test-drb January 2014

test-drb@ccmp.vtda.org

224 participants
263 discussions

by bob＠jfcl.com

Does anybody have a source or replacement for LA120 DECwriter III ribbons? I've actually got about 8 "new old stock" ones, still shrink wrapped, but all that I've tried are pretty much dried out despite the shrink wrap. They barely make a mark on the paper, even with the little print impression lever cranked all the way up. Thanks, Bob

10 years, 5 months

Apple Lisa, for those that asked

by sales＠elecplus.com

The Apple Lisa is complete, does not appear to be screen burned. Includes hard drive and floppy drive and keyboard. Somewhat yellowed due to age. Does NOT power on, no repairs attempted. (Is there someplace else to turn it on, besides the white square button above the keyboard jack?) Cindy Croxton Electronics Plus 1613 Water Street Kerrville, TX 78028 (830)792-3400 phone (830)792-3404 fax AOL IM elcpls _____ No virus found in this message. Checked by AVG - www.avg.com Version: 2013.0.2805 / Virus Database: 2634/5952 - Release Date: 12/11/12

10 years, 8 months

6809 SBC

by lynchaj＠yahoo.com

http://classiccmp.org/pipermail/cctalk/2010-January/282022.html It always suprised me that hre BBC micro used the 6502 rather than the 6809. By the time the Beeb was designed, Acorn had made a 6809 processor board for their System machines, so they must have had experience with the chip. THe Beeb is nice, but a Beeb with a 6809 processor would have been something else :-) -tony Hi! When I designed the N8VEM 6809 host processor it is loosely based on an article I read for the BBC computer called "Dragon in the tube". I am not very familiar with the UK microcomputers but apparently 6809 "coprocessors" were fairly common peripherals on their Z80 and 6502 designs. I used a similar concept for the N8VEM to allow its Z80 SBC to access the 6809 as a "host processor" peripheral on the ECB. One of the builders was able to get CUBIX running on the N8VEM 6809 host processor using the Z80 as its "IO processor". However, I can see how the implementation can get confusing because it is either a Z80 based system with a 6809 coprocessor or a 6809 based system with a Z80 IO processor. In reality it doesn't really matter but it's a matter of perspective. The N8VEM 6809 CUBIX implementation allows the use of ECB peripherals like IDE, video, floppy, serial, parallel, etc but it requires the Z80 to serve all the IO based on 6809 commands. I added the 6809 IO mezzanine board (power, ACIA, PTM, 2 VIAs, expansion bus) to give builders the option of using the 6809 host processor as a stand alone computer or to add separate IO to the N8VEM system when connected to the bus. The idea being to let the 6809 host processor interact with the outside world using its own IO and only involve the Z80 when absolutely necessary. The hardware seems to work OK but we'll see where the software goes. I think with CUBIX the 6809 N8VEM system becomes a lot more practical. The IO mezzanine fits on top of the 6809 host processor. You can see some photos here. These are out of date but give a good idea. Recently I fitted an improved serial cable and the nylon standoff hardware. Also the PTM seems to be working and that's good. http://n8vem-sbc.pbworks.com/browse/#view=ViewFolder&param=m6809 I have many 6809 host processor and IO mezzanine PCBs so if anyone is interested please let me know. This would be a great opportunity for anyone who would like to do some 6809 hardware and software hacking. I think the N8VEM 6809 host processor is the only system I am aware of other than Dave's homebrew that is running CUBIX. There maybe some other homebrew systems out there too I can't find them after some searching. Thanks and have nice day! Andrew Lynch

10 years, 8 months

WTD - 40-track (360K) 5.25in floppy drive

by classiccmp＠philpem.me.uk

Hi guys, I'm trying to get my hands on a 5.25in double-sided 40 tracks per side "360K" floppy drive with the Shugart or IBM PC 34-pin connector (either edge connector or pin header is fine). Does anyone have a spare they'd like to part with? Slight preference for Teac or Mitsubishi, but anything will do at this point. I've checked Ebay, there are tons in the US (complete with "seller does not ship internationally, don't even ask"), but the only ones I've seen >from UK sellers are parts scalpers wanting stupid money for them (?149 "sold untested with no guarantee"? really?). A BBC Micro 40-track drive would also be fine -- as long as it's native 40-track, not 40/80 track switchable or double-stepping (an 80-track drive mated to a PCB which double-steps the head). Cumana, Viglen and a few other companies made these, they were extremely common a few years ago. I'm on the verge of getting DiscFerret write support working (at least for UNIX PC disks) but the sodding thing won't read anything my 80-track drives have written! I'd rather not borrow the 3B1's drive - the DiscFerret is experimental and a benchtop lashup is hardly an ideal scenario. Thanks, -- Phil. classiccmp at philpem.me.uk http://www.philpem.me.uk/

10 years, 8 months

SCSI2SD

by aek＠bitsavers.org

Just saw this on Erik's web site, and hadn't seen it mentioned here http://www.codesrc.com/mediawiki/index.php?title=SCSI2SD Currently getting around 900kb/sec R/W

10 years, 10 months

minimum temps for running old hardware?

by jules.richardson99＠gmail.com

We're all reasonably aware of the tendency for vintage hardware to get a little flaky if it's too hot - but what about the other side? I expect that the electronics aren't particularly troubled by the cold, but what about tape units, floppy drives, hard drives, magnetic media? When is it too cold for them to work reliably? cheers Jules

10 years, 10 months

Easiest way to get MAINDEC diags onto a PDP-8 (sans paper tape)

by cramcram＠gmail.com

Hi, I've been bringing up a PDP-8a system over the past few months. It has 2 x TU56 (TC08 controller), 3 x RK05J and a 3rd party RX01 dual floppy. The processor itself is an 8e board set w/EAE and 32K core. As for media I have 7 RK05 packs, one floppy and about 60-75 dectapes. My first attempt at booting was with the RK05. It took a ton of cleaning (and capacitor replacement/reforming) to bring up the 8, followed by cleaning one of the RK05 drives. (BTW, this stuff apparently was in the equvalent of a barn for at least 20 years by what I could see). Anyway I cleaned 2 of the RK05 packs that seemed most likely to be bootable media but no joy. The drive just seeks to cylinder 0 and sits there, although I think a data transfer *might* have occured. I suspect that all of the RK05 packs were for individual user backup. Apparently from the documentation I have this system at one time had a RL01 attached. Next I worked on the better looking of the two TU56's. I've got one drive shuttling okay; the other half has no torque in one direction; I suspect I need to replace yet another AC motor run capacitor. The TC08 checked out okay and I replaced all of the das blinken lights with new bulbs, it looks really cool. Then the big test. I picked out a tape that had a listing with it indicating that it was a system tape of some sort (Focal, editor, etc.) I toggled in the TC08 boot code (since my M8317 has the wrong boot roms for it) and hit run. The tape wound back to the beginning, reversed, seemed to transfer many blocks of data and then just spins in a loop. So the next step would obviously be to run some TC08/TU56 diagnostics but I don't have any way of loading them. If I had an RK05 pack with OS8 + diags on it that would work but I don't see that happening. Perhaps another alternative would be to get the equivalent on RX01 floppies from someone, but I don't even know if the floppy system works yet. So for now I think figuring out how to make a combo terminal emulator/raw data file thingy might be the best way to go. I'm thinking of putting a beagleboard to use for this unless anyone out there has a simpler/quicker solution. Suggestions anyone? Thanks, Marc

10 years, 10 months

accepting pre-orders for the S-100 Z80 CPU V2 board

by LYNCHAJ＠YAHOO.COM

Hi! We are about to do another run of our popular S-100 Bus Z80 CPU V2 board. This board can run in systems (with bus termination etc.) at up to 10MHz. Apart from all the then common features found on many older S100 Z80 boards (and being completely S-100 IEEE-696 compliant), it had an extremely clever and powerful ability to allow the Z80 to address up to 1 MG of RAM in 16K "windows" within the Z80's address space. This is described here:- http://www.s100computers.com/My%20System%20Pages/Z80%20Board/Z80%20CPU%20Boa rd.htm Its primary importance is that it can be used to address greater than 64K of RAM for CPM3 and that it can be used to load/examine 8086 code at the top of the 1MG address space. The new "V2" version of the board now has the ability to (under software control) dynamically switch between two 4K blocks of code in its onboard 28C64 EEPROM (or EPROM) yet still only occupy 4K in the Z80's 64K memory space. This in effect almost doubles the size of a possible Z80 monitor. The extra code (currently being written) will include things like directly downloading binary files from a PC into the Z80's 64K (or 8086's 1M) address space. In addition, the S-100 Z80 CPU V2 has the ability to use an external CPU clock from an external source (S-100 bus pin 66 aka NDEF3). This is essential for CPU to video synchronization for MSX compatibility particularly in games. There will be a corresponding ability to export a CPU clock signal on the next version of the S-100 VDP board although this could come from any S-100 board. Current owners of the V1 board can just switch the IC's to this new bare board. The S-100 Z80 CPU V2 PCBs will be $20 each as per the usual arrangement. Shipping in the US is $3 for a single PCB and $2 for each additional PCB. Shipping internationally is $12.75 for a single PCB and $3 for each additional PCB. This is for the bare basics USPS first class postage with no tracking or insurance. The builder assumes all risk of delivery as per usual arrangement. My preference is to sell these PCBs to vintage computer/home brew computer/classic computer hobbyists first but if there are any remaining boards I will put them on eBay. Please send a PayPal to LYNCHAJ at YAHOO.COM with the subject "S-100 Z80 CPU V2 board" and I will reserve your board(s). I need about 20 pre-orders to warrant a manufacturing run. I will post more information as it becomes available. Thanks and have a nice day! Andrew Lynch

10 years, 10 months

Papertape Source (was: Re: Request for purchase of ASR-33)

by bobvines00＠gmail.com

On Sat, 11 Jan 2014 16:14:31 -0800, "Mark J. Blair" <nf6x at nf6x.net> wrote: [snip] > > * I'm having trouble finding 1" wide paper tape for my machine. It came with a small bit of black paper tape, and I see a single expensive roll of dark-colored 1" tape on eBay. I'd like to get a few rolls of plain old oiled paper tape in 1" width with a 2" core. There are several listings for narrower tape on eBay, but I'm not seeing the 1" width that I need. I'm looking forward to filling that chad box... > > * Last, but not least, I will naturally need a suitable computer such as a PDP-8 to go with it! :) > [snip] > > -- > Mark J. Blair, NF6X <nf6x at nf6x.net> > http://www.nf6x.net/ Mark, Try westnc.com at http://www.westnc.com/paper-tape-rolls.html#tty for papertape. They have both oiled & unoiled 1-inch paper tape, but recommend the oiled tape for ASR 33s. A 1/4 case of oiled papertape (7 each 1000-foot rolls) may be affordable to you at $92 plus shipping. (And they have rolls of paper for the Teletype's printer too at $112 for a case of 12 rolls, plus shipping.) Good luck on finding a PDP-8 to go with it though. :) Bob

10 years, 10 months

AT&T UNIX PC - default interrupt/break key

by classiccmp＠philpem.me.uk

Does anyone know what the default BREAK/Interrupt key combination is on the AT&T 3B1 / 7300 UNIX PC? I was expecting Ctrl-C, but that doesn't seem to do anything. (I'm trying to kill off a long-running task which I've lost patience in ever completing!) Thanks, -- Phil. classiccmp at philpem.me.uk http://www.philpem.me.uk/

10 years, 10 months

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test-drb January 2014