hybridfree/eevblog-posts huggingface dataset:
Nice Pentium mini laptop - Page 1
Forum section: electronics / general

author: Kilrah
author_rank: Unknown
timestamp: April 08, 2020, 10:09:41 pm
content: A cute little 8.4" mini laptop from 1999. Got it for $5 on auction a few days ago.Unfortunately someone went berserk on it at some point, case was cracked in 2 locations and the whole left hinge is missing. Pisses me off because the auction photo did not have any cracks and the left hinge while mangled still had all the parts that I never gotI repaired the cracks but the hinge will be difficult.At least the LCD is flawless, and as crazy as it sounds the 2 batteries still last 1h-1h30 eachAcer Travelmate 313T, Pentium MMX 266, 800x600 TFT, 16MB soldered RAM and came with a 64MB stick added, HDD was removed at some point. Has one USB1.1 port which is super handy to be able to use a modern flash drive to move stuff to. 2 PCMCIA slots as well, pretty impressive for such a tiny machine back then.The supplied AC adapter was apparently dead (case had been cracked open and some "skid marks" visible on the plastic and shielding) so I didn't even bother trying to plug it in. Laptop didn't power on with another supply, but upon disassembly the solder on the DC in jack looked a bit awkward - resoldered it and it fired right up.Changed CMOS battery, added a CF-IDE and a small 1GB card (snatched a 8GB one on auction in the meantime), installed W98SE and it works just great. Was relatively easy to find the video driver, a bit more of a pain to get the audio one, found the one for the modem, so everything is fine now. Unfortnately I can't find the Acer Notebook Manager version that works with this, and the screen brightness buttons don't work without it - which might explain why the screen is pretty dim, likely set low and I have no way of changing itThe LCD cable seems a little flaky as well, I have some distorsion depending on how I move it. Probably due to the same abuse that caused the rest...Can't find much information at all about this model online. Haven't even found a single picture - found some magazine ads mentioning the model and matching specs but with a picture of a completely different machineI feel like attempting a repair of the left hinge and hopefully fixing the LCD cable, and maybe adding something to control screen brightness without the soft buttons. It's such a nice machine, pretty powerful for the generation, small and uncommon, and exactly my style - I'm very much into reduced size portables and it was actually a pleasant surprise because I hadn't noticed at all from the auction that it wasn't a full size machine...Ordered some bigger RAM as well.The CPU has pretty uncommon packaging:http://www.x86-guide.net/en/cpu/Intel-Pentium-MMX-266-Mobile-(TCP)-cpu-no2092.htmlThis has nice pictures too:Auction... although it hurts that it's listed as "for scrap gold recovery"

author: dexters_lab
author_rank: Unknown
timestamp: April 09, 2020, 12:15:58 pm
content: ooh that's nice!
Build files now available for the nicest 8085 bus monitor I have seen - Page 1
Forum section: electronics / general

author: Ccandrews
author_rank: Contributor
timestamp: April 07, 2020, 04:34:07 pm
content: To all the 8085 enthusiasts or 8085 curious out there, the build gerber files for a bus monitor on the SBC-85 system have been uploaded.In addition to all the blinky LEDs for binary, this monitor also has a hexadecimal display of the address and data.Single step and slow step capabilities allow the user to follow the software. A feature that is really nice is the bus monitor allows the user to select which of the six types of bus cycles should be used for the single step, e.g., stop only at memory reads, I/O writes, only opcodes, etc. This is fantastic for watching things go out a port, for example, since the program can run at full speed and then go into single or slow step mode only when it hits the OUT instruction.Finally, this bus monitor has programmable address and data breakpoints as well as software control of the step override and bus cycle filtering. This allows the user to determine the address where the monitor should switch to step mode or it allows the user's software to control what type of bus cycle should be monitored and at what address the monitor should shift into step mode.All in all, this bus monitor is an excellent tool for anyone working with the SBC-85 single board computer.Download files and documentation are on the project website atSBC-85.COM. More info onHackaday.ioDownload and build is best, but boards are available ontindieorwatch onregardsCraig
Roland DXY1100 - Page 1
Forum section: electronics / general

author: Ernestpw
author_rank: Newbie
timestamp: April 06, 2020, 06:59:31 am
content: Good Day I am desperately searching for a driver for the Roland plotter for Windows XP Does anyone have a copy of this that they are willing to share with me Many thanksErnest

author: drussell
author_rank: Super Contributor
timestamp: April 06, 2020, 07:05:06 am
content: According to Google, maybe try here:http://download.rolanddg.jp/en/cutting.html#dxy1k

author: drussell
author_rank: Super Contributor
timestamp: April 06, 2020, 07:44:52 am
content: P.S. How's Vern?
Inside 1974 Air Traffic Control Data Terminal - Page 1
Forum section: electronics / general

author: liquidice
author_rank: Newbie
timestamp: March 04, 2020, 06:15:04 pm
content: This computer terminal has been sitting around my house for a few years now. From what I can tell is was made around 1974 by a company called MegaData. The computer terminal is made from 7400 series logic chips with date codes ranging from 1970 to 1974. I suspect this was a prototype.https://photos.app.goo.gl/amhkExaHP4KEFv8z6The display is 80 columns with 25 lines. The keyboard has 27 unique function keys with names such as "Altitude, Route, Departure, Hold, Quawk, Speed, Altimeter, Flight Level, Frequency Change, Approach, etc" which has lead me to believe it was used for Air Traffic Control.Baud rates of "110, 150, 300, 600, 1200, 2400, 4800, and 9600" can be selected on the back of the machine. The Keyboard uses individual mechanical keys, and there are two 40cm by 10cm circuit boards stacked underneath the keyboard.The backplane of the computer is wire wrapped. There are two 40 pin ceramic packages; one a Standard Microsystems Corp COM2502; the other a "78372C-006" with a date code of 1973-10 I can't find a data sheet for.I have two of these machines, picked up at a garage sale a few years ago. See pictures in Google Photo's Albumhttps://photos.app.goo.gl/amhkExaHP4KEFv8z6

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: March 05, 2020, 02:48:36 am
content: Garage sales in my neighborhood are usually board games and ratty furniture...Love that machine's look, that keyboard... Yes!

author: helius
author_rank: Super Contributor
timestamp: March 05, 2020, 04:34:49 am
content: The first Air Traffic Control system was the SAGE network. SAGE stood for Semi-Automated Ground Environment, and was also the first distributed, fault tolerant computer system with real time data processing. The system was very large, occupying several huge bunker-like buildings and employing hundreds of operators. Parts of it were later used for civilian ATC.https://history-computer.com/ModernComputer/Electronic/SAGE.htmlhttps://www.computerhistory.org/revolution/real-time-computing/6/120SAGE used vector graphics on a huge, 20" round CRT, with characters drawn by a special tube called a Typotron. Efforts to modernize ATC led to high-resolution, square-aspect displays with 2048x2048 pixels, which was close to the limit of CRT technology in the 1980s.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: March 05, 2020, 04:48:33 am
content: Quote from: helius on March 05, 2020, 04:34:49 amCurious Marc should try to get his hands on such a display, or a Charactron (same thing maybe? Different companies?) or maybe a Eidophor projector. I love these crazy physics or complex tube thingies!
DEC Corporation 16 bit one shot dc output card m6011 - drawings wanted! - Page 1
Forum section: electronics / general

author: Chris56000
author_rank: Frequent Contributor
timestamp: February 11, 2020, 11:36:20 am
content: Hi!I'm looking for the original DEC Information for the Digital Equipment Corporation 16 bit one shot dc output card M6011 - there's a bit of print damaged on it near E18!!I've had a look in the enormous collection on the Bitsavers Site but I can't seem to find any data for the M6000 interface modules!Some say the M6011 is part of the PDP11 and some state it's s "QBus" card - anybody any ideas?Chris Williams

author: gslick
author_rank: Frequent Contributor
timestamp: February 13, 2020, 08:28:14 pm
content: INDUSTRIAL PRODUCTS I/O SUBSYSTEM USER GUIDE, EK-0PIOS-UG-005, 5th Edition, July 1980http://www.bitsavers.org/pdf/dec/pdp11/industrialProducts/EK-0PIOS-UG-005_IO_Subsystem_User_Guide_Jul80.pdfPage 6-12-1 (page 228 of the PDF)M6011 16-BIT ONE SHOT OUTPUTFUNCTIONAL DESCRIPTIONThe M6011 module provides 16 program-controlled dc outputs. These outputs are nonisolated, single wire, one shot, open collector, Darlington switches used for operating devices that must be activated for only a short duration, such as relays, solenoid valves, etc. Output timing is selectable from 100 microseconds to 5 seconds on a per-byte basis via switches located on the module. Provision is made for reading the module's output status or generic code and for disabling all outputs. The module also features a common output fuse and switches for address selection.There is a Detailed Description section and a Simplified Block Diagram, but no full schematic. You would need to find a Field Maintenance Print Set. That probably existed at the time, but might be difficult to find a copy now.
Washing & cleaning PCBs with BGA components - Page 1
Forum section: electronics / general

author: dexters_lab
author_rank: Unknown
timestamp: January 24, 2020, 10:51:52 am
content: Normally when i am fixing up old computers i like to wash the entire PCB in mild detergent and then shower it clean but this has always been on regular component packages where it's easy enough to dry and remove any water from under the componentI've yet to do this on anything that uses BGA, fearing any residue left under/around the balls might encourage corrosion etci now have a large PC motherboard that is filthy and contains two large BGA devices (the north and south bridge ICs), it's going to need a serious cleanwhat are the thoughts of the collective?

author: senso
author_rank: Frequent Contributor
timestamp: January 24, 2020, 05:01:33 pm
content: Done it hundreds of times with laptop mobos, used either water with a bit of IPA in an ultrasonic cleaner then a rinse in IPA, or just IPA and a brush, then dried with a blow gun at 5-6 Bars with dried and filtered air, never had a problem.

author: SiliconWizard
author_rank: Super Contributor
timestamp: January 24, 2020, 07:04:26 pm
content: If it's really dirty, I would blow air thoroughly first to get rid of most dust (that can contain metallic/conductive particles), and then wash it. Blow dry after that again.

author: fourtytwo42
author_rank: Super Contributor
timestamp: January 24, 2020, 08:07:34 pm
content: I must admit to me this thread made me laugh (apologies) just the concept of a BGA package being vintageBut then are my ideas of vintage somewhat out of dateTo me being of a certain age for computing devices I look back to maybe 1970's tops.............

author: dexters_lab
author_rank: Unknown
timestamp: January 25, 2020, 11:34:25 am
content: thanks, sounds like i am worrying too much, i'll give it some canned air before & after washing

author: German_EE
author_rank: Super Contributor
timestamp: January 26, 2020, 04:32:11 pm
content: I should point out that the computer mentioned in this post is almost certainly a vintage item (as seen on the excellent Dexters Lab You Tube channel).

author: dexters_lab
author_rank: Unknown
timestamp: January 28, 2020, 09:00:05 am
content: Quote from: German_EE on January 26, 2020, 04:32:11 pm

author: Rasz
author_rank: Super Contributor
timestamp: January 29, 2020, 11:14:52 am
content: gonna be fine as long as you rinse all the water with ipa and dry it well. You might want to bake it before later rework.

author: dexters_lab
author_rank: Unknown
timestamp: February 01, 2020, 11:51:21 am
content: just went to clean the board, blew it off with an air-duster and it came up lovely, no washing needed
Panasonic JU-257A 216P floppy drive interface on sub models - Page 1
Forum section: electronics / general

author: gkmaia
author_rank: Frequent Contributor
timestamp: January 29, 2020, 10:58:10 pm
content: I've got a Panasonic JU-257A 216P floppy drive.I know the JU-257A is the main model.And then there are model variations like the 216P, 606P, 083P.... and most of the variations have extra jumpers to config different things.In regards the 34 pin interface.Does all the JU-257A model variations share the same pin configuration? I suppose the whole 257A is shugart. Is that correct?
Programming the Commodore: "SNAKE" game for C64 and PET - Page 1
Forum section: electronics / general

author: Bicurico
author_rank: Super Contributor
timestamp: January 11, 2020, 10:34:57 am
content: Hi,I was bored so I got myself into the retro-computing trip...Here a few kick-starters:MiSTer: FPGA emulation of many (all?) 8 bit computers and consoles and moreTheC64 Maxi: Newly marketed Commodore 64 replica with 1:1 full size and shape and working keyboard, based on VICEBMC64: "Bare metal" Raspberry Pi that is ONLY running VICE and required libraries - for Raspberry Pi 2 and 3 - I run it with the 2 and its composite video output: looks amazing ly realC64C: The original newer model, purchased cheap at eBay - it take quite a while to find a good deal nowadays...So I thought to relive the old moments of when I was 18 (32 years ago) and program something on the C64.So I did the SNAKE game.First in BASIC and the code fits exactly one screen.Then I challenged myself to program this came in Assembly (6502/6510). Back in the days I learned a bit of how to do it and I wanted to refresh my memory. I am amazed on how much I retained!So I ended up with the same game for the C64.Then I set a new goal: port it to the Commodore PET, which I never owned.This is done, too! I thought it might be nice for the PET owners, as the existing amount of games is limited.Attached are the games, if you want to give it a try - bugs guaranteed!Regards,Vitor
LGP-21 -- replicating a 1963 magnetic disk computer - Page 1
Forum section: electronics / general

author: ebastler
author_rank: Super Contributor
timestamp: January 05, 2020, 05:04:18 pm
content: In the spirit of "If you do something pointless, at least do a complete job!", I have completed my FPGA-based replica of the LGP-21 computer (www.e-basteln.de/lgp21).The LGP-21 was the last member of a family of bit-serial "personal" computers made by Librascope/General Precision in California, and built under license for the European market by Schoppe & Faeser in Germany. These machines achieved very simple CPU designs by relying heavily on a magnetic drum (or later a disk) as the computer's main memory, but also as the storage for all CPU registers. The computer's clock and various sequencing signals also came from dedicated drum/disk tracks.The LGP-30, released in 1956, was a major commercial success; the second-best-selling computer of the time with about 500 units built. The high-end successor RPC-4000 was a bit late to the party in 1960, and never became as successful as the LGP-30, because the competitors had already released computers based on ferrite core memory. But that didn't deter Librascope from following up with a low-cost family member in 1963, the LGP-21 -- "the first full-capability computer priced from $16,250”.I now have hand-held versions all three family members to play with (www.e-basteln.de/computing). Up next, I will hopefully be able to contribute to the restoration of tworealLGP-21s at the technikum29, a private computer museum in Germany. (http://www.technikum29.de/en/)

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: January 05, 2020, 10:46:45 pm
content: Isn't that the computer model Lorenz used to discover chaotic behavior?

author: ebastler
author_rank: Super Contributor
timestamp: January 06, 2020, 05:02:21 am
content: Yes, Edward Lorenz used the LGP-30 (the first of this line of computers, still tube-based) for his weather simulations, which led him to discover the critical dependence of the outcome on starting conditions, and then to the development of chaos theory.MIT actually borrowed my LittleGP-30 replica for a memorial symposium in 2018, marking Lorenz' 100th birthday (slightly late), since they couldn't get their hands on a real working LGP-30.
Apple IIe components  - Page 1
Forum section: electronics / general

author: Ben sage
author_rank: Contributor
timestamp: November 21, 2019, 08:57:54 pm
content: Hey guys I have a few questions about the Apple IIe like where the computer was made and also does anyone make new keys for it thanks

author: Halcyon
author_rank: Unknown
timestamp: November 22, 2019, 10:42:01 am
content: I just checked my IIe; The system unit was "Assembled in Singapore" while the CRT monitor was made in Korea (by Samsung).I have no idea what you mean by "keys" though. Do you mean keyboard keycaps? The best you'll probably find are non-working models for parts.

author: GeorgeOfTheJungle
author_rank: Super Contributor
timestamp: November 22, 2019, 11:46:58 am
content: Quote from: Ben sage on November 21, 2019, 08:57:54 pmExcept the very early ones, it was "Made in China" so to speak. The keyboard was a PITA. And the many clones/compatibles were made all over the world: United States, Canada, Brazil, China, Hong Kong, Taiwan, Bulgaria, France, Ireland, Germany (better than the original!), Italy, The Netherlands, Norway, Slovenia, Spain, Japan, Singapore, South Korea, Australia and the Soviet Union.

author: Ben sage
author_rank: Contributor
timestamp: November 22, 2019, 04:07:52 pm
content: Hi guys thanks for the comments and I meant the key switches and key caps

author: SiliconWizard
author_rank: Super Contributor
timestamp: November 25, 2019, 02:12:44 am
content: Quote from: Halcyon on November 22, 2019, 10:42:01 amIs there any indication of the date of production? If I'm not mistaken, the //e was produced from 1983 to 1993, and I had heard that Apple was still assembling them in the US until the late 80's or so, but that may just be a myth. Does anyone have more precise dates and info (history) on how Apple generally handled its production (not just with the Apple // line) from like 1977 to 2000? Would be interesting.As to the keycaps, just look up on eBay for instance: "apple IIe keycaps". I've found many sellers. Can't guarantee they are genuine scavanged parts, or copies, but there are certainly a lot.

author: barbeque
author_rank: Contributor
timestamp: November 30, 2019, 03:51:48 pm
content: There are (at least) two kinds of Apple IIe key switches, so make sure you got the right ones. I bought a bag of ones that don't fit mine.
Looking For The IMSAI Guy A,K,A, 'IMSAIGUY' - Page 1
Forum section: electronics / general

author: German_EE
author_rank: Super Contributor
timestamp: November 30, 2019, 08:24:57 pm
content: Does anyone have contact details for The IMSAI Guy? I need to get in touch with him about one of his old projects and all I know is that he lives somewhere in Silicon Valley and has a ham radio callsign. There are no contact details on his web pages and Google has unfortunately failed this time.Please reply by PM so that he isn't submerged by spam.Thanks!

author: Gerhard_dk4xp
author_rank: Frequent Contributor
timestamp: November 30, 2019, 09:49:24 pm
content: Are you an IMSAI catcher?regards, Gerhard

author: German_EE
author_rank: Super Contributor
timestamp: December 01, 2019, 10:07:28 am
content: No, but I am thinking of building a sixteen bit version of his homebrew CPU and I have a few questions about the instruction timing.
Dutch Home Computer Museum Video Tour - Page 1
Forum section: electronics / general

author: ebastler
author_rank: Super Contributor
timestamp: February 15, 2020, 12:15:59 pm
content: I got dizzy and had to stop watching around 2:20. What nincompoop was driving the camera there? Didn't even manage to get proper shots of all the devices the presenter was mentioning.

author: SL4P
author_rank: Super Contributor
timestamp: February 16, 2020, 02:55:00 am
content: The clip feels like a segment from a news magazine show... unfortunately a bit too shallow on detail to really catch nerd attention.
Single Board Relay Computer - Page 1
Forum section: electronics / general

author: jhallen
author_rank: Newbie
timestamp: September 10, 2017, 04:37:23 pm
content: Hi EEVblog,I made an anachronistic relay computer: it's like a 1970s KIM-1, but the CPU is all relays. Here is the project page:http://relaysbc.sourceforge.netHere is a video of it:Thanks for looking!Joe

author: alkmar
author_rank: Newbie
timestamp: November 13, 2019, 05:11:16 am
content: I built one of these, and it was a cool build. If you have a bit of experance building kits, and want to play with a relay based computer its a no brainer. He sells the Motherboard and programmed PIC's on Tinde and eBay, you will need to source the other parts from your favorite supplier (aka Mouser, Digikey, etc.)The CPU is implemented on 83 relays, he uses a micro-controller for the RAM, clock, and to control the keyboard, 7-digit output along with TTL serial. I think this is a reasonable tradeoff otherwise this thing would be ALOT more relays!The system includes an assembler, disassembled, and basic debugging. From a practical perspective its bit limited as it only 256 memory locations, however from the LEARNING perspective its rich and accessible.Be warned it will take some time to build as its about 400 comments and 2500 solder points, but its worth it!
C64 diode bodge - Page 1
Forum section: electronics / general

author: ascomm
author_rank: Contributor
timestamp: November 09, 2019, 10:24:32 pm
content: HiAre there any Commodore 64 gurus here? I was wondering what's the purpose of this C64 motherboard's four 1N4148 diode bodge? Anyone know anything about it?

author: Quarlo Klobrigney
author_rank: Super Contributor
timestamp: November 09, 2019, 10:48:47 pm
content: Looks like diode clamping of the inverter's open collector output. One diode to ground another to VCC. A no schematic opinion. Which U number is it? Is it the U8 or is it a different reference number?

author: ascomm
author_rank: Contributor
timestamp: November 10, 2019, 07:29:41 am
content: The diodes are connected like this to data and clock lines.The schematics is snipped fromhttps://myoldcomputer.nl/

author: thinkfat
author_rank: Unknown
timestamp: November 10, 2019, 07:53:00 am
content: The diodes clamp the signals to the supply and ground rail. Looks like somebody tried to curb some voltage overshoot due to ringing. Strange for an open collector driver, though.EDIT: no, not ringing. I see those signals going to external connectors, user port and serial port. Likely, it's just a protection for the CIA port.

author: Chris_Walch
author_rank: Contributor
timestamp: November 10, 2019, 12:39:03 pm
content: The diodes are there to protect the input lines of the serial bus, they are connecterd to the OC drivers 7406 of the output lines.Quite a common "upgrade" on older C64 boards, later revisions do come with these protection diodes on board.
Kaypro 4/83 speed mod... - Page 1
Forum section: electronics / general

author: alank2
author_rank: Super Contributor
timestamp: November 19, 2019, 04:43:03 am
content: I picked up a Kaypro 4/83 and so far it is working pretty well. It has two full height drives which I followed a YouTube video to clean up its connectors and add a small bit of lube to a few places and clean the heads. They are working great now, but are still quite noisy still. I think they are Tandon TM100's or something. It had a horizontal video jitter issue, but reseating the video board connector may have fixed this.One issue I am having is that when the floppy drives turn on, it is quick voltage drain on the 12V rail that makes the monitor image get less wide for a brief sub second and then it returns to its normal width. This rail is running 11.5V, but I think it might drop to 11.3V for maybe a couple hundred milliseconds. I tried to measure the caps on the power supply with a LCR meter (I've got a Peak one) and there are 3 caps in parallel (16V 2200uF * 2 + 16V 1000uF). When I measure one point on it, it didn't detect as a cap and said 25 ohms, then measuring the other 2200uF comes up 15.23 mF or something which is too large. The power supply board is old so I'm hesitant to pull one of the caps off of it.Second question is about a CPU speed mod that I plan to do to it. It is running 2.5MHz, but a speed mod is known that requires a could of jumpers on the main board. What people commonly do is mount a toggle switch on the back panel that can switch between 2.5MHz and 5.0MHz. My concern here is that I have to route 3 wires from the front of the mainboard to the back of the case, about 12". One wire 2.5MHz, one 5.0MHz, one the selected or returned speed. Should I be concerned about these wires and isolation? It seems like I've seen pictures of this mod and they just used an unshielded wire - is that workable or should I do something else?
Help Wanted! Pinout/Manual Of VAKO DISPALYS CL501/CS CRT Modual - Page 1
Forum section: electronics / general

author: TheEPROM9
author_rank: Frequent Contributor
timestamp: October 06, 2019, 08:30:27 pm
content: I have a VAKO DISPALYS CL501/CS CRT Display Modual. It is a really neat greenscreen display that I want to use for a retro computer project. However I have had 0% luck with this, I have however found the 12V power input & when I power it up the HV works as you can hear the 15KHz. However there is no raster on the display or any other sign of life.I have tryed to find documentation on line but I have currently found nothing. I don't know if anyone has tips & tricks or has worked with these at some point as it is from 1988, or can help me reverce engineer it as I am not to familour with the nitty grity detailes CRT circitry.Only IC Is UPC1031H2 Vertical Deflection Driver. The rest of the active comonets are transistors.I have attached sevrail images to provide at least some context.

author: TheEPROM9
author_rank: Frequent Contributor
timestamp: October 06, 2019, 08:31:50 pm
content: Images: upload giving grif

author: TheEPROM9
author_rank: Frequent Contributor
timestamp: October 11, 2019, 08:26:37 pm
content: Well I found my own solution. Used an old BW CCTV monitor & swaped the CRTs. Works a treat.
AV to HDMI - Page 1
Forum section: electronics / general

author: blacksheeplogic
author_rank: Frequent Contributor
timestamp: December 11, 2019, 07:26:02 am
content: I have several 8-bit computers (Atari mainly) and it's getting harder to find native composite AV inputs. I've tried using a Mini AV2HDMI 1080P Upscale but that has artifacts which I don't like. I recently tried a H18 8:1 HDMI switch that has 8 inputs, two of which are Analogue AV (1080P upscale) and it's does a excellent job but was quite expensive for my limited needs.Any other converters worth trying that don't have a considerable lag, I've tried some of the capture devices but the lag makes them unusable. These are fully restored/original condition and I want to keep them that way.

author: PA2HK
author_rank: Contributor
timestamp: December 11, 2019, 09:38:08 am
content: I am using a couple of these converters:https://www.ebay.com/itm/283578877709also on Atari 800 (NTSC) machines. Converters accept PAL and NTSC analog video on SCART and upconvert selectable to 720p or 1080p to HDMI. Units are based on a Philips/NXP SOC that is designed to used on LCD TV sets and works well without artifacts and movement lag. There are several vendors on eBay that offer said converter, the one in my link come with a (tiny) heatsink installed on the SOC, these chips run hot without a heatsink. Downside is that you need SCART input that may not be so available depending on where you are, in Europe SCART video connectors are very common.

author: blacksheeplogic
author_rank: Frequent Contributor
timestamp: December 12, 2019, 06:50:32 am
content: Quote from: PA2HK on December 11, 2019, 09:38:08 amThanks I did not consider SCART, not that common here but it was used, I will grab one and see how it goes. Many of mine are also NTSC (NA) but I also have a couple of PAL (AUS/NZ) as well.

author: dexters_lab
author_rank: Unknown
timestamp: December 13, 2019, 09:34:44 am
content: i can highly recommend using a professional scaler from the likes of Kramer, TVOne, Blackmagic etc the quality of the output and configuration options make them far superior to the cheap stuff from chinai have a collection of 4 TVOne scalers from the C2-XXXX range, now discontinued you should be able to pick them up off ebay for around £50-£80. That particular range doesn't do HDMI but they do DVI.i did a short video on them a while back...
PDP-11/04 Console Repair - Part 1 - Page 1
Forum section: electronics / general

author: intabits
author_rank: Frequent Contributor
timestamp: July 16, 2019, 07:49:37 pm
content: Continuing with my PDP11/04 and 11/34 repairs, now that the power supplies are sorted,next comes the console and its interface, the M7859 board (together termed KY11-LB)These work properly on the 11/34, but there are multiple issues with this section of the 11/04.Having a working set of interchangeable parts from the 11/34 was a huge help in identifyingwhere the problems lay in the 11/04. (all three PCBs involved had faults)I've invested quite some time coming up with a detailed block diagram of the M7859, and thenmore time was spent in making an input protection board for a simple logic analyzer.Block Diagram:-In this console repair part 1 video I find and repair two problems, both broken conductors,but realize that the remaining problem(s), even with the aid of the logic analyzer willneed a more rigorous and "clever" approach.Since recording this, I'm well on the way with my new problem determination design, and I'mextremely confident that it will locate the fault(s) on the failing M7859 board. I'm stillworking on it, and will present it soon in part 2 of the video.

author: intabits
author_rank: Frequent Contributor
timestamp: July 24, 2019, 04:15:52 am
content: This is becoming quite a saga!In this video, I find and fix a fault in the M7859 board (a 74175 Quad D flip-flop), plus uncover and fix a bug in my testing hardware.But after that, the board is still faulty!I'm not sure why, as I believe I've tested every part of the board involved with its basic operation when in the computer.But as the video is already more than long enough, I've ended it at this stage of the troubleshooting, and will have to make a part 3.And to continue further , my test system needs to be rebuilt, which will take a bit of time.So when that's done, and I've been able to delve further into the problem, I'll present part 3...

author: Kean
author_rank: Unknown
timestamp: July 24, 2019, 08:59:24 am
content: Nice test jig setup & control application

author: intabits
author_rank: Frequent Contributor
timestamp: September 29, 2019, 03:27:51 am
content: Finally, part 3 of the PDP 11/04 console repair is ready. While I did a lot of work for this, there was also a lot ofprocrastination, partly due to getting a pretty tired with this project, and maybe also some fear of not being able to fix it!In this video, the testing of the M7859 console interface card continues, and now extends to cover almost every part of it.The testing reveals some strange and hard to explain behavior - can it be fixed?At the end of the video, I've added a description of the M7859 operation, in a bit more detail than given previously.The block diagram has also been updated:-
Acorn System 1 Build - Page 1
Forum section: electronics / general

author: TheEPROM9
author_rank: Frequent Contributor
timestamp: April 07, 2019, 08:46:03 pm
content: I have wanted one of these computers for years now. So I when I came accross the PCB's on eBay I could not resist. Building with as menay old 70s parts where my component stock allows.

author: Conrad Larsen
author_rank: Newbie
timestamp: August 18, 2019, 11:07:48 am
content: This is cool.

author: TheEPROM9
author_rank: Frequent Contributor
timestamp: September 11, 2019, 07:42:09 pm
content: Quote from: Conrad Larsen on August 18, 2019, 11:07:48 amThanks, I have now got it working. Just need to do a latest video.

author: TheEPROM9
author_rank: Frequent Contributor
timestamp: September 11, 2019, 07:43:30 pm
content: Programming the EPROM

author: TheEPROM9
author_rank: Frequent Contributor
timestamp: September 19, 2019, 10:46:02 am
content: Latest video. The machine is up & running minus the tape interface electrnics. I also give a little demo & rambel on a little about the project & my intentions for th project.

author: bd139
author_rank: Super Contributor
timestamp: September 19, 2019, 11:04:49 am
content: Nice job. I've been following this on YT

author: TheEPROM9
author_rank: Frequent Contributor
timestamp: September 19, 2019, 01:39:51 pm
content: Thanks =-)Also here is the ROM image I stuck on a 2716 EPROM from the late 70s.
Starting a ZX Spectrum clone project - Page 1
Forum section: electronics / general

author: Bud
author_rank: Super Contributor
timestamp: August 18, 2019, 01:07:48 am
content: Got a PCB from the developer and a load of parts from Digikey for another version of countless ZX Spectrum clones, called ZX Nuvo. The developer's page with schematic, BOM and PCB build info is here:https://onedrive.live.com/?id=E0ADBB58ADB8D869%21204571&cid=E0ADBB58ADB8D869PCBs available either from eBay or on SellMyRetro marketplace:https://www.sellmyretro.com/offer/details/zx-nuvo-128-%3A-zx-spectrum-128k%2C-%2B2a~~%2B3-clone-pcb-include-divmmc-on-board-25385This particular variant was selected because it has a built-in SD Card interface as well as joystick port, RGB port and sound chip. And the author supplies the PCB with a Xilinx chip for the SD pre-programmed and soldered.Will see what comes out of this.

author: Conrad Larsen
author_rank: Newbie
timestamp: August 18, 2019, 10:24:24 am
content: Very nice

author: pcmad
author_rank: Regular Contributor
timestamp: September 03, 2019, 01:05:06 am
content: i got a z80 and supporting chips if you want to buy them off me based in uk

author: nigelwright7557
author_rank: Frequent Contributor
timestamp: September 03, 2019, 01:19:57 am
content: The fun part is coming up with a ULA for the screen hardware etc.What are you doing about the ROM software ? I would guess it is copyrighted ?

author: ebclr
author_rank: Super Contributor
timestamp: September 03, 2019, 12:22:13 pm
content: Why make this board?http://www.zxspectrum4.net/

author: dave j
author_rank: Regular Contributor
timestamp: September 03, 2019, 01:06:48 pm
content: Quote from: nigelwright7557 on September 03, 2019, 01:19:57 amAmstrad, current owners of the Spectrum,have given permission for the ROMs to be used in emulators for non-commercial purposes. The OP's project is just emulating the Spectrum in hardware.

author: Bud
author_rank: Super Contributor
timestamp: September 03, 2019, 02:42:43 pm
content: Quote from: pcmad on September 03, 2019, 01:05:06 amThanks, there is no shortage of Z80 in all sort of packages, I have a few from the era on old PLC boards, Digikey sells them as well.

author: Bud
author_rank: Super Contributor
timestamp: September 03, 2019, 02:44:00 pm
content: Quote from: ebclr on September 03, 2019, 12:22:13 pmThis is a hardware project. No fun whatsoever using software emulators.
Harlequin rev g Spectrum clone black screen on boot - Page 1
Forum section: electronics / general

author: Conrad Larsen
author_rank: Newbie
timestamp: August 18, 2019, 06:26:00 pm
content: HiI have built a Harlequin rev g Spectrum clone and get a black screen on boot. I have tried a few different roms also a diagnostic rom from from facebook Superfo Harlequin 128 page. I have checked the 5 volts and i am getting 5.77 volts on each chip. Not to sure where from here.http://trastero.speccy.org/cosas/JL/Harlequin/Documentacion/harlequin_rev_g.pdfThanksConrad

author: Ian.M
author_rank: Super Contributor
timestamp: August 18, 2019, 07:46:01 pm
content: A black screen + white border is normal for a speccy running its bootup memory test. Its therefore starting to run but is crashing before it does anything useful.5.77V is too high for the output of a LM2596-5.0, which shoud be in the range 4.8V to 5.2V. It might be a good place to start.Otherwise its time for a wide logic analyser to trace execution and try to figure out if its crashing predictably. Alternatively as this clone uses SRAM, you might be able to get somewhere with only a logic probe if you build a circuit to assert Z80 /WAIT after N M1 cycles, then allow you to single step the Z80, one M1 cycle at a time.
HP 9000/300 Workstation [still looking for a keyboard] - Page 1
Forum section: electronics / general

author: PA2HK
author_rank: Contributor
timestamp: June 30, 2019, 02:12:59 pm
content: Nice set of a classic HP machines. You need a HIL keyboard (e.g. HP 46021) and mouse (e.g. HP 46060B), with some patience you can find those NOS relative cheap on eBay.

author: spudboy488
author_rank: Regular Contributor
timestamp: July 01, 2019, 11:42:45 am
content: Those take me back. I used those for years to control test equipment. I never used a mouse, though. I always had the keyboard with the wheel up in the corner for my scrolling needs.

author: Stray Electron
author_rank: Super Contributor
timestamp: July 01, 2019, 07:45:17 pm
content: FWIW that's not the standard keyboard for the 9816, that's the optional "Nimetz" keyboard. It was called that due to it's size. Most of the HP 9000 220s came with that keyboard but all of the HP HIL keyboards are interchangeable.I like those little 9816s. They are the smallest of the HP 200 series computers. I put a handle on one and I used to carry it around and I used it to test HP-IB disk drives and equipment. Mine had, or rather HAS, the optional HPL in ROM card. I rescued it from a scrapper and 15 or 20 years ago, he actually had it up on his work bench and was taking it apart when I found it. He'd already thrown away the rear top cover so mine is missing that. I think I paid $5 for it.

author: jayco242
author_rank: Contributor
timestamp: August 06, 2019, 08:05:36 pm
content: Hi,welcome to the old computers club. A very nice setup. Luckily you got hp software on it already. My system has netBSD on it. I have to recondition a tape drive before I have a got putting HP-UX on. There is some very interesting add on cards for sale on ebay cheap.Jason
can somebody tell me what chips they are? - Page 1
Forum section: electronics / general

author: aqarwaen
author_rank: Regular Contributor
timestamp: July 24, 2019, 01:58:34 pm
content: can somebody tell me what chips they are?i found 3 chips in my grandparents house,but cant identify them cuse they have russia letters..what theys chips do?

author: ataradov
author_rank: Super Contributor
timestamp: July 24, 2019, 02:34:37 pm
content: The small ones are mediocre opamps.The big one is a specialized IC for radio receivers.They are not rare or useful.

author: fzabkar
author_rank: Super Contributor
timestamp: July 30, 2019, 09:38:18 am
content: КР140УДhttp://kazus.ru/guide/chips/ud7.htmlК174ХА6http://tec.org.ru/board/mikroskhemy_dlja_radio_i_tv/k174kha6/289-1-0-3522http://tec.org.ru/_bd/35/3522_1746.pdf]=http://tec.org.ru/_bd/35/3522_1746.pdf]http://tec.org.ru/_bd/35/3522_1746.pdfGoogle suggests that the TDA1047 is an equivalent for the К174ХА6:http://www.rigpix.com/components/tda1047.pdfEdit: Russian IC cross-referencehttp://home.tiscali.cz/wansi/Rus.pdf
Model 33 Teletypes down under... - Page 1
Forum section: electronics / general

author: bsudbrink
author_rank: Frequent Contributor
timestamp: June 28, 2019, 03:14:21 pm
content: This message is making the rounds in vintage computer collecting groups. The message title references Australia. I know nothing other than what's in the message below. I doubt this guy wants his email all over the internet, so PM me if you are interested and I will give it to you.Original message:3 x 33 ASR1 x 33 KSRNone working, one almost works but needs adjustment. All 110V 50Hz with 240V step-down transformers. Mostly complete missing a few minor items. Printed documentation available too.POC: Nigel Williams <email redacted>
Color Dot Matrix Printer - Page 1
Forum section: electronics / general

author: Ampera
author_rank: Super Contributor
timestamp: June 01, 2019, 05:10:32 pm
content: I don't think I've ever seen such a high print quality from a dot matrix printer. My old monochrome Epson certainly can't hold a candle. That being said, I'm very glad my printer takes 10-20 seconds per page instead of 10-20 years.

author: pamperchu
author_rank: Contributor
timestamp: June 02, 2019, 07:04:01 am
content: that's cool. i have a p321 dot matrix printer ive been trying to make work.

author: TomS_
author_rank: Frequent Contributor
timestamp: June 03, 2019, 08:20:16 am
content: Quote from: Ampera on June 01, 2019, 05:10:32 pmI think he mentioned that it was a 24 pin head, so it should be able to do some reasonably nice quality printing.Personally I quite like the crudeness of a 9 pin.

author: oPossum
author_rank: Super Contributor
timestamp: June 03, 2019, 08:40:33 am
content: The full 40 minute hot dog print in real time.

author: Ampera
author_rank: Super Contributor
timestamp: June 03, 2019, 06:07:21 pm
content: Quote from: TomS_ on June 03, 2019, 08:20:16 amSo is my Epson. Ink is perfectly fine too, it just doesn't look as nice. Could just be the human inability to distinguish differences in shades as well as we can brightness. So any differences and banding in colour would be nowhere near as bad as differences in a monochromatic image.

author: westfw
author_rank: Super Contributor
timestamp: June 08, 2019, 04:31:23 am
content: Heh. Diablo Daisy Wheel printers had a micro-spacing capability, designed to support proportional spacing and .... stuff.But you could also put in that mode and print periods, to get crude graphics. Something like 72x48dpi, IIRC.(a set of graphics primitives for this printer "compatible" with a higher-end display library was my final project for computer graphics class. ~1978.)There was also "Printronix", which did a sort-of dot-matrix printer, of somewhat higher resolution, that tje computer center I worked at briefly evaluated. (huh. They actually seem to have survived a long time; acquired by Corona in 2013!)

author: eugenenine
author_rank: Frequent Contributor
timestamp: June 27, 2019, 10:25:50 pm
content: I had saved up for months to buy a Citizen color dot matrix to use in college and just after the second ribbon a couple pins in the printhead quit working and i found out they considered it a consumable and not under the warranty and the cost to replace was more than what I paid for the printer just a few months prior.
Motorola ARNWESH SBC5204 - missing ROMs - anyone has a copy? - Page 1
Forum section: electronics / general

author: legacy
author_rank: Super Contributor
timestamp: June 25, 2019, 04:01:08 pm
content: Hi guysI have finally just received my Motorola ARNWESH SBC5204 Coldfire board. According to themanualit needs two ROMs to operate.QuoteMy board doesn't have anything on U13 and U14, sockets are empty, I can program UVPROMs but I cannot find an image on the internet with the proper firmware.Does anyone happen to have this board? Can he/she dump ROMs? Is there a sort of OpenSource alternative?Thanks in advance
The Commodore Amiga Story. - Page 1
Forum section: electronics / general

author: BrianHG
author_rank: Super Contributor
timestamp: September 29, 2018, 07:46:16 am
content: Well, everything you want to know about the invention, hardware developers, Commodore's investments, Commodore's blunders and the death... 2 Parts, full 2 hours of behind the scenes details... Including why the Commodore Amiga never advanced graphically and audio custom chipset where at the beginning, they were far ahead...

author: nad007007
author_rank: Contributor
timestamp: March 08, 2019, 09:43:56 am
content: Interesting.

author: Jan Audio
author_rank: Frequent Contributor
timestamp: March 10, 2019, 04:17:09 pm
content: The best thing is the custom software.I wish all game consoles allowed homebrew, why is there no modern thing like this ?

author: TheEPROM9
author_rank: Frequent Contributor
timestamp: March 12, 2019, 12:25:53 am
content: You documentorys on retro computers are really good. Wish I could get my videos half as desent.

author: TomS_
author_rank: Frequent Contributor
timestamp: May 31, 2019, 03:08:18 pm
content: Also look for some videos by Bil Herd, he has some tales and stories from Commodore.
What Z80 assembler do you use? - Page 1
Forum section: electronics / general

author: obiwanjacobi
author_rank: Super Contributor
timestamp: June 14, 2019, 01:29:27 pm
content: I am researching what the most popular Z80 assemblers are.I am writing some code in the hope to make a decent modern feeling IDE and for parsing and syntax highlighting I want to support a couple of wellknown/most used assembler syntaxes (syntaxi?) and directives.If you could also include a link to where I could download it, or read the manual...Thanks

author: rhodges
author_rank: Frequent Contributor
timestamp: June 14, 2019, 03:18:12 pm
content: If I wanted to do Z80 assembly today, I would start with the one that is part of SDCC:https://sourceforge.net/projects/sdcc/files/In there is a Z80 test file:sdcc-3.8.0/sdas/asz80/tz80.asmI like SDCC a lot (for STM8), so if I were using Z80, I would use the SDCC tools.EDIT: The latest version is 3.9.0 now.

author: obiwanjacobi
author_rank: Super Contributor
timestamp: June 15, 2019, 05:15:30 am
content: Note: I am not looking for recommendations, I am looking for popular assemblers that peopleactuallyuse.

author: oPossum
author_rank: Super Contributor
timestamp: June 15, 2019, 07:03:12 am
content: You're about 40 years too late.

author: ebclr
author_rank: Super Contributor
timestamp: June 17, 2019, 07:45:16 am
content: http://wwwhomes.uni-bielefeld.de/achim/z80-asm.html

author: Bruce Abbott
author_rank: Frequent Contributor
timestamp: July 15, 2019, 07:48:05 am
content: For cross-assembling in Windows I usezmac, which I modified to make all output formats optional.

author: GeorgeOfTheJungle
author_rank: Super Contributor
timestamp: July 15, 2019, 08:23:20 am
content: This one is for the 6502, can upload the program to the Apple II via the cassette port (compile, then press play, but be sure toTURN DOWN THE VOLUME FIRSTit's a full amplitude square wave that can (and will) damage mercilessly your laptop's loudspeakers if you don't):http://apple2.duckdns.org/assembler/There are others for the Z80:https://duckduckgo.com/?q=z80+online+assembler
Open Source Amiga 500 512kB RAM Expansion Card - Page 1
Forum section: electronics / general

author: knapik
author_rank: Regular Contributor
timestamp: May 23, 2019, 10:58:41 am
content: Just wanted to show off a little design I made a while ago to expand my Amiga 500's RAM to 1MB. It shows up in Workbench that I have the RAM available which tells me it works, but still can't play those 1MB games. Guess I need to upgrade my Agnus for that first. I also need to buy some jumpers.These are the design files:https://github.com/AlexanderKnapik/Amiga-A501-RAM-Expansion