test-drb March 2005

test-drb@ccmp.vtda.org

291 participants
840 discussions

Catweasel opinions, sources of info etc.

by dwight.elvey＠amd.com

>From: "Vintage Computer Festival" <vcf at siconic.com> > >On Wed, 9 Mar 2005, Jules Richardson wrote: > >> On Tue, 2005-03-08 at 20:40 -0600, Jim Leonard wrote: >> > Or, you could try a simple parallel cable and Disk2FDI: >> > http://www.oldskool.org/disk2fdi >> >> How does that work? From past discussions on this list, the PC parallel >> port isn't fast enough to sample the bitstream from a floppy drive... > >It doesn't work over the parallel port: it uses the actual PC floppy drive >to read GCR disks natively using an incredibly clever trick. Read the >information in the downloads on how it works. You can get the trial >version for free, but it requires two drives to work. > Hi Wow! Clever trick. Once the controller starts dumping the sector, you just switch drives on it. Running it until it completes. It just thinks it is a big sector. I wish I'd thought of it first. Dwight

19 years, 4 months

Must have books for Vintage Computing

by tyger69＠chartermi.net

I'm building my personal library for vintage computing. I need to probe the collective wisdom of the list in what books must a "wannabe" collector (like me) should have on his/her bookshelf. Although I collect primarily DEC stuff, I don't want my knowledge to be just restricted to what DEC had to offer. p.s. Don Lancaster's books are the first on my list. :-) /wai-sun Lancaster's TTL Cookbook is a great place to start. The most indispensible book in my collection is _Bowker's 1985 Complete Sourcebook of Personal Computing_. This 1050-page (2.25" thick) buyer's guide is just loaded with information about the state of personal computing for that year. (I used to have the 1984 edition too, but I gave it away long ago). If you can get your hands on any of thier sourcebooks you will be very happy with it. A couple of other suggestions also come to mind. If you're at all interested in CP/M, then you should have The Waite Group's _CP/M Bible_ and it's companion book _The Soul of CP/M_. --T Jam the computer...trash every lethal machine in the land! --Timothy Leary

19 years, 4 months

PDP/8 on a chip implementation (Scott's post)

by Saquinn624＠aol.com

I'd be interested- couldn't start 'till we spring the kids for summer break, though. - Scott Quinn

19 years, 4 months

Catweasel opinions, sources of info etc.

by dwight.elvey＠amd.com

>From: "Randy McLaughlin" <cctalk at randy482.com> > >From: "Dwight K. Elvey" <dwight.elvey at amd.com> >Sent: Wednesday, March 09, 2005 12:34 PM >> >From: "Jim Leonard" <trixter at oldskool.org> >> ---snip--- >> >I should note that, since FDI images are 100% exact bitwise dumps, they >aren't >> >exactly easy to read (they're not nice clean formatted-track-and-sector >images) >> >so getting them translated back to an actual floppy diskette is not >currently >> >possible (since nobody has written the software to do so yet). >> ---snip--- >> >> It is not a matter of software. It is a matter of hardware. Unless >> someone can comes up with a trick, the controller won't do it. >> >> Dwight > >You might look at: > >http://www.rothfus.com/SVD/ > >It uses a PIC. It only has 256K of RAM right now but he is upgrading it to >1mb. > >I'm looking into using an eZ80 and a Flash card. By using track buffering >it is possible to emulate almost anything with very little RAM. > > >Randy > Hi Randy I'm familiar with Eric's work. I was stating that without specific hardware, writing these unusual formats is not possible with a PC. Eric's stuff is a good way to handle things. Does anyone know the specifics of what is different between the SVD format and the FDI's?. The SVD is an ASCII octal format. Is the FDI a binary or something? Dwight

19 years, 4 months

Three books added to collection

by paulrsm＠buckeye-express.com

--- Wai-Sun Chia <waisun.chia at gmail.com> wrote: > Any chance of these getting into bitsavers? > /wai-sun I hope not. Don is alive and still selling his books. -- Paul R. Santa-Maria Monroe, Michigan USA

19 years, 4 months

Mick & Brick's Bit-Slice MicroProcessor Design Re: Must have books for Vintage Computing

by dwight.elvey＠amd.com

>From: "Joe R." <rigdonj at cfl.rr.com> ---snip--- > > Another suggestion is Mick & Brick's book 'Bit-Slice MicroProcessor >Design'. Hmmm. I was getting ready to put some books on E-bay and I have ---snip--- Hi I was digging into some piles of things and came on some data sheets for a few of the 2900 chips. I think I have for the 2901 and 2911, as well as one or two others. If these are not already posted someplace, I can bring them to Al to put on his site. Dwight

19 years, 4 months

RLL vs. MFM

by ard＠p850ug1.demon.co.uk

> > No you can't use a RLL with an MFM controller. Similar but not the same. Sure you can. If the interface is the same (most likely the ST506/ST412 interface here), then you can use an RLL-capable drive with an MFM controller. You won't be able to read what's on the drive, you'll have to low-level format it, and you'll only get about 2/3s the stated capacity. But if you're trying to replace a hard drive in some old machine with an MFM controller and you happen to have an RLL-capable drive around, it'll work. -tony

19 years, 4 months

Bamboo computer

by dwight.elvey＠amd.com

>From: "Jim Battle" <frustum at pacbell.net> > >Ron Hudson wrote: > >... >> If the desert island has vines you could make a rope computer, as >> described in a >> Scientific American, I don't remember the issue. > >It was an april fool's issue, I believe. If memory serves, the island >was called APRLFUL or something like that. The article showed how, with >clever arrangements pullies, toggles, springs and such, inverters and >simple logic gates could be produced. Entertaining enough. > >The problem with that "computer" is that the logic gates have no gain. > >Each gate has no power supply other than the mechanical power of the >input signals (ropes getting pulled). For instance, say you pull an >input rope of a NAND gate one foot (OK, let's keep it metric) ten inches >:-) and the output rope moves nine inches, so the gain is 0.9. Put N of >these gates in series and the output signal is (0.9**N) of the input >signal. After half a dozen gates, very little is left at the output. >The rope gates had a gain much less than 0.9 -- probably 0.5. > >It is the same reason why computers aren't built of of just diodes and >resistors. You can have a gate or two in series, but then the signal >needs to be reconditioned before being applied to the next stage. > > Hi Relays work great. They have a lot of gain. Maybe much more than is needed for a computer. I've always wanted to build a calculator using marbles that are feed from a hopper and the addition of a manual lever to work as a clock ( and additional power ). Dwight

19 years, 4 months

Catweasel opinions, sources of info etc.

by dwight.elvey＠amd.com

>From: "Jim Leonard" <trixter at oldskool.org> > >Jules Richardson wrote: >> On Tue, 2005-03-08 at 20:40 -0600, Jim Leonard wrote: >> >>>Or, you could try a simple parallel cable and Disk2FDI: >>>http://www.oldskool.org/disk2fdi >> >> How does that work? From past discussions on this list, the PC parallel >> port isn't fast enough to sample the bitstream from a floppy drive... > >Not all are, but a few can. I believe the website has suggestions on $15 PCI >parallel port cards that are known to work. The distribution also has a speed >testing utility (doesn't require a cable to run). > Hi Most have some capacitors added to slow the signals down. One can just remove the capacitors. Then you need to worry a little about transmission line effects. Dwight

19 years, 4 months

TI-99 Stuff

by steerex＠mindspring.com

Hey gang, I've got a couple of TI-99 thingys that need a new home: 1.) Pair of joysticks 2.) RF Modulator 3.) Donky Kong game 4.) Star Trek game 5.) Speech Synthesizer >From what I understand, some of this stuff is hard to come by... So, I'd like to get something for it. Offers anyone? BTW: I'm in Western North Carolina SteveRob

19 years, 4 months

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test-drb March 2005