test-drb June 1998

test-drb@ccmp.vtda.org

158 participants
941 discussions

"Computer Hobbyist" + Homebrew computers

by jon＠techniche.com

After a fair amount of effort on my part, I found and obtained a copy of the July 1974, Radio-Electronics mag that has the cover story "Build the Mark-8, your personal minicomputer". I was less than delighted to find that in this instance, R-E left out most of the construction details (including any skematics). They have an offer on the second page of the article where you should order the kit with circuit board patterns, and the rest of the details. The article includes some theory of ops, a parts list and a few photos. Although I'd love to see all these old mags on-line, I guess the copyright issue will prevent that from happening. Jon >On Fri, 5 Jun 1998, Allison J Parent wrote: > >> I'm not trying to kill homebrew but having done it...well I have no >> problem with building a mark 8 useing an 8008 and some modern rams >> as it not an antique and it would save days of work. > >Anybody know where I can find a reprint of the Mark 8 article? A good >web-ized version would do the trick. > >> dddameron(a)earthlink.net... >> >> If you hadn't posted to the list I would not have seen this as earthlink >> is in my killfile due to excessive porn spam. IF anyone needs to email >> me they will ahve to use another ISP. > >earthlink.net is one of the better anti-spam ISPs. They were one of the >first to win a lawsuit against a spammer. For details, see > http://www.earthlink.net/nethelp/spam/ > >What you are seeing are most likely forged headers, an almost universal >practice among spammers. If you can, take a minute to look at the real >headers to track down the offending site. It is often an unsuspecting site >that left their mail server open to be used as a spam relay. I've had >good success in getting sites to close up these relays, get spammers to >lose their accounts with the originating ISP, and even get entire ISPs >shut-down (at least temporarily) by their upstream ISP. Try it -- it's a >fun and rewarding hobby :-) > >-- Doug > >

26 years, 1 month

"Computer Hobbyist" + Homebrew computers

by ddameron＠earthlink.net

Thanks for the information. At 08:39 AM 6/5/98 -0400, Allison wrote: >If you want to run the software of the era using more modem parts would >not prohibit tht but could be easier to work with. For example one 62256 >32kx8 ram replaces 256 2102s! I assure you after wirewrapping and >debugging 4k of 2102(32 of them plus TTL) the x8 parts suddenly look a >lot better. > Yes, I still have some 1101A rams and wiring them would be even 4X worse! By the way, they have "ETC 4" stamped on them. I have seen this on other IC's. Does anyone know what it means? >I'd suggest finding one of the non first line machines or nearly so like >an IMSAI, Northstar, Compupro, CAlifornia Computers, SWTP, or other >machine that were still from the 70s. > Have been looking for over a year in thrift shops, etc. The only thing I've seen was a Kaypro or Osborne, when I went back to examine it, it was gone. >I'm not trying to kill homebrew but having done it...well I have no >problem with building a mark 8 useing an 8008 and some modern rams >as it not an antique and it would save days of work. > >You could also build with z80 (circa 1976) it is still used and common, >it runs virtually tons of software and there are PC emulators for it as >well. > Yes, a z80 is pretty easy to use. I built a small unit about 1991 with a 6116 ram and a monitor in a 2716 with a 8255 as I/O as a piece of test gear. It has been handy to test LCD displays, ram chips, etc. I was going to use a Mac to Sunol card which had a z80, 2764, 6264, and 74LS244 type ic's as I/O, as well as RS422, but tracing the circuit to find the I/O addresses took too long. >dddameron(a)earthlink.net... > >If you hadn't posted to the list I would not have seen this as earthlink >is in my killfile due to excessive porn spam. IF anyone needs to email >me they will ahve to use another ISP. > Earthlink is my first ISP, is it widely known for this? Are others much better? All the spam I've seen in newsgroups doesn't seem to be earthlink, but most doesn't have a "from" address anyway. The email spam is annoying, haven't noticed any particular place where it comes from. -Dave

26 years, 1 month

4004/8008 in calculators? Which ones?

by bill_r＠inetnebr.com

Recently, someone made the comment that the 4004 and 8008 were used in some old calculators. Can anyone supply brands and/or models that would have used these? My company is having a big junk sale of tables, chairs, and old calculators and typewriters soon, and the state is having an auction this weekend. I already snuck into the store room and opened up one of the oldest calculators, but it had some big 40-pin ceramic chip on it with a number I'd never heard of. I'll probably pick up a couple just because they have some nice nixie tubes in them, if they go cheap enough, but I'd like to score some old CPUs at one of these events if they're there. Any suggestions? -Bill Richman bill_r(a)inetnebr.com http://incolor.inetnebr.com/bill_r (Home of the COSMAC Elf Simulator!)

26 years, 1 month

Atari hard drives? The actual Atari Answer :)

by thedm＠sunflower.com

Okay gang. I just can't take it, I gotta help this guy become an atarian. :) Okay, this is what; you need. You need an ATSCI to SCSI converter controller. The most common for the ST series is made by ICD. They can still be had from ICD but they are around 79.00. There is an Atari dealer, yes, dealer, amazing in my area. [KCMO] Their home page is www.systemsfortomorrow.com. They are a great bunch of guys and I got my ICD SCSI controller for them for a 1040 Swap. [I had two]. But he has a few used ones and can get you one if you want. This machine is very worth spending the money to get a HD for. My 1040ste I have upgraded to 4 megs, it has a 14.4 modem and a quantum 105lps scsi HD on. It will currently connect to the internet, and i mean with PPP an PAP authentication, will do IRC, FTP, Popmail and graphically surf all via freeware. Please let me know if I can be of any assistance. Bill Girnius -----Original Message----- From: Tony Duell <ard(a)p850ug1.demon.co.uk> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Wednesday, June 03, 1998 6:26 PM Subject: Re: Atari hard drives? >> >> > MFM and RLL are encoding schemes. They define how to turn a stream of 0's >> > and 1's into the magnetic patterns on the disk. They have nothing to do >> > with how a drive talks to its controller >> >> Of course, I was just using the vernacular... (About like "CMOS setup" - > >I don't normally mind - in fact I often misuse the terms myself. But whem >we're talking about hard disk operation, it helps to be exact. > >CMOS setup is less worrying. After all you are setting up parameters >which are stored in CMOS RAM (part of the real time clock chip). I do >object to people who don't know the difference between the CMOS RAM that >stores the BIOS setup parameters and the BIOS ROM itself. > >> you didn't make any comments about that one though. :-)) But I didn't >> remember that it was called ST506. Sounds like a Seagate part number. >> Was it a PC hard drive, or even earlier? > >The SR506 interface is named after the ST506 drive (5 Mbytes) which was >(AFAIK) the first drive to use this interface. Actually, the right name >should be ST412 (which was a 10 Mbyte drive that was used in the original >IBM XTs, etc), since there are minor differences. But if I called it an >ST412 interface few people would understand me. > >> > You're probably thinking of the servo bursts - the signals that keep the >> > heads on a track. Some drives did use a particular side of one of the >> > platters for these. Other drives 'embedded' them in the sector headers on >> > the data platters. The latter is not common on ST506 interfaced drives, >> > but is common on SCSI/IDE drives >> >> Hmmm, interesting. So low-level formatting doesn't rewrite these? > >Absolutely not. That's one reason why bulk-erasing hard drives can ruin them. >The only way to rewrite the servo data is to open up the disk in a clean >room, afix a position transducer (laser interferometer !) to the head >arm, position the heads accurately where you want them using a special >electonic system linked to the positioner coil and the transducer and >write the servo bursts. I know of nobody who has the equipment to do that. > >> That would imply that the servo bursts are not involved in determining >> sectors at all. I used to use an RLL card with a couple of formerly > >Correct. On embedded servo drives, the number of sectors/track is fixed, >since you want the servo bursts in the headers, and not in the middle of >user data. But on servo surface drives (with the 'wasted' surface), the >servo data is pretty much continuous and doesn't have anything to do with >the sectoring > >> MFM drives, and it made more sectors per track, so I thought the >> wasted platter had something to do with that. > >No, it's similar to the fact that I can take a 5.25" floppy and format it >in my TRS-80 model 1 with 10 sectors (88K) or in my Apple ][ with 16 >sectors (143K). Both machines have 35 tracks, in the same position. > > >> > Are you sure: While almost all clone controllers have a formatter routine >> > at C800:5, >> >> Yep, that's the one. > >Well, unless you move the BIOS to CC00:0000 or somewhere... > >> >> > I couldn't find it in the original IBM XT hard disk BIOS. >> >> Hmmm. Well I think I remember using a full-length IBM controller with a >> 30 meg drive, and only being able to format 10 megs of it because it was >> the XT controller designed for the 10 meg hard drive. But I don't remember >> if I used debug to format it, or something else. This is my mom's machine >> which she never uses, so one of these days I can replace it with something >> more useful and refesh my memory about its contents. I'm going to try >> to restore it to original condition since it is so close already. > >It's not in the BIOS source in my Techref. The first few lines of that >source are : > >0000 55 DB 055H ; Generic BIOS header >0001 AA DB 0AAH >0002 10 DB 16D ; ROM length byte (ARD) >0003 DISK_SETUP PROC FAR >0003 EB 1B JMP SHORT L3 >0005 3530.. DB '5000059 (C)COPYRIGHT IBM 1982' ; Copyright notice > >So on the true-blue IBMs, there's a copyright notice there, not a jump >to the low-level formatter. > >> _______ KB7PWD @ KC7Y.AZ.US.NOAM ecloud(a)goodnet.com >> (_ | |_) Shawn T. Rutledge on the web: http://www.goodnet.com/~ecloud >> __) | | \__________________________________________________________________ >> * quantize the universe * 808 State * virtual reality * mad science * >> > >-tony

26 years, 1 month

"Computer Hobbyist" + Homebrew computers

by allisonp＠world.std.com

<Am also thinking of building a early/mid 1970's era computer. If made wit <"old stock" parts, how would it fit in with the other "classic" computers <far as the history? The original factory made types (Altair, Mark 8, SWTP <sound too hard to find and too much money for me. Am thinking of using <Vector type cards with the common 2x22 pin edge connector. If more pins a <needed, there is the 56 pin "STD" bus size or the 2x36 pin connectors. Th If you build you own bus you will not have the ability to use other cards >from contemprary machines. Cost to build will rival that of a used IMSAI and likely you will quit before the system can run software of the era. Some processors like the 8008 used in the Mark 8 were a bear to use and are hard to find now. If you want to run the software of the era using more modem parts would not prohibit tht but could be easier to work with. For example one 62256 32kx8 ram replaces 256 2102s! I assure you after wirewrapping and debugging 4k of 2102(32 of them plus TTL) the x8 parts suddenly look a lot better. I'd suggest finding one of the non first line machines or nearly so like an IMSAI, Northstar, Compupro, CAlifornia Computers, SWTP, or other machine that were still from the 70s. I'm not trying to kill homebrew but having done it...well I have no problem with building a mark 8 useing an 8008 and some modern rams as it not an antique and it would save days of work. You could also build with z80 (circa 1976) it is still used and common, it runs virtually tons of software and there are PC emulators for it as well. dddameron(a)earthlink.net... If you hadn't posted to the list I would not have seen this as earthlink is in my killfile due to excessive porn spam. IF anyone needs to email me they will ahve to use another ISP. Allison

26 years, 1 month

4004/8008 in calculators? Which ones?

by allisonp＠world.std.com

<> state is having an auction this weekend. I already snuck into the <> store room and opened up one of the oldest calculators, but it had <> some big 40-pin ceramic chip on it with a number I'd never heard of. <> I'll probably pick up a couple just because they have some nice nixie <> tubes in them, if they go cheap enough, but I'd like to score some old <> CPUs at one of these events if they're there. Any suggestions? Well if it's a 40 pin it's not a 4004/8008 as they were small 18 pins packages. If you get a number or logo off it it may be identfiable here. Allison

26 years, 1 month

Apple ][ video

by tomowad＠earthlink.net

>BTW, I just picked up a coffee-table book called "Apple Design" which >shows a lot of pretty pictures of Apples and Apple prototypes. The Lisa >appears to be the only machine whose product name matched its project >name. Apple seemed to be into girl's names at the time. The Apple /// >was developed under the project name "Sara." Who was Lisa named after, >anybody know? The Lisa was named after the daughter of Steve Jobs, Lisa Nicole. Officially, Lisa stood for "Logical Integrated Software Architecture." The names of females, usually family of Apple employees, were often used to code name projects at Apple in the late 70's/early 80's. Tom Owad

26 years, 1 month

Wang 2200

by jb＠chromatic.com

While searching the web for references to machines that I grew up on, I found a posting of yours: > Having just received the donation of a Wang 2200 mini for the > Windsor Science Centre, (no documentation of course,) am wondering > if anyone can give me any information on it? > We also received a Kim-1, but lots of info on that. > > Thanks > Charlie Fox The first machine I programmed on, in 1978 & 1979, were a pair of Wang 2200 machines; one was a Wang 2200S. Just to be sure, since I'm not informed on any machine Wang made other than the 2200, it was a "desktop" unit with integrated monitor and a rounded cabinet design. I don't know if it will help, but here's what I recall of the machines. The 2200S was more sophisticated of the pair, as it had lower-case character generation ability. Both machines had a 32KB ROM that implemented Wang's dialect of BASIC. Both had 8KB of RAM. Both used digital cassette tape drives. The BASIC was/is pretty sophisticated in that it had a whole host of matrix operations. It was primitive in that, like most BASICs of the day, all variables were either a single letter or a letter and number. The only basic types were float and string; there were no INTs or such. So, I see you posted that about half a year ago. Did you end up finding out more? Would you consider selling the machine? Anyway, good luck.

26 years, 1 month

Former Disk Costs (was: 32 bit Macs (was Atari hard ))

by allisonp＠world.std.com

<(I doubt anyone wants to go through a routine of converting files <back and forth. I strongly doubt TeX would run on a regular IMSAI <with reasonable speed). Not so. Runs fairly well on similar machines. DRI evern did a version of tex for CP/M. Have the manual and software. Personally I used runoff a lot, it was quite fast. Allison

26 years, 1 month

"Computer Hobbyist" + Homebrew computers

by ddameron＠earthlink.net

Hi All, I have found all but issue No.4 of "The Computer Hobbyist", written in 1975. Has anyone found this issue and would be willing to trade copies? Am also thinking of building a early/mid 1970's era computer. If made with "old stock" parts, how would it fit in with the other "classic" computers as far as the history? The original factory made types (Altair, Mark 8, SWTP) sound too hard to find and too much money for me. Am thinking of using Vector type cards with the common 2x22 pin edge connector. If more pins are needed, there is the 56 pin "STD" bus size or the 2x36 pin connectors. The S-100 bus seems to have many more pins than needed. Cards would be the roughly 4.5 x 6.5 inches. Cards used to be sold in this size using the 2102 static ram's, I think 4k. The 2102's are still relatively easily found, as well as standard TTL IC's. In 5 or more years, this may not be true. Sure there are 62256 static ram chips, 27256's, etc, but they came later. -Dave

26 years, 1 month

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test-drb June 1998