test-drb May 2008

test-drb@ccmp.vtda.org

199 participants
350 discussions

by technobug＠comcast.net

On Tue, 06 May 2008 07:53:52 -0500 Jules Richardson wrote: >> Jules Richardson noted: >> >>> Hmm, I've got a deep mistrust of any 'data over the mains' >>> technology, but >>> might that be an option here? I assume *most* of your systems are >>> physically >>> plugged into the mains anyway, so it'd meet the ideal requirement >>> for no extra >>> cabling. Data rates presumably not lightning fast, of course... >> >> I don't think security is of concern here unless you are extremely >> paranoid or are transferring prohibited material [...]. > > Ahh, no - on that note I meant 'mistrust' as in reliability. Running > data over > power lines always seems like the sort of thing that'd work in the > lab, but be > a little unreliable out in the real world with all sorts of 'noisy' > devices > plugged into the system. > [...] Actually the X10 home automation system is quite reliable as its longevity attests. Currently, broadband over power is being deployed in a number of test cities in the US (much to the chagrin of Hams - it tends to raise the noise floor in ham bands excessively) and the usual suspects are peddling home networking over the mains (e.g. <http://www.dlink.com/products/?sec=1&pid=561d >). To get around the noise issue, these systems use burst transmission at the zero voltage crossing point when line noise is statistically the least. As I mentioned previously, a number of folks make transceivers for this purpose. Echelon <www.echelon.com> has made their entire business based on this technology used mainly in commercial applications. <http://www.powerlinenetworking.co.uk/component/option,com_frontpage/Itemid,… > is a UK firm pushing the technology locally. IC transceivers are available from ST, Maxim, and SiConnect. The addition of a small micro to do the RS232, support logic, and power supply should make a useable system meeting Tony's requirements. CRC

16 years, 7 months

Interconnecting classic computers

by dm561＠torfree.net

Has anybody ever tried interfacing a modem to a cordless phone handset? It shouldn't be too hard to use a C/L phone as the wireless link between two modems. I believe Tony also has a NetCommander which would let him select which remote system to connect to and, with a few SS relays, even remotely turn the selected system power on and off. m

16 years, 7 months

Minimal CP-M SBC design

by dm561＠torfree.net

--------------Original Message: Date: Mon, 5 May 2008 21:21:49 +0000 From: Ethan Dicks <ethan.dicks at usap.gov> Subject: Re: Minimal CP-M SBC design On Mon, May 05, 2008 at 12:10:39AM -0700, Chuck Guzis wrote: > Hi Andrew, > > Just sitting here wondering why you're not using one of the enhanced- > functioning Z80 chips. Even going with the 64180 or Z180 would give > you 2 UARTS and an MMU, in addtion to 2 DMA channels and a timer. I can't speak for Andrew, but for me, I already have this SBC with CPU, some RAM, enough ROM, and a peripheral bus with 5 or 6 PIO chips, all in a package a little smaller than an Apple II PSU. -------------Reply: You might ask on comp.os.cpm; at least one person there claims to have installed CP/M on a printer buffer/sharer. m

16 years, 7 months

Interconnecting classic computers

by dm561＠torfree.net

-----------Original Message: Date: Tue, 06 May 2008 11:14:08 -0400 From: Sridhar Ayengar <ploopster at gmail.com> Subject: Re: Interconnecting classic computers To: General Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org> Message-ID: <482075C0.7020507 at gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed M H Stein wrote: > Has anybody ever tried interfacing a modem to a cordless phone handset? > It shouldn't be too hard to use a C/L phone as the wireless link between two > modems. With an acoustic coupler, or with a direct connection? Do cordless handsets carry the entire spectrum of sounds a corded phone does? Peace... Sridhar ---------Reply:----------- I was thinking direct connect; seems to me all you'd need is a small matching transformer and some attenuation. Bandwidth ought to be good for 1200 bd absolute worst case, but I'd be surprised if you couldn't go faster. More research is needed... m

16 years, 7 months

FS: SGI Iris Crimson

by silent700＠gmail.com

The time has come to move the big red box from my hallway (to make room for other big boxes, of course.) I was going to go straight to ebay but thought I'd offer it up here first. It's marked as a "Server" model but as been upgraded to "Elan" gfx, and I've got the replacement case badge for Elan. I've got one hard drive in there now which boots IRIX but fails looking for other volumes, so consider it ready to reload the OS. RAM is at 256mb. A few pics here: http://flickr.com/photos/chiclassiccomp/sets/72157604070207238/ Pickup only on this one, unless you're *really* serious about owning a Crimson :) I'm in 60074, NW of Chicago. -- j

16 years, 7 months

duh.... Tektronix 4010 has no microprocessor!

by djg＠pdp8.net

> I can probably coalesce them into a single PDF. How good are the > scans? > I think the scans are pretty good. The combining isn't the issue, I can easily do that. The last step of my scans is to flip though the document checking to make sure the scans are ok for each page, in the right order, remove scanning artifacts etc. Since you have the manual if you want you can do that. If not I will see if I can fit it in this weekend. > I am not sure if my scanner will get some of the larger diagrams all > in one image. > The one I scanned on can do 11x17 which I think fitted the foldout pages.

16 years, 7 months

Minimal CP/M SBC design?

by tshoppa＠wmata.com

Ethan asks: >From some recent reading of various materials I've been finding >as I do my research, it does seem that a lot of post-S-100 systems >had 56K or 62K of RAM and 2K or 4K of ROM, still. Since I don't >know specifics, let me ask a general question in the hopes that >someone can figure out what machines and answer accordingly... for >those 2K/4K ROM systems, did any portion of those ROMs get accessed >once CP/M was up, or were they vestigal at that point? I can imagine >some sort of monitor program or such being mapped in for when the >OS got lost in the weeds, but what was that ROM space still good for? You mention boot ROM's, but there's more uses that chew up "useful" address space too: A certain fraction of CP/M machines had memory-mapped video and this stopped them (or only through mapping trickery they got there) from having all 64K of RAM available to the user. For example, 24x80 of character-cell video will take up 2kbytes - add some video attribute bits (flash, blink, underline, bold for common video chips), and then the software (which has to be in either RAM or ROM, doesn't matter which because it will eat up some memory space in either event) to drive the memory-mapped graphics and you can have 4K or more taken up by the overhead of memory-mapped video. That 2K or 4K bytes doesn't have to actually eat up user RAM if it is accessed only via I/O space mapping. Some systems made good use of shadow-mapped ROM that was mapped in to do the actual BIOS (disk and terminal I/O) work and then mapped itself back out to give the user more RAM. This only affects a fraction of the "middle-aged" CP/M systems because the oldest assume a real video or hardcopy terminal at an I/O port, and the newest assume that a PC-clone is doing all that work for them, again at an I/O port :-). Tim.

16 years, 7 months

RM600 mainframe issues

by zampala0＠yahoo.it

Hi, I got a Siemens-Nixdorf Sinix RM600 mainframe consisting of a terminal and two cabinets, the SY53 (Zentraleinheit) and the BG54 (I/O Beisteller). For ease of transport I had to cut a 50-wire cable that was connecting the two cabinets, but now the cable has been put together again. Well, I fire it up and I see on the screen that it's going through a number of tests (cpu, memory, adapters). All is ok till it comes to the booting point. There it fails with the following complains Warning 51763 ios0/scon00 Poll fails. Command response block not valid Warning 33243 ios0/scon00 Controller initialization fails. Command response B SASH error: unable to access SASH root device ios0/sdisk000s0 /stand and it returns a limited SASH shell. Since I am assuming that the ios0/sdisk000s0 device is the hard disk on the I/O cabinet, I guessed that there was something wrong with my home-made replacement of the 50-wire cable. I power it down, go to lunch and get back to find out that, when turned on, random weird characters and symbols are displayed on the screen. It looks like that it entered a sort of editor mode, as it shows a top line in which rows and columns are counted. This top line reads ON LINE | FDXA | R=10 | C=5 | AUX=NONE After a while it hangs. I didn't touch a thing since my almost-ok first boot, I only remember to have played a bit with the console keyboard. Any ideas? shall I call the assistance number at the back of the unit? :-) thanks mirko

16 years, 7 months

C64 Cartridge disassembly (using MMC Replay w/RR-Net)

by billdeg＠degnanco.com

> >Strange question, but does anyone know how to get a C64 cartridge >case apart without breaking it? I have a bad "Epyx Fast Load" >cartridge, and need a case for my "MMC Replay" w/RR-Net. > >I still haven't really had time to do much with the MMC Replay, I >have managed to get a few things to run from it (the C1541 emulation >is pretty bad). I have managed to successfully get a DHCP lease for >the RR-Net, but haven't gotten it to talk to anything. I finally got >some of my floppies back out of storage (put them up on accident just >before I bought the MMC Replay, and I want to see about making and >writing out D64 images. Zane, If you heat the cart in the oven at a temperature less than that which will melt the case, but enough to melt the glue? I have had considerable adventures with this combo of hardware, here is a link that spells out the steps I took to interface my C128 (in c64 mode) using MMC Replay and RR-Net with the second Ethernet card in a PC formatted with WinXT. I can make a D64 image of a disk in less than 30 seconds. I prefer the c128 because after each image, I get better performance if I restart the C128 using the reset button (rather than have to power cycle the c64). I have a lot of the files you need on my web site, directions and links for the files you'll need are here: http://www.vintagecomputer.net/browse_thread.cfm?id=85 -Bill

16 years, 7 months

DECserver 90TL...

by ms＠vaxcluster.de

Hello, i found two DECserver 90TL last week at the local flea market. They seem to be in good shape, but i can't find the boot software for them - the file MNENG1.SYS should be all i need... The Digital Networks web site is no more, and after one week of googling and researching i give up: Does anybody where i can find this file? Greetings ms -- Michael Schneider email: ms at vaxcluster.de Germany http://www.vaxcluster.de "Man hat Gedanken, die bleiben ewig d?mlich..." (Campino)

16 years, 7 months

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test-drb May 2008