It had a fussy startup and shutdown. and a 3.5" floppy at that time was new, expensive but bigger(360k) and lower power. Never really made prime time. I have two of them in a system that work well but speed is lower than 5.25 40track SD floppy and power is the same. Allison

18 years, 1 month

cctalk Digest, Vol 54, Issue 37 FS: Bytes and Interface Age mags

by trebor72＠execpc.com

cctalk-request at classiccmp.org wrote: > Today's Topics: > > 1. FS: Bytes and Interface Age mags (Jason T) > Message: 1 > Date: Sun, 17 Feb 2008 12:53:28 -0600 > From: "Jason T" <silent700 at gmail.com> > Subject: FS: Bytes and Interface Age mags > To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> > > Time to unload the last of my duplicates. Hello All; My collection of Byte Magazines begins with May 77 and runs thru Oct 84 with maybe a couple of Issues missing. 90 Magazines in all\Anyone Interested. Let me Know Bob in Wisconsin USE trebor72 at execpc.com

18 years, 1 month

Bubble memory devices

by ajp166＠bellatlantic.net

> >Subject: RE: Bubble memory devices > From: "Gavin Melville" <gavin.melville at acclipse.co.nz> > Date: Mon, 18 Feb 2008 15:11:19 +1300 > To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> > >Hi, > >Bubble was very, very expensive, and about that time SRAM was becoming >available. I don't have any complete 7110's left -- Intel took them >all back, but I do have the internals. Inside the various coils was a >garnet "chip" and under a good microscope you can see the Chevrons that >steered the magnetic bubbles. Really? I have two complete BKK72s operational. >The problem for the company I worked for at the time was temperature -- >at about 0 deg C all the bubbles wandered off. I still clearly remember >the Intel FAE telling me, with great conviction "you still have every >bubble -- none have been lost". My explanantion that that was of little >use -- I don't know which byte or address they belong to was lost on >him. Never tried them over temp. >Steering the little bubbles around was fun -- you could rotate the >majority loop, rotate the all minority loops, and replicate from one >loop to the other. Random access it wasn't... It never tried to be. Howver it was trying to fit in the floppy slot and at 128k for the smaller it was a tad small. >Because of supposed military uses Intel were REAL serious about security >-- they had to know where they all were, who the customers were etc. ??? Really. Never been so much as contacted. Allison >> -----Original Message----- >> From: cctalk-bounces at classiccmp.org >> [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Andrew Burton >> Sent: Monday, February 18, 2008 1:42 PM >> To: cctalk at classiccmp.org >> Subject: Bubble memory devices >> >> >> Hi, >> >> Whilst waiting for a video to download (I'm still on dial-up) >> I decided to have a flick through an issue of 80 >> Microcomputing. It's issue 10 (October 1980) and inlcudes an >> article about the row about whether the US government and/or >> patent office should honour copyrights for computer software. >> >> Anyway, on page 46 I stumbled across an interesting article >> (called "A Slow Road To Bubble Memories") about bubble >> memory. The main bubble memory manufacturers of the time were >> Intel Corp., Texas Instruments and Rockwell Int. The article >> also mentions that Rockwell had a bubble system, a 256K bit >> board, available for $1,800. Meanwhile Intel had a bubble >> system in kit form - 7110-1 Magnetic Memory board came with >> all control and support circuitry - and sold for $2,000. >> >> What happened to bubble memory? Did it die out due to the >> costs, or did people prefer to use cassettes, disks etc. instead? >> >> >> Regards, >> Andrew B >> aliensrcooluk at yahoo.co.uk >> >> >>

18 years, 1 month

Apple // europlus

by pdp11_70＠retrobbs.org

Hey guys, Someone gave me an Apple // europlus. I don't have any system disks for it at all. If I send someone a 5 1/4 inch disk or disks, would this kind soul send me a DOS 3.3 system master disk? Now if I could get that together, and find a super serial card, I could transfer software of disk images to it. Take Care, Mark

18 years, 1 month

TU10 tape drive restoration

by djg＠pdp8.net

I am working on restoring a DEC TU10 tape drive for my PDP-8/E and want to see if anybody has experience repairing them before I do too much to it. It was made in 1973 and probably last powered up in 1988. I have the maintenance manuals and prints for it. Though for some reason they don't have the 20 year idle maintenance procedure. Does anybody have a TU10 with a good capstan who can accurately measure the diameter or the coating thickness? Also does anybody have a 9 track 800 BPI alignment/skew tape? A bunch of the maintenance procedures use it. So far I have cleaned it and taken stock of its condition. The vacuum switches are bad but it looks like they are still made by World Magnetics so I should be able to get new. The markings on them don't exactly match the new parts so hopefully the manual 10" H2O is correct. If anybody knows more it would be appreciated. The capstan is past dead and seriously into decomposing. The price for a NOS one is scary. It is about 1.8" in diameter and directly moves the tape. Since this is a critical component to the tape path I suspect my skills with the do it yourself repairs will leave it too lopsided. Has anybody tried www.terrysrubberrollers.com. I saw a couple references on the list but didn't see any reports of results. It looks like he uses some black rubber which I don't know if it will have similar friction to the original. >From whats left it looks like the original capstan was translucent amber. The blower sound noisy when turned by hand. Plan to see if I can open and inspect. One of the reels doesn't turn easily. The manual has a section on cleaning the brakes so plan to do that. Plan to do the standard power supply checkout. A lot of the old equipment like this tape drive has parts with permanently lubricated ball bearings. So far I have decides that if the device sounds fine to leave them alone since it won't get that much use and taking it apart enough to get the bearings out has some risk. They also are sometimes pretty well sealed making cleaning and relubricated difficult. I have wondered how good 20-30 year old grease can be. What do other people do? Has anybody found a good way to relubricate these type of bearings to prolong the life? Or wait until they fail and hope the bearing assembly matches something you can buy? Thanks, David Gesswein http://www.pdp8online.com/ -- Run an old computer with blinkenlights

18 years, 1 month

SC/MP CPU (INS8060)

by doug＠stillhq.com

Hi, I am on the scrounge for a SC/MP CPU for a project I am working on. A search of ePay has failed to turn up any options. Does anybody here know of a supplier? Doug -- Doug Jackson, I-RAP, MAIPM, MIEEE Principal Information Security Consultant EWA-AUSTRALIA PO Box 6308 O'Connor ACT 2602 Level 1, 214 Northbourne Ave, Braddon ACT 2612 Tel: +61 (0)2 6230 6833 Fax: +61 (0)2 6230 5833 Mob: +61 (0)414 986 878 http://www.ewa-australia.com ============================================ IMPORTANT: This email remains the property of Electronic Warfare Associates - Australia. If you have received this email in error, you are requested to contact doug.jackson at ewa-australia.com or Ph +61 2 62306833 and delete the email. This message is not to be copied or distributed to other parties without the express permission of the author. Any personal information in this email must be handled in accordance with the Privacy Act 1988 (Cth). ============================================

18 years, 1 month

Anyone in Toronto Canada area with a Vax Magtape (reel) drive?

by dgahling＠hotmail.com

I should have posted this years ago. But does anyone on the list have or know someone (company or individual) that has a Magtape (reel) drive that can read an old Vax Magtape? I have about a half dozen tapes I'd like to get the data off, and it seems like a lost art. I'm not about to try and restore my uncles Wabash PDP hard disk though (external disk pack) I'd be willing to pay a small fee for time/trouble, though I'm not made of money. I'd rather trade equipment if there's something you need (sparc?) :) Dan. _________________________________________________________________

18 years, 1 month

VCF/Midwest 4 - Purdue - April 26-27

by pat＠computer-refuge.org

I just wanted to get the notice out there.. A date has been chosen for the 4th VCF/Midwest, and it's going to be on Saturday and Sunday, April 26th and 27th, and will be held again at Purdue University, in West Lafayette, Indiana. Sellam is working on getting the website set up, and hopefully it will be up soon. If anyone here is interested in doing a talk for this year's VCF/MW, please let me know. I'm working on a few leads for speakers right now. I also hope to have a piece of Big Iron from my own collection up and running at the show this year. Pat -- Purdue University ITAP/RCAC --- http://www.rcac.purdue.edu/ The Computer Refuge --- http://computer-refuge.org

18 years, 1 month

Oldest operational computer

by compoobah＠valleyimplants.com

On Feb 17, 2008, at 10:00 AM, Vince wrote: > But won't Tony refuse to *use* the TARDIS until it is documented > well enough for him to *repair* it :-)? That would be a good idea, don't you think, considering the chances of finding a factory authorized service center and spare parts in 1900?

18 years, 1 month

cctalk Digest, Vol 54, Issue 23

by roger.holmes＠microspot.co.uk

On 13 Feb, 2008, at 02:53, cctalk-request at classiccmp.org wrote: > > Have a HP N3390 laptop, 8 years old. An antique... > Are you kidding? My machine is 46 years old and that is a SECOND generation computer.

18 years, 1 month

RFC: Floppy reader/writer project

by classiccmp＠philpem.me.uk

Seems pacbell don't like my mail server (funny, just about everyone else does). Anyway, the questions Jim asked are probably ones that other folks want to know the answers to, so I'll post them here instead... Jim Battle wrote: >> It would be nice to have a 50 pin interface as well, for 8" disks. Well the idea is that you have the 40-pin connector, and make up an adapter cable for whatever drive you want to handle, then tell the software that (say) output 1 needs to be high when track_number > 46, or whatever you need. >> One problem is that a handful of the signals are non-standard. Ideally these signals would have a wirewrap header where one could wire them to +5, gnd, or perhaps to I/O pins on the FPGA under software control. Again, 50-pin cable to adapter board, which plugs into the FDR and converts the signals to suit the drive. >> Is this intended as a read-only interface, or read/write? *points at subject line* Read/write. >> For writing hard sectored disks, one has to initiate a given sector write >from the relevant sector hole -- you can't write the whole track starting from sector 0. This would imply some means of counting the sector holes, or at least a way in the data stream of saying: wait until sector 0, data, data, ..., data, wait until next sector marker, data, data, ..., data, etc, stop. Would you believe I've thought of that? :) The writing side of things is controlled by a small microsequencer (think 'special purpose CPU'). The instructions it can handle are: - Timer Load N - wait N clock periods, then write a flux transition - STOP - stop processing further instructions and halt the machine - Set Write Gate State - enable/disable the write amplifier - Wait for hard-sector index mark - Wait for N index pulses So typically you'd do this: WAIT_TRACKMARK ; sector 0 - wait for track start marker WRITE_GATE_ON TIMER_LOAD 123 TIMER_LOAD 42 ... WRITE_GATE_OFF WAIT_INDEX ; sector 1 WRITE_GATE_ON .. more write commands .. WRITE_GATE_OFF STOP Thanks, -- Phil. | (\_/) This is Bunny. Copy and paste Bunny classiccmp at philpem.me.uk | (='.'=) into your signature to help him gain http://www.philpem.me.uk/ | (")_(") world domination.

18 years, 1 month

RiscPC 610 PSU - 110 VAC?

by bear＠typewritten.org

Howdy, folks. I just acquired an Acorn Risc PC 610 from a chap in the UK. The PSU in it is labelled as a 220V-only affair. I understand there was an autoranging PSU revision, but this does not appear to be one of them. Does anybody have information on modifying this unit to work with 110V mains? Or a lead on a replacement PSU that has a switchable or autoranging input voltage? ok bear

18 years, 1 month

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