hybridfree/eevblog-posts huggingface dataset:
ATXMega32A4 as Arduino? - Page 1
Forum section: electronics / general

author: panoss
author_rank: Frequent Contributor
timestamp: February 01, 2019, 05:52:10 pm
content: I have a few ATXMega32A4 chips.Can I use them as Arduinos?Are they compatible?

author: mvs
author_rank: Frequent Contributor
timestamp: February 03, 2019, 10:59:29 am
content: Quote from: panoss on February 01, 2019, 05:52:10 pmATXMega MCUs are not supported. But Arduino code is open source, so you can add support by yourself.Look atXMega For Arduino projecton github.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: February 03, 2019, 11:14:40 am
content: Why would you bother?The BluePills are at least twice as fast and the populated boards cost around EUR 1.50.https://www.aliexpress.com/wholesale?SearchText=stm32f103c8t6The processor itself is a bit old fashioned and has some quirks, but because it is already supported by arduino, so you do not have to worry about it.More info on:https://www.stm32duino.com/And while you are upgrading, give Platrofmio a try. It is a huge improvement over the arduino ide.I've used AVR's for hobby projects since almost the beginning (way before arduino existed), and it was a very nice processor for it's time.Recently I wanted some more and did some research, and it is not even a contest. Just toss those Xmega's in the bin and use one (or several) of the many ARM processors. The Xmega's are trying to squeeze in a to small niche to be taken as a serious product.On itself they are capable processors, no doubt here, but that's not the point i'm trying to get trhoug.You will very likely get some responses under here from people who have used and like these processors.It's human nature & basic psychology. We defend what we know and are used to.

author: NivagSwerdna
author_rank: Super Contributor
timestamp: February 03, 2019, 11:29:10 am
content: https://playground.arduino.cc/Main/ArduinoOnOtherAtmelChipsYou could probably save yourself some grief by programming them direct in AVR Studio or whatever it is called.

author: maginnovision
author_rank: Super Contributor
timestamp: February 05, 2019, 04:10:34 am
content: Quote from: Doctorandus_P on February 03, 2019, 11:14:40 amSo you think he should toss in the trash what he has and just buy something else? That's pretty poor advice.Quote from: NivagSwerdna on February 03, 2019, 11:29:10 amI'd agree with this, just use atmel studio. It's really easy to use. Head to avrfreaks.net for help. The XMega MCU's never really caught on it seems but they had some really cool and interesting features.
Arduino Explained | Hardware and Software explained including schematic - Page 1
Forum section: electronics / general

author: epy
author_rank: Regular Contributor
timestamp: January 23, 2019, 01:52:03 pm
content: Hi,Following is the tutorial which explaines following things,1. Schematic Explained2. Bootloader3. How to use Web Editor4. How to Use Arduino IDE5. Example on LED Blink6. Example on Serial Interface7. Example on Switch interface using polling method8. Example on Switch interface using interrupt method9. Example on ADCHere is the tutorialhttps://youtu.be/k1g4uVNTA8o
Arduino USB_ID circuit? - Page 1
Forum section: electronics / general

author: Jester
author_rank: Frequent Contributor
timestamp: January 06, 2019, 05:21:43 pm
content: Can anyone explain this USB_ID circuit? (this is an open source Arduino MkrZero board USB power circuit)This entire circuit seems more complicated than it needs to be: 6 FET's to choose USB or external power?I prototyped a project using an official MkrZero board and now need to shrink the circuit onto a new board, getting rid of the unnecessary components; battery charger, SD cards etc. while maintaining compatibility with the code I wrote. I don't need the USB power source, but do need to be able to use the USB port with the Arduino IDE for future firmware tweaks.If I simply eliminate the entire 6 FET circuit and provide power via an existing 3v3 power supply, does anyone see a problem with this?

author: ataradov
author_rank: Super Contributor
timestamp: January 06, 2019, 08:53:33 pm
content: This circuit is for the OTG functionality. It makes it provide 5V on the USB connector when the board acts as a host. If you don't use this functionality, then yes, you can remove all of this.

author: Jester
author_rank: Frequent Contributor
timestamp: January 06, 2019, 10:01:32 pm
content: Quote from: ataradov on January 06, 2019, 08:53:33 pmataradov,Thanks for the quick response.I'm about to delete it, is there any chance the Arduino IDE needs this signal to operate, for regular program loading etc?

author: ataradov
author_rank: Super Contributor
timestamp: January 06, 2019, 10:07:36 pm
content: I don't think so. If there is some dependency, it would be in error.But also, if you just left it unconnected, it all should default to the device state where the power is not provided to the external device. So I'm not sure how there can even be a dependency.
Comrex Commander Deluxe joystick - Page 1
Forum section: electronics / general

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: October 10, 2025, 05:50:55 pm
content: I've seen these since decades, they still sell on eBay, but I've never seen anyone use one, like ever.Have you? I mean they still go for decent money.https://www.ebay.ca/itm/146857749612They claim to be compatible with the Commodore VIC-20 and 64, while true at the hardware level, there's probably no more than 5 programs that support analog joysticks (as opposed to paddles.)Just curious.
Cost cutting in the IBM PC - Page 1
Forum section: electronics / general

author: Scratch.HTF
author_rank: Regular Contributor
timestamp: October 10, 2025, 07:24:08 am
content: Examples I know as per schematics are:* A single 14.31818 MHz (4 times NTSC colourburst frequency) crystal for all of the clocks which can be used by the CGA video card for NTSC colour TV output* The monochrome display Horizontal output stage is directly driven by the MDA video card without any Horizontal sync processing; incorrect Horizontal Sync polarity and/or an excessively long active period can cause damage to the display* To reduce the number of ICs, I/O address mirrors show on all motherboard devices below 0x100 (no devices are at 0xC0-0xFF) - this is also the case with the AT including AT-specific devices at 0xC0-0xFF; I've encountered an instruction referring to an I/O mirror in a Vadem HDD BIOS used in the Sharp PC-4700 even though the BIOS was correctly dumped with a valid checksum* DRAM refresh being handled by the DMA controller* Instead of an ADC, the game port adapter uses a 558 (quad 555) timer which is triggered and then polled to determine X/Y axis position* Multiplexing of hard configuration switches* An RGB-CVBS encoder in the Colour Graphics Adaptor not being used for NTSC colour TV output
Microsoft’s 6502 BASIC is now Open Source - Page 1
Forum section: electronics / general

author: Andy Chee
author_rank: Super Contributor
timestamp: September 27, 2025, 06:36:45 am
content: For anyone who's interested in playing with ancient CPUs, either the actual antique chips or virtualised in software or FPGA, some might be interested to know that this month Microsoft has released their BASIC for 6502 as open source.https://opensource.microsoft.com/blog/2025/09/03/microsoft-open-source-historic-6502-basic/https://github.com/microsoft/BASIC-M6502Given that people have already decompiled and published unofficial source code over the years, there's probably not much value to Microsoft releasing it.Or is there?

author: kite31
author_rank: Regular Contributor
timestamp: September 27, 2025, 07:40:44 am
content: At the end of the 1970s I had an Ohio Scientific C1P with external 5.25" floppy. That meant I was using MS Basic for a little, before I became bored and switched to 6502 assembler, Next computer (CP/M) meant MT Pascal and Z80 assembler, so I retained no interest in Basic.I kept that lovely CP/M machine around until about 2014 before selling. Perhaps someone here has it.

author: ledtester
author_rank: Super Contributor
timestamp: September 27, 2025, 09:29:15 am
content: The comments may prove to be interesting to read.Here's a blog post comparing the various versions of BASIC that MS produced for 6502-based computers such as the KIM-1, OSI, Commodore machines, Intellivision, ...https://www.pagetable.com/?p=46
Do you use a AC power control center thing? - Page 1
Forum section: electronics / general

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: September 25, 2025, 05:12:46 pm
content: You know those old school AC power control centers you can plop a monitor on top? If so, how big is it? Does it look awesome?I found a big plain one at Goodwill, but now I want a fancy 1980s themed one, like thishttps://youtu.be/cImJqqtnLHsI mean, doesn't everyone want one like this?

author: edavid
author_rank: Super Contributor
timestamp: September 25, 2025, 05:40:18 pm
content: Quote from: Alex Eisenhut on September 25, 2025, 05:12:46 pmI do use a couple of them in the lab. They are 12" wide and look pretty boringThe first one has some test equipment plugged in that uses too much standby power, an IEC cord, and a power strip. The last 2 items are for when I'm working on some equipment and I want to be able to make sure it's turned off (especially if it has a soft power switch).The second power center is connected to my soldering equipment, so I can make sure it's all turned off when I leave.

author: BrianHG
author_rank: Super Contributor
timestamp: September 26, 2025, 02:22:23 am
content: OMG, talk about going down memory lane...

author: edpalmer42
author_rank: Super Contributor
timestamp: September 26, 2025, 03:28:28 am
content: I bought a couple of them a few years ago for use on my test bench. I use them with equipment that either doesn't have a power switch or has the switch on the back.
Arduino UNO clone CH340G Serial design flaw & fix. - Page 1
Forum section: electronics / general

author: Gelf54
author_rank: Contributor
timestamp: May 19, 2019, 08:44:05 am
content: I don't know if it's been mentioned that some of the cheap Arduino UNO clones using the CH340G USB-Serial chip have a correctable design flaw!They've fancied the board up by adding LEDS to the Tx & Rx lines, but in the process they've violated the ATmega328p Input Low Voltage limit on the RXD input, which is now only pulled down to about 1.7V instead of below 1.5V. This can cause intermittent serial operation.The fix is easy enough...just remove either the Tx LED, or R7. This restores the full 0-5V swing.HTH,Steve

author: westfw
author_rank: Super Contributor
timestamp: May 19, 2019, 09:31:03 am
content: Which nano clone are you talking about? There are a bunch of different designs out there...

author: mikerj
author_rank: Super Contributor
timestamp: May 19, 2019, 11:21:40 am
content: Quote from: westfw on May 19, 2019, 09:31:03 amThe OP mentioned UNO rather than Nano. Any of the UNO R3 boards with the CH340 seem to have these LEDs. The problem is that the design includes a 1k resistor between the CH430 TX output and the AVR RX input pin, so that the AVR pin can be used for other functions without the CH430 output loading it. Unfortunately the LED has been placed downstream of this resistor, resulting in a much reduced voltage swing.

author: Peabody
author_rank: Super Contributor
timestamp: May 19, 2019, 02:05:52 pm
content: From this schematic:http://actrl.cz/blog/wp-content/uploads/nano_ch340_schematics-rev1.pdfit looks like:CH340TX(low) <-- 1K <-- LED <-- 1K <-- 5V|AVRRXWhat would the voltage be at AVRRX? If the LED drops 1.8V, then AVRRX is at the middle of a 1K/1K divider between 3.2V and ground, or 1.6V. Is that right, or is it more complicated?Edit: I guess I should have asked what color the LED is. It looks like this setup would be more likely to work of it's a green LED instead of red.
About Arduino Uno's Xtal Osc - Page 1
Forum section: electronics / general

author: dhumx
author_rank: Newbie
timestamp: March 25, 2019, 05:44:53 pm
content: Hi all, is there any way that I can output a clock in arduino uno? I want to have a clock of at least 1 Hz. I know about PWM of the arduino but to my best knowledge, the PWM output of arduino has fixed frequency. I want to produce a variable clock frequency

author: agehall
author_rank: Frequent Contributor
timestamp: March 25, 2019, 06:00:04 pm
content: PWM is not what you are looking for. The hint is in the name - Pulse WIDTH Modulation.You can get a lot more than 1Hz from an Arduino by simply toggling the pins in your code. Even with the digitalWrite() function (which is horrible in terms of performance) you should get a lot more than single digit hertz.

author: Ian.M
author_rank: Super Contributor
timestamp: March 25, 2019, 08:00:55 pm
content: Although the PWM functionality exposed by the Arduino analogWrite() function is fixed frequency, the underlying hardware PWM is not. e.g. on ATmega328P based Arduinos, if you take direct control of the Timer 1 registers, you can set up a PWM with a frequency ranging from 0.12Hz to over 1MHz. See section 20. TC1 - 16-bit Timer/Counter1 with PWM, of the ATmega328P's datasheet.Ardunos based on other MCUs generally have fairly similar capabilities although the limits of their hardware PWM frequency range will be different - consult the specific MCU's datasheet for details.

author: PCB.Wiz
author_rank: Super Contributor
timestamp: March 25, 2019, 09:32:10 pm
content: Quote from: dhumx on March 25, 2019, 05:44:53 pmWhat frequency range do you expect, and what precision do you need ? (step size, in Hz or %f )

author: luxetveritas
author_rank: Newbie
timestamp: March 31, 2019, 03:40:58 am
content: Quote from: dhumx on March 25, 2019, 05:44:53 pmMaybe use tone(pin, frequency [, duration])? It outputs a square wave with 50% duty cycle. Frequency is an unsighed int so can go to 65535Hz. Use noTone(pin) to stop.

author: Nusa
author_rank: Super Contributor
timestamp: March 31, 2019, 05:50:48 am
content: ^ If your frequency needs are modest, the tone() library should suffice.https://www.arduino.cc/reference/en/language/functions/advanced-io/tone/If your needs are more extreme, I suggest the Timer1 library:https://github.com/PaulStoffregen/TimerOneThere are other ways to slay the beast, none of them terribly hard, but the fact you asked the question at all indicates you are a beginner, at least on the software side of things.
The 50th anniversary of the Altair 8800 - Page 1
Forum section: electronics / general

author: Picuino
author_rank: Super Contributor
timestamp: August 24, 2025, 10:56:14 am
content: January 2025 marked the 50th anniversary of the launch of the first personal computer, the Altair 8800, with an Intel 8080 running at 2 MHz inside. Shortly after, in July, Altair Basic, programmed by a young Microsoft, was released.https://en.wikipedia.org/wiki/Altair_8800https://en.wikipedia.org/wiki/Altair_BASIChttps://newsroom.intel.com/de/client-computing/50-years-ago-celebrating-the-influential-intel-8080https://app.daily.dev/posts/microsoft-celebrates-50-years-since-the-creation-of-altair-basic-lndy7l3l8https://www.eevblog.com/forum/chat/altair-8800-videos/msg820831/#msg820831

author: RJSV
author_rank: Super Contributor
timestamp: August 24, 2025, 06:06:06 pm
content: Those first few years, with practical micro's and kits like this, I had the (mistaken) impressions that a person could learn most of it, by putting a analog scope (Tectronics 465) on the pins and BUS. Then, somebody pointed out: there were BOOKS that taught microprocessors.Like 'The Z-80 Developer's Guide' (paraphrased title) Rodney Zak's.Previously, I had thoughts of de-capping microprocessor ICs, to connect with internal traces (on the die). That's, maybe, illustration of how revolutionary the IC industry has been...
Running ancient software(c. 1999). Any tips? - Page 1
Forum section: electronics / general

author: Langdon
author_rank: Frequent Contributor
timestamp: March 13, 2025, 12:56:06 am
content: I have some old software CDs.I have:3x Autodesk CAD Overlay 2000Way too many Autodesk Volo View ExpressArtCAM (Still at my high school over March break).A copy of Microsoft Windows 98

author: Stray Electron
author_rank: Super Contributor
timestamp: March 13, 2025, 01:07:49 am
content: Seriously, your best bet is to get an old computer that was capable of running W98. it's not hard to find old computers for next to nothing in thrift stores, garage sales etc. But you probably want to be sure that no one has stolen the hard drive or the memory out of it. The memory can be found for a price $ (Ebay, etc) but if the HD is missing or has been erased then you're probably going to have a hell of a time finding all of the SW drivers and such.

author: themadhippy
author_rank: Super Contributor
timestamp: March 13, 2025, 01:18:55 am
content: run a virtual machine.virtualbox is free and w98 runs in it fine.

author: brucehoult
author_rank: Super Contributor
timestamp: March 13, 2025, 06:24:53 am
content: Qemu will run that stuff on any kind of machine -- a current gen Mac is probably going to emulate x86 faster than a 1999 machine. If you have a modern x86 then vmware or virtualbox should work -- or actually qemu will be similar on same-ISA too.

author: abeyer
author_rank: Frequent Contributor
timestamp: March 13, 2025, 07:22:52 am
content: Quotemove on and cut your losses?

author: Langdon
author_rank: Frequent Contributor
timestamp: March 14, 2025, 04:03:56 pm
content: I was planning to use a PC from the IT guy at my chool which was originally destined for E-Waste, though they seem a bit prone to random sporadic failure.(Sometimes, they just no longer turn on for no reason)I also can use a 2011 21.5" iMac with QEMU on Pop!_OS (Ubuntu does not work).

author: jrmymllr
author_rank: Regular Contributor
timestamp: June 27, 2025, 04:18:28 pm
content: Quote from: Stray Electron on March 13, 2025, 01:07:49 amNah, there's good repositories of old drivers. For devices older than that even, and I don't consider the Win98 era to be all that old.I have found drivers for 286 and 386 stuff, no problem.

author: coromonadalix
author_rank: Super Contributor
timestamp: August 06, 2025, 09:53:14 am
content: i run very old stuff with otvdm help in a x64 machine loll
Open source silicon - Z80? - Page 1
Forum section: electronics / general

author: paulca
author_rank: Super Contributor
timestamp: July 10, 2025, 08:45:11 am
content: https://github.com/rejunity/z80-open-siliconDoes anyone know the likely hood this project is actually going to work and be for sale in the next year or so?Taking a quick read through some of it, I find there is a stark contrast/spectrum of "development levels".On one end you have the fact they designed silicon at the gate level. At the other end you have them using MicroPython to test it. Extremely low level to extremely high level.

author: RJSV
author_rank: Super Contributor
timestamp: July 25, 2025, 10:26:47 pm
content: Thanks for the mention !I've heard someone say, that the Z-80 (and 6502) are about the last fully comprehendable unit. Now things go more specialized. I obtained a lot of my Z-80 training by way of'The Z-80 Manual's by Rodney Zak's.Plus the usual 8-bit numbers are easy, compared with memory segmented functions, as in the 68000 IC.

author: edavid
author_rank: Super Contributor
timestamp: July 25, 2025, 11:35:57 pm
content: Quote from: paulca on July 10, 2025, 08:45:11 amThey did not:"The implementation is based around Guy Hutchison's TV80 Verilog core."
Apple PowerBook 100 (mc68k-era), LCD interface? - Page 1
Forum section: electronics / general

author: DiTBho
author_rank: Super Contributor
timestamp: July 19, 2025, 10:32:27 pm
content: I'm curious about the PowerBook 100 display.It appears to be 1-bit color, and it looks a STN kind.Is the display interface documented anywhere?I mean, Timing and Signals. Is there a datasheet?YouTube videohere

author: tooki
author_rank: Super Contributor
timestamp: July 20, 2025, 12:00:46 am
content: The schematic is here:https://bitsavers.org/pdf/apple/mac/powerbook/100/PB100_Schem_Jan1991.pdfIt seems to indicate it’s an 8-bit parallel bus. But no info on timing.A tiny bit of Googlingfoundthat the PowerBook 100’s LCD is a Sharp LM64P791. Perhaps you can find info on it.

author: squadchannel
author_rank: Frequent Contributor
timestamp: July 20, 2025, 01:46:46 am
content: STN parallel interface is completely different the parallel RGB.https://elm-chan.org/junk/mz211/report.html

author: DiTBho
author_rank: Super Contributor
timestamp: July 20, 2025, 12:22:37 pm
content: Quote from: squadchannel on July 20, 2025, 01:46:46 amDamn, I cannot translate. Anyway, it seems a STN with more than 1 bib per pixel (bpp). Right?Is there a way to get the datasheet? I cannot find it.
Recommendations for a quality ISA/PCI POST/Diganostics Card - Page 1
Forum section: electronics / general

author: Halcyon
author_rank: Unknown
timestamp: May 28, 2025, 01:43:23 am
content: I've been meaning to add a diag. card to my kit for a while, and have recently had a need for one. There's a ton of cheap Chinese ones out there and from what I've read, some are even damaging boards in some cases.Can anyone recommend a reputable brand or source for these kinds of cards? I don't mind if I have to buy a used one or a "new old stock" card from eBay.

author: m k
author_rank: Super Contributor
timestamp: May 31, 2025, 04:13:55 pm
content: Not so long ago I bought one, its PCI style is facing left.

author: Halcyon
author_rank: Unknown
timestamp: June 01, 2025, 01:13:07 am
content: Quote from: m k on May 31, 2025, 04:13:55 pmDo you recall where you got it from?

author: m k
author_rank: Super Contributor
timestamp: June 01, 2025, 10:12:48 am
content: It's a 4-digit version from ebay.https://www.ebay.com/itm/267090405976ISA bus is connecting D0-7 and +5V from other side, so rear is clear and this one has a correct guiding arrow with text.It also has a small pin 1 text and arrow pointing ISA bus at the other end, so that is wrong.The one with 'remote' display is more flexible, no mirror needed for PCI.https://www.ebay.com/itm/293996537191

author: darkspr1te
author_rank: Frequent Contributor
timestamp: June 01, 2025, 10:17:30 am
content: I purchased one of these and it's been fine. does pci/isa/LPC bus diagnosticshttps://www.amazon.co.uk/KALEA-INFORMATIQUE-Multi-Function-Motherboard-Desktop-Interface/dp/B0156S99I4/ref=sr_1_12?crid=X1FYZ9106ND2&dib=eyJ2IjoiMSJ9.uKRhfZ0HgIrvBKRoxj1NU90_u5EGI4QNR88DO5V_raB6WzF-htHXyoOK-_MiR5f3uaNBlxyV0VbuSo3t2dVMw3rysF8eg7Zq0Qko49dmaZjLVWa18Lhwucq_A58juIP8dyITUZHgYil0CKX0t2QlLXo5JZ6MT5VxBUcxVYfqZaxK4SUWZ_VOesBm5QOyNHiBlqnHTEKGzR3G0vlZUfnu9EJaTBamHFMaWDnTK_NuWk0.7WVx5S4_6H--9RsMNaWiLZBXx6MdIzdxZ_725fovFRg&dib_tag=se&keywords=pc+motherboard+diagnostic+post+card+pci-e+pcie&qid=1748772667&sprefix=pci+Post+card+%2Caps%2C289&sr=8-12
IMSAI 8080 and Repair Parts : Now Available - Page 1
Forum section: electronics / general

author: w9gb
author_rank: Contributor
timestamp: May 22, 2025, 11:20:56 pm
content: Earlier this month (May 2025), I acquired an OEM case for the IMSAI 8080 (no font panel or S-100 cards).Sadly this Generation #1 (001821) case was damaged in shipping.So, I began disassembly and found a very good resource for my restoration work.Robert E. Weatherford, CEO of Parastream Technologies, a former IMSAI employee,created an IMSAI division of his company.He has begun to offer IMSAI cases, parts, and eventually full kits for the IMSAI 8080.https://www.parastream.com/imsai/Cross-references of IMSAI Part Numbers to Specific Parts can be found here,with those “in stock” available for purchase.https://www.parastream.com/imsai/parts/cross-reference.aspxIMSAI Systems & Cabinetshttps://www.parastream.com/imsai/systems/i-cabinets.aspxIMSAI Boards (Processor, Front Panel, I/O, Backplane)https://www.parastream.com/imsai/boards/default.aspxNew PS-28S (Rev 1) Switch-Mode Power Supplyhttps://www.parastream.com/imsai/boards/ps-28s.aspx==A great resource for IMSAI restorers.gregw9gb
HP 85 computer with HP 7225 Plotter and HP 82901 floppy  - Page 1
Forum section: electronics / general

author: KeepTheSmokeIn
author_rank: Newbie
timestamp: May 16, 2025, 11:59:39 am
content: I realize that this is an old post, but just wanted to thank you for it anyway. The first company I worked for was a small PC retailer carrying, originally, Commodore and Apple computers. Saturdays at the store were absolute nerd-fests (I loved it). I remember when we brought in an HP 85 and the first Saturday it went on display. Standing room only and people lined up to run their benchmarks on it. I miss those days.
Signetics 2650 IcePi Prototype - Page 1
Forum section: electronics / general

author: cfbsoftware
author_rank: Regular Contributor
timestamp: May 13, 2025, 09:46:52 pm
content: The prototype of S2650 IcePi, my Signetics S2650 / Raspberry Pi RP2350 ICE combo retrocomputing project, worked for the first time yesterday. The RP2350 generates the 1 MHz clock and the S2650 (an 8-bit MCU from the 1970's) executes the code. The Signetics Monitor ROM, Pipbug (or other ROM code) and the user's application are loaded into RAM on the RP2350 which then services the OPREQ signals from the 2650.The RP2350B board I used is theOlimex Pico2-XL. (Note: I am using the PICO2-XL variant which currently sells for 5 Euro) Being able to access up to 48 GPIO pins came in very useful. There are two USB / RS232 adapter boards on this prototype. One communicates directly with the 2650 SENSE and FLAG serial IO running at 4800 Baud. The application shown is the game of Othello (a.k.a. Reversi) which I wrote in 2650 assembler back in the 1980'sS2650 IcePi is an RP2350B application 100% coded in Oberon using ourAstrobe IDE. The second USB / RS232 adapters connects to RX/TX on the RP2350 to communicate via the Astrobe terminal. The opportunities for tracing and debugging in realtime are endless as all of the data and address traffic to / from the 2650 is intercepted by S2650 IcePi. This came in very useful during development.
Apple ][ - I made this card for April fools day :) - Page 1
Forum section: electronics / general

author: deanclaxton
author_rank: Regular Contributor
timestamp: April 03, 2025, 12:33:01 am
content: https://jdmicro.com/hardware/fluxI posted the flyer on the Apple ][ Enthusiast facebook page - bit of fun

author: woofy
author_rank: Frequent Contributor
timestamp: April 03, 2025, 07:59:12 am
content: Brilliant, I love it.

author: Halcyon
author_rank: Unknown
timestamp: April 09, 2025, 03:48:25 am
content: That's officially the best lighting I've seen inside a computer... period!How much?

author: EEVblog
author_rank: Unknown
timestamp: April 09, 2025, 04:31:42 am
content: PCI version when?

author: deanclaxton
author_rank: Regular Contributor
timestamp: April 14, 2025, 04:27:13 am
content: Quote from: EEVblog on April 09, 2025, 04:31:42 amI hadn't thought about it, but it would be easy enough! Might have to 3D print the rear bracket though.
Picodac 80 training computer - Page 1
Forum section: electronics / general

author: step
author_rank: Newbie
timestamp: February 14, 2025, 06:33:57 pm
content: I found that on a old US magazine from the 70s. A very early 8080 application from the "Laboratoire d'électronique et d'automatisme du Nord" in northern France.If anyone have any info.... At least this "Picodac 80" is now referenced somewhere in the WWW

author: Stray Electron
author_rank: Super Contributor
timestamp: February 14, 2025, 08:33:35 pm
content: What magazine? What kind of application? What is a Picodac computer and who made it?Details, details, we want details!

author: step
author_rank: Newbie
timestamp: February 14, 2025, 09:06:21 pm
content: Quote from: Stray Electron on February 14, 2025, 08:33:35 pmI found a wiki ! It's a "Picodidac" from Léanord.didaclike in didactic.Probably used for teaching engineers automation in steel production in mid 70.https://en.wikipedia.org/wiki/L%C3%A9anordIt can't be more prehistoric than that !

author: GGMM
author_rank: Frequent Contributor
timestamp: April 13, 2025, 03:45:01 pm
content: Hi,My first job was in Léanord from 1977 to 1983.I knew the whole series of materials type Picolog, Picodidac, etc. I was in the control department and tested everything that came out of the workshop. Everything was assembled on site.I travelled throughout France to install equipment, in particular a telephone recorder. (Companies and large luxury hotels)Then, the time came to the computer, the range was created with the Sil'Z, etcI left the company just when Siemens bought it.It was a good experience.With the keyword Léanord on the net you will find many things about this "family" business.Greetings to Mr. pronnier (+) and all former colleaguescdt
Unix v7 filesystem spec - Page 1
Forum section: electronics / general

author: JamesIsAwkward
author_rank: Contributor
timestamp: August 20, 2025, 03:18:17 pm
content: Hey guys, I'm trying to implement the Unix V7 filesystem on my z80 project but I'm having a really hard time finding some concrete information on the spec.I've read the V7 manual and it gives a general idea of how the filesystem and inode system works but there isn't anything concrete.I know the general logical layout on disk was:1 block == 512 bytes (aka 1 sector)Boot block (block 0)Superblock (block 1)Inode section (block 2 to ??)Storage section (after inode section)But I don't know what all the superblock actually included besides a bit of disk info.I'm not sure what the inode section even looks like.What about the formula to calculate the amount of inode blocks vs the size of the disk/partition?I also know there's a free block linked-list stored somewhere too.There's a couple of z80 projects that use modified versions of this filesystem but it's harder to derive the spec from code than it is an actual datasheet or something.Those projects are UZI and Fuzix. The UZI source is really, really annoying to read. He rarely uses curly braces, I really hate that style of C lol.Do you guys have any links or documents that has the full spec? Finding the spec for something like FAT16 is crazy easy, but Unix 7 FS... not so much.Thanks!

author: ejeffrey
author_rank: Super Contributor
timestamp: August 20, 2025, 03:58:19 pm
content: The inodes are just concatenated in an array. The superblock tells you how many inodes there are, so you know how much space it takes.

author: edavid
author_rank: Super Contributor
timestamp: August 20, 2025, 04:07:25 pm
content: Have you seen the filsys(5) manpage?https://www.unix.com/man_page/v7/5/filsys/

author: bsdphk
author_rank: Regular Contributor
timestamp: August 20, 2025, 07:59:00 pm
content: It really is very simple:Some sectors for booting - a superblock - an array of inodes - the rest is Datablocks.Inode number two is the root directory of the filesystem, and directories are arrays of entries are a 16 bit short inode number, and 14 characters for name.The only tricky part is the block numbers in the inode may be weird 3-byte values, where the last ones are the exponential indirect blocks (which you can ignore if you dont need huge files).But if you have trouble wrapping your head around it, hexdump a V7 filesystem and work it out by hand ?Here is one analyzed with my "AutoArchaeologist" software, scroll past the green/white table and it is all dissected and laid out for you:https://datamuseum.dk/aa/cbm900/5e/5ec4c54f2_more.html

author: JamesIsAwkward
author_rank: Contributor
timestamp: September 02, 2025, 04:23:08 pm
content: Thanks guys! I'll check out these links.
PiDP-10 - Page 1
Forum section: electronics / general

author: bson
author_rank: Unknown
timestamp: April 09, 2025, 11:40:23 pm
content: I just finished building a PiDP-10 (https://obsolescence.wixsite.com/obsolescence/pidp10) and must say I absolutely adore this thing. It's even cooler in person! It now sits on a shelf here and runs TOPS-20. Makes me really want the PiDP-11 as well since the pdp-11 is what I really learned to program on (in assembly).Apologies for Youtube which seems to think all shorts should be vertical. Sigh. But I wanted it to loop. Rotate your screen to view!https://www.youtube.com/shorts/hzaSfwNaeQ4Just running a default power-on LED test pattern here.125 LEDs, 74 key switches... to carefully align and solder. But it worked out great!

author: brucehoult
author_rank: Super Contributor
timestamp: April 10, 2025, 05:09:39 am
content: Very nice.I've never had anything to do with the DEC mainframe, but I toyed with 6502 machine code (hand assembled) over the 80/81 summer holidays between high school and university, then learned asm properly (as a side quest, not part of the course work, we were just supposed to be learning Pascal) on a PDP 11/34 in first year university in 1981. And wrote a PDP-11 simulator on the 6502 back at my parents' house in one holidays ... the sim wasn't large, and the PDP11 code was SO MUCH more powerful and compact than 6502, though of course rather slow to emulate -- really painful to parse out those 3 bit fields, especially the ones that spanned bytes.

author: BKD
author_rank: Newbie
timestamp: April 10, 2025, 07:33:02 pm
content: Nice! I really want one too and am hoping the exchange rate magically gets a little better soon :-)
What was the Computer in Electric Dreams (1984)? - Page 1
Forum section: electronics / general

author: EEVblog
author_rank: Unknown
timestamp: March 16, 2025, 11:22:44 pm
content: I've always wondered this.As suggested, it looks like a hand made prop with non-functional boards, probably some telecoms related system boards.

author: Simmed
author_rank: Frequent Contributor
timestamp: March 16, 2025, 11:42:35 pm
content: i found the KB modelhttps://en.wikipedia.org/wiki/DECmate
looking for MikroTik, rb500 SDK - Page 1
Forum section: electronics / general

author: DiTBho
author_rank: Super Contributor
timestamp: February 25, 2025, 09:04:28 pm
content: uhm, some U.M. mentions a "rb5000 SDK", but I couldn't find anything.It it includes code-examples, it might help to develop myMonitor/MIPS for the rb532a board.Does anyone know this mysterious SDK? And how to get it?
Searching for info, digital data tape storage unit: TEAC: MT-1000-15-UD - Page 1
Forum section: electronics / general

author: TomasB
author_rank: Newbie
timestamp: January 26, 2025, 05:48:35 pm
content: Hi all,I just got my hands on a brand new, unboxed, digital data storage tape unit but cannot find information on it.The brand is TEAC and the model it MT-1000-15-UD.It is made for being inserted in some type of rack, possibly 19" rack and this means it is naked on the sides and rear.Probably it is used in the Ericsson telecom system AXE10 where I saw a picture of it in some manual.Does anyone else have info on this?See the attached picture,Best regards,Tomas

author: NF6X
author_rank: Unknown
timestamp: January 26, 2025, 06:26:55 pm
content: I do not know anything about your tape drive yet, but I'd enjoy seeing higher resolution photos of it. It appears that you just attached a tiny little thumbnail of the photo. Good luck with funding your retirement! 😆

author: TomasB
author_rank: Newbie
timestamp: January 26, 2025, 07:31:50 pm
content: Oh, sorry... I dragged and dropped from google-drive and... it seems like it was only the icon that was transferred... :-)Thanks,/Tomas

author: NF6X
author_rank: Unknown
timestamp: January 26, 2025, 07:43:03 pm
content: That tape drive is pretty!

author: TomasB
author_rank: Newbie
timestamp: January 27, 2025, 01:13:01 pm
content: Indeed!

author: Simon
author_rank: Unknown
timestamp: January 28, 2025, 08:15:57 am
content: Please don't double post.https://www.eevblog.com/forum/buysellwanted/searching-for-data-on-unknown-item/msg5796021/#msg5796021
Copy MD2202-D16 to another new - Page 1
Forum section: electronics / general

author: charlessauvat
author_rank: Newbie
timestamp: December 30, 2024, 01:43:33 pm
content: Hello,I am a complete beginner in this field.I have an industrial tool that works with a DiskOnChip MD2202-D16 card, and which includes a Windows CE 3.0.However, this card encounters a problem and crashes after a while, which prevents the industrial equipment from working properly.I saw on the internet that you can buy blank ones, and I would like to proceed with a complete copy of the old card to the new one. However, I do not have the equipment or the knowledge to do this.Could you tell me how to do it or if someone is motivated so that I can send them both cards (the old and the new one), and proceed with the copy in exchange for a few $.Thank you for your help.

author: coromonadalix
author_rank: Super Contributor
timestamp: January 16, 2025, 05:43:02 pm
content: http://www.digital-circuitry.com/MyLAB_IC_PROG_DISKONCHIP.htmhttps://www.os2museum.com/wp/diskonchip/
looking for RouterBOOT v2.18 MIPSle (MikroTik, router) - Page 1
Forum section: electronics / general

author: DiTBho
author_rank: Super Contributor
timestamp: February 17, 2025, 12:48:12 pm
content: hiI need to upgrade the firmware of my MikroTik routers rb532a.I currently have RouterBOOT v2.9 on board#1 and RouterBOOT v2.12 on board#2.I think RouterBOOTv2.18is thelast for "MIPSle"(mip32/little endian).Since it is EOL, I can't find it on MikroTik website.Does anyone know where I can download it?

author: Nominal Animal
author_rank: Super Contributor
timestamp: February 18, 2025, 03:09:38 am
content: http://download2.mikrotik.com/routeros/6.32.4/routeros-mipsle-6.32.4.npkandhttps://download.mikrotik.com/routeros/6.32.4/netinstall-6.32.4.zip. The latter has a Windows 32-bit executable you should be able to use with the RouterOS NetInstall instructions. As I understand it, this uses the backup booter in ROM. After installation, you should be able to update the booter firmware (on separate Flash) from within the RouterOS; it might not be included in the netinstallation, but is definitely included in the .npk package. The package format is encrypted and not documented by Mikrotik, so I believe installing RouterOS first (it does allow testing for 24 hours or something like that even if you do not have a license) and updating the booter from within that, is the Way.

author: DiTBho
author_rank: Super Contributor
timestamp: February 18, 2025, 06:39:36 pm
content: Thanks, searching inside their webside didn't produce any result, except 404I think I will subscribe to NordVPN, as I have too many troubles searching, finding, and downloading the files I need.Thank you very muchI want to dispel the doubt that there is a problem with the firmware causing the strange error I see with tftpbootPlus, a second weird behavior with the PCI I am experimenting during the development of myMonitor(I am adding PCI device scan)I'll get a Windows laptop tomorrow for that executable!
Help me identify this sticker on an 80836 - Page 1
Forum section: electronics / general

author: liudr
author_rank: Contributor
timestamp: December 25, 2024, 05:21:42 pm
content: I just bought an 80386 on ebay with this white sticker with red half circle and arrow. The sticker looks original to the CPU. I wonder what it may mean. It's supposed to be from US. With all the super clean vintage CPUs I saw on ebay that ship directly from China, I can use some help identifying the origin of the processor just to give it a sense of authenticity in lieu of an actual test on a computer.

author: Halcyon
author_rank: Unknown
timestamp: January 02, 2025, 01:17:02 am
content: It's likely part of a warranty label that was applied to the CPU by an computer store/builder. Back in those days, particularly when CPU's didn't require heatsinks, it was common practice to stick a tamper-evident label over the socket and CPU to indicate removal. CPUs were a high value item, and the labels were used to prevent claims of people who didn't know what they were doing, removing the CPU, bending or breaking pins, and then claiming warranty on the unit.
z80 with udp/ip, CS8900 10baseT: size of RAM and ROM? - Page 1
Forum section: electronics / general

author: DiTBho
author_rank: Super Contributor
timestamp: January 23, 2025, 01:35:14 pm
content: hiI am considering a very simple design, likethis(Grant's 7-chip Z80 computer, ~2007)It hasCode:Memory Map0x0000..0x1FFF ROM 08Kbyte0x8000..0xFFFF RAM 32Kbytewith a CS8900 10baseT network card memory mapped between 0x2000 and 0x2000+8Kbyte.The gadget application I have in mind is very simple:- it has no operating system like FreeRTOS, ucOS/2 or similar- it just needs to communicate via serial line to receive simple commands- it just needs to communicate via network via UDP/IP to receive data.- it also needs to show a few messages on a text-LCD.So, the ROM should contain:- serial 6850 driver, interrupt driven.- a tiny monitor, able to show the memory in hex, jump to an address, and to load SREC from the network- the cs8900 driver- the udp/ip network primitives { send(), receive() }- HD44780 LCD driver, 2x16 textDo you think it is feasible with CC=SDCC/z80 in 8Kbytes of ROM?Otherwise, I can write parts in z80-assembly, to integrate with the udp/ip part that I would like to write in C insteadWhat do you think

author: DiTBho
author_rank: Super Contributor
timestamp: January 23, 2025, 01:38:25 pm
content: (I'm terribly busy with that bloddy rb532a router fix as I need to bring that router with meI haven't tried to write a skeleton of what I would like to do, just to understand if it's feasibleI'm asking here, as apreliminary feasibility analysis, just to save timebecause then I have to leave for a long business trip)

author: Ian.M
author_rank: Super Contributor
timestamp: January 23, 2025, 02:22:51 pm
content: There's very little prior art online re: interfacing a CS8900 with a Z80.I think it would be prudent to *either* map the CS8900 higher *or* as a window in the ROM space, to allow a larger ROM to be used. Also the CS8900 only requires a 4KB window.Microchip still produce the AT28C256, a 32KB x 8bit parallel EEPROM, so you could have up to 28K ROM using A15 to select RAM / ROM + memory mapped IO, and a 74x138 to decode A12:14 (+ A15 on a nEN pin) to decode a 4K page in the bottom half of the memory map for the CS8900, + also inhibit ROM in that range.Grant's 7 chip Z80 uses 2 74LS32 OR gates to decode /CE for theRAMROMin the bottom 8K of the address space, and has two spare 74HCT04 inverter gates, one of which could be used to invert the '138 output selected for the CS8900, and feed it to the U7d OR gate controlling ROM /CS to make the window. Additionally, as there is still a spare inverter and U7c becomes spare, a second 4K window could be implemented if you ever need to add another 4K memory mapped device.

author: SiliconWizard
author_rank: Super Contributor
timestamp: January 23, 2025, 10:32:49 pm
content: I'm sure it is doable within 8 KB of code, but possibly not all in C.
classic xbox has a xecuter 3 mod - Page 1
Forum section: electronics / general

author: lokin4areason
author_rank: Contributor
timestamp: November 05, 2024, 09:06:54 pm
content: hello alli recently acquired one of these and have no clue if it works or notit was an odd ball unit that stood out and was cheap enough for me to pick it upfrom what i can tell its a mod called xecuter 3 ( like stated in the title ) from the limited searching i have donewas wondering if anyone knew anything about this or anyone has one that they can like explain at what it is or at what it doesits missing a few button(s) and a red lense off on the left hand of it ( and would need to source out a replacement for them ) along with it needing a power cable and a connection wire from the unit to the tvthanks again for any insight or input on itPS ; also have a foto attached to a similar one i have at hand

author: lokin4areason
author_rank: Contributor
timestamp: November 05, 2024, 09:10:55 pm
content: foto

author: Andy Chee
author_rank: Super Contributor
timestamp: November 05, 2024, 09:37:48 pm
content: If the xecuter 3 has failed for any reason, it won't be worth seeking an original replacement.Instead, use a raspberry pi
Mac-128k on a $14 MPU, say hAllo to the pico-mac! - Page 1
Forum section: electronics / general

author: DiTBho
author_rank: Super Contributor
timestamp: October 27, 2024, 03:10:41 pm
content: Pico Micro Mac, seehereVGA hat kit, seehereFirmware for flashing to the Pico, seehere

author: brucehoult
author_rank: Super Contributor
timestamp: October 27, 2024, 03:56:25 pm
content: 133 MHz Arm has an order of magnitude more power than an 8 MHz 68000?I don't think so! He's apparently forgotten that M68k takes 8 clock cycles for a 32 bit register-to-register add/sub/cmp/and/or/eor while the Arm takes 1 clock cycle for this. Shifts and rotates on the M68k take 8+2n cycles where n is the number of bits shifted by -- the Arm takes 1 cycle regardless of the shift amount. Conditional branches take 8 cycles on the M68k even if not taken, 10 if taken. The Pi Pico takes 3 cycles if taken, only 1 if not taken.Generally speaking, the Pi Pico is going to be more than TWO orders of magnitude faster than the Mac 128k, when running native code.Of course 68k emulation will eat up some of that. But even if it's a pure interpreter (like in the first PPC Macs) that should eat up only one of those orders of magnitude.

author: tggzzz
author_rank: Super Contributor
timestamp: October 27, 2024, 06:33:06 pm
content: If it won't run Apple Smalltalk, it isn't a Mac.

author: SiliconWizard
author_rank: Super Contributor
timestamp: October 27, 2024, 08:21:26 pm
content: Quote from: brucehoult on October 27, 2024, 03:56:25 pmYes it's much more powerful than this, plus there are two cores in the RP2040!I don't know how the emulated 68k they implemented performs. But the overall speed is probably way higher than an original Mac indeed, at least several times.Using a RP2350 with QSPI PSRAM could emulate much more powerful 68k Macs too. Using the second core and PIO for generating VGA video in color would be possible as well without much problem.All that for just a few bucks. Fun stuff.

author: brucehoult
author_rank: Super Contributor
timestamp: October 27, 2024, 09:41:27 pm
content: Quote from: SiliconWizard on October 27, 2024, 08:21:26 pmThe Milk-V Duo costs about the same as a Pico -- mine cost $2.99, Arace now has them at $4.99. It doesn't have the PIO, but it has a 1 GHz 64 bit Linux core, a 2nd 700 MHz 64 bit microcontroller core, and 64 MB RAM. It could run qemu-m68k (I have actually used qemu-riscv32-static on it) I expect faster than a 40 MHz 68040 and probably qemu-ppc faster than a PPC601 (first gen up to 100 MHz came with 8 or 16 MB RAM). The MCU core could very easily bit-bang 24 bit VGA or DVI -- Olimex have got a 48 MHz CH32V003 bit-banging mono VGA in their €1 RVPC kit.
Amiga as a Workstation Series... - Page 1
Forum section: electronics / general

author: BrianHG
author_rank: Super Contributor
timestamp: July 22, 2024, 01:31:14 am
content: Here are the first 5 parts, 0,1,2,3,4:

author: BrianHG
author_rank: Super Contributor
timestamp: October 10, 2024, 09:34:00 pm
content: Parts 5,6,7,8