hybridfree/eevblog-posts huggingface dataset:
CompuTone Micro-VIP Computer Terminal : What is this thing?! - Page 1
Forum section: electronics / general

author: AndyBeez
author_rank: Frequent Contributor
timestamp: September 06, 2022, 10:54:28 am
content: Spotted on ebay, aCompuTone Keypact Micro-VIP Portable Computer Terminal.It's a computer teletype terminal with built-in accoustic coupler and, the most insane keyboard since the Enigma machine. Plus it's portable. User manual included.https://www.ebay.co.uk/itm/385096421614

author: Fraser
author_rank: Super Contributor
timestamp: September 06, 2022, 11:01:24 am
content: Just Google Computonehttps://www.computerhistory.org/collections/catalog/X780.86It dates back to 1977 and was used to access the Computone mainframe computer in Atlanta. CPable of making computations using the combination of the numerical ‘keyboard’ and overlay cards that detailed functions. Basically a dedicated 1970’s terminal roughly equivalent in topology to the modern thin client / Citrix solution.Fraser

author: Fraser
author_rank: Super Contributor
timestamp: September 06, 2022, 11:08:23 am
content: The common versions….http://www.computinghistory.org.uk/det/50795/Keypact-Computone/

author: AndyBeez
author_rank: Frequent Contributor
timestamp: September 06, 2022, 11:27:18 am
content: Quote from: Fraser on September 06, 2022, 11:01:24 am@Fraser "Computone Mainframe" such a cool retro computing name. I'll have to name a media server thatThinks: what if on the TCP highway, someone left a long forgotten port open which means these antiques can still dial in? Maybe we could communicate with the mainframe technician... living in the year 1978.
Locating/De-compiling Teltone telephone line simulator configuration software - Page 1
Forum section: electronics / general

author: Halcyon
author_rank: Unknown
timestamp: July 25, 2021, 01:06:49 am
content: Does anyone happen to have a copy of the old Teltone configuration software for their line of telephone line simulators (screenshot below).I've done the usual Googling and archive.org doesn't seem to have a copy.

author: Halcyon
author_rank: Unknown
timestamp: July 25, 2021, 02:48:50 am
content: It seems as though the latest version (3.04) used to exist at ftp.teltone.com/pub/TLE_V304.exe however archive.org didn't crawl it.

author: Halcyon
author_rank: Unknown
timestamp: July 25, 2021, 03:59:07 am
content: Disregard, found a copy at:https://web.archive.org/web/20081210200329/http://www.teltone.com/downloads/tle_v305.zip

author: sarge
author_rank: Contributor
timestamp: August 01, 2021, 03:37:28 pm
content: Thanks for that! Once mine shows up, I may take the time to dump the ROM and maybe even attempt to manually poke at the serial port.Cheers, mate.

author: sarge
author_rank: Contributor
timestamp: August 04, 2021, 09:34:41 pm
content: So, the line simulator showed up today, and a day early, at that. Yay.That said, I already took the time to dump the ROMs, so they are attached. There are three different ICs in question, and I included a text file detailing the labels, and what ICs they correspond to. Cheers!

author: sarge
author_rank: Contributor
timestamp: August 04, 2021, 09:39:12 pm
content: And here is a zip file of both the PDF file of documentation, plus the software, for historical/archive reasons.

author: Halcyon
author_rank: Unknown
timestamp: August 24, 2022, 03:53:47 am
content: We are still working on this project... it's been a while. Is anyone experienced with de-compiling old Windows executables? We could really use your help.

author: Zoli
author_rank: Frequent Contributor
timestamp: August 24, 2022, 05:18:09 am
content: Quote from: Halcyon on August 24, 2022, 03:53:47 amIf you looking for some know-how: see attached file. Website rip from February 2000, a couple of months before in changed to something different.Tools of trade back then were Windasm and Ida(low #'s); if you're interested, I can dig out some copies.The website is just over 5MB, so is two volumes, two posts.

author: Zoli
author_rank: Frequent Contributor
timestamp: August 24, 2022, 05:18:46 am
content: Fravia, part 2.
Micromax II - eprom programmer/Training kit for 8085 - documentation Wanted! - Page 1
Forum section: electronics / general

author: mancausoft
author_rank: Contributor
timestamp: November 24, 2017, 08:09:44 pm
content: Micromax II, Eprom programmer and Training for 8085 microcontroller.Should be made Germany back in the 80s.I'm looking for documentation.features:- 2 kb of ROM: with monitor program. Address: 0000-03FF- 1 kb of internal ram. address: 0800- 1 k of external ram (on the second socket) .Address: 8000- socket for eproom- 1 ADC and 2 DAC- 8 leds (i don't know how they are connectect)- 24 digtal I/O- Connectort for audio tape, to dave and load program- A 7-character and 8-segment display- hexadecimal keypad- command keypadRS: resetRN: run?AD: addres selectDT:data selectFN: unknowRB: unknowBS: previous addressNX: next addressProbably in the next days i will performa a teardown, to try to figure out how it's works, and try to create a schematics of it. I will post other photos.

author: mancausoft
author_rank: Contributor
timestamp: November 25, 2017, 03:32:57 pm
content: The board inside say: Weidner - Computer System CCS 85

author: daMicha
author_rank: Newbie
timestamp: August 16, 2022, 10:50:25 am
content: Hello,here I have some Information about this Computer. Unfortunatly the Manual is in German but it is a German Product.I know i is a bit late, but maybe another user can use these Info's too.Greetings
Eprom question - Page 1
Forum section: electronics / general

author: Wawavoun
author_rank: Regular Contributor
timestamp: June 17, 2022, 06:00:22 pm
content: Hello there !I just experienced something very strange with an eprom.The chip is a SGS M2716F1 eprom.After 6 months of storage i get troubles with my Elektor Junior Computer and I check everything and mainly the eproms (I know it's a sensitive point).On my eprom burner Vcc is 5 V.During reading the vpp pin is connected to Vcc (in fact 4.56 V = 5 V less a shottky diode direct voltage). There is also a pull down 10 KR resistor from vpp pin to gnd.After 20 minutes into the uv eraser if I read the eprom with Vpp pin high the eprom look empty ($FF everywhere).But If I read it with Vpp pin to gnd via the resistor some datas are still there.Then I put the eprom again in the uv eraser by two minutes steps and progressively (2 or 3 steps) all the datas were erased (always reading with Vpp pin to gnd)...Of course with Vpp pin high the eprom also look empty...Then I program the eprom and everything went fine.The question is if this eprom has some defaults or not and if I can use it safely (in the destination assembly Vpp is always high) ?Because the datasheet say Vpp high during read operations what can explain these observations ?Thanks for help and advises.Regards.Philippe

author: rob77
author_rank: Super Contributor
timestamp: June 17, 2022, 06:08:49 pm
content: datasheet says clearly:"VPP must be at 5V for all operating modes and can be maintained at 25V for all programming modes."VPP pulled down to ground is not a defined state and therefore you can't expect consistent behavior.
Thomson EF9367 question - Page 1
Forum section: electronics / general

author: Wawavoun
author_rank: Regular Contributor
timestamp: May 24, 2022, 06:20:58 am
content: Hello there,I am working on a hi res graphical board based on a Thomson EF9367.Its a Elektor design published in 10/1985.They can work into 512 pixels (H) x 256 (V) non interlaced or into 512 x 512 interlaced.In the first mode no problem at all, the lcd tv used via composite video input works well.Into 512x512 interlaced mode the top of the display is on the bottom of the screen (see picture).The board is initialized by a kind of driver that I have only in binary format.I give a look to the EF9367 datasheet and I dont find any information about video timing control like for a 6845 for example.What is the best way to improve the situation ?Thanks, regards.Philippe

author: Wawavoun
author_rank: Regular Contributor
timestamp: May 24, 2022, 06:31:03 pm
content: Problem solved...
Video: Doom's Ray Tracing Upgrade - Page 1
Forum section: electronics / general

author: PKTKS
author_rank: Super Contributor
timestamp: May 13, 2022, 12:41:40 pm
content: Looks very cool...but it seems to rely on specific hardware..... so you may be restricted by which PCs will run these mods..My nephew ( and I encourage and pump him a lot ) is a DOOM nerd...We already run all possible mods for modern doom in which light bumps and shade maps looks really cool.Almost like these . but ... they do not require any particular hardware....A good PC should be enough.. even iGPUs can do themGet yourself if not already a good engine likehttps://zdoom.org/downloads(or ZANDRONUM)Search the best maps to suit your prefs.. like COD (Call of Duty) weapon arsenalAltBrightmaps for Doom1 and 2 +brightmaps and lightsdoubleDHTPand HIGH RESOLUTION textures and maps..There is already a good old Quake high resolution equivalent..You will have even better results than above.. in cheap hardware..The kid loves them.. total doom nerdPaul

author: PKTKS
author_rank: Super Contributor
timestamp: May 13, 2022, 12:44:46 pm
content: forgot to say... very important..Nothing compares to AlisBrutalDoom Sgt MarkiV mods... absolute outstanding ..(alternative Brutalv21is also a good check)Impossible to take the kid from ComicBlood levelPaul
Older Post has decent YouTube take on Commodore 64 Engineering  - Page 1
Forum section: electronics / general

author: RJSV
author_rank: Super Contributor
timestamp: May 10, 2022, 03:19:30 am
content: Hello:Wouldn't normally repost old stuff, but this historical video, narrated by Bill Herd, is irresistible! His delivery is funny, and light...nice for the non-educated layman, along with technical details, that get you thinking...https:youtu.be/-Zpv6u5vCJ4Narrated by Bill Herd.YouTube listed as VCF Midwest

author: RJSV
author_rank: Super Contributor
timestamp: May 10, 2022, 03:21:41 am
content: Sorry there: I think I need to post that as a link (??)

author: ledtester
author_rank: Super Contributor
timestamp: May 10, 2022, 04:03:28 am
content: https://youtu.be/-Zpv6u5vCJ4
PCMCIA mode selection - Page 1
Forum section: electronics / general

author: dmendesf
author_rank: Frequent Contributor
timestamp: April 04, 2022, 12:01:21 am
content: I have some PCMCIA cards that can operate in either true ATA mode or Memory Mode. Does someone know how the card is set to either mode? I imagine that's by strapping pins during reset but I can't find much info about it.
SIPP & SIMM RAM chips database - Page 1
Forum section: electronics / general

author: Teti
author_rank: Regular Contributor
timestamp: January 03, 2022, 01:39:02 am
content: Hi guys, I have processed a lot of data to generate out my database of vintage SIMM and SIPP DRAM chips and modules:http://martenelectric.cz/simm-sipp-ram-chip-database.htmlThis should be handy for those brewing at home

author: Halcyon
author_rank: Unknown
timestamp: January 27, 2022, 12:37:55 am
content: Thank you! That's amazing.

author: SHTechnics
author_rank: Regular Contributor
timestamp: April 03, 2022, 07:16:30 pm
content: Nice! Thank you !
x=5; print x; doesn't print 5 - Page 1
Forum section: electronics / general

author: rfclown
author_rank: Frequent Contributor
timestamp: March 21, 2022, 01:14:57 am
content: I was watching a YouTube video about getting a old Data General mini computer running. The guy commented that the unit didn't come with a multiply/divide card. It made me remember a time in college in the early 80s when I couldn't figure out why my BASIC program wasn't working correctly on a PDP 11/70. There was a conditional statement that was never getting executed and it didn't make any sense. In desperation to figure it out (although it made no logical sense) I assigned a variable and then printed it, something like x=5; print x.... and the display showed something other than 5.? Right after that the guy in charge of the system came out of the back to say that something was wrong with the system. Apparently there was some arithmetic processing card that went bad. Any other weird computer stories that you'd never see on modern systems?

author: Phil_G
author_rank: Regular Contributor
timestamp: March 21, 2022, 09:48:48 am
content: Hoping that this will amuse. I recall one of the routine maintenance jobs on our GEC2050 was changing the filters in the cooling system. This was a sturdy aluminium case about the size of a shoe-box. It was strictly drilled into us that these were microfine molecular filters and would be packed with germs, Bubonic Plague and worse. Consequently it was a surgical operation, wearing full gear, a meticulously careful but swift transfer from the chassis to a sealed container for disposal, followed by an operating-theatre standard of cleaning the machine and its surroundings. The old filter and its deadly contents were disposed of in a special sealed bin collected by the hazardous waste guys from the local council. By that time of course, the bin was actually empty - I'd stay late and take the aluminium filters for project boxes - 40+ years on I still have a mains inverter built into one and I never caught any zombie virus from them

author: m k
author_rank: Super Contributor
timestamp: March 23, 2022, 12:03:15 pm
content: How you know you are not actually dead, do you have mirrors?I was once repairing a PC, warranted 286/386 era Schneider and a new model.Its RS-port speed was 8x, it was also a BIOS programming error.Maybe the use of a serial port was already so rare in Germany.
Q for users of single-sided 5.25" drives - Page 1
Forum section: electronics / general

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: December 30, 2021, 01:56:51 pm
content: Has anyone, ever, in the history of computing, replaced the pressure pad inside the mechanism?

author: precaud
author_rank: Frequent Contributor
timestamp: January 23, 2022, 02:22:31 pm
content: I have on an old HP 8" drive, but not a 5.25" .

author: ejeffrey
author_rank: Super Contributor
timestamp: January 23, 2022, 09:58:04 pm
content: Nope. Although granted I haven't used a single sided 5.25" drive since the Osborne 1 was only completely obsolete rather than vintage.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: February 01, 2022, 07:29:02 pm
content: Thanks. It's just one of those weird idle questions that pop into my mind from time to time.
The Impossible Dream: Computing e to 116,000 Decimal Places... - Page 1
Forum section: electronics / general

author: ledtester
author_rank: Super Contributor
timestamp: February 12, 2022, 11:41:04 pm
content: Just ran across this gem written by Wozniak in 1981:https://archive.org/details/byte-magazine-1981-06/page/n393/mode/2upIt's very well-written and an easy to follow article. I found these closing thoughts at the end especially bemusing...QuoteThe current record, btw, is 31trilliondigits (2020):http://www.numberworld.org/digits/E/

author: Haenk
author_rank: Super Contributor
timestamp: February 18, 2022, 12:00:59 pm
content: I just watched pi to the pi to the pi to the pi:That's the next level

author: Ed.Kloonk
author_rank: Super Contributor
timestamp: February 18, 2022, 01:43:50 pm
content: Quote from: Haenk on February 18, 2022, 12:00:59 pm42.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: February 18, 2022, 03:34:26 pm
content: Lemme just sweep all this under here...Tim

author: coromonadalix
author_rank: Super Contributor
timestamp: March 07, 2022, 03:33:50 pm
content: 62.8 trillion digits - August 2021 (UAS Grisons)

author: SiliconWizard
author_rank: Super Contributor
timestamp: March 07, 2022, 06:16:14 pm
content: Quote from: T3sl4co1l on February 18, 2022, 03:34:26 pmOf course the solution to determining that many decimals of irrational numbers is not to determine them in the first place, given that it has little practical value beyond a few tens of them if that.

author: free_electron
author_rank: Super Contributor
timestamp: March 07, 2022, 06:44:48 pm
content: and what's the error margin ?

author: Haenk
author_rank: Super Contributor
timestamp: March 09, 2022, 05:29:32 pm
content: Quote from: SiliconWizard on March 07, 2022, 06:16:14 pmI doubt "a few tens of decimals" has any practical use at allIn theory, about 40 digits seem to be the maximum number to properly relate one atom to the universe:https://www.jpl.nasa.gov/edu/news/2016/3/16/how-many-decimals-of-pi-do-we-really-need/
Apple ][ (euro) plus: how to hook it to hdmi and colour - Page 1
Forum section: electronics / general

author: Moriambar
author_rank: Unknown
timestamp: December 31, 2021, 08:20:26 am
content: Hello.A buddy of mine went out and gifted me an apple ][ plus (europlus since we're in Italy) which seems fully functional and has actually been repaired (has a daughter board in place of the roms).I don't know what to use to hook it up to a standard hdmi display though (or usb-c) nor how to have colour. I understand the latter is quite a hassle on the europlus. can you please help me?Cheers

author: mjj
author_rank: Contributor
timestamp: December 31, 2021, 02:38:29 pm
content: Retrotink is the generic solution for HDMI:https://www.retrotink.com/This might work too if you have a monitor with composite in:https://www.ebay.com/itm/193393714278

author: dave j
author_rank: Regular Contributor
timestamp: December 31, 2021, 04:04:44 pm
content: If you don't mind a DIY open source project solution,this supports Apple IIs.It needs a Raspberry Pi Zero though, so if you haven't already got one spare, you will probably be able to get all the other bits (including a custom board) delivered and built before you can get a Pi Zero.

author: Moriambar
author_rank: Unknown
timestamp: December 31, 2021, 04:31:40 pm
content: Quote from: mjj on December 31, 2021, 02:38:29 pmhi, thanks for the reply.I have no composite monitor and the retrotink is incredibly superexpensive plus 50$ of int'l shipping.Unfortunately it's a no-no

author: Moriambar
author_rank: Unknown
timestamp: December 31, 2021, 04:32:23 pm
content: Quote from: dave j on December 31, 2021, 04:04:44 pmI'll take a look into it because, believe it or not, I just happen to have a spare pi zero W which I bought some time ago and ended up not using.Thanks

author: Emo
author_rank: Regular Contributor
timestamp: December 31, 2021, 04:44:28 pm
content: Hi,A2heaven also does make VGA adapters for this purpose.http://www.a2heaven.com/webshop/index.php?rt=product/product&path=71&product_id=142Eric

author: coromonadalix
author_rank: Super Contributor
timestamp: January 07, 2022, 09:10:27 am
content: Since you receive it as a gift, i would not mind to pay some $$ to have an already developped interface, if you take into account the time / parts / and tryouts to get a result, you may end with a costly''er' solutionChecked some wikis on the net, the europlus model did need an video card to work properly, it has some hstory with ntsc and pal video signals and the troubles to get it working ??By default it has an component video output, for a start get an multi input monitor capable IE: component video input, vga, rgb, hdmi you have some very cheap china monitors who can handle tons of mixed signalsDO a good read before any attemptsgood luck
I need to know, the slowest cd-r writing speeds of sony AW-Q170A CRX320E - Page 1
Forum section: electronics / general

author: OverclockVintage
author_rank: Contributor
timestamp: February 23, 2022, 01:55:51 am
content: Hi, i have searched trough the internet really alot, but i could not find that information, so i wonder if somebody here may have had or has one of those DVD/CD burners and may know about it. Thanks.

author: SeanB
author_rank: Super Contributor
timestamp: February 23, 2022, 05:56:36 am
content: Have not met any that cannot do 1x or 2x writing at a minimum, though a lot of the writer software hides the ability to change this. As most typically have decent buffers these days the only reason to drop would be to use old media that only supports slow speed.

author: retiredfeline
author_rank: Frequent Contributor
timestamp: February 23, 2022, 07:16:08 am
content: I seem to remember that the burning software, at least on Linux, told me what speeds the drive could do. A hit on a search suggests that it burns CDs but can only read DVDs.

author: OverclockVintage
author_rank: Contributor
timestamp: February 23, 2022, 07:58:52 pm
content: SeanBI was thinking on buying one of those writers, actually some programs i've managed to force slower speeds on mine, but it did not recorded well, while other programs automatically switch back to the slopwest supported speeds of my drive.retiredfelineYes, it is for cds that i want. It's hard to find information and specs for some of those old cd writers.

author: mariush
author_rank: Super Contributor
timestamp: February 23, 2022, 08:05:33 pm
content: You have to be careful about the actual media, the discs .... modern CD-R / DVD-R / DVD+R use substances optimized for higher speeds and the discs can actually be damaged if you burn them at low speeds because of the amount of time the laser stays on top of some area.It's quite common for DVD+R discs to require burning at minimum 4x or risk damaging them.I wrote my first CD-R on an external HP 1x CD writer unit connected to the PC through the parallel port ...that was a boring 60 minutes of write time.Then I bought a 24x CD-RW unit and wrote discs at 6-8x because that was the lowest speed that enabled protections for empty write buffer and all that.imgBurn is what I use on Windows -https://www.imgburn.com/index.php?act=download- it's freeware but when you install it you have to be careful to uncheck some option, otherwise it installs a toolbar.It shows the disc information, as filled by whomever made the disc, and says the minimum recommended write speeds and all that.

author: OverclockVintage
author_rank: Contributor
timestamp: February 23, 2022, 10:54:28 pm
content: mariushYes, most of the new media that you find locally is only good for higher speeds, and they are quite fragille, they warp with the heat of low speed burning and get scratched quite easily, i've got some old Elgin that record the best with 4x when you don't limit to 4x but use 4x as the botom speed, and also some Nipponic from markolon that are great for 4x but they are not so durable.
History of the Amiga music tracker and it's offspring up to today. - Page 1
Forum section: electronics / general

author: BrianHG
author_rank: Super Contributor
timestamp: November 26, 2021, 10:31:54 pm
content: Enjoy:

author: John B
author_rank: Frequent Contributor
timestamp: November 29, 2021, 09:03:32 am
content: Got around to watching the whole thing, and it brought on a tidal wave of nostalgiaIt clarified a few things about the sound of the early stuff, and why they tended to use that rapid arpeggiation instead of chords (it was down to the available polyphony).It was also cool to see Unreal, Unreal Tournament and Deus Ex get a mention in there too. I still have those original music files. They were in a crossover period. CD audio and even MP3 was available at the time I think, but the tracker music provided longer sound tracks and even dynamic/situational music which wasn't really feasible with wave audio.Tracker music had the useful characteristic that it's file sizes where "logarithmic" in nature, where regular sampled audio is linear. Once the sound samples were stored in the tracker file, the tracking data was much smaller and repeated patterns further reduced file sizes of longer pieces. Total song lengths could be 10s of minutes while being less than 2MB, and the sound wasn't compressed or low sample rate. Super impressive at the time when games were struggling to fit all the needed data on a CD, and downloading MB of game content was out of the question.

author: Phil_G
author_rank: Regular Contributor
timestamp: November 29, 2021, 04:55:53 pm
content: Interesting. I'm probably wrong as I'm not an Amiga user, but at 22:00, his description of the contemporary meaning of 'chiptunes' is that its "tracker modules that emulate the style of earlier 8-bit music... using small looped samples...". I've always thought 'Chiptunes' were streamed AY3-8910 register dumps (YM format etc) is this not the case? I'm probably out of touch
PCMCIA Development Tools - Page 1
Forum section: electronics / general

author: e_60
author_rank: Contributor
timestamp: February 18, 2021, 04:49:15 am
content: Anybody a past designer/developer of 16-Bit PCMCIA Cards?I have been collecting little card testers, books etc but this stuff is so rare. Especially the software for stuff that comes without discs.

author: ebclr
author_rank: Super Contributor
timestamp: February 18, 2021, 05:35:45 am
content: Why are you doing that ?

author: srb1954
author_rank: Super Contributor
timestamp: February 18, 2021, 07:30:46 am
content: Quote from: e_60 on February 18, 2021, 04:49:15 amAbout 25 years ago I designed a custom PCMCIA card containing a speech synthesiser to allow blind people to use a laptop computer.A difficult design challenge back in those days as we didn't have access to the super-miniature components that are so readily available these days. I only had 0805 or 1206 sizes SMD passive components available to use and I even had to squeeze a DIP package inside the card as one IC was not available in an SMD package.

author: Treehouseman
author_rank: Unknown
timestamp: February 18, 2021, 04:04:17 pm
content: Quote from: srb1954 on February 18, 2021, 07:30:46 amDid this happen to be your card? Your description almost exactly fits this which I picked up off ebay a few years ago.

author: srb1954
author_rank: Super Contributor
timestamp: February 18, 2021, 07:53:56 pm
content: Quote from: Treehouseman on February 18, 2021, 04:04:17 pmNo, but is it quite similar.My card also used a Xilinx FPGA (XC3030 as I recall) with a parallel EEPROM for the FPGA configuration memory. I also used a cut-out in the PCB to accommodate the DIP packaged IC.

author: dmendesf
author_rank: Frequent Contributor
timestamp: December 30, 2021, 03:48:22 am
content: I'm developing an interface for PCMCIA cards that operate in memory mode. I need to better undestand CIS memory space. Do you have any info to share about it?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: December 30, 2021, 04:09:45 am
content: I don't know, but I've seenscanlimedoing some vintage debugging with some card, she must have some resources.Tim
PC/PCI DMA Arbitration and Protocols specification - Page 1
Forum section: electronics / general

author: amyk
author_rank: Super Contributor
timestamp: November 15, 2021, 03:03:44 am
content: I'm looking for the above-named document for some historical research, and it apparently used to be on Intel's FTP atftp://ftp.intel.com/pub/IAL/PCI/dma22.docbut is no longer, and I can't find a copy anywhere else. Does anyone happen to have a copy?

author: Rasz
author_rank: Super Contributor
timestamp: November 15, 2021, 07:56:21 pm
content: try Michal Necasek athttp://www.os2museum.com/wp/
TANDY 1000SX Restoration - Page 1
Forum section: electronics / general

author: rkabz
author_rank: Contributor
timestamp: November 15, 2021, 06:48:49 am
content: Hi group. I have recently come across an ancient Tandy 1000SX computer. I only have the base unit and it came with a 20MB Kyocera HDD and one 5.25" 360K TEAC floppy drive. I have disassembled the unit and was going to recap the power supply, so removed all caps and tested each one with an ESR tester. All were good, capacitance within limits and no leakage out of the ordinary. To make sure all caps would not stress out on power up, I 'formed' each one at rated voltage (this was a secondary leakage test) on a DC power supply, (200V mains caps at 50 volts). I then put them back in, hooked up mains power and loaded the PSU up with requisite minimum load as per tech manual. Low and behold, PSU ran perfectly, voltages near spot on and ripple OK and nothing exploded! So that saved a recap. Next on to the main board. Due to age I removed all socketed IC's and checked for corrosion and then put them back. I hooked up a composite monitor (NTSC compatible) and powered up the board. Garbage video. But there was one line that vaguely resembled text, so not all was bad and the board not completely dead. Anyway, removed all socketed IC's again. This time I cleaned all pins and because sockets were not machine pinned but old leaf contact types, I cleaned and lubed each IC pin with a switch cleaner/lubricant...made them a bit easier to get in and out. After quite a while of doing this I replaced all IC's and powered on again. And this time - a flashing cursor at top left and text on screen announcing "err I/O 3F8", some progress at least. No doubt the error has something to do with the printer interface which is a custom IC, thanks Tandy)...anyway the board is now stuck in a loop trying to, I guess, read from the port to see if it's there...So a question to the group - does anyone out there have any experience with what the Tandy BIOS is looking for here, or 1000SX's or EX's for that matter? And does anyone have any Tandy 1000SX or EX parts? Any help much appreciated. By the way, the HDD was MFM type which would have been great, but it did not spin up...and after trying to rotate the motor gently with no luck, I decided to take the cover off and found that one head is essentially welded to the platter due to a head crash. Damn.
An address generator - Page 1
Forum section: electronics / general

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: October 29, 2021, 07:28:59 pm
content: The idle thought occurred to me that a possible test of a 6502-based board is to drive the address bus through all states. The usual solution is to strap a "NOP generator" somewhere, but it seems easier to just replace the 6502 with a test harness that drives the address lines. The purpose being to observe the address decoding circuitry on the board.A 40 pin DIP board with a 16 bit counter connected to the clock, plus whatever is needed for the phase signals.Does such a thing already exist?

author: Benta
author_rank: Super Contributor
timestamp: October 29, 2021, 08:21:26 pm
content: Quote from: Alex Eisenhut on October 29, 2021, 07:28:59 pmYes. It's called an in-circuit-emulator (very expensive, though). But I fail to see the real purpose on a system as simple as 6502. Just follow the PCB traces, combined with the 74LS138/139 data sheets.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: October 29, 2021, 08:48:12 pm
content: The 6502 might be simple, but the system it's in might be crap.
Corsham SWTPC 6809 + floppy interface + Flex - Page 1
Forum section: electronics / general

author: Wawavoun
author_rank: Regular Contributor
timestamp: October 21, 2021, 02:28:09 pm
content: Hello,I have Corsham Tech 6809 SWPTC clone with motherboard, 6809 cpu board, MP-S serial board and // board + SD Arduino floppy emulator.Everythings works well.Now I try to get a real floppy system attached to this computer so I will rebuild a Peripheral Tech FD-2 interface (doc and good pictures available, easy).I have a 5 1/4 360 ko drive and a 3 1/2 1.44 mo I can attach to this system. I also can connect a Gotek with flashfloppy.In this case no need of the // interface and of the SD card system.According to Corsham Tech documentation the serial board should be in slot 1. But the PT FD-2 doc say also that this interface should be attached to slot 1.I imagine this depend of the monitor...My question are :- can I use the PT FD-2 with the Corsham system ? For sure yes, the questions are more what adjustment to do ?- should I modify the Corsham monitor to do that ? what are roughly the modifications to do ?- can I use the original SWPTC Monitor SBUG18 instead of Corsham monitor ? With modification or not ? What are the modifications ?- what Flex image should I use to boot this system (found more than one on the internet but I dont know what to choose) ?Thanks for help and opinions about that.Regards.Philippe

author: granzeier
author_rank: Regular Contributor
timestamp: October 22, 2021, 11:58:52 am
content: Quote from: Wawavoun on October 21, 2021, 02:28:09 pmPhilippe,I also have a couple SWTPC computers, but have never heard of those boards for using the Arduino as a floppy emulator. Could you elaborate, please?

author: Wawavoun
author_rank: Regular Contributor
timestamp: October 22, 2021, 12:18:55 pm
content: Hi,have a look here :https://www.corshamtech.com/product/sd-card-system/Its well done and works perfectly !But you need a modified monitor on the cpu board...On my side its just that I really like floppies, sound of floppies, slowness of floppies etc... No no I do not live in the past !!!

author: Kean
author_rank: Unknown
timestamp: October 22, 2021, 12:40:50 pm
content: I miss my 6809-based SWTPC computer I had back in the mid 80's when I started University.I do not miss the floppy drives! They were so unreliable, especially the 8" drives. I never worked out why, and I didn't have the experience or parts back then to troubleshoot.

author: granzeier
author_rank: Regular Contributor
timestamp: October 22, 2021, 02:44:23 pm
content: Philippe,Thanks for the link, I had been to Corsham's site before, but had not noticed this.
Video: M8650 working on PDP-8/F - Page 1
Forum section: electronics / general

author: intabits
author_rank: Frequent Contributor
timestamp: October 09, 2021, 02:41:15 pm
content: For anyone who might interested, a video where I get my PDP-8/f to do some I/O at last.Using the M8650 board for serial communications (but only at 110 baud).

author: granzeier
author_rank: Regular Contributor
timestamp: October 10, 2021, 01:58:02 am
content: Nice!I really like how you show all the steps you took to get the data out. It can be pretty confusing to describe the levels in TTL, versus RS-232.I like the speed, it reminds me of using the old ASR-33 teletypes back in school. Before you upgrade the speed, load up a BASIC interpreter, and show us a bit of playing with that.(Although, you will want to keep that to a minimum and get the speed up to a usable speed after that.)This also makes me want to get my own PDP, or a Nova, or some other minicomputer.

author: intabits
author_rank: Frequent Contributor
timestamp: October 12, 2021, 05:58:59 am
content: Quote from: granzeier on October 10, 2021, 01:58:02 amThanks, I'm glad you enjoyed it!This was the first, and currently the only, means of any form of I/O on this computer.I do also have a rudimentary parallel interface for inter-computer communication still to try out, but it's usefulness would be limited.It has no form of mass storage, and therefore no way to load a Basic interpreter. (I think one exists, but I'm not even sure about that)I'll be working on that, but it's a fair way off...
6522 + 6850 questions - Page 1
Forum section: electronics / general

author: Wawavoun
author_rank: Regular Contributor
timestamp: August 25, 2021, 05:02:05 pm
content: Hello there,I have a SBC with a 6522 and a 6850 connected as per image.So the CB1 output of the 6522 act as RXClock and TXClock for the 6850 and fix the baud rate.Reading the datasheet it seems to me that I have to use the SR Mode 4 on the 6522 to do that... Is that right ?If Yes how should I initialize the 6522, how can I fix the baud rate and is the port B still usable as parallel port for other topics ?Thanks for help. Regards.Philippe

author: retiredfeline
author_rank: Frequent Contributor
timestamp: August 25, 2021, 05:18:49 pm
content: Have you considered the possibility that CB1 is not the clock source but rather a clock input and shares the same clock that drives the Tx and Rx of the 6850? What are those lines connected to on the right of the schematic that we don't see?

author: Wawavoun
author_rank: Regular Contributor
timestamp: August 25, 2021, 05:44:34 pm
content: This wire is just going to the output connector...I am sure. The clock is generated by the 6522 CB1 pin.

author: guenthert
author_rank: Frequent Contributor
timestamp: September 04, 2021, 06:09:03 pm
content: Incidentally I just became interested in those chips while troubleshooting a Keithley 705 scanner. The MC6850 data sheet makes it look like the TX- and RX-clock pins are inputs only. So yes, the clock must then be generated by that VIA 6522.I haven't progressed on the manual of the 6522 sufficiently to be of any actual help though.

author: Wawavoun
author_rank: Regular Contributor
timestamp: October 07, 2021, 11:14:36 am
content: Hello,After tests I can confirm that CB1 output of 6522 can act as a free run clock (into SR mode 4).Regards.Philippe
Videos:  Testing DEC H740 PSUs  and PDP-8/f power on and simple tests - Page 1
Forum section: electronics / general

author: intabits
author_rank: Frequent Contributor
timestamp: September 20, 2021, 07:02:27 pm
content: A couple of PDP related videos.First video is testing the H740 power supplies from the PDP-8/f and PDP-11/05, with a dummy load.I made the mistake of running the first PSU from a variac with the load attached, and damaged it.The second PSU blew a fuse under load, not sure why.After getting replacement parts, I fixed the 8/f PSU, tested it and installed it to the computer.(repair of the 11/05 PSU can wait)Second video is powering up the PDP-8/f for the first time in over a decade.At first I thought it wasn't working (yet another dumb mistake), but then realized it was OK after all.I was able to enter and run a couple of small test programs.
Cipher machine 1963 reconstruction ...IEEE Spectrum  - Page 1
Forum section: electronics / general

author: jonpaul
author_rank: Super Contributor
timestamp: August 31, 2021, 09:09:54 pm
content: Hello all: My IEEE Spectrum article about a 1963 cipher machine and a huge espionage case Rubicon just went onlinehttps://spectrum.ieee.org/the-scandalous-history-of-the-last-rotor-cipher-machineabout a years work. Last photo has some HP and TEK equipment.Your thoughts appreciated!Jon

author: granzeier
author_rank: Regular Contributor
timestamp: September 03, 2021, 10:33:55 am
content: Great article, and a great read.Your description of fixing the printer after it exploded made me want to give up, and I wasn't even working on it!Thanks for a very enjoyable reading time.

author: Benta
author_rank: Super Contributor
timestamp: September 03, 2021, 10:00:33 pm
content: The references to NSA are totally off.Crypto AG was majority owned by CIA and BND. Get the facts straight.Apart from that, it's an interesting story.

author: ebastler
author_rank: Super Contributor
timestamp: September 14, 2021, 06:12:10 pm
content: Quote from: Benta on September 03, 2021, 10:00:33 pmI think you misread Jonpaul's article. (And might want to use less harsh language in light of that.)To my knowledge, the NSA was indeed "involved" with Crypto AG by providing technology help, and getting breakable crypto implementations in return. In addition, and a bit later, the CIA and BND became owners of Crypto AG as you state. And that's exactly what the article says:Quote

author: granzeier
author_rank: Regular Contributor
timestamp: September 20, 2021, 01:08:12 am
content: I noticed your article was written up on Hack-A-Day's Links.Congrats.
OLIVETTI P602 SERVICE MANUAL NEEDED - Page 1
Forum section: electronics / general

author: harrimansat
author_rank: Regular Contributor
timestamp: February 18, 2016, 12:25:22 pm
content: Hi anyone knows where I can find a service manual copy of this thing, Olivetti P602

author: HAL-42b
author_rank: Frequent Contributor
timestamp: February 18, 2016, 12:38:00 pm
content: Wow! This seems like a real piece of history, probably the descendant of the legend Olivetti Programma 101.This is by all accounts a museum piece. Matter of fact just found amuseumthat wants one

author: snuci
author_rank: Newbie
timestamp: September 09, 2021, 10:28:25 pm
content: Hello,I have an Olivetti P602 that I am now looking at restoring. I am wondering if you ever found the manual?If you'd like the documentation I have, I have scanned it at:https://vintagecomputer.ca/files/Olivetti/P602%20Microcomputer/Hope this helps you (if you still have it).Santo

author: harrimansat
author_rank: Regular Contributor
timestamp: September 10, 2021, 06:41:36 am
content: Hi Santo, thanks!Yes, I still have it!Best regardsMiguel

author: harrimansat
author_rank: Regular Contributor
timestamp: September 10, 2021, 07:11:54 am
content: Quote from: snuci on September 09, 2021, 10:28:25 pmYou know where I can buy a magnetic card?

author: harrimansat
author_rank: Regular Contributor
timestamp: September 10, 2021, 07:14:30 am
content: But I don´t have service manual, I don´t konw if this thing is working. It powers up, but i´dont have ink and paper neither

author: harrimansat
author_rank: Regular Contributor
timestamp: September 10, 2021, 08:07:16 am
content: I only have some old catalogs

author: snuci
author_rank: Newbie
timestamp: September 10, 2021, 04:50:50 pm
content: Quote from: harrimansat on September 10, 2021, 07:14:30 amAre all the belts in good condition? When you power it on, does the light turn green? Can you type in and add two numbers? You don't need cards right away for it until the basics work.Santo

author: TimFox
author_rank: Super Contributor
timestamp: September 10, 2021, 05:36:28 pm
content: There is an interesting history behind this device; see:https://www.abebooks.com/servlet/BookDetailsPL?bi=30785940198&searchurl=n%3D100121501%26sortby%3D17%26tn%3DThe%2Bmysterious%2Baffair%2Bat%2Bolivetti&cm_sp=snippet-_-srp1-_-title2for "The Mysterious Affair at Olivetti" by Meryl Secrest, Knopf 2019.

author: harrimansat
author_rank: Regular Contributor
timestamp: September 10, 2021, 05:42:09 pm
content: I will try it, when I when i got it i didn't have any manual, i had no idea how it workshttps://media.nature.com/original/magazine-assets/d41586-019-03082-6/d41586-019-03082-6.pdf
To Whom it May Concern: Daniel_K Says Farewell - Page 1
Forum section: electronics / general

author: Le_Bassiste
author_rank: Frequent Contributor
timestamp: August 25, 2021, 01:26:17 pm
content: https://danielkawakami.blogspot.com/2021/08/final-updates-for-my-support-packs.htmlthank you for your outstanding contribution to the soundblaster-community, daniel!
Dummy Load for DEC PDP computer Power Supplies - Page 1
Forum section: electronics / general

author: intabits
author_rank: Frequent Contributor
timestamp: August 17, 2021, 09:08:27 am
content: Dummy Load for DEC PDP computer Power SuppliesA while ago I made this dummy load for testing the H777 power supplies in my PDP 11/04 and 11/34.And I have three other PDPs that have power supplies that need to be tested. But I was too lazy to allow for them when I made the unit above. So now I've made a more versatile version.The front, showing barrier strips where the dummy load resistors connect to the top row of screws. A cable customized for each type of power supply (the one shown is for the H777) will connect to the appropriate screw terminals on the bottom row.First power supply to be tested is the H740 in the foreground (for PDP 8/f and 11/05). Behind that is the PDP 8/A power supply.Rear view showing the banana jacks for monitoring the supply voltages under load.The resistor banks that go into the two oil-filled cylinders.The wiring to the barrier strips.Schematic and wiring diagram.video
is it possible to input audio/data from a phone to an Atari XE130 casette port? - Page 1
Forum section: electronics / general

author: Deactivated-1
author_rank: Frequent Contributor
timestamp: April 11, 2021, 01:08:26 pm
content: So I had taken appart the program recorder for an atari 130XE when I was a kid, and now I can't record any program...I was looking at shematics for the program recorder and I can't really wrap my head around how it works, it seems that maybe it uses 1 the right track for music/audio effects, and the left track for the program itself but it like... amplifying it a ton... idk.here's the shematic for the program recorder:https://oldcomputer.info/8bit/aptaperec/xc12.gifhere's a pinout for the connector (seems it's not correct, not sure...):http://www.kbrnet.de/projekte/sdrive-max/sio.pngso it seems when it records data, it just connects straight to the record head from the computer?... also how does the erase head oscillator even work?or it just magnetizes the head? well I know nothing about tape drives so it's probably all fine there...but the part where it gets the program data is confusing to me... do I just connect an RCA cable to pin 4 and 3?what about the +5V/ready and Motor Control pins? I have tried inputting data into pin 3 but it did nothing. (yes I did type the load command)and perhaps it like... converts the analog signal from the tape into digital 0/5V for the data track...I am just completely lost on that part...

author: gcewing
author_rank: Regular Contributor
timestamp: August 11, 2021, 02:43:03 pm
content: Yes, it looks like the playback circuit is decoding the tones from the tape and producing a digital signal. So you won't be able to feed audio straight into the Atari's cassette port.Here's my take on how it works: Q5 and Q6 amplify the signal from the head, then it goes through a limiter (U1C) and then to two bandpass filters (U1A and U1B) which are presumably tuned to the tone frequencies used. The outputs of those are rectified and compared by U1D, giving a 1 or 0 depending on which one is giving the strongest output.You seem to be right that the computer directly feeds the head during recording; it must be generating the tones in software.The right head is just connected to an audio amplifier.I don't think there's any erase oscillator, it's just passing DC through the erase head. Which is probably fine for this application -- it hardly needs to be hi-fi!
PDP-8/F Quick look and Teardown - Page 1
Forum section: electronics / general

author: intabits
author_rank: Frequent Contributor
timestamp: September 25, 2020, 06:56:26 am
content: Leaving the best to last, here is the pride of my PDP collection, the PDP-8/F.Here we just open it up and have a look around. The power supply and its capacitors still need to be tested before I'll try to turn it on.

author: AaronLee
author_rank: Regular Contributor
timestamp: July 19, 2021, 01:53:18 am
content: I enjoyed the video. Brought back lots of memories when I had a chance to play around on one of those many years ago. That front panel was the best looking of all the DEC machines I had a chance to work with. I never saw the insides of it though, so it was nice to finally see that.

author: peter-h
author_rank: Super Contributor
timestamp: July 21, 2021, 06:40:56 pm
content: Intersil put that on one chip - later sold by Harrishttp://www.bitsavers.org/pdf/dec/pdp8/cmos8/_dataSheets/HD-6120.pdf

author: TimFox
author_rank: Super Contributor
timestamp: July 21, 2021, 06:52:55 pm
content: About that time, Amtrak seemed to adopt that color scheme for interiors, especially food and beverage service cars.

author: AaronLee
author_rank: Regular Contributor
timestamp: July 22, 2021, 01:43:57 am
content: Quote from: peter-h on July 21, 2021, 06:40:56 pmWow, that's amazing they actually made that onto a chip.

author: peter-h
author_rank: Super Contributor
timestamp: July 22, 2021, 06:28:36 am
content: The 6100 was the original chip, I think.