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101090 discussions

by Marty＠itgonline.com

I ran some service calls on Columbia pc's around 1987. As I was raised in the Washington, DC suburbs (Silver Spring, Maryland) and had been to Columbia, Maryland (which is located halfway between Washington and Baltimore many times, I was surprised when reading the documentation of the pc which stated it was made in Columbia, Maryland. Several years later I needed to order a replacement motherboard and discovered they had moved to Florida. Marty ______________________________ Reply Separator _________________________________ Subject: Re: Collectable PCs Author: classiccmp(a)u.washington.edu at internet Date: 11/9/98 4:10 PM Innfogra(a)aol.com wrote: > > In a message dated 11/9/98 8:37:45 AM Pacific Standard Time, > Marty(a)itgonline.com writes: > > << Does your Columbia list it as having been made in Columbia, Maryland? > I believe their early pc's were made in Columbia, Maryland, later they > moved to Florida. > >> > I will look. I didn't know that. Thanks for the info. i will let you know when > I find out. > Paxton I have 3 Columbia portable XT's.. Didn't know they were made in Florida. Could be why there seem to be so many in the thrift stores down here in Florida.. I have never been able to find anything on the internet about these machines, looked everywhere and nothing found.. If anyone has any web sites with info on them, or knows some history on them sure would like to hear from you... Phil... ------ Message Header Follows ------ Received: from lists3.u.washington.edu by smtp.itgonline.com (PostalUnion/SMTP(tm) v2.1.9i(b5) for Windows NT(tm)) id AA-1998Nov09.161030.1767.76473; Mon, 09 Nov 1998 16:10:30 -0500 Received: from host (lists.u.washington.edu [140.142.56.13]) by lists3.u.washington.edu (8.8.4+UW97.07/8.8.4+UW98.06) with SMTP id NAA17730; Mon, 9 Nov 1998 13:08:14 -0800 Received: from mxu3.u.washington.edu (mxu3.u.washington.edu [140.142.33.7]) by lists.u.washington.edu (8.8.4+UW97.07/8.8.4+UW98.06) with ESMTP id NAA50904 for <classiccmp(a)lists.u.washington.edu>; Mon, 9 Nov 1998 13:08:00 -0800 Received: from raven.prod.itd.earthlink.net (raven.prod.itd.earthlink.net [209.178.63.9]) by mxu3.u.washington.edu (8.9.1+UW98.09/8.9.1+UW98.09) with ESMTP id NAA04 536 for <classiccmp(a)u.washington.edu>; Mon, 9 Nov 1998 13:07:59 -0800 Received: from server (ip53.fort-myers3.fl.pub-ip.psi.net [38.30.206.53]) by raven.prod.itd.earthlink.net (8.8.7/8.8.5) with SMTP id NAA05623 for <classiccmp(a)u.washington.edu>; Mon, 9 Nov 1998 13:07:56 -0800 (PST) Message-Id: <36475A0B.54F3(a)pop.a001.sprintmail.com> Date: Mon, 09 Nov 1998 16:09:31 -0500 Reply-To: classiccmp(a)u.washington.edu Sender: CLASSICCMP-owner(a)u.washington.edu Precedence: bulk From: Phil Clayton <handyman(a)sprintmail.com> To: "Discussion re-collecting of classic computers" <classiccmp(a)u.washington.edu> Subject: Re: Collectable PCs References: <a009459f.36475602(a)aol.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Listprocessor-Version: 8.1 beta -- ListProcessor(tm) by CREN

27 years, 10 months

1802 docs

by allisonp＠world.std.com

< Ooh. I don't have anything from DDJ or Kilobaud. What issues? I'd have to dig them out to get the dates. Likely around 1978-79. < > I also have a copy of quest tiny Basic, hex dump, paper tape and it's < > manual. < < How big is tiny BASIC? How did you communicate with it? A terminal < over a 1854 UART? It's 2k (fits in a 2716), romable and was sold that way as well. IO in the version I have expects UT4 (monitor) or the equivelent. UT4 uses EF4 and Q to do bit serial to tty. Oh, I bought it because it was cheap ($10 in 1978) and never used it! I was having more fun running small stuff in asm. Allison

27 years, 10 months

Saved Altair 4K BASIC

by allisonp＠world.std.com

< It's all a matter of time, place and comparison. What was DEC charging < for a box, OS and BASIC at the time? An 8E with basic, enough core and tty would likely be about 14-18k maybe less. Used it could be in the under $3000 range in '77. In 1972 I was offered a pdp-8I with he works(TTY, RS08, DECTAPE, 32k core) for a mere $10,000 operating! It was a bit steep for me but a new chevy truck then was $3300. < >Absolutely. I agree 100%. If he had priced it in the range that a < >hobbyist could afford, and proportionate to the cost of the system ($50 < >for the kit?) then people would buy it. Its nothing to throw down $25 < >$50 if you're getting a manual and support with that. < < Pish-posh. In 1978, we're talking about a bunch of scroungy ex- < or current- ham radio operators who'd cross the street to pick up < two pennies on the sidewalk. Even today, why do people routinely < pirate software that can be had for $20 in the CompUSA discount bin? That characterization was at best inaccurate. The members of LICA (LI computing ASSOC) were less than 25% hams, many(60%) were professionals in the industry (mostly large iron). Most were techs and hard wroking slobs that the price of a KIM-1 was stiff for them and $350 for Basic was several weeks pay. Allison

27 years, 10 months

1802 docs

by allisonp＠world.std.com

< I have broken out the box box 'o 1802 stuff. In it are: I don't have the VIP but I have the manuals for one. I also have the articles from Popular Electronics, DDJ and Kilobaud. I also have the basic DOCS for the 1802. COS/MOS Memories, Microprocessors, and support systems 1979. This includes data and schematics for the CDP18S6xx series modules. MPM201 User manual for the RCA CDP1802 CPSMAC Microprocessor. MPM203 Evaluation kit manual for the RCA CDP1802 COSMAC Microprocessor (1976) MPM206 Binary Aritmetic subroutines for RCA cosmac Microprocessors I also have a copy of quest tiny Basic, hex dump, paper tape and it's manual. Allison

27 years, 10 months

1802 docs

by franke＠sbs.de

> < I have broken out the box box 'o 1802 stuff. In it are: > I also have the basic DOCS for the 1802. The 1802 data sheets are still available from Harris. New, and PDFied. Also for most of the pheripheral parts. > MPM206 Binary Aritmetic subroutines for RCA cosmac Microprocessors > I also have a copy of quest tiny Basic, hex dump, paper tape and it's > manual. These two ar e very interesting. Servus Hans -- Ich denke, also bin ich, also gut HRK

27 years, 10 months

History of "Multimedia" (Was:iMac AddOn (was:Future Collect

by allisonp＠world.std.com

> On Tue, 10 Nov 1998, Doug Yowza wrote: > In 1970 a college art prof told me that "multimedia" is 2 or more Koda > Carousel projectors plus a sound track. In response to questions he d > insist that no substitutions were permitted. How pandatic of him. When I was in school a few years before that multimedia was sound, pictures in the form of Video, Still pictures, moving pictures, lights and maybe action! The concept of the time was hit as many senses as was possible. Allison

27 years, 10 months

Saved Altair 4K BASIC

by allisonp＠world.std.com

< Absolutely. I agree 100%. If he had priced it in the range that a < hobbyist could afford, and proportionate to the cost of the system ($500 < for the kit?) then people would buy it. Its nothing to throw down $25 o < $50 if you're getting a manual and support with that. The KIT was $500, but that only got you the box and a CPU. Ram was expensive then and the IO was either serial, tape, or parallel so you also needed a TTY or CRT(I used CT1024). Still BASIC for MITS prices was ok but as Billy's price it was out of reach. FYI at the time of the article (early '75) a system with 32k of ram, cassette and serial IO would be over $3500! The 8800 was cheap, but not that cheap. Three years later (early 1978) that price would have dropped to 1500 or less due to the lower cost of memory boards and the lower cost of the system itself. The Disk system would be around late '76 early 77 with software to lag behind it. In 1977 you could get languages, for far less than $100 and many offered features that MSbasic did not have. Examples of this were PT basic, Focal and NS* disk BASIC. Also Tiny basic was published along with a little later LLL8k Basic as examples of free software with sources available. That trend nearly killed MS and did put a few others under. It was very hard to make a buck on paper tape or cassette based software. Affordable disk systems opened up the market and made it a serious force for applied software. Allison

27 years, 10 months

Elf99 - rebirth of a classic

by allisonp＠world.std.com

< > < > for a intersil 6100 (12 bit pdp-8) based system. < > < < < Do tell. A small potload of them for the Intersil sampler, there was an article in Microcomputing December 1979 (P54), also the intersil data books and schematics for some of the board level porducts and app notes. Also several megabytes of PDP-8 software and a DECMATEIII to run it on. < That wasn't memory mapping. The 1861 DMA'ed the video data out. No, that was how it transfered the data to the CRT (it would read memory with DMA and serialize it add sync and all). the User would write data to the memory map that was display memory to change the pattern on the screen. That makes it memory mapped. the fact that it used DMA was a simplification of the hardware. < I saw one at the Computer Museum of America, but I don't think it is < available. There are still a bunch around. They only made maybe 20-30,000 of the 8E/8A series. < Well... they _were_ nice and bright. Ah, the countless hours I spent < staring at those ember-bright dots, counting toggle pulses in my head < to fix a one-byte bug. First thing I added was four more to latch the address. < Ob1802Trivia - don't execute the one "missing" instruction, 0x68. ISTR < that the CPU went berserk and whomped memory randomly. Well, all of the 6Xh instructions manipulate the X register directly or indirectly. 60 inc X R(X)+1->R(X) ! memory pointer pointed to by R(X) is ! incremented What's significant is the operation is a dummy output but since having the N lines with 000 on them was a nop all it does is increment the pointer. 61->67 out M(R(X)) ->BUS; R(X)+1 -> R(X) Effectively output a byte pointed to by R(X) to the device and increment R(X). The N lines will have a value of 1->7 depending on opcode. 69->6F input BUS -> M(R(X)); BUS -> D Now... the cosmac uses the high bit of the N register to signal internall that the instruction is a input so.... 68 inpGarbage BUS -> M(R(X)); BUS -> D In this case bus content is undefined so you just trashed the accumulator (D) and the memory pointed to by R(X). On my system due to the pullups on the bus and all that meant a FFh was loaded every time. Handy way to stuff a -1. The COSMAC is a real simple machine and it's behavour is very predictable with one general exception... The CMOS process in the late 70s had horrendous propagation delays and the timing of the chip was very variable with voltage. So at very fast clocks the timing on some signals could have a negative setup at one voltage and a positive setup if the voltage was higher. I know of few people that ever ran successfully at the rated maximum. At moderate speeds it was easy to use. Allison

27 years, 10 months

Saved Altair 4K BASIC

by allisonp＠world.std.com

< and deluging the market with bad software. The only problem is, everyon < said "OK, Bill. Here's my checking account. Don't worry about fixing the < kinda gives your software 'character'." The early BASIC he did was buggy as hell too. The first version that was semi OK for 8k basic was 3.51. Allison

27 years, 10 months

Saved Altair 4K BASIC

by allisonp＠world.std.com

< At the time, MITS had an absolutely miserable 4K dynamic memory board. < This was one of the few ways that they could entice folks to buy it. The 88MCD was poor, the S4K slightly better and neither would work with z80s without being severely hacked! I had three of each and they were all junk. Why three of each... at one point S4Ks were offered less rams to anyone that had 88MCDs at a ok price. I was able to make them acceptably reliable by pulling the Drams and putting in compatable static parts (NEC uPD410). The board layout still stank and the general noise level on the bus didn't help. Up grading the bus to a WAMCO or compupro with terminations helped. Replacing the whole machine with a NS* Horizon was a vast step forward. Allison

27 years, 10 months

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