test-drb June 2007

test-drb@ccmp.vtda.org

224 participants
486 discussions

(another) Floppy disc reader status update and RFC

by classiccmp＠philpem.me.uk

Hi guys, Progress is going a little slower than I'd hoped.. I've been roped into working most of the past few weeks, so all I've got done is the final block diagram and part of the schematic. What I have got is a box containing ?200 worth of CPLDs, Molex connectors, and other parts I had to order from Digikey. What this basically means is that after I've got the schematic and PCB done, I can get a prototype built up within a day or so of finishing the PCB. Assuming, that is, I manage to etch the PCB without any bridged/broken tracks (especially on the CPLD and PIC, which are both QFP parts). So here's the final spec as I see it: - USB interface -- USB2.0 Full Speed (12Mbit/sec) - 40-pin disc interface connector. All outputs are open-collector -- the first 34 pins are wired exactly as the standard PC floppy connector is. The remaining 6 pins are all open-collector outputs with internal 680R pull-ups to +5V. The state of these pins can also be read back in, assuming they're set to 'output high' mode. - Replaceable bus drivers. 74LS07 O/C buffers are used - these are not generally ESD sensitive, and are rated to 20V over the outputs. All the buffers will be socketed and can be replaced easily in the field (as long as you have spares, that is). - Flexible triggering options: - Start of capture: - MFM sync word detection, with programmable sync word (*) - Rising or falling edge of index pulse - Hard-sector track mark detection - "Wait for N start events before triggering" option - Termination of capture: - MFM sync word detection, with programmable sync word (*) - Rising or falling edge of index pulse - Hard-sector track mark detection - "Wait for N start events before triggering" option (*): The capture CPLD only has one MFM sync detector, which is shared between the Start and Stop events. Note that the acquisition clock divider must be set correctly in order for the sync word detector to function. [ A future version of the CPLD may offer the option of independent clock generators for the sync detector and acquisition system - currently Facq is locked at 32 times the disc's bit-rate, e.g. 500kbit * 32 = 16MHz for 3.5-inch HD. This is a fairly simple mod, so I might do it before release, but 32*Fdata should be enough to get a usable scan ] - 128 kilobytes onboard high-speed SRAM buffer with end-of-capture-address storage. - Disc writes controlled by a simple microsequencer - commands are: - Wait N cycles and strobe WR_DATA - Stop writing - Open/close Write Gate - Wait for hard-sector track mark - Wait for N index pulses (where 1 <= N <= 31) - Onboard flash upgrading feature for both the main microcontroller and CPLD, with failed-flash recovery and forced-reflash options for both devices (as long as the bootloader is still intact). The boot block will also be protected against overwriting, to reduce the possibility of irrecoverable 'bricking'. - Multi-platform (Linux and Windows initially, OSX if someone ports it) programming library to handle disc read/write operations, including full source code and example 'dartutil' application. - Open-source hardware design, but with hardware available for purchase either fully-assembled or as a complete or partial kit (optionally with SMD parts soldered down). - Power supply: USB bus power or external 7-12V power supply unit. Can anyone think of anything else before I start drawing up the schematics? I'm also thinking about an extension to the ImageDisk file format to allow storage of raw MFM data, though I'm not sure how to go about doing this... creating a whole new format may be a better idea. So to recap, this is done: - Block diagram and outline design - CPLD code (all major functional units tested and working) And this needs doing: - Schematics - PCB layout - Prototyping I'm currently toying with the idea of moving the half-done schematic from OrCAD/SDT to KiCAD [<www.kicad-eda.org>] (on the basis that KiCAD is open-source, newer, and can do just about everything OrCAD can do), though I've not decided yet. Other suggestions (please don't suggest EAGLE...) will be given due consideration :) -- 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.

17 years

AMD2901s (was e: Inside old games machines,was: Re: Simulated CP/M-68K?)

by ajp166＠bellatlantic.net

> >Subject: RE: AMD2901s (was e: Inside old games machines,was: Re: Simulated CP/M-68K?) > From: "Antonio Carlini" <arcarlini at iee.org> > Date: Mon, 25 Jun 2007 21:58:01 +0100 > To: "'General Discussion: On-Topic and Off-Topic Posts'" <cctalk at classiccmp.org> > >der Mouse wrote: >> Ah. Then "undocumented (as far as I can tell)" here really means "I >> haven't found the right manual yet". >> >> I'll keep your message around and go digging for the scans you refer >> to some time when I have the leisure. Thanks for the pointer! > >Before I forget I should say that slipping "78032" into Manx gets >you the CPU Chip guide and the KA630-AA User's Guide (which is >equivalent to what was later usually called the CPU Technical >Manual). > >Antonio Then again there are odball hardware like the DEC ADVICE a MVII(78032) on a board for in curcuit testing and development. I'm still hunting for manual for that board or even a schematic. Allison

17 years

Bitmap images

by aliensrcooluk＠yahoo.co.uk

Hi, i was reading up on bitmap (mainly .bmp, with some .wbmp) images last night and was wondering why everything is stored backwards (e.g. BGR instead of RGB and the bottom of the image first, instead of the top)? Also would i need to pay a license if i wrote a program to create .bmp files? My main aim is to write a .bmp to (amiga) .iff format, but would love to add full .bmp support to an art program i wrote for the amiga and then stick it online (on Aminet.com ) for other people to use if they wish. - Andrew B (via mobile phone) --- cctalk-bounces at classiccmp.org <RodSmallwood at mail.ediconsulting.co.uk> wrote: > Yes definitly existed.. > Same case as a VT52. > Difference may have been > > a) 12 x 80 > b) Uppercase only > c) 20mA only. > > Rod Smallwood > DEC Terminals Product Line 1973 > > -----Original Message----- > From: cctech-bounces at classiccmp.org > [mailto:cctech-bounces at classiccmp.org] On Behalf Of Ashley Carder > Sent: 12 June 2007 18:28 > To: General Discussion: On-Topic and Off-Topic Posts > Subject: Re: Strange VT50 Decscope > > >> Are there any former DEC employees (or anyone else) here who have > ever seen or heard of anything like this? > > Richard said: > >I saw one of these for sale on ebay recently, advertised as a VT52. > > > This is the one that was on ebay. It was listed as a VT50. It also > came with the VT50 engineering prints and a VT50 manual. > > Ashley > > >

17 years

AMD2901s (was e: Inside old games machines, was: Re: Simulated CP/M-68K?)

by ethan.dicks＠gmail.com

On 6/19/07, woodelf <bfranchuk at jetnet.ab.ca> wrote: > Providing the word length is a multiable of 4 bits that is. It sure would be "fun" to debug microcode issues with nine of those puppies chained together. -ethan

17 years

VCF/Rocky Mountains?

by legalize＠xmission.com

Any interest? -- "The Direct3D Graphics Pipeline" -- DirectX 9 draft available for download <http://www.xmission.com/~legalize/book/download/index.html> Legalize Adulthood! <http://blogs.xmission.com/legalize/>

17 years

VCF/Midwest 3.0 - July 14/15

by pat＠computer-refuge.org

It's just 3 weeks until the third annual Vintage Computer Festival, Midwest edition. We've got a few interesting speakers lined up, and more to be added shortly. So come all ye collectors, see the speakers, and even exhibit your favorite items from your collection! We still have plenty of space to fill up with exhibitors. If you're interested in being an exhibitor, please sign up before Sunday, July 8th. Don't wait until the last minute, or there may not be space left! VCF/Midwest 3.0 will be July 14-15, at Purdue University's Stewart center. Speakers will run from 11a to 2p each day, and exhibits and the marketplace will be open from 2p to 6p. Admission is $5 per day for access to the whole event, and kids 17 and under get in for free. For more details, and to sign up as an exhbitor or vendor, please see the official VCF/Midwest 3.0 website at: http://www.vintage.org/2007/midwest/index.php If you have any questions, feel free to send me a message at: vcfmw at computer-refuge.org. Pat -- Purdue University Research Computing --- http://www.rcac.purdue.edu/ The Computer Refuge --- http://computer-refuge.org

17 years

What are the really unusual or weird computers?

by tshoppa＠wmata.com

My taste for the last several years is to play around with 1: dedicated industrial logic (e.g. elevator and machine controllers) 2: Analog computers 3: Electromechanical stuff, especially if somewhat programmable Now, none of the above are things with video screens and keyboards, and in most cases they don't even have readily recognized "instruction sets", but they all do computing in a pre-Von-Neumann sense. I heavily, heavily try to stay away from stuff with keyboards and video screens and, even worse, anything with an "operating system" of any sort! I don't want to have anything to do with installing software. I want to solder tube sockets, read meters, turn knobs, and watch scope traces. Tim.

17 years

removing epoxy potting, etc.

by rtellason＠verizon.net

Just wondering, do any of you guys know of something that'll remove epoxy potting compounds? Only suggestion I've seen so far is some pretty nasty acid that I really don't want to mess with.... -- Member of the toughest, meanest, deadliest, most unrelenting -- and ablest -- form of life in this section of space, ?a critter that can be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters" - Information is more dangerous than cannon to a society ruled by lies. --James M Dakin

17 years

Best solvent to remove sticky tape residue.

by aek＠bitsavers.org

> a citrus based liquid (orange juice I reckon) read the material safety data sheet for 'goo gone' the active ingredient isn't the citrus

17 years

My sale or swap list (Update)

by RodSmallwood＠mail.ediconsulting.co.uk

Well if you if you will pardon the expression, "Its heading in the right direction" I agree, the charges build up is a bit of an unknown. > 'has 1 cubic meter of volume and the first 1000 kilos' That seems to be a lot of weight in a small space. Port to port is less of a problem for me as the UK is that much smaller than the US. I can get to most of the UK ports in an hour or two. Thers a good chance that there's a service from US east coast ports to UK west/south ports. So... Boston to Liverpool or Southampton New York to Liverpool or Southampton. Etc. Rod -----Original Message----- From: cctech-bounces at classiccmp.org [mailto:cctech-bounces at classiccmp.org] On Behalf Of Mike Ford Sent: 11 June 2007 19:05 To: On-Topic Posts Only Subject: Re: My sale or swap list (Update) Rod Smallwood wrote: > Hi > I am curently investigating shipping costs between the UK and US. > As collectors we don't need next day delivery but we do need full > cover insurance. > > Don't go away. The cost is not that bad. > > Rod I'm looking at LCL oceanic shipping, its Less than Container Load, basically a rectangular box that fits about 20 to a container, has 1 cubic meter of volume and the first 1000 kilos is part of the base shipping cost of about $150. As usual lots of quicksand around the treasure, port fees, brokerage, customs, and its a port to port service, not terminal to terminal or door to door without adding a local ground shipper to the mix. Also its targeted to business, not private goods, so some places don't seem to want to even talk to a one time shipper. Complete and accurate paperwork seems essential. It does tend to be SLOW, as in couple weeks transit, with a month or more of sitting on a dock at either end.

17 years

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test-drb June 2007