- test-drb@ccmp.vtda.org - classiccmp.org

by dgriffi＠cs.csubak.edu

While fantasizing having a PDP-11 of my own, I was reading about TRIPOS and decided that would be fun to play with. This line from the TRIPOS wikipedia article caught my attention: The most important TRIPOS concepts have been the non-memory-management approach (meaning no checks are performed to stop programs from using unallocated memory) Does this mean that any process is allowed to scribble anywhere in memory without provoking a segfault? -- David Griffith dgriffi at cs.csubak.edu A: Because it fouls the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail?

18 years, 2 months

4
4
0 0

Daystar Universal PowerCache & SE/30...

by trag＠io.com

>Date: Sun, 22 Jun 2008 19:51:17 -0700 (PDT) >From: Cameron Kaiser <spectre at floodgap.com> >> The Daystar SE/30 adapter has a Programmable Logic Device on board >> which massages the connections. The PowerCache will not work >> plugged in directly. > >Wouldn't a IIsi adaptor work? IIRC the SE/30 PDS slot and IIsi PDS slot >are electrically compatible (but don't take my word for it). Hi Cameron. Good to see you around. Yes, the IIsi adapter will work, except, it will point it's expansion slot horizontally where there isn't room for a card. So one needs to use an extra Euro-Din connector of the right-angle type to adapt it to vertical. No soldering is required, as the pins of the connector will fit nicely in the IIsi adapter's connector's holes. This is explained in clearer detail on Gamba's site. Jeff Walther

18 years, 2 months

1
0
0 0

Amiga Development System and Sage IV

by daviderhart＠oldzonian.com

>> I was recently contacted by a software developer that had an old Sage IV >> computer that needed a new home. He found me through my Sage and Stride >> website (http://www.sageandstride.org). He used the Sage IV in the 1980's >> as part of an Amiga Development System. > >Was it like this unit? > > http://www.floodgap.com/retrobits/ckb/secret/cbm-rlorr-agony.jpg > http://www.floodgap.com/retrobits/ckb/secret/cbm-rlorr-agony2.jpg > Yes, it's the same Sage IV model. I'm familiar with 'Agony'. I met Dale Luck last year and he let me get my grubby hands on Agony to help revive it (still ongoing...). I've added pictures of the Sage IV I just received to the group of photos of the Amiga Development System at: http://entertainment.webshots.com/album/563890692JxMvHh The Sage IV pictures are the last in the batch. >This is the one Dale Luck exhibited and was christened, in typical Amiga >humor, as "Agony." The rest of the developer prototype photos I have are >on > > http://www.floodgap.com/retrobits/ckb/secret/lorraine.html > >They look slightly different than yours, which seems to be a later version? > >> From the docs and what I've learned by talking to other early Amiga >> developers, the Sage IV was used in developing a lot of the early Amiga >> code. > >This is also my understanding. > >-- >------------------------------------ personal: http://www.cameronkaiser.com/ >-- > Cameron Kaiser * Floodgap Systems * www.floodgap.com * ckaiser at floodgap.com >-- Whenever people agree with me I always feel I must be wrong. -- Oscar >Wilde

18 years, 2 months

1
0
0 0

FS: MMJ plugs & cables

by given_todd＠wblake.com

Do you have any of the Amp plugs left? Todd A. Given Engineering Manager-Assembly Operations Whitney Blake Company Tel: (802) 463-1120 Fax: (802) 463-1111 given_todd at wblake.com

18 years, 2 months

1
0
0 0

George Carlin died :(

by sellam＠vintagetech.com

This is on-topic, I swear, as I'll demonstrate in a moment. But first, if you haven't yet heard, George Carlin died yesterday. For those outside of the US not familiar with his work, Carlin was an iconoclastic icon, and I use those terms explicitly literally in this case. The world will truly bu a suckier place without him. Today on Fresh Air (NPR talk program) Terry Gross ran old interviews with Carlin. In a 2004 interview (which I must've missed) he mentions that he enlisted in the military (he explains he did this to avoid the draft, i.e. the idea was he would get to choose what he wanted to do) and ended up in electronics and computers, and he specifically mentioned that he worked on analog computers. So besides being awesome, George Carlin was a hacker! LONG LIVE GEORGE!! Shit, piss, fuck, cunt, cocksucker, motherfucker, and tits!! -- 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, 2 months

1
0
0 0

Corestore - the Big Move

by mtapley＠swri.edu

At 12:00 -0500 6/22/08, Cameron Kaiser wrote: >Clearly his internal drives were hard. ...but warped, to the point of possibly causing a head crash. <smack> I did *not* just write that... -- - Mark 210-379-4635 ----------------------------------------------------------------------- Large Asteroids headed toward planets inhabited by beings that don't have technology adequate to stop them: Think of it as Evolution in Fast-Forward.

18 years, 2 months

1
0
0 0

Sun 3/60 for trade

by cclist＠sydex.com

> Date: Mon, 23 Jun 2008 07:36:33 -0700 > From: Lyle Bickley > If you're interested in vintage Sun gear - and it's not available in your > area - you might want to join the "Suns at Home" list. It's a low volume > list which keeps "on topic": The only vintage Sun gear that I own are a couple of coffee mugs and a couple of oddball (e.g. "The Last Bug") T-shirts. That's enough for me--at least both are still state-of-the-art in terms of utility. Cheers, Chuck

18 years, 2 months

1
0
0 0

Need Mac OS 6.0.4

by sellam＠vintagetech.com

I need Mac OS 6.0.4 in a format that can be downloaded with a PC (under WinXP), then moved to a disk that will boot on a Mac (IIci). Can someone help? If so, 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, 2 months

5
4
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Sun 3/60 for trade

by wdonzelli＠gmail.com

> Realistically "common as dirt" doesn't sound very accurate to me. I've only > ever seen one Sun 3 system, and that was one being used by the Navy back in > '92. This might be something like someone from near one of the old DEC > sites saying PDT-11's (note I said PDT, not PDP) are common as dirt. > > Remember commonality can be location based. Yes, in some parts of the country, Sun-3s of all flavors were extremely common. I just saw one at the MIT Flea last week. They are drying up now, but still easy to find with some legwork. Maybe "common as galena". -- Will

18 years, 2 months

1
0
0 0

Daystar Universal PowerCache & SE/30...

by trag＠io.com

>Date: Sun, 22 Jun 2008 01:19:33 -0700 >From: Josh Dersch <derschjo at msu.edu> >Subject: Daystar Universal PowerCache & SE/30... >To: cctalk at classiccmp.org >Message-ID: <485E0B15.1080706 at msu.edu> >Content-Type: text/plain; charset=ISO-8859-1; format=flowed > >Scored a nice find for 50 cents today, a 50Mhz 68030 Daystar "Universal >PowerCache" accelerator card. From my research on the web this should >be SE/30 compatible, but requires some manner of a PDS adapter which is >essentially impossible to find. > >The card won't physically fit in the SE/30 due to the metal chassis >getting in the way -- anyone know if this is the only reason the adapter >is needed, or are there electrical differences as well? As my SE/30 is >kind of a mongrel anyway I wouldn't mind hacking up the chassis a bit to >allow the card to fit, but if the adapter is actually necessary I won't >bother... The Daystar SE/30 adapter has a Programmable Logic Device on board which massages the connections. The PowerCache will not work plugged in directly. However, the connector will physically fit, so there's some good opportunity there for electrical drama if you manage to plug it in without the adapter. The PowerCache only works in the IIci, IIvx and IIvi (and corresponding Performa models) without an adapter. The same is true for the 68040 based Turbo040. There is a large amount of discussion on this topic at 68kmla.net. Also at applefritter.com, but less active. And searching in Google on Gamba and SE/30 will turn up a very useful page of information. There is a fellow in Japan who apparently reverse engineered the PLD and designed and built (or caused to be designed and built) his own adapter design. However, he charges $200 for his adapter. Given the costs and risks involved (he probably has ~$10,000 sunk in the project) it is a reasonable price to charge, but most folks do not think it is a reasonable price to pay. I think Artmix and Twinspark would be good search terms to turn that up. Jeff Walther

18 years, 2 months

2
1
0 0

Corestore - the Big Move

by mross666＠hotmail.com

Well, here's what happened: http://www.corestore.org/coremove.htm Some days I wish I had taken up stamp collecting... Thanks to all who volunteered to give a home to the Convex! Mike http://www.corestore.org _________________________________________________________________ Search that pays you back! Introducing Live Search cashback. http://search.live.com/cashback/?&pkw=form=MIJAAF/publ=HMTGL/crea=srchpaysy…

18 years, 2 months

24
41
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CP/M Z80 home brew computer circuit board

by lynchaj＠yahoo.com

> -----Original Message----- > From: Andrew Lynch [mailto:lynchaj at yahoo.com] > Sent: Friday, June 13, 2008 6:58 PM > To: 'cctalk at classiccmp.org' > Subject: CP/M Z80 home brew computer circuit board > > Hi, > > If anyone would like to make their own low cost home brew Z80 CP/M > computer please contact me by email. > > I have manufactured PCBs available for sale for $20 each plus shipping. > Preprogrammed EPROMs are also available for sale. > > The hardware and software are documented including schematics, source > code, binary images, PCB layout, parts list, etc. > > Details of the single board computer are available at: > > http://groups.google.com/group/n8vem > > Thanks! > > Andrew Lynch [AJL>] Hi All, Just in case anyone is still interested in building their own Z80 CP/M home brew SBC here is your opportunity. I have sold most of the PCBs in the first batch. As of this morning, I have less than 25% of remaining stock. I recommend that if you are going to order one of these PCBs then you should do it soon. I do not know if or when there will be another batch. If there is, it takes three weeks from my order to delivery and delivery to you is on top of that. Most likely, the demand for home brew / classic computer PCBs is fairly limited to a small group of enthusiasts. Ordering more PCBs at a practical unit cost is a delicate issue since I would like to get them out for people but also want to limit my personal expenses on this to a reasonable level. I do not expect to fully break even on the project but at least not lose my shirt on it either. Probably it means the next batch will involve a waiting list until there are enough people signed up to make the order practical. If anyone has better suggestions on how to do an amateur electronics project or a better idea, I am open to *constructive* input. I do appreciate your helpful comments. Please do not reply with "I don't like your project because..." Those comments aren't very helpful and IMO generally just contribute to the noise on CCTALK. Thank you in advance and have a nice day! Andrew Lynch

18 years, 2 months

1
0
0 0

INFOREX Core Memory Controller with DATARAM core memory cartridge / daughter card.

by billdeg＠degnanco.com

I received a box a while back containing an INFOREX Core Memory Controller >from late 1970 / early 1971 and a DATARAM core memory cartridge / daughter card. The DATARAM core is 4K I believe, but I did not open it to check. The box also contained a document (not the product docs) ranging from 1971-1978 about this type of 4K and 8K core memory, and some interesting pages about installing and using core memory with an S-100 data bus. It looks like the original owner was trying to figure out how to use this card. I assume that this particular DATARAM core memory could be used in both the pictured below DEC-like controller and a homebrew S-100 controller, but it was originally built for systems in the late 60's early 70's before the S-100 bus, etc... Given the condition of the card and memory, it's very possible that these components work. Now I just need a computer to put them in...hmmm. I have a basic idea of what the A, B and C card connectors do from some notes included with the board on a scrap of paper (assuming they're correct). For example pin 22 of connector A is a master reset, 25 is read enable, 26 is write enable. B 9 is a strobe and 13-19 are data in, etc. Let me know what info I can provide. I am not an engineer however. Pictures: http://www.vintagecomputer.net/inforex/ Can anyone shed light on the history/use of this? Thanks. Bill

18 years, 2 months

1
0
0 0

Listing paper FTGH (Yorks, UK)

by roger.holmes＠microspot.co.uk

On 21 Jun, 2008, at 08:52, cctalk-request at classiccmp.org wrote: > > Message: 33 > Date: Fri, 20 Jun 2008 22:12:04 +0100 > From: "John & Rachel" <john.haigh at zoo.co.uk> > Subject: Listing paper FTGH (Yorks, UK) > To: <cctech at classiccmp.org> > Message-ID: <000501c8d31a$4fa20dd0$4401a8c0 at JOHN> > Content-Type: text/plain; charset="iso-8859-1" > > Must be a common problem getting rid of spare paper. Did you get > any takers as I have some too. Anyone who was disapointed? Hi, Not disappointed, but Yorkshire is just too far away and paper is heavy so shipping is too expensive. If anyone in the Kent/Sussex/ Essex area has any cheap listing paper at least 13" wide (for a 120 column drum line printer) I would be interested. I am also interested in punched card drawers, paper tape cabinets, one more paper tape winder, an engineer who can repair IBM keypunches, 4mm patch cables for IBM patch panels (they have ball bearings in the plugs), an IBM keypunch control drum, data plugs or cables for connecting to IBM keypunches and Flexowriters. Any documentation or other items related to the ICT 1300 series, especially the mysterious 1302 would be a real gem to find. I have quantities of blank paper tape and blank punched cards if anyone needs them, though I am always on the look out for more in different colours so I can easily recognise programs at a distance. Roger Holmes

18 years, 2 months

1
0
0 0

Good Composite->VGA converters for classic computers (& video games...)

by derschjo＠msu.edu

Anyone out there use a composite->VGA upscaler for their classic computing and/or gaming needs? I've been looking to shave a bit of space off my workbench and just use a single SVGA monitor instead of that and an old composite monitor. I picked up one of these: http://www.amazon.com/gp/product/B000XXZQWQ and while it works great for certain systems (the C64 and NES, for example) it gets really confused by the composite signal coming from other systems (like the Apple II and Sega Genesis) and is unusable with them. Anyone have any recommendations? Thanks, Josh

18 years, 2 months

9
28
0 0

Daystar Universal PowerCache & SE/30...

by derschjo＠msu.edu

Scored a nice find for 50 cents today, a 50Mhz 68030 Daystar "Universal PowerCache" accelerator card. From my research on the web this should be SE/30 compatible, but requires some manner of a PDS adapter which is essentially impossible to find. The card won't physically fit in the SE/30 due to the metal chassis getting in the way -- anyone know if this is the only reason the adapter is needed, or are there electrical differences as well? As my SE/30 is kind of a mongrel anyway I wouldn't mind hacking up the chassis a bit to allow the card to fit, but if the adapter is actually necessary I won't bother... Thanks, Josh

18 years, 2 months

1
0
0 0

One tonne 'Baby' marks its birth

by ray＠arachelian.com

http://news.bbc.co.uk/1/hi/technology/7465115.stm One tonne 'Baby' marks its birth By Jonathan Fildes Science and technology reporter, BBC News Baby project team The four remaining members of the Baby team will be honoured in Manchester Sixty years ago the "modern computer" was born in a lab in Manchester. The Small Scale Experimental Machine, or "Baby", was the first to contain memory which could store a program. The room-sized computer's ability to carry out different tasks - without having to be rebuilt - has led some to describe it as the "first modern PC". <snip>

18 years, 2 months

2
1
0 0

Ted - Historian George Dyson tells stories from the birth of the modern computer -- from its 16th-century origins to the hilarious notebooks of some early computer engineers.

by ray＠arachelian.com

http://www.ted.com/index.php/talks/view/id/278 Historian George Dyson tells stories from the birth of the modern computer -- from its 16th-century origins to the hilarious notebooks of some early computer engineers.

18 years, 2 months

1
0
0 0

sell/donate: Wang Professional Computer in Columbus Ohio

by tosteve＠yahoo.com

------------------------------------------------------------ This is not my system, please email Martha if interested. ------------------------------------------------------------ From: Martha Shaw <mshaw at columbusschoolforgirls.org> Subject: RE: selling a Wang Wordprocessor Date: Wednesday, June 18, 2008, 3:45 PM I have a Wang word processor from the 1980's. I would like to sell it or donate it (take a deduction) if I can. It's called the Wang Professional Computer in it's manual which is copyrighted 1985. This one was used for training when the person who owned it worked at home and trained others when she worked for Wang. It works and has a printer, as well as 10 printer wheels and 11 ribbons. Martha Shaw ------------------------------------------------------------ This is not my system, please email Martha if interested. ------------------------------------------------------------

18 years, 2 months

3
2
0 0

IBM Switch assembly

by cclist＠sydex.com

> Date: Fri, 20 Jun 2008 20:45:45 -0700 > From: jim s > not impossible it's off a 1620. have you searched photos of it? Not a 1620--the system used a much wider row of switches and indicators. Not a 1401 or 7090 match either, from my memory, but could be a 704 power switch assembly. Cheers, Chuck

18 years, 2 months

2
1
0 0

photo of IBM lab?

by hardware＠ees1s0.engr.ccny.cuny.edu

Hello. I ran across this photo: http://w140.com/kurt/ibmlab2.jpg Do you think it is an IBM lab? What are they working on? thanks, -kurt

18 years, 2 months

5
5
0 0

big bucks for a Tek computer on eBay

by aek＠bitsavers.org

> apparently 6800 based. O woe is me. 322$ + 90$ ~$400 isn't 'big bucks' The days of getting this stuff cheap are LONG gone. The original 4051 used a 6800, 4052s simulate a 6800 with 2901s and are MUCH faster. 'posthuman' buys up a lot, along with 'futuresources' and 'wehavedealt', I wonder who they are?

18 years, 2 months

11
10
0 0

Looking for AMD9511 datasheet

by ragooman＠comcast.net

Would someone have a datasheet for the AMD9511 ? This is a FPU coprocessor from '79 =Dan -- [ "go get 'em" ] [ Pittsburgh --- http://www2.applegate.org/~ragooman/ ]

18 years, 2 months

4
5
0 0

photo of IBM lab?

by aek＠bitsavers.org

> What are they working on? IBM 705

18 years, 2 months

5
8
0 0

NEC D7220AD datasheet wanted

by ajp166＠bellatlantic.net

> >Subject: Re: NEC D7220AD datasheet wanted > From: "Seth Morabito" <sethm at loomcom.com> > Date: Fri, 20 Jun 2008 10:26:59 -0700 > To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> > Cc: "General Discussion: On-Topic Posts Only" <cctech at classiccmp.org> > >On Fri, Jun 20, 2008 at 7:14 AM, maurice smulders ><maurice.smulders at gmail.com> wrote: >> Make sure you google for uPD7220 (that's the NEC prefix) >> >> Maurice >> > >That was my mistake -- I kept searching for NEC 7220 and NEC D7220, >without the 'uC'. Couldn't find anything. Yes it would muck up the works. The part was uPD7220. I have a few and likely apnotes and all as well. Allison >I have a copy of it now, thanks! > >-Seth

18 years, 2 months

2
1
0 0

Looking for AMD Microprocessors and Peripherals data book(early 80's)

by ragooman＠comcast.net

Would anyone have this databook ? Looking for AMD Microprocessors and Peripherals data book(early 80's) This would contain the programmers reference for the AMD9511 fpu chip. I'm working with this chip and like to get a copy for this. thanks, Dan -- [ Pittsburgh --- http://www2.applegate.org/~ragooman/ ]

18 years, 2 months

1
0
0 0

request to post a message

by info＠vintagetechnology.co.uk

Hi, Could I please post the following message to cctalk? thanks. It's as follows: Title: July '08 Vintage Technology magazine is available Main text: July '08 edition of Vintage Technology magazine is now out and can be obtained from www.vintagetechnology.co.uk . Only ?0.99p / $1.99 for a 40+ page magazine devoted to the collection, preservation and history of all aspects of digital and electronics technology, including computers, arcade games, calculators, led watches, phones, appliances, gadgets and robots. This issue features: The first pocket computers Historic hypertext and how the WWW could have started much earlier The development of car driving games Vintage personal data-calculators Entex handheld games Cordless phones Flip clocks Merits of using traditional auction houses vs. eBay Commodore PET repairs Daisy wheel printers ZX Spectrum memories Plus sections on museums & collections, latest events & news and book reviews. VTM aims to explore the legacy of recent past technology, explore new 'electronica' which could become or already is collectible, be an enjoyable resource for collectors & historians and celebrate the history and personalities surrounding this subject.

18 years, 2 months

1
0
0 0

DEC H7441 Powersupply

by asholz＠topinform.de

Hello all, was there a similar manual for for the H7441 PSU available as for the H720 PSU (which can be found on bitsavers pdf/dec/pdp11/pwrSupply/H720_PowerSupplyMan.pdf )? If yey could someone provide a scan? --Andreas

18 years, 2 months

2
1
0 0

Westinghouse W1642 terminal... any info?

by ian_primus＠yahoo.com

I posted this over at comp.terminals, but I figured I'd send it out to this list too... I've just accquired a Westinghouse W1642 terminal, and I'm looking for any kind of documentation I can find on it. It's clearly somewhat of a single purpose terminal, originally used at airlines. The keyboard is weird, and is missing many "useful" characters, like brackets, slashes, pipe and comma. Instead, it has various weird symbols, command keys, and such. It has no shift key, and only displays upper case. It also appears to support multiple sessions, with keys to switch between them, and display a split screen mode. Typing in any of the sessions will echo to the screen, even with nothing connected. On the back are four female DB25 connectors - LINE/PRINT, PRINT1, PRINT2 and AUX. I've tried connecting it up to a computer and sending text to it, at 9600 baud. Connecting an RS232 cable to AUX causes the CTRL-DOWN indicator at the bottom of the screen to go away, but only for the full screen session. Sending random junk to the terminal through the serial port occasionally is able to bring up a message at the top, something about an invalid printer, but no other garbage displays. So far, I've only tried it at 9600 baud, I didn't have time last night to try other speeds. Inside the terminal seems rather conventional, I haven't dismantled it completely, but near each port is a 75154 (quad line receiver), and it appears that farther back on the board are other comms chips (socketed). I was expecting to see 1488/89 pairs, but haven't seen those in there yet. Two of the ports are on a daughter board, the other two are on the main board. The boards are partially hidden by the monitor chassis, and I've not pulled them out to look yet. There are some dip switches on the main board though. So.. basically, I know that this isn't going to be a great computer terminal, with it's lack of important command keys, (no ESC either!). That's too bad, since it's very well built, has a very nice keyboard, and a very sharp, clear screen. But, I would like to be able to do something with it, send text to it, use it as a console command monitor, something. Does anyone have any kind of documentation or information on this beastie? Thanks! -Ian

18 years, 2 months

4
4
0 0

Listing paper FTGH (Yorks, UK)

by john.haigh＠zoo.co.uk

Hi, Must be a common problem getting rid of spare paper. Did you get any takers as I have some too. Anyone who was disapointed? Thanks, John

18 years, 2 months

1
0
0 0

Apple I back up on ebay

by evan＠snarc.net

>>>http://www.brielcomputers.com/replica1.html That's been around for a few years. Catch up on your list messages from 2005. :)

18 years, 2 months

2
1
0 0

Apple I back up on ebay

by tiggerlasv＠aim.com

. . . . and, it has sold, for about $2000 . . . <Thud> (That was me passing out, from disbelief.) T

18 years, 2 months

9
13
0 0

NEC D7220AD datasheet wanted

by sethm＠loomcom.com

Folks, Does anyone have a NEC 7220 datasheet? I was just given two of these chips (D7220AD, 1986 datecodes), and was interested in tinkering with them. I have no earthly idea what the specs are, though, other than "graphics controller". -Seth

18 years, 2 months

5
5
0 0

RGB to VGA converter, your posting at classiccmp.org/pipermail/cctech/2005-March/041987.html

by giidii＠gmail.com

Hello, would your circuit work for RGsB to VGA, 1280x1024 resolution, to connect an old digital workstation to a TFT? thank you! best regards Gunter

18 years, 2 months

2
2
0 0

NEC D7220AD datasheet wanted

by dm561＠torfree.net

---------ORIGINAL MESSAGE: Date: Fri, 20 Jun 2008 09:32:24 -0400 From: Steve Stutman <steve at radiorobots.com> Subject: Re: NEC D7220AD datasheet wanted Seth Morabito wrote: > Folks, > > Does anyone have a NEC 7220 datasheet? I was just given two of these > chips (D7220AD, 1986 datecodes), and was interested in tinkering with > them. I have no earthly idea what the specs are, though, other than > "graphics controller". > > -Seth > Used these once in a Nav product. If you do not find data on Net, let me know. Believe I still have the book. Steve -------------REPLY: I also have it in Vol.2 of the 1987 NEC Microcomputer Products Data Book. It's 28 pages; unforch I don't have a scanner set up at the moment, but if there's no other source... mike

18 years, 2 months

1
0
0 0

NEC D7220AD datasheet wanted

by fjkraan＠xs4all.nl

cctech-request at classiccmp.org wrote: > Folks, > > Does anyone have a NEC 7220 datasheet? I was just given two of these > chips (D7220AD, 1986 datecodes), and was interested in tinkering with > them. I have no earthly idea what the specs are, though, other than > "graphics controller". > http://electrickery.xs4all.nl/comp/qx10/doc/nec7220.pdf or http://oldcomputers.dyndns.org/public/pub/rechner/epson/~fjkraan/comp/qx10/… > -Seth > > Fred Jan

18 years, 2 months

1
0
0 0

NEC D7220AD datasheet wanted

by cclist＠sydex.com

> Date: Fri, 20 Jun 2008 08:14:06 -0600 > From: "maurice smulders" > Make sure you google for uPD7220 (that's the NEC prefix) You can also look for the Intel 82720, which is the Intel-packaged version of the same chip. Both are on the web and the text for the datasheets and programming manual is essentially identical. Cheers, Chuck

18 years, 2 months

1
0
0 0

Earl(y|iest) recording of computer music

by roger.holmes＠microspot.co.uk

> Message: 28 > Date: Thu, 19 Jun 2008 21:41:57 -0500 > From: Jim Leonard <trixter at oldskool.org> > Sellam Ismail wrote: >> This is very cool: >> >> http://news.bbc.co.uk/2/hi/technology/7458479.stm > > Unfortunately, no mention of how the machine produced the sound... I expect it was the same as slightly later mainframes, every time a conditional jump instruction actually jumps, it flips the speaker to the opposite state. When single shotting a program this is useful as you can hear a click and know to not carry on down the list of instructions, and when a program is running you can hear the tone change as it does different tasks (because the size of the loops are different). My 1301 has a three of four instruction program which uses the variable delay of the multiply instruction to make a ghostly sound.

18 years, 2 months

1
0
0 0

Earl(y|iest) recording of computer music

by sellam＠vintagetech.com

This is very cool: http://news.bbc.co.uk/2/hi/technology/7458479.stm -- 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, 2 months

6
5
0 0

Low Cost EPROM programmer (Ben, this is for you)

by lynchaj＠yahoo.com

Ben, if you need a low cost EPROM programmer just go get yourself a junk PC (practically free) and for $20 on Ebay Buy-It-Now (or less if you are patient), get a Willem Programmer. Here is a link: http://search.ebay.com/willem-programmer_W0QQfromZR40QQfsooZ1QQfsopZ34QQsbrs rtZd Decent EPROM programmers are so cheap now as to be hardly an issue. These are super simple to use and practically disposable. They are amazingly durable and useful. They won't work with first generation EPROMs but anything 2716 or later is good. 2816s should be no problem. Good luck with your project. Andrew Lynch

18 years, 2 months

6
6
0 0

Free Compaq Portable II (?) from 1986 In Phoenix, AZ

by oldcomputers＠oldcomputers.net

Contact "dan goforth" if interested: godanphx at aol.com

18 years, 2 months

1
0
0 0

Corestore - the Big Move

by tiggerlasv＠aim.com

>> And FWIW, I am much more >> likely to want to see the computer than the person > > In other words, the photographer would have better engaged your > prurient interest if the person had obscured interesting parts of > the computer, rather than vice versa. Obscuring parts of the computer? With large feather-fans? Grape leaves? How avante-garde. How risque. Yet curiously titillating. Hehe. T

18 years, 2 months

1
0
0 0

AT&T 3B1 Unix PC

by korpela＠ssl.berkeley.edu

I have one as well. I think mine has the 7300 stamp rather than the UnixPC name. It's got the 8086 coprocessor board to run DOS apps. I have the dev kit, a few OS revs, and a pile of documentation. For it's time it was a pretty decent low-end workstation with a fairly good (non-X11) windowing system. Biggest problem was how slow it was at floating point, probably due to a crappy math library. I don't even think there was an option for a 68881. Since it was designed by convergent, the machine itself it a lot like the Convergent Miniframe (possibly even software compatible). The unix itself was pretty good with virtual memory and memory mapped files, but the max per-process address space was a 2MB which was also the max-RAM supported, IIRC. Eric On Thu, Jun 19, 2008 at 1:57 PM, Mark Tapley <mtapley at swri.edu> wrote: > At 12:04 -0500 6/19/08, Michael Lee wrote: > >> Anyone collect and/or need parts to the AT&T Unix PC? I've got a pile >> of systems I dismantled over a decade ago, and don't really want or know >> how to put back together. >> > > All, > I have a working one, and a fair amount of documentation. I have not > spent enough time with it to be considered any kind of "expert" but I may be > able to answer some questions. Hopefully someone more knowledgeable can pipe > up here. The systems seem pretty cool, although they are kind of rudimentary > as unix workstations. > > Michael, > where are you? I.e. where would shipping be from? > -- > - Mark 210-379-4635 > ----------------------------------------------------------------------- > Large Asteroids headed toward planets > inhabited by beings that don't have > technology adequate to stop them: > > Think of it as Evolution in Fast-Forward. >

18 years, 2 months

2
2
0 0

IBM 5120 in austin, tx

by frustum＠pacbell.net

A few years back I bought an IBM 5120, then I spent more money collecting some manuals. Sadly, I've never had the time to do anything with it, and I don't foresee doing so. Here is a picture of one and some info, directly from IBM: http://www-03.ibm.com/ibm/history/exhibits/pc/pc_6.html Now, this thing weights a ton (>100 lbs), and I don't feel like packing it and shipping it. It is in Austin, TX. Although I have about $500 sunk into it, I realize that by not shipping it my market is dramatically reduced. Therefore, I'll sell it for $250 if you can come and get it. It boots into BASIC and runs fine. Because I don't have the terminator, and because the internal floppy disks hang off that bus, they floppies won't work until you acquire or build a terminator. The machine also comes with a technical and user manuals, although nothing that isn't already on bitsavers, I believe. There are also four 8" floppies, including a diagnostic disk. Cosmetically it is decent, used but not too yellowed, except for an unfortunate cracked off corner in the rear, which I still have. Despite that defect, it is still a functioning unit.

18 years, 2 months

2
1
0 0

non-CP/M Z80 board

by ajp166＠bellatlantic.net

> >Subject: Re: non-CP/M Z80 board > From: ard at p850ug1.demon.co.uk (Tony Duell) > Date: Thu, 19 Jun 2008 04:42:01 +0100 (BST) > To: cctalk at classiccmp.org > >> > I think the chips under discussion were the 8085 specialty chips, >> > 8155, 8355, 8755, etc. Got tubes of those? >> >> I've got a dozen or so 8755s, two or three 8155s, and no 8355s. >> Not tube quantities, unfortunately. > >IIRC the 8355 was the mask-progeammed part, so it's not suprising you >don't have any of those, If you did, they proably wouldn't contain the >code you wanted :-). Yes, but it' still useful as an IO device with 16 IO port lines that could individually set for input or output. >The 8755 was the EPROM part, and at least one >version had a quartz windo for erasure (I don't know if there was an OTP >type). The 8155 was RAM. All had I/O as well. There was never an OTP, all were windowed Eprom devices. the 8155 and the '56 were the same device save for CS polarity. they are very useful with 256bytes ram, a programable timer/baud rate generator and 22 IO pins that can be set as output, input or strobned outpus and inputs. >There's also the 8156, which is the same as the 8155 (RAM + I/O) but with >an active-high chip select. Not as common as the 8155. Not as widely used but I have a bunch. >Of course you can use normal RAM and EPROM with the 8085 is you add and >address latch. An 74x373, or the 74x573 which as a saner pinout, is a >common choice. > There was also the 8185 wich was a 1Kx8 ram with muxed address/data. Those were uncommon as intel was the only supplier. The 8085A (or A-5), 8755, 8155 in three chips gave 256bytes ram, 2Kbytes Eprom, 38 configurable port lines, A timer/baudrate generator, 4 interrupt lines and the handy SID and SOD IO pins. Very handy for small applications. The base part ran at 3mhz (3.072mhz) and the faster A-5 was a 5mhz (there were 6mhz HmosII and CMOS parts later). Substitute a 8088 (or V20) and 8284A for the 8085 and you had a 16it cpu with all the Eprom, ram and IO listed. Allison >-tony

18 years, 2 months

1
0
0 0

CP-M Z80 home brew computer circuit board

by cclist＠sydex.com

Date: Mon, 16 Jun 2008 20:06:07 -0400 From: Allison > I've built my fill of floppy based, IDE based, CF based, ROMdisk based > systems and the latter two are far easier to construct and get going > and if your trying to run CP/M and mess with programming and > applications the smaller lower power SBC can be its own form of fun as > you can put it in a small box with a wall wart and use the laptop as a > terminal anywhere. Having a few PX-8s, Darth Vaders lubch boxes and > S100 systems with all the disks and what not is fine but when you want > to move them it's not so fun using hand truck. Where my tiny Z80 with > 32MB CF in a 5x4x1.5" box is rather fun to bring and show CP/M and > what it can still do, on batteries! You could simply skip the work with soldering iron and implement the same with an emulator on, say, an iPod Touch, with full color graphics, sound and gigs of memory that runs at many times the speed of the Z80. No need for a terminal--program while you're standing in line at the DMV--and no messy sticking things together with bits of hot metal. But then, why do people on this list collect slow bulky old iron that drink power like there's no tomorrow and require careful nursing of ageing components? I submit that they're not collected (for the most part) to do useful work, but rather to recreate an experience or attempt to gain a shadow of one. I remember that my late father started to collect old radios from the 1920s and then abruptly stopped and disposed of his collection. His reason was that "it just wasn't the same". The radio stations didn't broadcast the same programs and he knew that there was better, easier to use equipment with great fidelity and ease of use. And he wasn't the same kid living in a tenement in 1925, scrounging batteries and odds and ends. So, perhaps even though you're not recreating an accurate circa-1978 CP/M experience Allison, it's just as well. We can't go home again. You don't have an audience with a circa-1978 mindset. Today's audiences have been conditioned by what they have around them. CP/M must seem as quaint as a leisure suit or love beads. Me, I miss the big iron. But even if I owned a full 7090 installation or STAR-100 "supercomputer" and could afford the utility bills to run them, there would always be the itch in the back of my skull that a personal computer could run rings around the behemoths-- and be one heckuva a lot quieter and more reliable. Cheers, Chuck

18 years, 2 months

5
8
0 0

invading varmints

by cclist＠sydex.com

> Date: Sun, 08 Jun 2008 16:07:31 -0400 > From: tiggerlasv > Kind of odd that he was bitten by "several" spiders, > merely by opening a disk drive door. Recluses aren't > at all aggressive, and generally don't go out of their way to attack. > It seems highly unsual that they would "charge out in numbers", > and bite. But, anything is possible. Well, I never met the guy face-to-face and am simply recounting what was told to me by him. We've got spiders all over the place here and generally I've never had any problems with them--they mostly try to flee. On the other hand, I shudder when I think about yellowjackets and stepping on a nest--but I've never run into electronic gear infested by the nasty buggers. Cheers, Chuck

18 years, 2 months

4
4
0 0

AT&T 3B1 Unix PC

by mtapley＠swri.edu

At 12:04 -0500 6/19/08, Michael Lee wrote: >Anyone collect and/or need parts to the AT&T Unix PC? I've got a pile >of systems I dismantled over a decade ago, and don't really want or know >how to put back together. All, I have a working one, and a fair amount of documentation. I have not spent enough time with it to be considered any kind of "expert" but I may be able to answer some questions. Hopefully someone more knowledgeable can pipe up here. The systems seem pretty cool, although they are kind of rudimentary as unix workstations. Michael, where are you? I.e. where would shipping be from? -- - Mark 210-379-4635 ----------------------------------------------------------------------- Large Asteroids headed toward planets inhabited by beings that don't have technology adequate to stop them: Think of it as Evolution in Fast-Forward.

18 years, 2 months

1
0
0 0

CP-M Z80 home brew computer circuit board

by cclist＠sydex.com

> Date: Sun, 15 Jun 2008 17:22:48 -0400 > From: "Roy J. Tellason" > I thought it was the 179x parts that had the data separator on-chip, > no? Nope. The 179x require an external data separator, as well as precomp ciruitry and floppy-interface buffering, as well as requiring +12 (although the Fujitsu clones need only +5). It's the 279x that have the internal data separators, but the 1770/72/73 have just about everything in a neat little 28-pin package. About all you have to supply is side and unit-select logic, which is easily done with a write-only latch. Add address decoding logic and you're pretty much done. DMA not required. This contributed hugely, IMOHO, to their being popular on a number of low-end "home" computer systems. The chip handles motor control (e.g. spin-up time from from motor on to ready, auto motor-off after a certain number of inactive revs), which the 179x doesn't do. The 765-based all-in-ones such as the National 8473 and the WD37C65A are about as hard to obtain and are a little more difficult to interface to a Z80 (just about require DMA and interrupts to work right). Cheers, Chuck

18 years, 2 months

4
3
0 0

CP-M Z80 home brew computer circuit board

by cclist＠sydex.com

Date: Wed, 18 Jun 2008 07:21:35 -0600 From: Les Hildenbrandt <les at hildenbrandt.com> > The 279x (1,3,7) series chips actualy had a working pll data seperator. > Here is a link to the 279x controller chip data sheet: > http://retrotechnology.com/herbs_stuff/fdc_datasheet.pdf > As I recall, the 179x series chips could not reliably do sector reads from > disks formated on a 177x controller. The 179x could do a track read of > the disk. Morrow provided a program with the Disk Jocky controller which > would do track reads, then write the track back out creating a disk which > worked well with either the 177x or 179x series controllers. It was not a > common issue, as very few people used single density once double density > became available, and new single density disks worked well with either > controller. Careful Les--the 177x that you're probably speaking about is the 1771- -the 70/72/73 are very different (and much later) animals with integrated data separators. AFAIK, the 1771 is the only member of your "177x" family. Well, there was the 1781, but that was a very different animal (M2FM) and is very hard to find (I doubt that even Unicorn has them or has ever had them). Fred's right--the 1771 *did* have an on-board data separator, but it was such a joke that even WD discouraged its use. Cheers, Chuck

18 years, 2 months

1
0
0 0

Computer love (Was: Corestore - the Big Move)

by tiggerlasv＠aim.com

> >> Being unmarried means I get to put my server rack > in the dining room. > >> That's better than sex. > > This is real geek porn: > > ftp://ftp.franken.de/pub/people/m/pix/comp/ > There's someone that has taken Kraftwerk a little too seriously. . . . http://music.yahoo.com/Kraftwerk/Computer-Love/lyrics/656721 I'm not sure if I'll ever be able to look at my 11/83 the same way again. ;-) T

18 years, 2 months

6
6
0 0

non-CP/M Z80 board

by ajp166＠bellatlantic.net

> >Subject: Re: non-CP/M Z80 board > From: Dave McGuire <mcguire at neurotica.com> > Date: Wed, 18 Jun 2008 23:13:54 -0400 > To: "General Discussion: On-Topic Posts Only" <cctech at classiccmp.org> > >On Jun 18, 2008, at 11:48 AM, Chuck Guzis wrote: >>> They're all over the place. I have at least one tube of *brand >>> new* NMOS Z80 (not-A) chips here...cost me all of three bucks on eBay >>> in '06 or so. Need any? >> >> I think the chips under discussion were the 8085 specialty chips, >> 8155, 8355, 8755, etc. Got tubes of those? > > I've got a dozen or so 8755s, two or three 8155s, and no 8355s. >Not tube quantities, unfortunately. > > -Dave I do. Several tubes of 8755A, 8155A, 8156A and 8085A and some A-5s. Those parts are not that uncommon and they did have multiple vendors. Most of the Z80 (2.5 ->8MHZ) and peripherals are available from many vendors including JDRmicrodevices. Not all the peripherals were availble to 8mhz though (DMA was never made faster than 4mhz if memory serves). Allison >-- >Dave McGuire >Port Charlotte, FL >

18 years, 2 months

1
0
0 0

Atari 2600 AV mods

by dgriffi＠cs.csubak.edu

A couple years ago there was talk about AV mods for the Atari 2600. Does anyone here have a Cybertech AV mod? How is it different from the standard CD4050 hack? -- David Griffith dgriffi at cs.csubak.edu A: Because it fouls the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail?

18 years, 2 months

7
8
0 0

with reluctance... pdp-10 for sale

by mross666＠hotmail.com

I've finally gone and done it: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=150256074674 Don't really want to, but if a deep-pocket collector decides to bite, it's gone. Mike http://www.corestore.org _________________________________________________________________ Search that pays you back! Introducing Live Search cashback. http://search.live.com/cashback/?&pkw=form=MIJAAF/publ=HMTGL/crea=srchpaysy…

18 years, 2 months

6
6
0 0

non-CP/M Z80 board

by cclist＠sydex.com

> Date: Wed, 18 Jun 2008 09:24:05 -0400 > From: Dave McGuire > > Are those parts even around any more though? Easy enough to find? > > I haven't > > looked in a while... > They're all over the place. I have at least one tube of *brand > new* NMOS Z80 (not-A) chips here...cost me all of three bucks on eBay > in '06 or so. Need any? I think the chips under discussion were the 8085 specialty chips, 8155, 8355, 8755, etc. Got tubes of those? Cheers, Chuck

18 years, 2 months

3
2
0 0

What's the value of. . . (Was: Apple I back up on ebay)

by tiggerlasv＠aim.com

>> The monetary value of something is the price that a seller and buyer >> are willing to agree to. If a replica sells for $2000, then its value >> to the seller and buyer must be $2000. > > I can't tell whether the responses along these lines are honest > misunderstandings or well hidden sarcasm. > > We all know the sale price of this item. One sale does not a trend > make. Why can't someone provide either a useful answer or some useful > information? I don't know that there is an authoritative answer to that, or to most other "what's it worth" type questions about vintage computer equipment. Consider for example "The Antiques Roadshow", or auction houses like Sotheby's. There are a number of folks out there who are experienced at appraising artwork, old furniture, classic automobiles, and a plethora of other items. Most of which has been around for many many years. Can the same be said of the computer and/or electronics industry? I think the market is still in it's infancy, and there's probably not enough interest in the vintage equipment to support expert opinions. (Yet.) Case in point: Check out this VERY cool Predicta television: http://www.flickr.com/photos/72154009 at N00/2186381451/ I'm sure there are a number of folks out there who could give you a reasonably accurate opinion about the overall value of this unit. This is in part due to the niche market interest in old electronics such as this. And it's been around for a number of years. Now, who could tell me definitively, the "value" of this 1976 Magnavox? http://www.tvhistory.tv/1976%20Magnavox%20TV.JPG Probably not a whole heck of alot of people. There were a large number of them made. But there's not alot of interest in it, because it's still "fairly" new, and by the time it started to wear out, we had moved into an age when people didn't hold on to their old electronics, they just threw them out, and got new stuff. I find that people who ask "what's it worth?" can be divided into two categories. Either they haven't a clue, and are too lazy to do the research, or, they have an idea of what they want, but don't want to lose out by paying too much, or charging too little. Buyer's / Seller's remorse. Do the research! Find out what they've sold for in the past. Look at ALL the prices, high and low, and see if it jibes with what you think it's worth. And don't assume that you'll get the same amount as others have; there are simply too many variables. Research is sometimes very difficult with unique or limited-availability items, which brings us back to the original topic: Is a potentially non-working Apple I clone worth $2000 to me? No. Is it worth $200 to me? No. But then, I'm not a collector of Apples. As a rule of thumb, we shouldn't be asking the question "What does someone else think it's worth?", we should be asking the more important question, "What is it worth TO ME?" This applies to both buying and selling. Either way, if you buy and sell based on the opinions of a limited number of people, you'll eventually end up getting burned. Um, yeah. . . If you give me $10, I'll be happy to haul away that old Altair for you. . . ;-) Regards, T ------------------------------------------------------------------------- ------ Note: The opinions expressed above do not necessary reflect the views and opinions of the author.

18 years, 2 months

1
0
0 0

CP-M Z80 home brew computer circuit board

by les＠hildenbrandt.com

The 279x (1,3,7) series chips actualy had a working pll data seperator. Here is a link to the 279x controller chip data sheet: http://retrotechnology.com/herbs_stuff/fdc_datasheet.pdf As I recall, the 179x series chips could not reliably do sector reads from disks formated on a 177x controller. The 179x could do a track read of the disk. Morrow provided a program with the Disk Jocky controller which would do track reads, then write the track back out creating a disk which worked well with either the 177x or 179x series controllers. It was not a common issue, as very few people used single density once double density became available, and new single density disks worked well with either controller. Les

18 years, 2 months

3
2
0 0

FW: time to part with my PDP-11 system

by dm561＠torfree.net

---------- From: M H Stein[SMTP:dm561 at torfree.net] Sent: Wednesday, June 18, 2008 9:38 PM To: 'cctalk at classiccmp.org' Subject: time to part with my PDP-11 system ----------ORIGINAL MESSAGE: Date: Tue, 17 Jun 2008 01:52:09 +0000 From: Ethan Dicks <ethan.dicks at usap.gov> Subject: Re: time to part with my PDP-11 system On Mon, Jun 16, 2008 at 03:26:15PM -0400, M H Stein wrote: > Date: Mon, 16 Jun 2008 03:54:51 +0000 > From: Ethan Dicks <ethan.dicks at usap.gov> > Subject: Re: time to part with my PDP-11 system > > <snip> > >...Eventually, I'll do another camping trip to Hamilton... > <snip> > -ethan > --- > > I'm in Hamilton every week or so, and I have to ask: why? > ;-) The serious answer is because I have friends who live in an arc between St. Catherines and the west edge of Toronto, and every June since the early 80s, they've done a largish camping event somewhere in the Hamilton area (Knight's Dunmark Park is where it was 20 years ago, but that was turned into a golf course). While these friends aren't into classic computers at all, it does give me incentive to spend the gas to drive 7-8 hours >from central Ohio, and puts me in that area for quick little side trips (like to Jerome's house) every few years. -ethan -----------REPLY: Ah, that explains it; although it's actually a very nice place aside >from the steel mills and smelters, Hamilton's not really known as a tourist hot spot. If and when you do get up here again, I'd love to meet for a coffee and say hi; haven't seen Jerome in many years either despite being in the same city, but then I'm not a DECcie... Looking forward... mike **********************************************************************

18 years, 2 months

1
0
0 0

home for Tandy PT210 manuals

by dgriffi＠cs.csubak.edu

Does someone have a website of Tandy manuals who'd like to host the scans of the user and service manuals for the PT210 printing terminal? I've been hosting them for a while, but I don't have very much bandwidth to spare. -- David Griffith dgriffi at cs.csubak.edu A: Because it fouls the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail?

18 years, 2 months

2
1
0 0

Congratulations Seth!

by lynchaj＠yahoo.com

Hi All, Seth just built his N8VEM SBC and it worked on the first try! Congratulations Seth! Great Job! Andrew Lynch PS, this is also an important milestone; it is the first of the shipped SBC PCBs I know of to see "first boot" in the field. -----Original Message----- From: n8vem at googlegroups.com [mailto:n8vem at googlegroups.com] On Behalf Of Seth Morabito Sent: Wednesday, June 18, 2008 2:28 AM To: N8VEM Subject: [N8VEM: 108] Re: How are things going for builders? P.S.: The completed board: http://www.flickr.com/photos/twylo/2588823197/ The software, in action: http://www.flickr.com/photos/twylo/2588826647/ -Seth --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "N8VEM" group. To post to this group, send email to n8vem at googlegroups.com To unsubscribe from this group, send email to n8vem-unsubscribe at googlegroups.com For more options, visit this group at http://groups.google.com/group/n8vem?hl=en -~----------~----~----~----~------~----~------~--~---

18 years, 2 months

1
0
0 0

Emailing CP-M Z80 home brew computer circuit board

by lynchaj＠yahoo.com

bfranchuk at jetnet.ab.ca bfranchuk at jetnet.ab.ca <mailto:cctalk%40classiccmp.org?Subject=Emailing%3A%20CP-M%20Z80%20home%20br ew%20computer%20circuit%20board.htm&In-Reply-To=CAD07A50FEA44B73BFD2864883FC 644B%40andrewdesktop> Sun Jun 15 20:05:45 CDT 2008 * Previous message: Emailing: CP-M Z80 home brew computer circuit board.htm * Messages sorted by: [ date ] [ thread ] [ subject ] [ author ] ________________________________ Andrew Lynch wrote: > That means compromises had to be made and some stuff had to go. > > Anyone can design a great computer on paper. Making a real, tangible part > is a lot more difficult. > > Using cool sounding but almost impossible to find parts seems easy but it > makes the SBC practically worthless. > > If you can make a low cost Z80 SBC that includes floppy IO, I would love to > see it. I'd even buy one or two. > But when you think about it, most early CP/M machines were 8 inch single density. Not much on a disk and that I think is the basic format to look at. I think I seen a data separator using a 16 bit counter at 4x? the data rate but I can't remember where. > I look forward to seeing your design. > > Thanks and have a nice day! > > I can't say I am having a nice day. I am still grumbling over not getting PAD's PCB and LAYOUT software when I could in the late 80's. I am looking to do a 16 bit (2901) cpu using EEPROM (2kx8 250 ns) and am still trying to find a schematic capture and PCB layout program that I can afford with through the whole parts. Sadly all seem to be Australia. :( > Andrew Lynch > > > Well, as my Mom likes to say "Talk is cheap. It takes money to buy whiskey." Data separators require either available chips or replacements with specific details. I designed an FDC data separator using plain 74LSxxx parts which is great in theory but there is no way I am going through the expense and time to build it when there are more pressing things to do. There is no guarantee it would work either. I am just an engineer, not a magician. If you look closely at those old 8" SSSD 8080 CP/M machines generally they use lots of SSI TTL and large PCBs. Were a similar computer designed today, it would cost a LOT of money to produce. They cost a lot then too. A home brew SBC using PCB of those sizes would be prohibitively expensive for most people. As for low cost EDA tools, have you tried KiCad and FreeRouting.net? There are links on the N8VEM website: http://groups.google.com/group/n8vem Originally, I designed the N8VEM SBC on notebook paper by hand. Later I recaptured the design with KiCad and used the FreeRouting.net autorouter/manual router. The N8VEM hardware documentation is done using KiCad/FreeRouting.net to create schematics, PCB layout, Gerber files, drill files, BOM, netlist, etc. KiCad is free (beer, speech) and FreeRouting.net is free (beer). They do a great job of schematic capture, PCB layout, have fairly complete parts library, have the ability to make custom parts, and do a great job of both autorouting and/or manual routing of PCB traces. Total cost $0. I doubt you'll find a 4 bit wide bit slice CPU (AMD2901) in the KiCad parts library. That part is a bit obscure these days. However, it'd probably be easy to do a custom part model since it is a plain 40 pin DIP with normal IO. The EEPROM is probably a 2816 or similar and is already in the extended parts library. Thanks and good luck with your project! Andrew Lynch

18 years, 2 months

11
15
0 0

Apple I back up on ebay

by tonym＠compusource.net

So much for his friend giving him $1500 for it... It was a scam attempt, plain and simple. Just so happened he got BuStEd in the process, which I am SURE he did not expect - I assume he thought he was selling it in the land of the dimwits. He could not have been more wrong. With such a small number of originals, and him KNOWING THAT, I don't understand how his little brain concocted what has to be the stupidest idea, and lamest execution, that I've seen in quite a while! It was a failed attempt - too many loose ends, too many trackable things, and a LOUSY job of hacking up the cassette adapter... Not to mention an EXTREMELY limited item with the following of a sports franchise! Those of you thinking otherwise, and are giving him the benefit of the doubt, boy, have I got some REALLY NICE land out here for you in Southwest Florida..... Tony -----Original Message----- From: Al Kossow aek at bitsavers.org Sent 6/16/2008 11:43:38 AM To: classiccmp at classiccmp.org Subject: Apple I back up on ebay http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=220246863432 only change from the original listing (along with dropping the price). "Up for bids is an Apple I Computer, many experts believe to be infact a good reproduction (of witch about 150 where made - my knowledge of more info is limited) in good shape. One of the genuine ones recently reported selling for in excess of $50,000, and with good reason, experts believe there is only 20-30 in existence of the original 200 handmade by Steve Jobs and Steve Wozniak in early 1976."

18 years, 2 months

11
12
0 0

UK PDP 11/10 - 11/40 NGTE Installations

by mike＠brickfieldspark.org

For those intersted in DEC equipment and one aspect of their their usage (UK I'm afraid) Details of a now defunct Military installation that used various DEC computers has recently gone online. These documents from about 1980 show PDP 11/10's and 11/40's used for jet engine research and how they were utilised. I was the tech involved in the installation of the 11/40 in the mid 1970's, and maintenance at that time of the PDP7, SDS9300 and Elliot 803B systems. I also lists an ICL1904s running George Mk 8.64. It was all decomissioned in 2002, who knows where all the kit went but the urban explorer forums say it has all gone. Typical UK government, we dont want it so nobody can have it. Main document - http://www.ngte.co.uk/doc/doc/etf1.htm Data processingsection - http://www.ngte.co.uk/doc/doc/etf5.htm Mike.

18 years, 2 months

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CP-M Z80 home brew computer circuit board

by ajp166＠bellatlantic.net

> >Subject: Re: CP-M Z80 home brew computer circuit board > From: "Eric Smith" <eric at brouhaha.com> > Date: Tue, 17 Jun 2008 11:53:23 -0700 (PDT) > To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> > >Allison wrote: >> As long as you can poll within the minimum read/write loop >> time it's fairly easy. If not in the 8080/8085/z80 world you can use >> processor ready line to do a stall-wait on DRQ to keep the loop in >> sync and save some 22 T-states. > >I think you also need some logic to release the ready line if DRQ >doesn't occur but an interrupt does, in order to handle error >cases. With the 765 you can OR the DRQ and the INT lines for that. Likely that works for 179x (and friends)as well. > >> I forget if 6502 has a ready wait line. > >It does, but on the NMOS parts it only can stall read cycles, not >writes. (In the early-to-mid 1970s, ROMs and EPROMs were much slower >than typical SRAMs, so the designers apparently didn't think there >was any need to stall on writes.) I know so well Eproms were slow. > >For the controller I designed, I dealt with that by having a special >address that could be read that only waited for DRQ, at an address >in the page below the FDC's data register. By itself, that wasn't >sufficient to get to 8" MFM on a 1 MHz 6502. However, by taking >advantage of the spurious read that occurs on indexed write >instructions when there is a page crossing, I got the read of the >special polling adress and the write of the data in a single >instruction. That gets it down to 16 cycles, which meets the >nominal rate but isn't actually good enough. By unrolling the >loop, though, it drops to 13 cycles per byte, which meets all >the requirements: Thats pretty crufty. > LDA (DPTR),Y ; get data byte from buffer > STA FDC_SPCL,X ; reads poll location, which stalls, > ; then writes data > INY > >The unrolled loop requires 6 bytes of code per byte transferred, which >is 1536 bytes for a 256-byte sector. Not great, but it did fit in a >2716 EPROM. I used two 2716s, one containing the read loop and one >containing the write loop, both mapped into the same address space >and selected by writing to another port address. The rest of the >FDC driver fit in the remaining space of the two EPROMs. > >I didn't anticipate that they would "fix" the RDY behavior and the >spurious read on the 65C02, so the same code wouldn't work on that. >However, the fix was simply to replace the indexed STA with an >absolute STA. Don't you love it when that happens. In the 8080/8085/z80 world that kind of processor tweek was less common by vendors as absolute compatability with intel (the compatition) was desireable. However having done that far to many times for many different cpus I'll pass on further floppy integration. CF or even IDE gets me to enough space and decent speed with far less pain. Allison >Eric

18 years, 2 months

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Pre-computer Internet

by cclist＠sydex.com

Here's a great little piece from the New York Times about a Belgian who envisioned a sort of Internet in 1934: http://www.nytimes.com/2008/06/17/science/17mund.html?_r=1&oref=slogin Check out the short video at the end. Cheers, Chuck

18 years, 2 months

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Apple I back up on ebay

by tiggerlasv＠aim.com

On Tue, 17 Jun 2008 David Griffith wrote: > So, what's the value of the replica anyhow? Hehe. I guess it's worth whatever someone is willing to pay for it. I just found it surprising that someone still bid, after all the various revisions to the auction. Heck, even the 2nd auction was edited once or twice after it was posted. It was most unusual. I'm still puzzled as to why he indicated that it came from a collector, and that there was a display case. . . but then went on to say that it was covered in a layer of dust. Normally, you put items in display cases to AVOID human hands, dust, and dirt. But, I digress. It's over with. We should move on to more important things. . . . . . like the 11/73 system that I just listed on e-bay. It's alot less expensive, and one can be reasonably sure that the processor isn't a knock-off. ;-) T

18 years, 2 months

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any building 6800 sbc's out there?

by tsw-cc＠johana.com

From: "Chris M" <chrism3667 at yahoo.com> Sent: Sunday, June 15, 2008 8:26 PM To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Subject: any building 6800 sbc's out there? > just curious. When I started piddling around with this > stuff in the late 80's I guess, that was one of the > chips I intended to use as the basis for probably a > small breadboarded computer. Never got around to it. > But I did *swipe* a coco off of a friend and played > with that for a spell (6809 based). Close enough! :) Oh, 6800 stuff. Brings back many old memories. When the 6800 was released back in 1975 (+- 1 year) I had the great idea to build a ham radio repeater controller. In the process I ended up doing a bunch more. Eventually we had a bunch of "cards" that used 44 pin edge connectors (look, it is what I had at work) and it worked out quite well. After the repeater project, I did some work in testing Qume printers (you remember the Daisy Wheel things) and ended up writing a small operating system using single density minifloppies and a WD1771 controller chip (much better than discrete hardware!!). The data rate was slow enough (64 us/byte) that I could get away with having the data use the non-maskable interrupt to transfer data. Somewhere I've got some of the hardware from that era. The boxes could be maxed out at over 60k bytes. One of the 'projects' I ended up doing was the basis of a company I worked at from '78 thru '83. One interesting thing was that GM had a special chip made that plugged into a 6800 socket, and ran 6801 code at 6801 cycle times (about 20% faster!). We got a couple and the system I've got in the garage still has it working. Never did get into S100/CP-M stuff. Oh, well.

18 years, 2 months

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non-CP/M Z80 board

by rtellason＠verizon.net

I'm thinking about building a z80 board, with varying amounts of "stuff" attached, with RAM and ROM that may be NMOS or CMOS, and some indeterminate number of Z80-family and compatible peripheral chips. My question is this: At what point do you _need_ to have address and data bus buffer chips? -- 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

18 years, 2 months

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Apple I back up on ebay

by aek＠bitsavers.org

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=220246863432 only change from the original listing (along with dropping the price). "Up for bids is an Apple I Computer, many experts believe to be infact a good reproduction (of witch about 150 where made - my knowledge of more info is limited) in good shape. One of the genuine ones recently reported selling for in excess of $50,000, and with good reason, experts believe there is only 20-30 in existence of the original 200 handmade by Steve Jobs and Steve Wozniak in early 1976."

18 years, 2 months

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non-CP/M Z80 board

by cclist＠sydex.com

IIRC, when there was only the NMOS Z80/Z80A parts, this was one of the reasons for the popularity of the Intel 8085. You could put together a functional system for a dedicated application with some of the made-for-8085 peripherals (e.g. 8155, 8355, 8755), with a very low chip count compared to what's needed for an equivalent Z80 implementation. Cheers, Chuck

18 years, 2 months

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IDT tape drive information

by aek＠bitsavers.org

Documentation for the transport and formatter are up now under http://bitsavers.org/pdf/innovativeDataTechnology

18 years, 2 months

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Low Cost EPROM programmer (Ben, this is for you)

by sethm＠loomcom.com

On Tue, Jun 17, 2008 at 8:33 PM, Zane H. Healy <healyzh at aracnet.com> wrote: > > You should also be able to find a dirt cheap, piece of crap Chinese EPROM > eraser that will do the trick off of eBay for about the same price. I just bought one of these dirt-cheap, piece of crap Chinese UVPROM erasers on Friday. It should be here tomorrow. I'll let everyone know whether it's capable of erasing anything once I've given it a whirl! (My modern electronics buddies practically did a spit-take when I told them I was still working with UVPROMs! The irony is, I'm only just now getting into this stuff, so 'still working with' isn't quite correct, either. I'm perfectly happy to be stuck in the past!) -Seth

18 years, 2 months

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Emailing CP-M Z80 home brew computer circuit board.htm

by lynchaj＠yahoo.com

Emailing CP-M Z80 home brew computer circuit board.htm Eric Smith eric at brouhaha.com <mailto:cctalk%40classiccmp.org?Subject=Emailing%20CP-M%20Z80%20home%20brew% 20computer%20circuit%20board.htm&In-Reply-To=D56A2F9DFFEA45C791E59FE9F179D5B 9%40andrewdesktop> Tue Jun 17 19:54:54 CDT 2008 * Previous message: Emailing CP-M Z80 home brew computer circuit board.htm * Messages sorted by: [ date ] [ thread ] [ subject ] [ author ] ________________________________ Andrew wrote: > Still how do you transfer stuff from a floppy ( or file online ) to a > CP/M system with no external I/O devices? I wrote: > I have yet to see a CP/M system with no external I/O devices. That > doesn't sound very useful, so why would one care about transferring > stuff to it? Andrew wrote: > Who said the N8VEM SBC has no external devices? I was replying to your question, quoted above. I never said anything about an N8VEM SBC. Eric -----REPLY----- Eric, Oh, I think I see what happened. The quote you attributed to me is actually >from Ben. Everything I said is below the -----REPLY----- I never asked that question and wondered why you asked it. Still, the response is valid. BTW, the N8VEM SBC is the actual name for the home brew Z80 SBC I built. I am offering the PCB to others of similar interests. Probably there has been enough discussion from me on the topic. If anyone is interested please contact me offline or join us on the N8VEM google group: http://groups.google.com/group/n8vem Thanks and have a nice day! Andrew Lynch 73 de N8VEM

18 years, 2 months

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Power requirements for a CDC 9410 Finch harddrive

by delcis＠gmail.com

Hello CCtalk, I'm hoping someone can help me with the pinout for the power connector of a CDC 9410 Finch 8" 32MB harddrive. It has a power interface that I haven't seen on other 8" drives. If you would like to see pictures: http://www.dusicyon.org/temp/cdc01.jpg http://www.dusicyon.org/temp/cdc02.jpg I appreciate any advice or suggestions you can give. Thank you, Theo Wiegmann

18 years, 2 months

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Apple I back up on ebay

by wdonzelli＠gmail.com

> But, I wonder if we've seen the last of that clone? I am wondering if we are ever going to see the last of this thread. Get a grip, guys. -- Will

18 years, 2 months

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Apple I back up on ebay

by tonym＠compusource.net

But, I wonder if we've seen the last of that clone? Tony -----Original Message----- From: tiggerlasv at aim.com Sent 6/17/2008 10:06:36 PM To: cctalk at classiccmp.org Subject: Apple I back up on ebay . . . . and, it has sold, for about $2000 . . . Thud (That was me passing out, from disbelief.) T

18 years, 2 months

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Emailing CP-M Z80 home brew computer circuit board.htm

by lynchaj＠yahoo.com

Emailing CP-M Z80 home brew computer circuit board.htm Eric Smith eric at brouhaha.com <mailto:cctalk%40classiccmp.org?Subject=Emailing%20CP-M%20Z80%20home%20brew% 20computer%20circuit%20board.htm&In-Reply-To=2A5D64469F2B4C2AAF06BA09719DFB0 1%40andrewdesktop> Tue Jun 17 18:19:21 CDT 2008 * Previous message: Emailing CP-M Z80 home brew computer circuit board.htm * Messages sorted by: [ date ] [ thread ] [ subject ] [ author ] ________________________________ Andrew wrote: > Still how do you transfer stuff from a floppy ( or file online ) to a > CP/M system with no external I/O devices? I have yet to see a CP/M system with no external I/O devices. That doesn't sound very useful, so why would one care about transferring stuff to it? Eric -----REPLY----- Hi, Who said the N8VEM SBC has no external devices? The SBC has some self contained memory drives but supports external devices over the ECB. The SBC supports a RAM drive (448K B:) and two ROM drives (32K A: and 992K F:) internally. The CBIOS *currently* (read the CBIOS source) supports IDE interface and three hard disk partitions (8M C:, 8M D:, 1M E:) via the Disk IO board. I know the 8M C: drive is fully functional since I have one on my workbench. You can transfer temporary files in and out of the system using the serial line into the RAM drive or burn them into EPROM. The data is available on each device exactly the same except ROM drives are RO and the RAM drive is RW. CP/M CBIOS treats them as block devices and from an operators view they are identical to disk drives. Were there floppy disk with the same DPB as the ROM, the ROM image would also work as a disk image. I do not see why someone who wanted to couldn't write a serial based block device in CP/M and treat the host PC as a block device disk drive. It is of no real interest to me but the modifications to the CBIOS would not be all that hard. You'd also have to write an application on the PC side to handle the serial IO block servicing and with the terminal emulation. It'd be tedious but probably not too difficult. For me XMODEM works just fine to transfer any files to/from the PC as needed. I also do a lot of work off target on the PC and transfer the final binary image to the SBC for testing. The SIMH simulator supports an N8VEM mode I use a lot for development and test (Thanks Howard!) The IDE interface requires the Disk IO board which I have on my bench as a prototype built with prototype cards. The schematics/CBIOS source are available if you'd like to build one too. It also includes a NEC 765 based floppy controller interface. The IDE interface works for sure as I used it for quite a while. The floppy interface is built but never fully tested. My prototype board based system started having problems with reliable grounding when I took a break to work some other projects. The next project is to make an ECB backplane and then a bus debugger from my existing prototypes. After that, recraft the Disk IO board as manufactured PCB. The first thing I did when I restarted the project is begin the conversion of prototype boards to manufactured PCBs. Compared to my original prototype computer, the new manufactured PCB SBC is MUCH more reliable and easier to build. If there are enough units out there to make it worthwhile, I may order several manufactured PCBs for other hobbyists. If not, I will probably just go with another small run of barebone prototype boards for the rest of my boards. I did a run of two SBC prototype PCBs to verify the design before I did this latest run of manufactured PCBs. As for CP/M, you are not REQUIRED to use it. Write your own stuff and burn your own EPROM. However, a plain Z80 SBC is perfectly useful without CP/M. CP/M is just an operating system. CP/M works fine loading and running programs from the RAM/ROM drives however you could just as easily just use the RAM monitor. Better yet, write your own kernel and application. Whatever you like. I split my usage about 50% between the monitor and CP/M. Home brew computers are *not* all nicely finished and debugged so it magically does everything want when you plug it into a wall. That is what makes them a challenging and an enjoyable hobby. People who take it on should expect to get their hands dirty. If you are expecting a pristine flawless commercial product then this project is not for you. Thanks and have a nice day! Andrew Lynch

18 years, 2 months

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Apple I back up on ebay

by tonym＠compusource.net

I think the "Vintage computer expert" stuff got his last one canned... If you notice, the ORIGINAL $10K listing had *NONE* of our "questions" posted. All of a sudden, in the second listing, there were "experts" popping up all over the place. Me, I'm no Apple 1 expert, by even the FURTHEST stretch of the imagination... Even *MY* untrained-on-Apple-1 eyes could see it was a fake. I'm hoping this dude ends up sharing a cell with a 6'5" 270lb guy named Bubba.... Tony -----Original Message----- From: Mike Loewen mloewen at cpumagic.scol.pa.us Sent 6/17/2008 7:22:55 PM To: General Discussion: On-Topic and Off-Topic Posts cctalk at classiccmp.org Subject: Re: Apple I back up on ebay On Tue, 17 Jun 2008, Grant Stockly wrote: Can you guys still get to the auction page? All I get is "This listing (220246863432) has been removed or is no longer available. Please make sure you entered the right item number. " Try this one: 220247416953 Mike Loewenmloewen at cpumagic.scol.pa.us Old Technologyhttp://sturgeon.css.psu.edu/~mloewen/Oldtech/

18 years, 2 months

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Emailing CP-M Z80 home brew computer circuit board.htm

by lynchaj＠yahoo.com

Emailing: CP-M Z80 home brew computer circuit board.htm bfranchuk at jetnet.ab.ca bfranchuk at jetnet.ab.ca <mailto:cctalk%40classiccmp.org?Subject=Emailing%3A%20CP-M%20Z80%20home%20br ew%20computer%20circuit%20board.htm&In-Reply-To=4855CBD5.9050403%40bellatlan tic.net> Tue Jun 17 11:09:33 CDT 2008 * Previous message: Emailing: CP-M Z80 home brew computer circuit board.htm * Next message: Emailing CP-M Z80 home brew computer circuit board * Messages sorted by: [ date ] [ thread ] [ subject ] [ author ] ________________________________ Allison wrote: > > Have you ever used 8"SSSD to do anything that required space? There > isn't > enough space to run a disassembled version of the BDOS through ASM > unless you have at least two drives and don't mind doing cleanup. > I never could run the CP/M system I was using for more than 30 minutes with out the floppy stepper sticking. That was fun working with it. Still how do you transfer stuff from a floppy ( or file online ) to a CP/M system with no external I/O devices? > Yes you can roll your own data sep it only needs three ttl packages. > With all the other hardware needed for the 765 case you end up with at > least 10 chips > though If you willing to miss a few features it's been done in 7 plus > the FDC > and that doesn't include the bus side of the FDC interface. > That I would like to see. > > Kicad for linux there are other like cadstd for winders. > Of course the last 2901 design I'd done in the early 80s was > with paper and pen! It's doable that way. I still am using paper & pen. Mind you I have to buy JAPANESE pens since the quality of the USA stuff is all cheap Chinese imports. Now that I have a serious cad program - DIPTRACE on order I think I will put the design in hardware. > FYI using 250nS eproms will make it terminally slow unless > you do two things, use a wide microword 64bits or more and > pipeline the address and decode so you can work right to the > eprom Tacc minimum limit. I got that covered if I read the 2901 data sheets correctly. I will be using a 6809 style memory cycle optimized for D-RAM access and clock the 2901 in 4th phase of the memory cycle. This is retro computing project for the feel of the late 1970's not using a 8 bit CPU. I am aming for a 800ns memory cycle and the slow access of micro-code is not a problem. The only thing pipelined is the next memory cycle - Read/Write/Refesh and the default is refresh while doing the the 1st cycle of op-code decoding. The front panel does RUN/STOP, Single Instruction,Address Load, Deposit,Read. -----REPLY----- Hi, I can answer the question on how to get programs and data into and out of the SBC. There are three ways with the basic SBC; 1) XMODEM at the CP/M prompt 2) Intel Hex format transfer at the RAM Monitor prompt and 3) burn your own EPROM with the supplied image or your own custom disk image (utilities are on the website) Here is a little background on the N8VEM SBC design principles The N8VEM SBC is meant to be flexible and low cost. If you start with the PCB only, you can minimize cost by not installing unneeded functions such as; 1) RTC 2) 8255 PPI and parallel port connector 3) ECB Bus transceivers and DIN 41612 connector You can also substitute some parts to reduce cost. Replace the 1Mx8 EPROM with a 128Kx8 27C1001 is a drop in replacement. Scrap and salvaged parts can be used directly or with minor modifications. All the chips are commonly available plain TTL and can be substituted. All of the other components can be substituted if you know what you are doing. Scrap 29C020 Flash ROM chips (PC BIOS) can be reused with a simple shim socket. Most likely 128Kx8 SRAM parts with a shim socket can be used but I haven't tested it yet Installing and running CP/M 2.2 OS is strictly a convenience and an option. Any generic CP/M application should work. The RAM and ROM drives are lightning quick and silent. You'll never see a hung stepper motor with SRAM! The SBC boots into the RAM monitor so you may never need to run CP/M at all if you don't want to. The system I built is rock solid. It runs for hours doing things without a sound or glitch. I used some CMOS components so the SBC runs cool. Power supplies are easy and cheap. Use spare ATX/AT PS or your own with the common Molex drive connector. Of course, all the hardware and software details are fully published and with datasheets for all the components. Except for the EPROM there are no custom or programmed devices at all. All components are bog standard common 74LSxxx TTL and LSI peripherals. It is designed to be built with low cost tools and simple test equipment such as 25W soldering iron and VOM. EPROM programmer, logic probe and/or oscilloscope are useful but optional. You can easily write your own replacement software like a FORTH kernel or custom Z80 boot code if you'd like. The EPROM on the N8VEM site is strictly optional and I actually discourage people from using the pre-programmed part. Write/burn your own and save $$$ on construction. With the low cost PCB available and using standard low cost components anyone can build their own SBC for low cost. You can add the features you like later on and even expand the system via the ECB to be a full blown microcomputer. Once a few of these systems get built "out in the field" I would like to start a challenge to see who can build an SBC for the least cost. Those with a well stocked junk box or access to scrap PC electronics would have an advantage of course. Compared to a design it yourself using wire wrap/prototype boards/breadboards, this SBC PCB will save you time and money on construction. Manufactured PCBs are also more reliable than temporary construction methods in the long term. It will be fun to make, useful, and educational. Thanks and have a nice day! Andrew Lynch

18 years, 2 months

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Apple I back up on ebay

by tonym＠compusource.net

Now it looks like his buddies are doing the "ask seller a question" One says: "Hello Sir, I am an expert in vintage computers, and you sir have the real deal, this is not a fake. The style of the board will show, and the use of vintage chips. Good luck" Wow - some expert. Actually, from the wording, sounds like that person wants to send a certified check for 3 times the amount, and then send the balance to his shipper in ....... Wish we knew who THAT was, so we know who else to avoid! There's also: "This looks like its the true Apple 1, how can you say its not?" What a scammer... Tony -----Original Message----- From: dwight elvey dkelvey at hotmail.com Sent 6/17/2008 1:27:21 AM To: General Discussion: On-Topic and Off-Topic Posts cctalk at classiccmp.org Subject: RE: Apple I back up on ebay Hi One might check out: http://www.newtontalk.net/archive/newtontalk.2006-02/0072.html Dwight _________________________________________________________________ Instantly invite friends from Facebook and other social networks to join you on Windows Live" Messenger. https://www.invite2messenger.net/im/?source=TXT_EML_WLH_InviteFriends

18 years, 2 months

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Emailing: CP-M Z80 home brew computer circuit board.htm

by ajp166＠bellatlantic.net

> >Subject: Re: Emailing: CP-M Z80 home brew computer circuit board.htm > From: "bfranchuk at jetnet.ab.ca" <bfranchuk at jetnet.ab.ca> > Date: Tue, 17 Jun 2008 10:09:33 -0600 > To: General Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org> > >Allison wrote: >> >> Have you ever used 8"SSSD to do anything that required space? There >> isn't >> enough space to run a disassembled version of the BDOS through ASM >> unless you have at least two drives and don't mind doing cleanup. >> >I never could run the CP/M system I was using for more than 30 minutes >with out >the floppy stepper sticking. That was fun working with it. BTDT.. :( >Still how do you transfer stuff from a floppy ( or file online ) to a >CP/M system with no external I/O devices? Explain no external IO? A serial line works fine, or a parallel bidirectional port. Since every cp/m system has a console no rule saus it can transfer files on that line either. >> Yes you can roll your own data sep it only needs three ttl packages. >> With all the other hardware needed for the 765 case you end up with at >> least 10 chips >> though If you willing to miss a few features it's been done in 7 plus >> the FDC >> and that doesn't include the bus side of the FDC interface. >> >That I would like to see. Goo look at David Dunfield's CUBIX system. CPU is 6809 but the FDC is 765 with minimal interface parts count. I'd say it was a good example of keep ing the chip count to a minimum. >> >> Kicad for linux there are other like cadstd for winders. >> Of course the last 2901 design I'd done in the early 80s was >> with paper and pen! It's doable that way. >I still am using paper & pen. Mind you I have to buy JAPANESE pens >since the quality of the USA stuff is all cheap Chinese imports. >Now that I have a serious cad program - DIPTRACE on order >I think I will put the design in hardware. I still use paper and pen too. I do everything engineering notebook style. That is black ink, no erasures and numbered pages. >> FYI using 250nS eproms will make it terminally slow unless >> you do two things, use a wide microword 64bits or more and >> pipeline the address and decode so you can work right to the >> eprom Tacc minimum limit. >I got that covered if I read the 2901 data sheets correctly. >I will be using a 6809 style memory cycle optimized for >D-RAM access and clock the 2901 in 4th phase of >the memory cycle. This is retro computing project for the feel >of the late 1970's not using a 8 bit CPU. I am aming for >a 800ns memory cycle and the slow access of micro-code >is not a problem. The only thing pipelined is the next memory >cycle - Read/Write/Refesh and the default is refresh while >doing the the 1st cycle of op-code decoding. The front >panel does RUN/STOP, Single Instruction,Address Load, >Deposit,Read. Using Dram is one way to make life hard. you can use larger static devices and save pain but retain the same cycle style. Last 2901 design was 16bit, horizontal microcode (56bits), one microword to a cycle. I was able to get the pipeline for Eprom address latch to overlap so that the 2732s used would run at 320ns with good timing. The macro cpu executed instructions in that time cycle in a four tick cycle. It was fairly fast for a single address machine. However, I didn't do the microaddress or micro program counter in the 2901 I did that with TTL. No front pannel either the system booted a rom minimal debugger. When I got it working I junked it and started thinking about a 32bit machine. Allison

18 years, 2 months

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CP-M Z80 home brew computer circuit board

by ajp166＠bellatlantic.net

> >Subject: Re: CP-M Z80 home brew computer circuit board > From: "Eric Smith" <eric at brouhaha.com> > Date: Mon, 16 Jun 2008 13:58:30 -0700 (PDT) > To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> > >Chuck wrote: >> the 1770/72/73 have just about everything in a neat little 28-pin package. >[...] >> DMA not required. > >Whether DMA is required or not has nothing to do with which member of >the 177x/179x/279x/MB88xx family you use. It's determined by whether >you can write tight enough transfer loops to avoid write underruns and >read overruns. > >On a 6502 a typical read transfer loop takes a minimum of 22 cycles, >so a 1 MHz 6502 can keep up with 5.25 inch single and double density and >8 inch single density with programmed I/O. 8 inch double-density >requires a faster processor, DMA, or special tricks. > >With a Z80 a typical read transfer loop takes a minimum of 52 clocks, >which on a 2 MHz Z80 meets the requirements for all but 8" double density, >which requires a faster processor, DMA, or special tricks. > >On either processor, unrolling the loop does not shave off enough cycles >to get to the 8" double density transfer rate. > >Note that the read loop has to be capable of reading bytes at about >20% faster than the nominal rate or overruns become likely. > > nominal nominal required read loop > format xfer rate byte time byte time > ---------- ---------- --------- ------------------- > 5.25" FM 125 Kbps 64 us 52 us > 5.25" MFM 250 Kbps 32 us 26 us > 8" FM 250 Kpbs 32 us 26 us > 8" MFM 500 Kbps 16 us 13 us > >> The 765-based all-in-ones such as the National 8473 and the WD37C65A >> are about as hard to obtain and are a little more difficult to >> interface to a Z80 (just about require DMA and interrupts to work >> right). > >The 765-based controllers work fine with or without DMA. Again, the >issue is the data rate. > >Eric You hit the nail on the head. Interfacing 765 or 179x or any of the other flavors is about the same from the bus side be it 8080/8085/z80 or 6502. As long as you can poll within the minimum read/write loop time it's fairly easy. If not in the 8080/8085/z80 world you can use processor ready line to do a stall-wait on DRQ to keep the loop in sync and save some 22 T-states. I forget if 6502 has a ready wait line. >From a simple SBC perspective even the 1770 series requires some glue and will inflate the parts count a fair amount. The more common 1793 or 765 will require enough parts to double or triple the parts count. All of the 37C65 (and 37C665) parts work ok (witness the P112) but go scarce as the PC industry drives their existance and disappearance. Easy yes, simple, only if your not doing the work. However add a floppy and who's supporting all them when someone wants to interface some oddball pertec or CDC or Amdek 3" that "doesnt work with the SBC floppy"? I've built my fill of floppy based, IDE based, CF based, ROMdisk based systems and the latter two are far easier to construct and get going and if your trying to run CP/M and mess with programming and applications the smaller lower power SBC can be its own form of fun as you can put it in a small box with a wall wart and use the laptop as a terminal anywhere. Having a few PX-8s, Darth Vaders lubch boxes and S100 systems with all the disks and what not is fine but when you want to move them it's not so fun using hand truck. Where my tiny Z80 with 32MB CF in a 5x4x1.5" box is rather fun to bring and show CP/M and what it can still do, on batteries! Allison

18 years, 2 months

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SBC6120 (Dec PDP 8 on a chip) on ebay

by rborsuk＠colourfull.com

Hi All, Never got around to assembling my Spare Time Gizmos SBC6120. Just put it on ebay if anyones interested. Item #300234398483 Rob Rob Borsuk email: rborsuk at colourfull.com Colourfull Creations Web: http://www.colourfull.com

18 years, 2 months

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CP-M Z80 home brew computer circuit board

by ajp166＠bellatlantic.net

> >Subject: Re: CP-M Z80 home brew computer circuit board > From: "Roy J. Tellason" <rtellason at verizon.net> > Date: Sun, 15 Jun 2008 17:22:48 -0400 > To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> > >On Sunday 15 June 2008 16:43, Chuck Guzis wrote: >> From: "Andrew Lynch" >> >> > Implementing floppy IO can take on many variations and picking the FDC >> > is just the first of many challenges [FDC1793? NEC765? SMC9266? >> > WD2797?]. What about the data separator? Few chips remain and viable >> > sources are scarce. Even integrated FDCs with built in data separators >> > are not readily available. >> >> The WD1770/1772/1773 is still my favorite "almost no external >> circuitry" chip, but they're getting harder to find, in spite of >> being used on Atari and Commodore boxes. You don't need to buffer >> the floppy interface and the things have integrated data separators-- >> and come in a 28-pin package. > >I thought it was the 179x parts that had the data separator on-chip, no? No. 1770 did as did 2793... Allison > >-- >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

18 years, 2 months

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IDT tape drive information

by aek＠bitsavers.org

This should be a Pertec formatted 800/1600bpi drive. I have a slightly earlier version. I'm pretty sure I have a manual for it, will dig around.. Curiously, I wasn't able to get it to work correctly with a Pertec to SCSI converter out of a Qualstar transport.

18 years, 2 months

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Emailing: CP-M Z80 home brew computer circuit board.htm

by lynchaj＠yahoo.com

CP-M Z80 home brew computer circuit board bfranchuk at jetnet.ab.ca bfranchuk at jetnet.ab.ca <mailto:cctalk%40classiccmp.org?Subject=CP-M%20Z80%20home%20brew%20computer% 20circuit%20board&In-Reply-To=5E5B27B6AB204FE39BB21B75D4C8713B%40andrewdeskt op> Sun Jun 15 12:06:33 CDT 2008 * Previous message: CP-M Z80 home brew computer circuit board * Next message: big bucks for a Tek computer on eBay * Messages sorted by: [ date ] [ thread ] [ subject ] [ author ] ________________________________ Andrew Lynch wrote: > -----REPLY----- > > Hi! Thanks Jim for the comments. Please let me address the issues raised > by Ben: > > If you look closely at the SBC design, you'll notice it has a feature even > better than a floppy controller -- it has a fully buffered IO bus! It > contains all the Z80 signals brought out to the DIN 41612 connector. The > peripheral bus adheres to the published ECB standard. > > If you want floppy IO, the solution is simple -- just design one and attach > it to the bus! I have already done this with my Disk IO board (IDE and > NEC765 FDC) which plugs into my home brew ECB backplane along with the SBC. > Assuming there is enough interest in these home brew SBCs, I hope to make a > PCB version of the Disk IO board. > Well when you get a PCB of the Disk I/O board , I'll take the set of PCB's. Will a 8272 (intel) Disk controler replace the NEC765? for the floppy controler for the track formatting for CP/M? Unicorn Electronics is my favorite shopping for electronic parts and I can find a 8272 there. -----REPLY----- Hi Ben, Of course, the NEC 765 and Intel 8272 are virtually the same part and are as common as dirt. I believe Intel licensed the NEC 765A and just renamed it the i8272 or something like that. However, getting the FDC chip is the trivially easy part. Getting a data separator is a much more difficult problem. Have you tried finding an FDC9229 recently? How about a SMC FDC9216 or UMC 8326? Even the FDC1793 requires a DS chip. I challenge you to even *FIND* a FDC9229 *datasheet* these days. DS chips are nearly unobtainium or at least very difficult to get. I have a few and but not many. They are hard to find. For a DS you can probably substitute a ROM based state machine or even hack it out using SSI TTL chips. However, then you'll have a much larger PCB that'll cost a small fortune to manufacture and few can afford. If you try to use an integrated FDC with DS built in, you'll run into even more problems. Chips like the WD2797 and SMC9266 have built in data separators but are even more scarce and expensive than the data separator chips. In short, if just adding Floppy IO to a SBC were an easy task, you see more home brew SBCs available with them. I am trying to build an SBC that any hobbyist can afford, build reliably, and have a reasonable chance of success. That means compromises had to be made and some stuff had to go. Anyone can design a great computer on paper. Making a real, tangible part is a lot more difficult. Using cool sounding but almost impossible to find parts seems easy but it makes the SBC practically worthless. If you can make a low cost Z80 SBC that includes floppy IO, I would love to see it. I'd even buy one or two. I look forward to seeing your design. Thanks and have a nice day! Andrew Lynch

18 years, 2 months

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IDT tape drive information

by ian_primus＠yahoo.com

I'm looking at buying an IDT (Innovative Data Technology) tape drive, model TD-1054/INTL. I don't have any information on it other than that. It's a manual thread drive, and appears to be 800/1600bpi. But, what I can't tell from the seller's pictures is the interface. He thinks it's Pertec, but doesn't know. I don't have a formatter board, all my machines are set up to communicate with formatted Pertec drives. It _appears_ to have two 50 pin connectors on the board, but it looks like a couple of the fingers aren't populated. I don't remember ever seeing a Pertec drive like that. (but I could be wrong...) I've emailed the seller asking for a better picture, but I was hoping that someone here might have some knowledge about this drive. Thanks! -Ian

18 years, 2 months

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Zork for CP/M setup question

by ethan.dicks＠usap.gov

Hi, All, With all the CP/M questions flying around (and some by me), I ran across an interesting archive at one of the CP/M respositories - Infocom games *plus* setup files for random CP/M environments. The source provided starts like this: ;Copyright 1982 Infocom, Inc. All rights reserved. ;Configuration Program for INTERLOGIC(tm) CP/M Files ;Configured for basic no-frills terminal ;This program should be edited to specify terminal and ;printer parameters for your CP/M system. Edit this ;file, then assemble, load, and run the program. ;Complete documentation of the setup procedure will ;be found in your INTERLOGIC Reference Card. ;Terminal and printer specific parameters start at ;the label CPMCPL, about 20 lines below. Nothing ;prior to that label should be altered. ... and what follows are a set of data storage spots to fill in with who-knows-what to customize interpreter behavior for your environment. Does anyone have a copy of the aforementioned "INTERLOGIC Reference Card" for CP/M versions of the games? I'm running things under the altair/altairz80 emulators that are part of SIMH. I have CP/M, etc., working fine - I just need the text from the Infocom reference card that would have come in the game box. Thanks, -ethan -- Ethan Dicks, A-333-S Current South Pole Weather at 17-Jun-2008 at 10:00 Z South Pole Station PSC 468 Box 400 Temp -64.8 F (-53.8 C) Windchill -92.1 F (-69.0 C) APO AP 96598 Wind 6.5 kts Grid 351 Barometer 673.2 mb (10886 ft) Ethan.Dicks at usap.gov http://penguincentral.com/penguincentral.html

18 years, 2 months

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Fixing a DEC Letterwriter (LA100)

by aek＠bitsavers.org

I just put a few documents up under http://bitsavers.org/pdf/dec/terminal/la100 that might be helpful.

18 years, 2 months

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CP-M Z80 home brew computer circuit board

by cclist＠sydex.com

> From: "Eric Smith" <eric at brouhaha.com> > Whether DMA is required or not has nothing to do with which member of > the 177x/179x/279x/MB88xx family you use. It's determined by whether > you can write tight enough transfer loops to avoid write underruns and > read overruns. More or less what I was trying to say (however clumsily). > On either processor, unrolling the loop does not shave off enough cycles > to get to the 8" double density transfer rate. For more conversation on transfer loop speeds, see my comments on Herb Johnson's Retrotechnology site. By getting clever with code, you can turn in some pretty fast transfer loops even on a lowly 2 MHz 8080. For example, if we assume that the controller will assert wait states if an input is attempted on the data port until a byte becomes available and interrupts on operation complete, a 2MHz 8080 transfer loop could handle an 8" MFM transfer like this: LXI H,floppy$byte floppy$byte: clocks 2mhz IN fdcport ;FDC port 10 5 uS PUSH PSW ;store 2 bytes 11 5.5 uS PCHL ;loop 5 2.5 uS Total: 26 13 uS Now, of course, you've got to unravel what you've got on the stack to get your data back, but you've gotten it--at 2MHz and on an 8080 yet. Caveat: I haven't tried this, except on paper. If you were to unroll the loop to a series of IN/PUSH pairs, the byte time should drop to 10.5 usec, more than fast enough for an 8" MFM transfer. But that discussion's from the days when silicon was expensive. An inexpensive async FIFO would get rid of the problem entirely and allow for transfer at one's convenience. The point that I was trying to make was that the 1770/2/3 make for very easy interfacing with a minimum of parts--and are very easy to program. They feature a small package and were designed for 5.25"/3.5" drives. Were I prototyping a small PCB with a Z80 and floppy support, they'd be my first choice. Cheers, Chuck

18 years, 2 months

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History of AMP?

by evan＠snarc.net

Per the subject line ... does anyone know of a good history of AMP? Either online or in book form ...

18 years, 2 months

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non-CP/M Z80 board

by dm561＠torfree.net

--------ORIGINAL MESSAGE: Date: Mon, 16 Jun 2008 22:04:49 -0400 From: "Roy J. Tellason" <rtellason at verizon.net> Subject: Re: non-CP/M Z80 board <snip> I'm not familiar with many 6800 designs, but I was somewhat surprised to see how limited some parts are, like the 8085 in the "8085 Cookbook" where you could really get away with very little. OTOH, the c64 doesn't use any buffering _at all_ and yet the CPU in there seems to have little trouble driving 3 ROM chips, a set of 8 4164s, plus all the peripherals. I'm guessing that the Z80 is probably somewhere in between, and that the datasheet probalby won't give me the whole story anyhow. <snip> --------REPLY: Don't forget that CPUs like the 8085 need data/address MUX chips anyway, which are usually also buffers. m

18 years, 2 months

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Fixing a DEC Letterwriter (LA100)

by dm561＠torfree.net

---------ORIGINAL MESSAGE: Date: Mon, 16 Jun 2008 22:23:39 +0200 From: "Steve Maddison" <steve at cosam.org> Subject: Re: Fixing a DEC Letterwriter (LA100) 2008/6/16 M H Stein <dm561 at torfree.net>: > Various patterns of DSR and POWER/FAULT flashing are the diagnostic > failure codes; what pattern do you have that is not documented? > > Defective RAM is 8 flashes BTW. Yep, I figured that one out the long way. I only have some user docs so this wasn't listed, just things like "out of paper" and "cover open". I'm now back to the original CTS and ONLINE combination (no flashing). --------REPLY: POWER/FAULT not flashing should indicate that it has passed POST; DSR means what you'd think, that DSR is active. Looks like it thinks everything's OK. 1 to 9 flashes indicate faults with ROMS 1 to 7 & normal/extended RAM. Steady flash, no bell: open cover or paper fault. Steady flash w/bell: head jam or servo motor/encoder m

18 years, 2 months

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non-CP-M Z80 board

by lynchaj＠yahoo.com

non-CP/M Z80 board Roy J. Tellason rtellason at verizon.net <mailto:cctalk%40classiccmp.org?Subject=non-CP/M%20Z80%20board&In-Reply-To=> Mon Jun 16 20:01:54 CDT 2008 * Previous message: Fixing a DEC Letterwriter (LA100) * Messages sorted by: [ date ] [ thread ] [ subject ] [ author ] ________________________________ I'm thinking about building a z80 board, with varying amounts of "stuff" attached, with RAM and ROM that may be NMOS or CMOS, and some indeterminate number of Z80-family and compatible peripheral chips. My question is this: At what point do you _need_ to have address and data bus buffer chips? -- 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 -----REPLY----- Hi, I think the safe range for 74LSxxx style TTL is about 5-10 or so connections per output gate. You can compute the ratio of the various datasheet currents and get a more exact figure. However, here is a pretty good set of "rules of thumb" for circuit design: http://kurser.iha.dk/eit/dtm1/DTM1_html/Wakerly/udgave3/xc03.pdf See line 3.49 for the table of the various combinations. They say 74LSxxx on 74LSxxx can do up to 20 but I'd keep it lower to be safe. That should be enough for some static RAM, a ROM, a couple of peripherals, some simple glue logic and that's about it. You can stretch it a bit using CMOS chips or the more recent TTL families as long as you keep the PCB fairly compact. Doing anything more than the above or going off board with a bus requires buffers. You'll find there are few if any absolute rules on the subject but lots and lots of opinions. If you examine the IBM XT motherboard schematic, you'll see it uses many buffer chips -- primarily due to the DRAM, ISA bus interface, and decent sized PCB. On the WaveMate Bullet schematic, it has many buffers to for similar reasons. There is only so big you can make the PCB and only so much current can be sunk before the signals start to degrade. If you want to avoid buffers, think 1) small PCB, 2) small number of chips, and 3) shortest wiring connections as possible. Thanks and good luck with your project! Andrew Lynch

18 years, 2 months

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time to part with my PDP-11 system

by dm561＠torfree.net

Date: Mon, 16 Jun 2008 03:54:51 +0000 From: Ethan Dicks <ethan.dicks at usap.gov> Subject: Re: time to part with my PDP-11 system <snip> >...Eventually, I'll do another camping trip to Hamilton... <snip> -ethan --- I'm in Hamilton every week or so, and I have to ask: why? ;-) mike

18 years, 2 months

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Fixing a DEC Letterwriter (LA100)

by dm561＠torfree.net

-----------ORIGINAL MESSAGE: Date: Mon, 16 Jun 2008 11:06:36 +0200 From: "Steve Maddison" <steve at cosam.org> Subject: Re: Fixing a DEC Letterwriter (LA100) 2008/6/14 Tony Duell <ard at p850ug1.demon.co.uk>: >> Anyway - the original problem is gone. With the (half) new RAM I'm now >> getting what at least appears to be a proper fault indication on the >> LEDs: both DSR and POWER/FAULT are flashing. This combination isn't in >> the user manual so my guess is it's failing the POST. If any of the > > Maybe soemthing like 'RAM Error' :-) That was my first guess too. Running the ROM through a simulator and forcing the RAM test to fail confirms it. The problem? I'd managed to gouge out a bit of track while removing the ICs - just so happens it was one of the very tracks connecting /all/ the RAM to the address bus, so checking for continuity between the sockets I'd soldered in didn't reveal the problem. So I fixed that and robbed a couple more 2114s from another machine. So all RAM is replaced but, lo and behold, ONLINE and CSR are back with a vengeance. So I'm basically back to square one, although not entirely as it would at least appear the RAM is OK. It could of course still be failing in one of the peculiar ways you mentioned and still pass the POST... Otherwise it would appear the original LED combination was directly asserted by the processor, so it should be traceable in the ROM code. -- Steve Maddison http://www.cosam.org/ "The great thing about standards is that there are so many to choose from." ---------REPLY: Various patterns of DSR and POWER/FAULT flashing are the diagnostic failure codes; what pattern do you have that is not documented? Defective RAM is 8 flashes BTW. You ran the ROM through a simulator??? There's an LA100 simulator? m

18 years, 2 months

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Anyone in or near Acton MA that could do me a favor?

by ian_primus＠yahoo.com

Is there anyone in or close to Acton MA that could pick up some computer terminals for me? Unfortunately, they need to be picked up during business hours M-F, and while I'm willing to make the drive to Acton to pick them up, I can't get there during the week because of work. There's only seven of them, so they'd fit in a car. But, shipping would be prohibitive. So, basically, I want to see if someone would be willing to pick them up and hold them for me until this (or next) weekend, where I could make the drive. Thanks! -Ian

18 years, 2 months

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Fixing a DEC Letterwriter (LA100)

by dm561＠torfree.net

---------Original Message: From: "Steve Maddison" <steve at cosam.org> Subject: Fixing a DEC Letterwriter (LA100) Hello all, I have a half-dead Letterwriter 100 KSR here I'd like to get working again. I get a short buzz from the paper feed motor at power-up but instead of flashing all it's indicator LEDs, both CTS and LINE stay illuminated. There's no carriage movement and the keyboard does nothing either. The basic vital signs are OK but I'm stuck without a service manual or schematics. Does anyone have access to these docs? I'd of course also be interested to hear of any common problems and/or things to check before I dive into all-out mending mode... Cheers, -- Steve Maddison http://www.cosam.org/ ----------Reply: Can't suggest where to start checking but I do have several RO LA100s awaiting the trip to the scrapper, in case I can help with any non-kbd parts before they go. I do also have the tech manual somewhere; unfortunately IIRC it's on 17" paper so I can't scan it. I believe Tony also has a copy and more knowledge/experience than I; maybe he has some suggestions. m

18 years, 2 months

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time to part with my PDP-11 system

by dgahling＠hotmail.com

I have a PDP-11 system, fairly recent, about the size of a mini-fridge, on wheels. last I checked it was still fully operational, but I can't speak to that now, it's spent the last 2 years in storage. I just don't have space for it, and it's a bit larger than I can find use for. its about 4 feet long, 2 feet wide and perhaps 3 feet high - thats by eye ball. it has a TK70 tape drive that's in excellent shape. the plastic cover over the front is missing which is why I'm not sure of the model. I'd rather sell or trade it, if there's interest. i'm looking for a vax station 3100 model 76 or a 4000 model 90 or some volker craig terminals. I'd prefer to avoid junking it. Keep in mind I'm not interested in shipping it, it weighs a bloody ton! located in Scarborough, Ontario (Canada), so anyone in the GTA area would be an easier pick up. Dan. _________________________________________________________________ If you like crossword puzzles, then you'll love Flexicon, a game which combines four overlapping crossword puzzles into one! http://g.msn.ca/ca55/208

18 years, 2 months

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Apple I on ebay

by marvin＠west.net

If this is the Apple I I'm thinking of, it WAS bought at a garage sale for a couple of bucks. The person selling it said they were going to put it on oBay, and a friend of his and mine asked me about it. I referred them both to Sellam, and this is the first I've heard about it since then. > From: Al Kossow <aek at bitsavers.org> > Subject: Re: Apple I on ebay > > "This computer will only be sold to a MUSEUM OR SERIOUS COLLECTOR ONLY" > > > eBay is absolutely the WRONG venue to try proving that. > > The whole notion of someone going to an estate sale and picking this > up is unfortunate as well. I though Sellam knew where all of them were?

18 years, 2 months

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