Selling: MITS Altair 8800
Selling my original 1975 "MITS Altair 8800", often described as the first "personal computer" (6 years before the "IBM PC"). A real piece of computing history! Complete and fully functional, this machine boots and runs a couple operating systems from the era. Includes: Main Altair 8800 system unit. Altair disk case with two Shugart SA-400 drives (1976) Multiple S-100 cards. Lear-Siegler ADM-3A terminal (1976) Dozens of 5.25" hard sector floppy diskettes! Original manuals and documentation. Jan+Feb 1975 Issues of "Popular Electronics" which featured the Altair. Also available: IMSAI 8080 (the first clone - also the "Wargames" computer) - 1975 North Star Horizon - 1976 Commodore PET 2001 - 1977 Two Tandy TRS-80 Model 1 - 1978 MicroMint SB-180 (by Steve Ciarcia of BYTE "Circuit Cellar") - 1985 More information and photos on "Daves Old Computers". Sorry, don't regularly follow this list anymore - contact me through my site. -- -- Search "Dave's Old Computers" see "my personal" at bottom!
MITS Altair availanle
Just wanted to let everyone know that I am still offering for sale my: Original (1975) MITS Altair 8800 (not the later A or B versions) I'm sure most of you know the historical significance of this machine, but just in case: It is often described as "the first personal computer" (before "IBM PC", Apple, Commodore and the others) - in other words, it is one of the first systems that "normal" people could actually own! Many well known pioneers in the software industry (eg: Bill Gates) did their early development on an Altair! Complete and fully functional, this machine boots and runs a couple operating systems from the era. Includes: Main Altair 8800 system unit. Altair disk case with two Sugart SA-400 drives (1976) Multiple S-100 cards. (I'll toss in all my extras as well) Lear-Siegler ADM-3A terminal (1976) Dozens of 5.25" hard sector floppy diskettes! Original manuals and documentation. Jan+Feb 1975 Issues of "Popular Electonics" which featured the Altair. You can see it and read more about it on "Daves Old Computers". This system is located: near Ottawa, Ontario Canada Note: I no longer actively monitor this list, the best way to reach me is: "Daves Old Computers" -> "Personal Site" -> "Contact" Dave -- -- Search "Dave's Old Computers" see "my personal" at bottom!
Floppy Cables & "twists"
After recently selling my ImageDisk system, and having a few spare older PC mainboards - I decided to make another - I did find a board that seems to have a decent FDC - it does all single density formats (many don't). Alas, it is "slightly newer enough" to only implement one floppy drive on it's interface - floppy B: does not appear at all to the system. Ripping the cable off the front panel drive to connect an external one is somewhat painful - Since the PC normally has a twisted cable to swap Select1&Motor1 with Select2&Motor2 to put each set on Select2&Motor2 of different connectors, I thought I could just use a flat cable and add a switch near the PC end to switch Select1&Motor1 to go to either Select1&Motor1 -OR- Select2/Motor2 on both connectors with the internal drive set to 1: and a cable coming out the back for drives jumpered as 2: That way I could just "flip a switch" to choose between internal drive 1: or the external drive(s) 2: (either would appear as A: depending on the switch). But when I try to access a drive jumpered as 1:, it does select, but the motor doesn't turn on. This happens even without my "special" cable. If I connect the drive (by itself) on the PC side of the twist on a standard cable, the motor doesn't work. The twist swaps Select1&Motor1 to Select2&Motor2 on the farthest connector, and since a standard drive is jumpered as 2: - This should put the 1: signals to 2: for a drive in that position - all other wires are "straight through". It looks as if some other signals is expected to behave differently when the drive is jumpered as 1: (I've tried this with a couple of different drives) - anyone know whats going on? Dave (I can use the message archive to check for responses every few days, so replying here is OK). -- -- Search "Dave's Old Computers" see "my personal" at bottom!
[cctalk] It's been a while - retirement project
Hi, this is "Dave Dunfield" - best known here for being the site owner of "Daves Old Computers" and the author of "ImageDisk" No longer have the email I used to use to access cctalk... (hence the change) Just in case anyone is interested: I've been working on a "retirement" project: I am publishing some 40+ years worth of source code to "stuff I've written". This includes my DDS products, lots of "internal tools and utilities" and other misc. "stuff". Of special interest to cctalk members, this include my Altair, Horizon, H8, D6809, MOD8, ImageDisk and some other related material. Most of it is C (mainly for my own compiler - one of the items), some in assembly, and a few "custom languages". Available from my personal site: https://dunfield.themindfactory.com or go to: "Daves Old Computers" -> "Personal" Please note that I no longer monitor these forums on a regular basis. Anyone wishing to reach me, please see the "contact" link on my site. Dave -- -- Search "Dave's Old Computers" see "my personal" at bottom!
[cctalk] Re: Intel 4004(sp?)
Sorry if not linked correctly - looking through the list via the archives.. "reply" option doesn't seem to work (at least for me - older Chrome) >but my understanding was that the 4004 and 8008 were effectively developed >at the same time? And were announced or available about within one month >of each other? I believe they were, although I never had much experience with the 4004... I did play a bit with the 8008 - and wrote a simulator/emulator for the 8008 system I had, a Canadian: MIL (Microsystems International Limited) MOD8 (Modular-8) it was also available as: GNC8 (Great Northern Computers) 8008 You can get MOD8 simulator from "Daves Old Computers" and actually experience using an 8008 based system including the built in "MONITOR-8" ROM software as well as "Scelbi 8008 BASIC" (one of the earliest) - source to both provided. If you care to, I included ASM88 (my 8008 cross assembler) so you can try writing and running 8008 code! -Be aware that MOD8.COM itself is pretty old and is 16-bit DOS software. This means it WON'T run under modern Windows, but it does work well in DosBox (I recommend the one I have on my site) Dave Dunfield - https://dunfield.themindfactory.com -- -- Search "Dave's Old Computers" see "my personal" at bottom!
[cctalk] Re: VT100 Monitor Board
> Rob Jarratt 25 Nov 2023 8:47 a.m. > Of course the worry is, why? There could be a fault on the board. > I am hesitant just to replace the fuse and try it... An older CRT terminal is probably a bit too much current draw for this, but you can prob use it in a setup to test parts... A very handy gadget you can make very easily, which I use all the time when testing small devices in "unknown operational state" is a simple current limiter. (following discussion based on North America power, numbers may be different if you are in a different part of the world). The "smallest" typical line circuit is 15A which is more than enough to cause damage to small devices experiencing excessive power draw through a fault (often indicated by a blown fuse). The "limiter" relies on the fact that an incandescent light bulb will draw/pass a fair bit of current when it is cold, and much less when it's warm. (this is because they are designed to "turn on" fast) In my case, I have three light sockets wired in parallel, all in series with the hot side of a receptacle. This lets me change from a single 25w bulb (very little current possible) up to 3 100w bulbs (a good part of amp before it seriously limits). For example, 100w bulbs draw .833ish (100/120) when operating fully lit - x3 = 2.5A max current - this would only happen if the device under test was "shorted", presenting 0 series resistance and would therefore effectively have 0 volts across it. In practice, you could prob. draw 1/2 amp (160ish ma per bulb) without warming them "too much" to seriously drop a lot of voltage. Much more than that and the bulbs will light up rather than hearing "popping" sounds from the device under test :-) -- Btw, I've given most of my CRT terminals away - For VT100's I use my "PC100" program - It provides very good VT100 emulation using an old DOS (or DosBox) PC - it remains "text" mode, so it turns "smooth scroll" into "slow scroll" and large fonts into "double spaced" fonts - but in all other respects nothing I've used it on has been able to tell it's not an actual VT100! (I'm sure there are better/graphical VT100 emulations "out there") Dave -- -- Search "Dave's Old Computers" see "my personal" at bottom!
[cctalk] It's been a while - retirement project
>26 Nov 8:14 p.m. >I was trying to format an HP LIF disk from IMD (77 tracks, 30 sectors, >5 interleave, 512 MFM encoding, 256 bytes per sector). Which I can configure >IMD for using the interactive user interface. EXCEPT it won't >accept entering sector numbering starting from 0 to 29. It always wants to >start at 1. >So it looks like it's just a trivial bug in the interactive user interface. Hi Marc, I'll look into it - it will take me a while as I have to dig out and set up a real DOS IMD system... [anyone know it there's a usable web interface to CCTALK? I browse it through the ARCHIVE on CCTALK.COM - it's a web interface which presents "reply" button - but it doesn't work - so I have to cut/paste/edit the existing post and send it back by email - and HOPE that it finds its way to the proper thread!] Dave -- -- Search "Dave's Old Computers" see "my personal" at bottom!
[cctalk] It's been a while - retirement project
>>[anyone know if there's a usable web interface to CCTALK? I browse it >>through the ARCHIVE on CCTALK.COM >KenUnix - 27 Nov 7:13 p.m. >When I try and connect to it I see in the tab chinese verbiage >CCtalk ???-?? and it tries to send me to public.hujia.104.cdn20.com Sorry, my mistake - I meant the CCTALK archives at: classiccmp.org Dave -- -- Search "Dave's Old Computers" see "my personal" at bottom!
[cctalk] Experience using an Altair 8800 ("Personal computer" from 70s)
I case anyone is interested... I've just passed on my "Mits Altair 8800" - this is a very historic system from the 70s - it is: First Personal Computer (long before IBM PC) First S100 buss system First system Bill Gates wrote code for (long before Microsoft) I did write a pretty decent emulator for my exact Altair system some years ago... And with recent interest in the system, I've just updated it with a few minor improvements and a "cleaned up" edition of the software I created to bootstrap a hardware front-panel based system (no on-board ROM) via a serial port card - requiring you to enter only 18 bytes through the front panel So .. if you'd like to experience what it was like to use a system from the 70s - here's some of the things you can do: Bootstrap it cold Run NorthStar DOS (one of the first commercial DOSes) Run DMF (Device Management Facility) - a DOS I created for it - can you tell that at the time I was working on an IBM mainframe ... my - OS name sounds a lot like various IBM mainframe packages at the time. A few other software setups (for example there's a stand-alone bootable FORTH) Has Editors, Assemblers, BASIC and other tools from the era. and a few games - some written by yours truly - some very early commercial offerings (like "Cranston Manor Adventure", or "Valdez") Note1: My Altair emulator was created under DOS and is a 16 bit program! It does work very well with DosBox (I recommend the one on my site) Note2: I've not updated the ALTAIR.ZIP on "Daves Old Computers" yet - you can get the updated one from: "Daves Old Computers" -> Personal -> Downloads -> OlderDownloadsFromPrevious - look for "ALTAIR" under: Simulators and Emulators *** I don't follow this list nearly as much these days - if you want to reach me, use the contact link on my site! -- -- Search "Dave's Old Computers" see "my personal" at bottom!
[cctalk] Re: Experience using an Altair 8800 ("Personal computer" from 70s)
Weill .. I certainly expected lots of "discussion" on these statements about my Altair: I have never claimed to be an "unknown drip"(*) on details of computer history, but here is my reasoning: > First Personal Computer (long before IBM PC) I am well aware of small systems that predated the Altair, but they are/were not neary as well known (mainly due to Jan/Feb 1975 Popular Electronics), and I don't recall that nearly as many of them were as commonly owned and operated by "people of modest means" and/or not "in the industry". And unlike most predecessors it was expandable by a means that grew onto a whole industry. I too generally avoid using "first" in history discussions... but At one time I discussed this with Ed Roberts, the creator of the Altair, and he said: "We coined the phrase Personal Computer and it was first applied to the Altair, i.e., by definition the first personal computer." ... "The beginning of the personal computer industry started without question at MITS with the Altair." > First S100 buss system Originally called "Roberts Buss" the Atair expansion buss was used by many systems that followed, and not wanting to use their competitors name, the buss became known as "S100" (presumably System buss with 100 pins) Again, Ed Roberts confirmed this to me. > First system Bill Gates wrote code for (long before Microsoft) I should have qualified this with "well known published" code. As far as I know, Bill's career really went off with his implementation of BASIC - which became: Mits Altair Basic And perhaps Microsoft started "only a few years" after (which WAS a LONG time in those days of the industry) - but it wasn't anywhere what it would become some years after that! - and I don't think it was at all well known till MS-DOS (post IBM-PC). But again, I don't claim to be: (*) X - marks the unknown Spurt - a drip under pressure .. and I don't claim to be an "unknown drip under pressure" (I'll happily leave that honor to others in the group :-) Dave
[cctalk] Re: Experience using an Altair 8800 ("Personal computer" from 70s)
Chuck Guzis wrote: > I don't think the "first" applies in this case. The MCM/70 used an 8008 On the subject of early 8008 designs - there was a Canadian one (1974 I think) the MIL (Microsystems International Limited) MOD-8 - later also released as the GNC-8 (Great Northern Computers) I also created an emulator for it as well - so you can experience using another very early system if you like... Sometime later, Scelbi 8008 BASIC was ported to it (also in my archive) - this has to be one of the very earliest (notice I didn't say F-r-t :-) BASICs. Dave
[cctalk] Re: Experience using an Altair 8800 ("Personal computer" from 70s)
>With respect, I have studied the 1956 Royal McBee LGP-23 (and later -30) at >length and found one could easily use this computer as a "personal >computer". I've not see one of these - that's a VERY early system! Sounds like it could have been used for "personal" computing - but was it common and inexpensive enough that "average people" could have one? I just went on Ed Roberts claim to be one who coined the term "Personal Computer" - I've not found any specific references to this term pre-dating 1975 ... but who knows! (I've not really looked that hard :-) >One might find it pretty easy to program "Hunt the Wumpus" ... Interesting reference.. My Altair eventually had a "North Star" MDC-A1 installed, this is a very early SSSD floppy disk system - a whopping 90k per diskette. When I created my Altair emulator (about 2003 IIRC), I made and included .NSI (NorthStarImage)s of all the non-junk floppy disks I had at that time. This included a couple "games" disks, and "Hunt The Wumpus" is there! Dave Dunfield - https://dunfield.themindfactory.com
[cctalk] Re: Pragmatically [was: Experience using an Altair 8800 ("Personal computer" from 70s)]
Always good to spark an "interesting discussion" "Personal computer" - Generic enough that it can have multiple interpretations: While technically somebody could have put a Cray1 in his (big :-) basement and used it for his own enjoyment (ie: a "personal" computer) ... I don't think I have ever seem such an arrangement promoter in a "marketing term". I tend to think along the lines of places where I've seen the term actually used in the industry: The most obvious is IBM - the "IBM Personal Computer" (5150) Perhaps there were others, but AFAIK this was a huge change in the way the most prominent company I was aware of at the time in the industry did business! Prior to the PC, IBM rented large mainframes which came with a whole support contract -- The first computer I ever saw was an IBM 360 at "University of New Brunswick" ** and I got to know the people to ran it and some of the IBM engineers who supported it quite well ** With the PC - IBM created a system that they could actually sell (and could be afforded by) most anyone who wanted a computer. Yes, MANY of there sales were to companies who wanted dozens of them, but they were offered in electronics stores, or could be ordered. Mits claimed to be the first to use term "Personal computer" which they used to reference their Altair - but most people are much more aware of the "IBM PC". And "along the way" I "personally" had a a few full-rack systems in my own basement (actually - Dining room - at least till I got married :-) These induced a couple "Data General Novas", a few "DEC PDP-8's and PDP-11's" and a few others - but I never really though of these as my "personal systems" - to me at the time, they were "lucky finds of industrial computers" that I had managed to acquire! Dave ::: https://dunfield.themindfactory.com ::: "Daves Old Computers"->Personal ** When I first "met" the universitys IBM 360, the only way for students to use it was with "punch cards", and a dedicates self serve room with a card reader and massive chain line printer. Then they got a room of Selectric 2741 printing terminals, after that one with serial CRT terminals and finally a row of five IBM 3270 page- mode CRT terminals across the end. I of course was the guy who was in there constantly, late at night, early mornings and weekends - learning about and putting the system through as many "tricky things" as I could! At one point I became friends with a couple of the operators, who told me than whenever the system went down, the first thing they asked was "Where's Dave"? And I had the pleasure (significant to me at the time) of seeing one of the 3270s being used by an IBM engineer who was running disgnostics and other system test/monitor programs (the kind of stuff I really wanted to see) - while the other four were being used by IBM engineers running a multi-user "tank game" that I had written (which really excercised page- mode updates to the terminals that had proven to be fairly upsetting to the stability of the system). I do recall one of the players of my game saying something like "I've never seem them used this way - quite cool!"
[cctalk] Re: interlace [was: NTSC TV demodulator ]
CAREY SCHUG wrote: > I think I tried a game on a flatscreen, and had issues. I've seen this lots - I'm not sure its entirely "interlace" - I tended to think more of the fact that CRT's scan causing the "pixel dots" to flash at high speed (not detectable to the human eye, but detecting a such a frequency is definitely possible for a bit of electronics. (Of course scan/interlace all contribute to the rate of picture elements flashing - all depends on what the particular device looked for) For example, I had an NES with the "light gun" - this was a gun you could use to shoot things moving around on the screen. When you pulled the trigger - the whole screen would flash - basically they quickly blanked it with only a small while square a the location of the moving item - during this time, they would look for a light image received by the (fairly highly focused) gun at the refresh frequency - so you couldn't just point it at a light source - it had to be the TV screen (or course you COULD fool it with another source "blinking" at the right frequency - but this was beyond the knowledge/ability of most who used the system :-) On an LCD TV - the gun didn't shoot! - LCD pixels tended not to be scanned/refreshed the same way, and are also slower - so whatever scan frequency might have been used isn't detectable. Dave ::: https://dunfield.themindfactory.com ::: "Daves Old Computers"->Personal
[cctalk] Re: Experience using an Altair 8800 ("Personal computer" from 70s)
Liam Proven wrote: > It needs to have a microprocessor to qualify. > ... No µP = not a PC. Not entirely sure ... http://dunfield.classiccmp.org/primitiv Dave
[cctalk] Re: Experience using an Altair 8800 ("Personal computer" from 70s)
Chuck Guzis wrote:
> I find myself in the position of trying to figure
> out what the latest posts have to do with 'Experience using an Altair
> 8800 ("Personal computer" from 70s)'.
Thanks! It's gotten so off-topic, I've all but stopped following this thread.
I recently found a new home for my Altair, and in doing so, I set it up and
run it to show it working. This reminded me of my Altair emulation I wrote
back around 2003 when I decided not to maintain the Altair in a "ready to go"
state and packed it away.
This is more than a "pretty picture" Altair Front Panel emulator, it gives a
pretty accurate emulation of my complete system which includes:
Hardware:
Mits: Front panel, 8080 CPU, 88-SIO serial
CDC: 64k Dynamic RAM
NorthStar: MDS-A1 floppy controlle
Compu/Time: CT-102 Real Time clock
Homebuilt: Dual serial
Lear Seigler: ADM3A terminal
Sugart: two SA-400 drives
It also contains .NSI (NorthStarImage)s with a fair bit of usable software
including (but not limited to - there's more - this was my working system
at the time)"
Bootable:
NorthStar DOS 5.1
My own DMF (one of the first OS's I wrote)
Fig-Forth system
Application software:
North Star BASIC
Byte Shop of Westminster XEK Editor/Assembler/Disassembler
MicroStuf RCONS/CBBS
Altair Memory test
My own BASIC
My own ALPS (Assembly Language Programming System)
Games:
Dynacomp Chess Master
Dynacomp Valdez Supertanker simulation
Cranston Manor Adventure
Hunt The Wumpus & many other simple games of the time
No longer having mu own Altair, I've made some minor enhancements to the
"Virtual Altair" and posted about it - just in case anyone would like to
experience actually RUNNING/USING a 70's Altair system!
This was mostly a cut/paste of a posting I had made in a different forum, and
included a bit of information (not needed here:-) about "What is an Altair"
which happened to include a quote from correspondance to me by "Ed Roberts"
which said
"We coined the phrase Personal Computer and it was first applied to the
Altair, i.e., by definition the first personal computer." ...
"The beginning of the personal computer industry started without question
at MITS with the Altair."
and a couple reasons I do think that this is a fairly reasonable statement!
This (or course) sparked the never-ending controversy of "what is a personal
computer" and "which was the earliest"...
My own interest in classic computing has always been about "Historical,
Technology" - it always seems odd (to me) how many others seems to be more
concerned with "Terminology"
To me a "personal computer" is one "anyone could have and you might find in
someone's home" - There are of course plenty of pre-Altair systems that could
fit in someones home, and "someone could have had" - but not at all common in
such and environment. I do think the Jan 75 issue of Popular Electronics
help a lot to get the Altair into such a environment.
And it was made less-clear by IBM's choice to name the 5150 the "Personal
Computer" (which made sense for them - prior to that most of their offerings
were large time-sharing mainframes!)
FWIW, my own "first personal computer" was NOT the Altair - my first ever was
a "COSMAC ELF" - it's been so long a don't remember much about it (and I got
rid of it before I started "Daves Old Computers") - IIRC is was an 1802
CPU, with a key-keypad - it DID have a "video display" but not character
based (just dots) - it has 256 bytes of memory which was ALL the memory in
the system (so you had to "see your program code on the screen"), and NO
storage (you always had to key in your program code).
This was very limited, and I soon replaced it with various homebuilt (mostly
8080 based) systems - at one point I managed to obtain some solenoid controller
reel-to-reel tape drives from a decomissioned lab - and built my own automatic
storage system (using some direct digital-to-tape methods I managed to get
working).
But the Altair was the first system I had with floppy disks and substantial
memory - and the first I could use for the kinds of things I had been doing
on the universities IBM 360 and PDP-11s - in other words a usable personal
computer!
Dave
[cctalk] Re: Experience using an Altair 8800 ("Personal computer" from 70s)
Having some fun reliving the memories ... I'll also mention that I do have other emulators for some of the classic systems I had on "Daves Old Computers" (look under "DOS Widgets") again - in case anyone wants to experience actually using one of these systems: NorthStar Horizon (Z80) - also does: Vector 1+ NorthStar DOS, CP/M Heathkit H8 (8080) Hdos, CP/M Mil MOD8 (8008) - Canadian Scelbi BASIC Dunfield 6809 (6809) [my original portable] My own CUBIX OS There's more software - these are the main OS's and significant -Dave
[cctalk] Re: Experience using an Altair 8800 ("Personal computer" from 70s)
Chuck Guzis wrote: > I never expanded my 8800 beyond the original 4-slot kit with > limp-wristed power supply. The construction (I built from the kit) I > found to be appalling. More than once I zinged myself brushing against > the line voltage traces on the front panel board. And that awful white > wire. Mine was "used" and already assembled when I got it. It had most of the final expansions - I added a few homebrew ones. Did improve the power supply , and agree completely on the "white wire" - I used mine LOTS - did much of my earliest software development on it! -Dave
[cctalk] Re: Experience using an Altair 8800 ("Personal computer" from 70s)
Bill Degnan wrote: > > Without looking through everything you have first (sorry)is the > NorthStar DOS genned for a 2SIO card? > Bill Most of the disk images I have in the Altair emulation are set up to communicate via my own homebuilt dual-serial card - There might be one set up for the original Mits serial card... The ones with the Horizon emulation are set up for the serial ports build into the Horizon, and the Vector 1+ images are set up for whatever I had in that machine. There is a an image of the NorthStar master system distribution disk - which has "unpersonalised I/O" this is what was first used to get it running on the Altair - it boots and hangs in an infinite loop at I/O initialization - you halt the system and then toggle in minimal I/O functions functions through the front panel - then you can restart DOS and get a console prompt, at which point you can load "fresh" DOS elsewhere in memory, then using the NorthStar monitor, poke in your I/O routines, then IN(itialize) a fresh disk and save that DOS to it - thereby creating a bootable disk that "talks to the console". This is one of things you can do on the "Virtual Altair", do/experience what it was was involved in getting an OS up on a front-panel system when you didn't already have this OS running! Something you had to do in the first days, but few people today have done! (other then list members or course) I do have information about how to do this included with the emulater! -Dave
[cctalk] Re: Experience using an Altair 8800 ("Personal computer" from 70s)
Bill Degnan wrote: > Thanks Dave - It has been many years since I genned a N* disk. I don't > always have success with the port assigning but eventually I get it to work. Although my Altair was "fully expanded" when I first owned it, I was involved with it quite some time before that: At University of New Brunswick I made friend: Gary -staff at computer center Gary found: Dan -former student -built the Altair -Decided to sell to Gary -- Dan had assembled a minimal system: Chassis, all Mits: CPU, 1K RAM, Serial -- Fortunately he had put in 3 of the 4-slot S100 boards (12 slots) Together Gary and I expanded it to a much more usable system --- 64K RAM, NorthStar Disks, ADM3A terminal and more I wrote an 8080 assembler on UNBs IBM 360 mainframe, which gave a good listing (code values) of our I/O routines. Using front panel: Run at E900 (Boot ROM - unpersonalized N*DOS), HALT, toggle-in I/O code, restart DOS in memory. This gave DOS talking to the ADM3A (yes - it took a few trys before we had it working) - then we loaded clean DOS into memory (DOS self-modifies in memory as it boots), use N*Monitor to copy our I/O to this copy, initialize a second disk and save DOS to it - this gave us a working DOS that booted! If you want to experience doing this, it can all be done on my Virtual Altair! For the true experience, you should stick to the front panel switches, but if you want to "cheat" - Virtual Altair has additional capabilities that original didn't: Full debugger with execution (disassembly) display, memory/register editors, 'L'oad Intel/Motorola hex images to memory while stopped! Sometime later, while testing bare code on a second Altair without disks, I created: MinimalCodeEntrySerialBoot This let me load/run large programs, having to toggle in only 18 bytes via the front panel! Ah, fond memories! -Dave
[cctalk] Re: Intel 8086 - 46 yrs. ago
Chuck Guzis wrote: > Scarcely innovative. 64 bit architectures predated the 64-bit x86 by > decades. Call it a natural evolution. I'm kinda surprised that nobody has mentioned this ... But.. even less innovative than that! - the subject mentions "8086" and 46 years - the 8086 was only a 16 bit CPU and came out close to the time suggested. The x86 architecture didn't get 32 bits till the 386 which was IIRC around 1986 or 7 - so word length was not AT ALL architecturally significant - and Chuck is quite right that there were MANY bigger/better machines when the 8086 made it's debut. I think the 86 came at a good time/place because the 8080 series had become quite popular in microcomputers and designers were feeling the limits of a 8-bit architecture - the 86 provided a fairly powerful (for the time) and easy upgrade which was enough like the 8080 that most developers didn't have a tough time "figuring it out". (and it didn't hurt that minicomputer pricing wasn't involved) Dave My own entry into the "microprocessor" design fray was something I called the: C-FLEA A very tiny/simple 16 bit CPU that was very optimal as a target for my C compiler. Never did see it to silicon, but did quite a few "virtual machines" - this let me efficiently put C code into little cpus that were not reasonable candidates for higher level languages.
[cctalk] Re: Intel 8086 - 46 yrs. ago
ben wrote: >> My own entry into the "microprocessor" >> design fray was something I called the: C-FLEA >> A very tiny/simple 16 bit CPU that was very optimal as a target for >> my C compiler. >> Never did see it to silicon, but did quite a few "virtual machines" >> - this let me efficiently put C code into little cpus that were not >> reasonable candidates for higher level,languages. > Where? I've recently posted much of the source code I've written over the years in a "Retirement project" section of my site. Various related documents and executables can be had from the packages in my main downloads, and at "Daves Old Computers". If you are interested in the C-FLEA CPU - the best place to see/try it is DVM (Dunfield Virtual Machine) this is a little VM I put together - available at the above locations. Here is a bit on information I put together about my compiler (Micro-C) with C-FLEA/DVM: (Sorry if spaces get munged - can't seem to post a simple "spaced" text document on must sites these days) My compiler is known for making small executables. One of the most common comments I received about it was "how can it make such small programs?". Here are the DVM application file sizes at the time of this writing: 3,281 CC.DVM - Compile command 6,320 MCP.DVM - Micro-C preprocessor 17,440 MCCDVM.DVM - Micro-C compiler 4,064 MCODVM.DVM - Micro-C optimizer 1,210 MCCILIB.DVM - Replaces calls to internal library 4,675 SLINK.DVM- Source linker 8,335 ASMDVM.DVM - DVM assembler 1,488 MCCVT.DVM- Convert .HEX from ASM into .DVM 8,656 EDT.DVM - My EDT editor 5,415 VLT.DVM - My large text file viewer 6,560 BASIC.DVM- My "BASIC" sample program Subtract 128 bytes from each of the above sizes because the free demo .DVMs have an integrated protection message. And here are the same program compiled with my PC/DOS compiler: 4,651 CC.COM 13,900 MCP.EXE \ 24,258 MCCDVM.EXE > As Micro-C was designed to be easily 12,792 MCODVM.COM > portable, these tools make very little 3,479 MCCILIB.COM > use of library functions. 12,274 SLINK.EXE/ 17,650 ASMDVM.EXE 4,361 MCCVT.COM 17,154 EDT.EXE 7,444 VLT.COM 12,115 BASIC.EXE Dave Dunfield - https://dunfield.themindfactory.com
[cctalk] Re: The magic smoke....
Chuck Guzis wrote: > Probably due to the failed film-in-oil (sometimes known as Rifa) line > filter capacitors--a very common failure and nonfatal. I never "just turn on" equipment that's been out of service for an extended period of time ... until I ... Over the years, I've had good luck "reforming" electrolytic capacitors. Very simple and easy to do, basically: - Disconnect at least one side of the cap. - Connect a variable voltage supply to the cap, through a few hundred ohm serial resistor (this both limits current in case the cap has actually failed, and makes it quite reasonable to do this to several caps in parallel (in this case, either make sure if you left one side connected that it's common (and not the lead from the supply that has the resistor) - or just disconnect both sides. - Start low (a volt or so) - let the cap sit at that voltage for some time (I usually do a few hours - more if the cap is really old/disused) - Make sure cap charges to set voltage and is not drawing current - repeat, raising voltage by a volt of two each "cycle" till you get to just above the normal operating voltage of the cap. When I was more active in collecting/acquiring old system of indeterminate state. I built a little gadget to do this automatically - so I could leave it to do it's thing overnight. Dave ::: https://dunfield.themindfactory.com ::: "Daves Old Computers"->Personal
[cctalk] Re: MS-DOS
> I can never remember which is which between Windows 2000
> and Windows ME ("Millenium Edition")
IIRC (It's been a long time) - 3.1, 95, 98 and ME were all on top of DOS
NT, 2000, XP, Vista, 7, 10+ were all NT
FWIW - At one time IBM actually gave-away PC-DOS - as part of a free "IBM
ServerGuide Scriptine toolkit"
A little project I did a while back, DBBD - "DosBox Boot Dos"
made up a little set of files and a command to easily boot various actual DOS
distributions under DosBox (I still sometime need to do/check something in
actual
DOS) - I included every DOS I could find freely available, including the above
mentioned
PC-DOS, FreeDos, Caldera OpenDos and PTS DOS - but I've never seen any version
of
MS-DOS available like that!
Dave ::: https://dunfield.themindfactory.com ::: "Daves Old Computers"->Personal
Classic equipment available & my bad year.
Hello Everyone. I have had a major health incident which means that I have been unresponsive for several months. As I need to move in closer to town, I will be disposing of what remains of my collection (Things like: Altairs, Imsa, PET 2001, Apple II, TRS-80s, lots of S100 carts etc.) I have posted some preliminary information at: http://www.classiccmp.org/dunfield/sale.txt This will be updated on a regular basis. If you are interested in what happened to me, I have posted some details at: http://www.classiccmp.org/dunfield/2019.txt Dave Dunfield
191109 Classic equipment available & my bad year.
191109: Added PDP-11s, KIM1, EDB9301, MMT-85 & FloppyDrives Thanks to everyone for the kind words on my situation. Had lots of correspondence from various people interested in certain systems, but no offers, and very little information on what people think they are worth. Many of these systems are very old, very rare and nearly impossible to acquire. As I am no longer working I want to maximize what I receive from them. I will be researching this over the next year and will add prices if/when I work them out. If price is unknown I will take the highest reasonable offer, so I cannot offer systems now without an idea of what they are worth to you. Had several messages asking about other systems I show on "Daves Old Computers". I have been dealing with several collectors in Toronto and Ottawa, and any systems not listed in sale.txt is already gone (still taking inventory so may add a few more, as well as a LOT of other technical stuff. > --- Original Message --- >I have had a major health incident which means that I have been unresponsive >for several months. As I need to move in closer to town, I will be disposing >of what remains of my collection (Things like: Altairs, Imsa, PET 2001, >Apple II, TRS-80s, lots of S100 carts etc.) > >I have posted some preliminary information at: > > http://www.classiccmp.org/dunfield/sale.txt Dave
191202 Classic equipment available & my bad year.
Hi, made a number of updates to the sale pages on my site, and brought back a copy of my commercial site (good for downloads). Unfortunately I screwed up the .html pages and lost some links. Should all me fixed now. Added an FAQ some more parts (eg: 8008 CPI for MOD8), some sample pricing (please see FAQ before complaining). If you've looked at the site before, do refresh each page as you go to it as many browers cache page and will happily show you the old one. http://www.classiccmp.org/dunfield/sale/index.htm Dave
Unable to download Dave Dunfield's ImageDisk
>Patrick Finnegan pat at vax11.net Tue Mar 24 18:14:05 CDT 2020 > >It looks like the magic that updates the 5-digit number in the URL doesn't >work after the classiccmp.org recovery. Try: >http://www.classiccmp.org/dunfield/img54306/imd118.zip > >The rest of the things should be in the same directory. >>On Tue, Mar 24, 2020 at 1:47 PM Christian Groessler >> Hi, >> >> the link on http://www.classiccmp.org/dunfield/img/index.htm for >> "ImageDisk 1.18" doesn't work. Apparently most (or all) links on this >> page don't work. The "magic" is me, it has nothing to do with the classiccmo recovery. The links are something I update manually from time to time, and I've recently updated some pages to correct links to my now expired commercial site, and failed to amend these with the current transient page. Should be fixed now - may have to refresh your browser if It cached the bad links. Dave
A tool many of you may make find useful!
Hi, Don't know if anyone is interested, but I'd guess that a lot of you like me have collected a big pile of digital "stuff" over the years, and also if like me, it may have gotten away from you a bit with a lot of duplication etc. Having some spare time, I've been organizing my collected documentation, software, drivers and other files. As part of this process I wrote "Duplicate File Finder", a WIn32/64 tool which can look at a VERY large file collection (can even be across many drives etc.) and produce a nice summary of what is duplicated and where all the duplicates are. I originally wrote it for my own use, but it has proven SO useful that I took a little time to clean it up and post it at my personal site.: http://dunfield.maknonsolutions.com If this sounds useful, have a look and grab the program. Hopefully it will be as useful to you as it has to me. Dave -- -- Personal site: http://dunfield.maknonsolutions.com --
A tool many of you may make find useful!
Sorry, can't respond easily because I read the list on the web, can't deal with the flood of email from it, and can't respond via the web interface. >I'm not clear on what "duplicate" really means. Perhaps you can clarify >things for me. > >Duplicate in name and/or size? >Duplicate in content? > >There are lots of duplicate file finders for Windows and some of them >are quite sophisticated, being able to compare the content of files with >different encodings and provide "almost the same" type of information. Duplicate means exact duplicate size and contect, name does not matter. (I copied lots of stuff around, sometimes renaming it and want to find all the dups). Yeah, lots of nifty tools, but I needed one where I could easily control what it looks and and process it's results (text files). Also had to deal with VERY large sets of data (terabytes) and do it all in a fairly reasonable time. So I just wrote one. I'm a bit unusual that way - tend to write stuff that does exactly what I need instead of trying to use something that sort of comes close but often also does a lot I don't want. >Downloading http://dunfield.maknonsolutions.com/dos/sw/ddw2020.zip >gets flagged by Windows Defender on Windows 10 Pro (1909) >as "Worm:Win32/Spybot". Not for me, it's something I compiled from my own source myself, is packed with UPX - maybe Windows Def doesn't like that but it raises no alarms on the Win7 Pro system I'm testing on. Have no control of Windows Defender .. just one of many reasons I don't use Windows much. Not the first time good clean code of my own has triggered false alarms. FWIW, I just downloaded DDW2020.ZIP from the site, and it exactly matches my original one. Contents also exactly match my original files, here is a DIR listing: Directory of R:\DDW2020 2020-06-24 09:08 PM 3,255 DDW2020.TXT 2020-06-24 09:08 PM23,584 DFF.EXE 2020-06-24 09:08 PM23,584 EDT.EXE 2020-06-24 09:08 PM31,907 EDT.TXT 2020-06-24 09:08 PM 6,688 FDF.EXE 2020-06-24 09:08 PM 9,760 VLT.EXE 6 File(s) 98,778 bytes Note, Windows did warn me that this file is not commonly downloaded and wanted to "discard" it, but I used "Keep" - no defender or antivirus alarms triggered. Dave PS: Noticed and fixed the spelling of "Download" - may need to reload to see due to browser cache. -- -- Personal site: http://dunfield.maknonsolutions.com --
A tool many of you may make find useful!
>this tool is really similar to "rdfind", which compares file sizes and >content, independently from file name, and is able to create a list of >correspondence, delete duplicate files, and create symbolic links to the >single instance. >This can work on large amounts of files, even on complex directory tree. Sounds good, don't know that I saw that one (tend not to look too hard as I enjoy creating stuff, and what I do is usually smaller, easier to use - at least for me - and more reliable). Didn't want to go into a lot of detail as this isn't exactly classic computer related.. although I expect a lot of classic collectors are like me and have use for it. Couple things I implemented in DFF which I don't know of in other tools: It uses an "index" file - first attempt just used the output of windows: DIR/S but I found it got big and unworkable fast, and changed from one version of windows to another. DFF creates its own which is small and consistent, having only the DIR names, and file sizes + names. This is normally a temp file, but you can Keep it, just Build it without processing, and process it later. You can also have DFF append to it so you can deal with as complex dir structure as you like, by /BAing it in various places. It can deal with files in arbitrary directory trees on multiple drives quite easily. You can also have it place and END marker in the file, which means that anything you append will be treated differently. Anything before the END marker is scanned and reported as you expect. After the END marker, files are considered as possible duplicates, but not checked and reported separately. And since the "index" file is a text file, you can add to it, change it and retrieve it's content very easily - you don't need special programs provided by the tool maker to do unusual things. Same is true for it's output. You can also have it list: - All files (dups have a dup instance number see below) - Only duplicate files - Only single files - Under each directory, you can get it to list where all the duplicates are (full path) This combined with the END marker makes some fairly powerful things possible. (Show me any files occurring here which are not also occurring there). Each instance of duplication is assigned a unique "duplicate instance" number which is shown next to all files which are part of that "duplicate instance". I thought about an automatic "delete duplicates" feature but didn't implement it as I am organizing a lot of data, much is duplicated, it's final resting place may not be one of the original locations and I want control over how the final archive is organized. Dave -- -- Personal site: http://dunfield.maknonsolutions.com --
A tool many of you may make find useful!
>Downloading http://dunfield.maknonsolutions.com/dos/sw/ddw2020.zip >gets flagged by Windows Defender on Windows 10 Pro (1909) >as "Worm:Win32/Spybot". A new tool now available on the site: Daves Distribution File Checker I have received reports that Windows Defenfer incorrectly lables some of my executables as naughty. I assure you this is not the case when published. They are freshly compiled from my own/known source code on a secure system. To help you know files are exactly as I uploaded then and not compromized in transit, I created this tool. It uses a proprietary/unpublished algorithm and multiple encrypted CRCs to validate that a file is exactly as I published it. The tool which makes the database will never be distributed in any way. You can check a complete .ZIP archive or individual files from it. The archive does not have to be present for DDFC to check individual files, but you do have to specify it so DDFC knows which file to reference in it's database. This program and it's database are self protecting, but can't insure they don't get replaced by something that looks the same without providing the protection. To help avoid this, I will reload this file every time I update my site. Dave -- -- Personal site: http://dunfield.maknonsolutions.com --
A tool many of you may make find useful!
> The file is empty. Not much I go do except stop trying and advise people to ignore all this. I've just downloaded the file from my site, and it is NOT empty and does work. I did notice a small bug, if you specify names not in it's database it doesn't tell you, and produces no output. I have corrected it. Dave -- -- Personal site: http://dunfield.maknonsolutions.com --
A tool many of you may make find useful!
Continuing to let you all know about developments, I do expect that many of you are facing a similar problem - trying to condense and preserve a lifetime of "collecting digital stuff". The DFF utility has been very helpful, however once I started organizing my files, I realized that although there are a lot of duplication, much of it is was downloaded at different times and/or from different sites making much of it different, many vendors don't go out of their way to make file content/purpose obvious in the names, and many files are dependent on other files - so manually reorganizing the data is NOT always easy. The best solution I have come up with so far is to invent a new archive format designed to eliminate duplicate data but capable of recreating the entire original directory trees (or parts thereof). To that end I created the two utilities described below (now included in the web archive). -- yeah, I do seem to have a fair bit of spare time on my hands these days... ;=BDA - Build Dave's Archive ;=EDA - Extract Dave's Archive Dave's Archives contain the smallest possible representation of a complete directory tree: - Only one copy of the data for duplicate files is stored. - Duplicate filenames are stored only once. - Path information is stored only once per directory, and only additions to a path are stored (adding/removing from last path). eg: Starting with a large DIR of support files for one of my systems. This has duplicates and a lot of pre-compressed install files: 314 dirs, 930 files using 3,762,691,033 bytes. Just "ZIP"ing it I get: SysSupt.zip 3,352,081,951 bytes 7zip does a bit better: SysSupt.7z 3,245,871,362 bytes Running BDA, I get: SysSupt.DA1 9,404 bytes and SysSupt.DA2 1,912,855,711 bytes Big improvement, but no compression yet, using ZIP and 7zip I get: SysSupt.zip 1,636,965,417 bytes and SysSupt.7z 1,609,663,862 bytes And YES, using ZIP/7zip to extract the .DA's, then EDA gives me a directory with exactly the same content that I started with. Like my other tools, these can deal with BIG directory trees, and the output file format is well documented should you ever want to recover the files by other means. Sorry if I've not responded to messages here, tend not to follow the list directly much these days due to the high content, but you can always reach me through the link on my site - might take me a few days to respond, but I do get to it from time to time... Dave -- -- Personal site: http://dunfield.maknonsolutions.com --
What I've been doing lately
Hi everyone, Might not be exactly classic computer related, but I know many of you have been following my progress through my recovery (thanks for the many kind words), and I do think many of you might find this a tad interesting. What I've been doing for the past little while - check out my latest project "Dunfield Virtual Machine" on my personal web site: http://dunfield.maknonsolutions.com Regards, Dave -- -- Personal site: http://dunfield.maknonsolutions.com --
RE: What I've been doing lately
>Very interesting. By the way I've been reading your comments about your >incident in 2019. I am impressed. All the best for you and your near people. >Kind Regards >Sergio Thanks! It's been an "interesting" year! Btw, for anyone who was interested enough to download my DVM demo... I've made a lot of updates, additions, improvements, and fixed a few bugs. Might be worth grabbing it again. Dave -- Personal site: http://dunfield.maknonsolutions.com Check out "DVM" - run custom apps. anywhere!
