Fixing the 9 PETs monitors turn-off spot (With Adrian Digital Basement) iz8dwf 2020-11-28 | Was the turn-off bright dot on PET's early 9" monitors intended? We'll discover that it was probably not intended and that Commodore did try to eliminate it in the later monitor revisions.We'll see also that someone didn't do the math in those times when rushing to have a finishedproduct was so important.Adrian Digital Basement youtube channel:youtube.com/c/adriansdigitalbasementAdrian's first part about PET's monitor fix:youtube.com/watch?v=jwgsaUtbH3IAdrian's second part about PET's monitor fix:youtube.com/watch?v=tBs8TisaDE4Commodore PET 2001 monitor schematic (all different known revisions):http://www.zimmers.net/anonftp/pub/cbm/schematics/computers/pet/2001/video-1.gifhttp://www.zimmers.net/anonftp/pub/cbm/schematics/computers/pet/2001/video-2.gifhttp://www.zimmers.net/anonftp/pub/cbm/schematics/computers/pet/2001/video-3.gifhttp://vintagecomputer.ca/files/Commodore/PET%202001/PET%20Service%20Kit%20-%20June%201978.pdfEasyEDA online PCB design & circuit simulatoreasyeda.comLTspice circuit simulatoranalog.com/en/design-center/design-tools-and-calculators/ltspice-simulator.html#(Long!) Oral History of Chuck Peddle (at around 2:25:00 he explain how they created the PET CRT monitor):youtube.com/watch?v=enHF9lMseP8
Zaccaria Space Pirate arcade repair. Mistakes happen! iz8dwf 2023-05-05 | In this video I show the repair process of a Zaccaria Space Pirate boardset (a clone of Cinematronics' Ripoff arcade game). I misunderstood the real problems a few times, but eventually all worked fine.My homemade vector monitor:youtube.com/watch?v=nMicXIlprQsTimeline: 00:00 - Welcome 01:12 - Logic PCB inspection 02:30 - Credits' PCB 08:37 - Logic PCB power on 13:08 - Audio/Video PCB inspection 14:08 - Using (and modding) my Vector monitor 16:10 - Audio dying saga
Making a MOS7501/8501 replacement adapter with a 6502 (Plus C16 upgrades). Part 2. iz8dwf 2023-04-21 | This is my second (and I'd say successful) attempt at making a "socket add-on" to use the more commonly available 6502 in place of the 7501/8501. The first attempt showed some flaws that I try to correct with a second revision. The adapter uses two 5V supply, 32-cells CPLDs.Many thanks to Gerrit Heitsch for providing scope captures of real 8501 signals and discussing the implementation details of these CPUs.First part video:youtube.com/watch?v=z5Evpt0pU9s6510 to 7501/8501 adapter and kernel hack:http://hackjunk.com/2017/06/23/commodore-16-plus-4-8501-to-6510-cpu-conversionTED architecture documents:http://www.zimmers.net/anonftp/pub/cbm/schematics/computers/plus4/264_Hardware_Spec.pdfhttp://www.zimmers.net/anonftp/pub/cbm/schematics/computers/plus4/264_Hardware_Spec_DocE.jpgMOS 7501 preliminary datasheet:http://www.zimmers.net/anonftp/pub/cbm/documents/chipdata/7501/index.htmlMOS 6510 datasheet:http://archive.6502.org/datasheets/mos_6510_mpu.pdfMOS 6502 datasheet:http://archive.6502.org/datasheets/mos_6500_mpu_nov_1985.pdfAtmel/Microchip PLD design resources:microchip.com/design-centers/fpgas-and-plds/splds-cplds/pld-design-resourcesDLC5 III parallel JTAG cable schematic:http://dev.ivanov.eu/index.php?page=dlc5-jtagUrJTAG for Linux:http://urjtag.orgTimeline: 00:00 - Welcome 01:01 - First adapter was not good 02:37 - C16 upgrade to 64k 05:16 - C16 5V regulator upgrade 11:01 - CPU adapter design fixes 14:10 - New adapter's PCB 17:12 - Testing on the C16 23:49 - Other adapters? 25:09 - Running a plus4 demo
Icom IC-E90 amateur radio transceiver TX fault repair. As lucky as it can get. iz8dwf 2023-04-14 | A friend asked me to try repairing his old handheld FM transceiver. It stopped transmitting on just one of the three bands covered by this little radio. It was luckily one of the easiest parts to be checked in circuit after however needing to take it apart completely.As bonus, we see how to find a good substitute for out of production PIN diodes and one way to measure the output power.IC-E90 service manual:http://www.radiomanual.info/schemi/ICOM_VU/IC-E90_serv.pdfTimeline: 00:00 - Welcome 01:35 - Testing TX output 03:30 - Disassembly 05:01 - Possible faulty circuits 06:51 - PIN diode substitution 11:05 - Testing the repair
Zaccaria Galaxia arcade repair #4. Last PCB but still not easy. iz8dwf 2023-03-22 | This is the last of four boards I've been sent for repair. This board showed the usual faults and a few new interesting ones. I needed to write even more diagnostic codeZaccaria Astro Wars repair video:youtube.com/watch?v=b4NDJMTLrw4Zaccaria Galaxia #1 repair video:youtube.com/watch?v=TVYFQGcRra4Zaccaria Galaxia #2 repair video:youtube.com/watch?v=2kPbGximviUZaccaria Galaxia #3 repair video:youtube.com/watch?v=KPmJRj6f5oEDiagnostic github repo:github.com/iz8dwf/zaccaria-2650-diagTimeline: 00:00 - Welcome 01:35 - EPROM/PROM checks 02:20 - Physical inspection 03:32 - Socket's nightmare 04:38 - Bad electrolytic 05:21 - First power-on 06:32 - BG RAM write fault 09:15 - Bad screen shifter 10:04 - Faulty starfield 10:50 - Bad Color RAMs 12:43 - The strange video bars 15:08 - Bad socket again 16:40 - Investigating the bad bombs 20:53 - Final checks 21:50 - The boards at home again
TPV effect on a Schottky diode iz8dwf 2023-02-23 | Short demonstration of the thermal photovoltaic effect, the less known variant of the well known photovoltaic effect. A normal diode generates a current when heated.en.wikipedia.org/wiki/Thermophotovoltaic_energy_conversionMusic on this video:Slow Times Over Here by Midnight North
Zaccaria Galaxia arcade repair #3. Did this PCB ever work?. iz8dwf 2023-02-10 | This is the third of four boards I've been sent for repair. This board is a /0 revision, proablythe first Galaxia PCB revision. As usual, almost all of the sockets needed to be substituted.The CPU reset circuitry needed an external 5V inputs, so I've jumpered this input directly on the PCB.Also, this board had different "timing capacitors" than the other /1 boards I've serviced.It seems it couldn't have worked in its current status.Zaccaria Astro Wars repair video:youtube.com/watch?v=b4NDJMTLrw4Zaccaria Galaxia #1 repair video:youtube.com/watch?v=TVYFQGcRra4Zaccaria Galaxia #2 repair video:youtube.com/watch?v=2kPbGximviUDiagnostic github repo:github.com/iz8dwf/zaccaria-2650-diagSignetics 2650 CPU manualhttp://datasheets.chipdb.org/Signetics/2650/2650UM.pdfTimeline: 00:00 - Welcome 00:37 - Broken pins 04:42 - Other physical issues 08:15 - First power on 08:34 - Reset issue 11:49 - Bad sockets 13:46 - Bad PVI 15:05 - Timing madness 22:23 - Final tests
Rebuilding my Commodore PET 2001 iz8dwf 2023-01-18 | After some years, I've finally decided it was time to put my CBM PET 2001 back together!Music in this video:Natural Light - Chris HaugenBright Skies - Audio Hertz
PET 2001s tape deck head azimuth alignment. A quick HOWTO. iz8dwf 2022-12-08 | A short video for an easy job: I needed to set the head azimuth on the old Commodore PET 2001 tape deck before re-installing it into the case. This is how I did it. I could of course use the better "oscilloscope" procedure, but in the '80s I've used this program very often and it always gave good results.Commodore 64 tape adjustment program:https://csdb.dk/release/?id=143459Oscilloscope based adjustment procedure:http://www.zimmers.net/anonftp/pub/cbm/schematics/datassette/datasette_schematic.pdfA great video on this subject:youtube.com/watch?v=2WrHqGm_LsA
Zaccaria Galaxia arcade repair #2. I decided I needed a diagnostic ROM. iz8dwf 2022-11-25 | This is the second of four boards I've been sent for repair. This had even more faults than the previous one, unfortunately even two Signetics 2636 PVI were bad. However, I decided to start a diagnostic ROM project that willhelp diagnosing these kind of arcade boards.Zaccaria Astro Wars repair video:youtube.com/watch?v=b4NDJMTLrw4Zaccaria Galaxia #1 repair video:youtube.com/watch?v=TVYFQGcRra4Diagnostic github repo:github.com/iz8dwf/zaccaria-2650-diagSignetics 2650 CPU manualhttp://datasheets.chipdb.org/Signetics/2650/2650UM.pdfThe macro assembler "AS"http://john.ccac.rwth-aachen.de:8000/as/DASMx disassembleroocities.org/pclareuk/DASMxTimeline: 00:00 - Welcome 00:32 - Physical inspection 01:03 - First power on 02:13 - Socket's nightmare 05:34 - Bad 74LS139 06:50 - First bad 2102 08:58 - Bad PVIs 10:10 - First bad 2x2114 12:48 - I need Diag ROM! 15:36 - Another bad 2x2114 17:19 - Another bad 2102 17:54 - Bad screen shifter 19:28 - Bad 2101 22:00 - Final tests
Zaccaria Galaxia arcade repair #1. It failed as I was fixing it. iz8dwf 2022-11-04 | This is a repair video of a Zaccaria Galaxia (a.k.a. Super Galaxian) arcadePCB and its sound board. The original faults were a bad 74S112 and a bad 74LS173 but other ICs failed during the repair of the previous faults.Online romident:http://romident.coinopflorida.comZaccaria Astro Wars repair video:youtube.com/watch?v=b4NDJMTLrw4Zaccaria arcade information and repair websitehttp://www.zzzaccaria.com/zzz/welcome.htmlTimeline: 00:00 - Welcome 01:05 - Physical inspection 02:56 - EPROMs checks 05:04 - Power ON 05:56 - Missing clock 07:20 - Starfield issues 11:28 - Bad TTL latch 14:05 - Bad color RAM 14:44 - First inputs check 15:54 - 74LS283 fails 21:31 - 74LS155 fails 26:23 - Sound PCB fix & test
Zaccaria Astro Wars arcade repair. An unusual arcade pcb.. iz8dwf 2022-10-22 | This is a repair of an Astro Wars CPU board made by the italian company Zacccaria. The board is quite unusual in many respects and it also had an unusual fault (two wrong IC soldered in). I also show a simple circuit to visualize the inverted (negative) color video output on a normal RGB monitor.Zaccaria arcade information and repair websitehttp://www.zzzaccaria.com/zzz/welcome.htmlZaccaria Astro Wars real cabinet playyoutube.com/watch?v=eSrQFBMeDlMTimeline: 00:00 - Welcome 00:46 - Physical inspection 02:31 - EPROMs check & MAME 04:31 - Video and power wiring 06:40 - S2650 CPU checks 08:50 - The wrong ICs 12:32 - Game booting & checks 16:07 - Sound PCB check 17:35 - RGB inverter circuit
The DEC VT05 computer terminal pt. 1. A short introduction iz8dwf 2022-09-24 | This is a short introduction to the digital equipment corporation VT05 serial computer terminal. This was the first CRT computer terminal made in the early 1970s. I plan to fully restore this wonderful device (S/N 02 07767) in the future, as time permits.Music in this video:Icelandic Arpeggios - DivKidNo.10 A New Beginning - Esther AbramiEverything Has a Beginning - Joel Cummins
Missile Command (bootleg) arcade repair #2: a current tracers job! iz8dwf 2022-09-17 | This is the repair process of a Missile Attack (a Missile Command bootleg made by U.Games) board #2 of the two I've been sent to be repaired. Thisboard have been reworked previously, but there were still issues with a couple of Motorola 74LS244 ICs.Atari Missile Command service manual:arcade-museum.com/manuals-videogames/M/MissileCommand.pdfBoard #1 repair video:youtube.com/watch?v=DmbbRx8pIHcTimeline: 00:00 - Welcome 00:36 - Physical inspection 03:02 - Refreshing tin layer on power pins 03:50 - CPU checks 04:30 - First databus shorted line 07:40 - Second databus shorted line 10:45 - Final tests
Missile Command (bootleg) arcade repair #1: a bad troubleshooting case. iz8dwf 2022-09-10 | This is the repair process of a Missile Attack (a Missile Command bootleg made by U.Games) board #1 of the two I've been sent to be repaired. I madesome mistakes during troubleshooting, but in the end the board was completely functional. No ICs needed substitution, all faults were solder/mechanical issues.Atari Missile Command service manual:arcade-museum.com/manuals-videogames/M/MissileCommand.pdfDRAM in-circuit comparator:youtube.com/watch?v=xRQRTc4lDlgyoutu.be/U0985Padg6cSecond Missile Attack game board repair video:youtube.com/watch?v=EF3GC0jiFw8Timeline: 00:00 - Welcome 00:21 - Bootleg introduction 02:02 - Physical inspection 04:22 - NOP generator checks 06:29 - Troubleshooting mistake n.1 08:17 - A custom test ROM 09:54 - Troubleshooting mistake n.2 11:02 - Finding a short circuit 14:51 - Video output 16:21 - Testing the trackball circuit
Solartron/Enertec 7151 multimeter repair pt. 1. Scrap or repair? iz8dwf 2022-09-02 | I've got an Enertec/Solartron/Schlumberger 7151 "Computing Multimeter" onebay. Unfortunately I've discovered it had a few missing parts (and not soeasy to find ones).In this video I try restoring at least all functionalities, so in the future I canattempt to calibrate it and see if it still met its specifications.Solartron 7151 manuals:http://www.ko4bb.com/getsimple/index.php?id=manuals&dir=06_Misc_Test_Equipment/Solartron/Solartron_7151_Computing_MultimeterGPIB to USB converter project:http://www.dalton.ax/gpib/Timeline: 00:00 - Welcome 00:24 - External inspection 01:26 - Instrument features 02:15 - Internal inspection 03:31 - Battery damage 04:12 - First power-on 05:08 - Shorted capacitor 07:46 - The missing parts 11:02 - Bringing it back to life 18:10 - Improving the backlight 19:13 - Testing the GPIB interface
Reverse-engineering and testing an old arcade power supply iz8dwf 2022-08-26 | This old power supply, from an Advisor (Space Fury's bootleg by Rumiano) arcade cabinet was sent for test and repair. I have reverse engineered the schematic, fixed the small problems and tested it.Timeline: 00:00 - Welcome 00:17 - Board inspection 00:56 - Schematics explained 04:48 - Calculating a working test load 06:32 - Testing the outputs
Galaga (gallag bootleg) arcade repair: The Fujitsu TTL disease. iz8dwf 2022-08-18 | This is the second part of another Gallag arcade boardset repair. Thisvideo shows all the troubleshooting of the CPU and Video PCBs. In this repair I've encountered a very unusual fault in my experience. In the previous video, I've shown my own syncbus daughterboard replacement with a ATF1502 CPLD using CUPL language. Timeline: 00:00 - Welcome 00:55 - UP8 failure 04:04 - UL8 failure 06:58 - UA1 failure 08:35 - UF9 failure 10:03 - Bad 2114 on Video UM6 11:15 - UJ7 failure 14:18 - "bad sprites" 14:50 - UA8 failure 16:15 - bad sprites fix (video UA2) 17:30 - really weird timing raceFirst video of this repair:youtube.com/watch?v=VK13G8KH0y8
Galaga (gallag bootleg) arcade repair: debugging CUPL for a replacement daughterboard. iz8dwf 2022-08-11 | This is the first part of another Gallag arcade boardset repair. The CPU pcb was missing the syncbus daughterboard so I implemented a replacement into an ATF1502 CPLD using CUPL language. It didn't come right at the first try though.Timeline: 00:00 - Welcome 00:38 - Board inspection 01:34 - New daughterboard design 04:02 - First revision doesn't work 04:56 - Correcting my CUPL mistakes 07:47 - Daughterboard workingSecond part of this repair:youtu.be/8aQs6MMEITA
Apple IIgs battery leak damage. The not so easy repair iz8dwf 2022-05-20 | Apple IIgs pcb # 8714. Backup battery leakage damaged PCB.Testing (almost?) all connections around the damaged area, adding partsand wires to restore full functionality. The clock oscillator drifted out of frequency enough to bring the NTSC colour carrier out of the detectionrange.Timeline: 00:00 - Welcome 00:19 - Assessing damages 01:20 - Restoring connections 04:20 - Missing video sync 05:51 - ADB port fault 08:05 - Get the colors back 12:54 - Drifted oscillatorApple IIgs schematics:applefritter.com/files/2021/03/18/Apple%20IIgs%20schematic.pdfMusic in this video:Lilac Skies - Corbyn KitesAccidents Will Happen - Silent Partner
Making a vector monitor Pt. 5: cathode driver & spot killer plus final tuning. iz8dwf 2022-05-06 | This is the fifth and last video about the construction of a complete 11" CRT monitor suitable for X-Y vector deflection to be used with Atari Asteroids arcade PCB.This last part covers the cathode amplifier (Z amplifier) circuit and the spot killer circuit. Last modifications and tuning of the other part of the circuits are also shown whenever they became necessary.Timeline: 00:00 - Welcome 01:37 - Metal chassis 02:20 - Cathode amplifier 13:07 - It lives! 14:27 - Spot killer 19:37 - Linearity & geometry 27:36 - Final result First part (how it all started and some theory about raster scan VS vector scan):youtu.be/-o5zJ1T778gSecond part (how can an ex-raster flyback be used without the old horizontal deflection circuit)youtu.be/5PQaKYQ3CRAThird part: (complete CRT power supply) youtu.be/PKXyUhuLZUMFourth part: (deflection amplifier & deflection yoke rewind)youtube.com/watch?v=xNVZ1HK8R1wA28-14W CRT datasheet:frank.pocnet.net/sheets/124/a/A28-14W.pdfRewinding the vertical coils on a yoke:youtube.com/watch?v=Ci9qiGVMF7sJürgen Müller X/Y deflection board and Asteroids pages:http://www.e-basteln.de/arcade/asteroids/intro/1943 Navy: The Cathode-Ray Tube educational youtube.com/watch?v=-Uh7XuM1eUARaster scan (wikipedia):en.wikipedia.org/wiki/Raster_scanTV and monitor deflection systems:http://repairfaq.cis.upenn.edu/sam/deflfaq.htmThe Secret Life of Vector Monitors:http://www.jmargolin.com/xy/xymon.htmElectrohome G05-801 XY monitor information:http://www.amazingarcading.com.au/G05-801_Dezbaz.htmVectrex game console:it.wikipedia.org/wiki/VectrexInformation about arcade vector monitors:http://www.andysarcade.de/vec_monitors.htmlAtari Asteroids arcade information:http://www.andysarcade.de/asteroids.htmlThe Secret Life of Vector Generators:http://www.jmargolin.com/vgens/vgens.htm
Home made 11 CRT vector monitor. Almost there. iz8dwf 2022-04-27 | My 11" CRT home made vector monitor is getting to an end. Geometry and linearity aren't perfect yet.#Shorts
Hantarex arcade vector monitor (2x) repair. The bad and the good. iz8dwf 2022-04-22 | Hantarex MTRV black and white arcade vector monitor repair. Two chassis with different faults on the flyback transformer. One of them could be fixed by adding an external high voltage diode.Timeline: 00:00 - Welcome 01:08 - Schematic description 03:53 - Initial checks 06:10 - Light bulb help 08:11 - One bad transformer 11:04 - 2nd chassis repair 12:38 - Testing the EHT diode 13:46 - Adding an external diode 17:18 - Testing with the real game 19:18 - Final diode replacementHantarex MTRV manual:https://usermanual.wiki/Document/HantarexMTRV.2796494215Hyperspace arcade:http://www.andysarcade.de/hyperspace.htmlarcade-museum.com/game_detail.php?game_id=18827
Apple IIgs disk interface issue. Substituting the IWM with a Macintosh one. iz8dwf 2022-03-17 | Apple IIgs pcb # 8806-2. No external floppy drive was recognized. Tracked the fault to a bad IWM IC 344S0041 (PLCC 28 pins). A 344S0062 IWM from a Macintosh IIx worked fine as replacement.Timeline: 00:00 - Welcome 00:28 - IWM troubleshooting 02:54 - IWM "options" 06:34 - Final tests Apple IIgs schematics:applefritter.com/files/2021/03/18/Apple%20IIgs%20schematic.pdfApple IWM documentationhttps://brutaldeluxe.fr/documentation/iwm.html
Apple IIgs lucky repair. Lets find a bad logic IC. iz8dwf 2022-03-10 | Apple IIgs pcb # 8718 repair. A bad address bus buffer (74HCT245) causing a "white screen".Timeline: 00:00 - Welcome 00:30 - Apple IIgs introduction 02:02 - Custom ICs 03:31 - Troubleshooting 09:07 - Final testsApple IIgs schematics:applefritter.com/files/2021/03/18/Apple%20IIgs%20schematic.pdf
Amateur radio transceiver Kenwood TS-180S repair pt. 2 PLL troubleshooting and fixes. iz8dwf 2022-03-03 | Kenwood TS-180S amateur radio transceiver, S/N 950052 repair. In this second video we'll see the troubleshooting and repair of the multi-band PLL circuits.First part video:youtube.com/watch?v=ZSsBRalmUaYTimeline: 00:00 - Welcome 00:57 - PLL dividers issue 12:14 - PLL BP filters issue 16:14 - Final checks
The longest Commodore PET 4032 repair ever, pt.2 iz8dwf 2021-12-31 | CBM PET universal board (originally 4016), S/N WG9369.Second part of the complete repair, more socket-rework-induced faults and a few bad 4116 ICs.Timeline: 00:00 - Welcome 00:38 - A missing GND to TTL chip 01:51 - The DRAM tester strikes again 02:51 - Another missing connection 03:55 - DRAM tester magic again 05:07 - Keyboard interface issue 06:02 - Another bad 4116 09:01 - 32Kbytes and test time 12:05 - The last broken trace Part 1 video:youtube.com/watch?v=vZ5CVQRKW-kRelated/useful videos:How to test a remarked 6502:youtube.com/watch?v=5MccK9MI9qI&t=272sIZ8DWF's PET RAM/ROM daughterboard:youtube.com/watch?v=bjyGk5zoDMsIZ8DWF's dynamic RAM in-circuit tester:youtube.com/watch?v=xRQRTc4lDlg&t=430sMusic on this video:Well Worth the Wait - Silent Partner
The longest Commodore PET 4032 repair ever, pt.1 iz8dwf 2021-12-24 | CBM PET universal board (originally 4016), S/N WG9369.First part of the complete repair after it was almost completely socketed.Timeline: 00:00 - Welcome 00:34 - Sockets! They're everywhere! 02:00 - Testing all RAM connections 05:36 - Power on tests 06:18 - All 40 pins IC are bad 08:33 - Half of the ROMs are bad 11:39 - Missing trace to one ROM 13:06 - The first bad 4116 14:41 - A long RAM troubleshooting 15:06 - Bad /RAS 17:40 - Identifying a short circuit 21:33 - More fixes to go.Second part video:youtu.be/U0985Padg6cRelated/useful videos:How to test a remarked 6502:youtube.com/watch?v=5MccK9MI9qI&t=272sIZ8DWF's PET RAM/ROM daughterboard:youtube.com/watch?v=bjyGk5zoDMsIZ8DWF's dynamic RAM in-circuit tester:youtube.com/watch?v=xRQRTc4lDlg&t=430sMusic on this video:Wise - Silent PartnerNatural - Endless LoveCologne 1983 - Josh Kirsch/Media Right Productions
Amateur radio transceiver Kenwood TS-180S repair pt. 1 Voltage regulator issues. iz8dwf 2021-12-14 | Kenwood TS-180S amateur radio transceiver, S/N 950052 repair. In this first video we'll see how to approach such a repair and how to test and repair the voltage regulator board (AVR) of this old radio.Second part video:youtu.be/K5wD9Gww_1cTimeline: 00:00 - Welcome 01:27 - TS-180S introduction 02:14 - Power on and symptoms 03:33 - Troubleshooting approach 05:00 - 8V regulator troubles 12:56 - Minus 6V regulator troubles
Commodore PET 8032 repair. ROM/RAM/IO and more faults fixed! iz8dwf 2021-11-19 | Complete repair of a CBM 8032 (Universal PET) motherboard S/N: WG17291Faults found:- NE555 on reset circuit- M53354 TTL decoder IC- 2 x MOS6520 PIA- 2 x MOS masked programmed ROMs- HM4716AP DRAM ICTimeline: 00:00 - Welcome 00:42 - Mechanical issues 01:16 - Voltage checks 01:43 - CPU reset missing 04:07 - Address decoder fault 09:03 - First bad ROM 10:21 - First bad MOS6520 13:15 - Second bad ROM 17:41 - It lives! (w/ a bad 6520) 20:38 - Fixing IEEE-488 22:26 - Bad RAM IC PET RAM/ROM daughterboard:youtube.com/watch?v=bjyGk5zoDMs8-bit NOP generator introduction:youtu.be/9Ms6QR4r93IMr. Li's 6502 NOP generator socket:laser.com/product_info.php/item/6502NOP-6502NOP_Chip/products_id/1981Re-tinning edge connectors:youtu.be/D3pSjQLOlrc?t=926Re-tinning faster method:youtu.be/IHRH3E0EtLg?t=1682Music on this video:Guava Juice by Aaron Lieberman
Commodore PET 8032-SK repair. Making a new old school troubleshooting tool. iz8dwf 2021-11-03 | Complete repair of a CBM 8032-SK (Universal-2) motherboard S/N: WG06991Faults found:- CR4 bridge rectifier - 5 x TMM416P-3 I succesfully made a test tool to help identifying bad DRAM chips in circuit, if absolutely sure that all the rest of a machine is working fine.Timeline: 00:00 - Welcome 00:55 - Checking the rectifiers 03:17 - First checks at power on 04:11 - Troubleshooting with Ram/Rom board 07:10 - The in-circuit DRAM comparator 10:35 - Finding more bad chips with BASIC 12:55 - Final testing of all portsPET RAM/ROM daughterboard:youtube.com/watch?v=bjyGk5zoDMsUniversal PET repair and "A7 ADDR BAD" error:youtube.com/watch?v=PTKSLsCMRosRe-tinning edge connectors:youtu.be/D3pSjQLOlrc?t=926Re-tinning faster method:youtu.be/IHRH3E0EtLg?t=1682Music on this video:Bright Idea by Geographer
IZ8DWF gets mail #3! SIDs are coming! Lots of chips and how to test quartz crystals iz8dwf 2021-10-27 | Thanks to Julian, I got a whole lot of spare chips and a whole lot of SID chips! Now my REV. A C64 PCB is complete!I've got also a few spare quartz crystals and I show a simple circuit to quickly test them.C64 SID tester:https://commodore.software/downloads/download/148-c64-testers/11835-commodore-64-sid-testerSID tester video:youtube.com/watch?v=IjlQsqx3_LAMusic in this video:Cologne 1983 by Josh Kirsch/Media Right ProductionsLunatico by LFT:https://csdb.dk/release/?id=151273Timeline:00:00 - Welcome02:30 - 27C512 EPROMS03:09 - Checking Temic PLS100 ICs06:37 - Checking ICT PEEL ICs08:07 - A Circuit for testing crystals10:25 - Checking the MOS8701 ICs11:21 - All SIDs tests18:15 - Rev. A C64 complete
Atari Asteroids Arcade PCB repair (#2 board). Bad DAC and early revisions sound fault. iz8dwf 2021-10-01 | Sponsor: $2 for 1-4 Layer PCBs, sign up to get $18 new user coupons: jlcpcb.com/DYE This is the complete repair process of one of my Atari Asteroids Arcade PCBs.Faults fixed:1) X deflection missing due to bad AD561 IC2) The previous "repair" person attempted to permanently kill the board with the help of a soldering iron (cut trace under a replaced IC, caused a fault in the vector generator state machine).3) Rev -02 board had a mistake in the "thump" sound generator.Timeline:00:00 - Welcome01:35 - First power on02:21 - Troubleshooting the X output05:05 - Vector generator issues09:04 - Thump sound issues11:36 - Rev -02 PCB errataRelated videos:first inspection and repairs of my Asteroids PCBs:youtube.com/watch?v=IHRH3E0EtLg Making a power supply and audio power amplifier for Atari Asteroids:youtu.be/35YR62yv3-EGreat video about Atary XY arcade vector generatorsyoutube.com/watch?v=smStEPSRKBsAtari Asteroids related information:en.wikipedia.org/wiki/Asteroids_(video_game)http://www.andysarcade.de/asteroids.htmlarcade-museum.com/game_detail.php?game_id=6939http://www.jmargolin.com/vgens/vgens.htm
Atari Asteroids game PCB repair (#1 board): lift that reset! 6502 arent made equal? iz8dwf 2021-09-17 | Sponsor: $2 for 1-4 Layer PCBs, sign up to get $18 new user coupons: jlcpcb.com/DYE This is the complete repair process of one of my Atari Asteroids Arcade PCBs.Faults fixed:1) A double-IC shorted /RESET line.2) The previous "repair" person attempted to permanently kill the board with the help of a soldering iron3) Some 6502 seems not really suited for the Asteroids game board.Timeline:00:00 - Welcome01:42 - First power on02:23 - CPU's Reset problem07:47 - The shacking vectors disease08:16 - Poor soldering job disease10:22 - Not all 6502s are made equal13:40 - Last checks Related videos:first inspection and repairs of my Asteroids PCBs:youtube.com/watch?v=IHRH3E0EtLg Making a power supply and audio power amplifier for Atari Asteroids:youtu.be/35YR62yv3-EAtari Asteroids related information:en.wikipedia.org/wiki/Asteroids_(video_game)http://www.andysarcade.de/asteroids.htmlarcade-museum.com/game_detail.php?game_id=6939http://www.jmargolin.com/vgens/vgens.htm
IZ8DWF gets mail #2! C64 PLA and how to quickly check a rebadged 6502. iz8dwf 2021-09-10 | Thanks to Marc for sending me a few spare chips! I've finally got an original "C64A" 82S100 so I can get the official fuse map. Plus, it's a 1982 chipthat's perfect for my Rev. A C64 PCB!A quick look at the somewhat rare 24 pins 8 kBytes eprom MCM68766.A few tests to determine what a "rebadged" or "remarked" 6502 from China can be.Timeline:00:00 - Welcome01:17 - MCM68766 EPROMS02:57 - Reading the 82S100 C64 PLA04:32 - A few checks on unknown 6502 chipsIZ8DWF's 82S100 PLA videoyoutube.com/watch?v=nicaN-IdzNI65C02 opcodes:http://6502.org/tutorials/65c02opcodes.html6502's wikipedia page:en.wikipedia.org/wikien.wikipedia.org/wiki/MOS_Technology_6502The CMOS 6502 from Byte Magazine Dec. 1983:http://archive.6502.org/appnotes/the_cmos_6502.pdf6502 functional tests code:github.com/Klaus2m5/6502_65C02_functional_tests
Atari Asteroids Arcade: making a power supply and audio amplifier for the game board. iz8dwf 2021-09-03 | Sponsor: $2 for 1-4 Layer PCBs, sign up to get $18 new user coupons: jlcpcb.com/DYE This is the second part in my Atari Asteroids Arcade project. I needed to make a complete power supply for the game PCB (and thevector monitor) and an audio power amplifier with a balanced input. Timeline:00:00 - Welcome01:47 - Power supply07:39 - Audio amplifier12:23 - Oscilloscope as XY displayRelated videos:first inspection and repairs of Asteroids PCBs:youtube.com/watch?v=IHRH3E0EtLg first video (of several ones) about making a CRT vector monitor:youtube.com/watch?v=-o5zJ1T778gAtari Asteroids links:en.wikipedia.org/wiki/Asteroids_(video_game)http://www.andysarcade.de/asteroids.htmlarcade-museum.com/game_detail.php?game_id=6939http://www.jmargolin.com/vgens/vgens.htm
Making a vector monitor Pt. 4: Deflection yoke and driver issues. iz8dwf 2021-04-24 | $2 for 1-4 Layer PCBs, sign up to get $18 new user coupons: jlcpcb.com/DYE This is the fourth video about the construction of a complete 11" CRTmonitor suitable for X-Y vector deflection of an Atari Asteroids arcadePCB.Exploring the X-Y deflection issues on both adapting a yoke meant forraster deflection and making a good driver circuit for it.First part (how it all started and some theory about raster scan VS vector scan):youtu.be/-o5zJ1T778gSecond part (how can an ex-raster flyback be used without the old horizontal deflection circuit)youtu.be/5PQaKYQ3CRAThird part: (complete CRT power supply) youtu.be/PKXyUhuLZUMFifth part: (Z-amp, spot killer, final tuning)youtu.be/nMicXIlprQsA28-14W CRT datasheet:frank.pocnet.net/sheets/124/a/A28-14W.pdfRewinding the vertical coils on a yoke:youtube.com/watch?v=Ci9qiGVMF7sJürgen Müller X/Y deflection board and Asteroids pages:http://www.e-basteln.de/arcade/asteroids/intro/1943 Navy: The Cathode-Ray Tube educationalyoutube.com/watch?v=-Uh7XuM1eUARaster scan (wikipedia):en.wikipedia.org/wiki/Raster_scanElectrohome G05-801 XY monitor information:http://www.amazingarcading.com.au/G05-801_Dezbaz.htmVectrex game console:it.wikipedia.org/wiki/VectrexInformation about arcade vector monitors:http://www.andysarcade.de/vec_monitors.htmlAtari Asteroids arcade information:http://www.andysarcade.de/asteroids.htmlThe Secret Life of Vector Generators:http://www.jmargolin.com/vgens/vgens.htmThe Secret Life of Vector Monitors:http://www.jmargolin.com/xy/xymon.htm
Making a vector monitor Pt. 3: The complete power supply and the first deflection tests. iz8dwf 2021-02-23 | This is the third part video (of at least five) about my project to make a complete (and reliable)vector XY monitor for my Atari Asteroids PCB.All the CRT power supply is described and I show the first XY deflection tests.First part (how it all started and some theory about raster scan VS vector scan):youtu.be/-o5zJ1T778gSecond part (how can an ex-raster flyback be used without the old horizontal deflection circuit)youtu.be/5PQaKYQ3CRA Fourth part (Deflection and yoke):youtu.be/xNVZ1HK8R1wFifth part: (Z-amp, spot killer, final tuning)youtu.be/nMicXIlprQsA28-14W CRT datasheet:frank.pocnet.net/sheets/124/a/A28-14W.pdfElectrohome G05-801 XY monitor information:http://www.amazingarcading.com.au/G05-801_Dezbaz.htmVectrex game console:en.wikipedia.org/wiki/VectrexUsing a Vectrex XY monitor with Atari Asteroids:http://www.e-basteln.de/arcade/asteroids/monitor/
Making a vector monitor Pt. 2: different options on using flyback transformers. iz8dwf 2021-02-13 | This is the second part video (of at least five) about my project to make a complete (and reliable)vector XY monitor for my Atari Asteroids PCB.It took quite some time to first understand a lot of details about the raster-based CRT power supplies and then explore a few different options to re-use properly the ex-flyback transformerof the 11 inches TV.Timeline:00:00 - Welcome01:30 - Raster scan based supply VS vector scan02:34 - How power is generated and recycled on a raster system08:00 - Cosmetic restoration on the 11" CRT08:57 - Power supply design goals11:08 - On using unmodified flyback trasformers20:52 - PWM flyback drive 22:57 - Adding new primary windings24:20 - PWM drive with a new primary30:37 - Hints about QR PWM32:11 - Resonant primary driveFirst part (how it all started and some theory about raster scan VS vector scan):youtu.be/-o5zJ1T778gThird part (the completed power supply):youtu.be/PKXyUhuLZUMFourth part (Deflection and yoke):youtu.be/xNVZ1HK8R1wFifth part: (Z-amp, spot killer, final tuning)youtu.be/nMicXIlprQsA28-14W CRT datasheet:frank.pocnet.net/sheets/124/a/A28-14W.pdfElectrohome G05-801 XY monitor information:http://www.amazingarcading.com.au/G05-801_Dezbaz.htmVectrex game console:en.wikipedia.org/wiki/VectrexHorizontal waveforms basics:http://www.gradllc.com/images/HORIZONTAL.pdfNew (great) video about Atary XY arcade vector generatorsyoutube.com/watch?v=smStEPSRKBs
Modern electronics repair: fixing an LCD monitors power supply. iz8dwf 2020-12-24 | Sometimes I happen to fix also more recent devices than the typical 8 bit machines and related peripherals.This is the only VGA LCD monitor I have at home (but I have plenty of CRT ones), so I thought it deserved an attempt to be fixed.The fault was easy to find and repair, but might be still interesting to show.Christmas tree Ascii Art shell script (slightly edited) I've used at the end of the video:raw.githubusercontent.com/sergiolepore/ChristBASHTree/master/tree-EN.sh
Commodore 64 many faults repair. Was it an auction scam? iz8dwf 2020-11-21 | I've decided to buy another C64 (S/N UKB1 883806) off ebay, but here what can happen sometimes.All (but one) socketed chips were bad or even not belonging to a PAL C64. I've found and repaired two other faults too. Music in this video: Plaidness by Francis Preve.UPDATE: the MOS6567R8 was actually good, when tested on a NTSC board.
IZ8DWF gets mail! MOS8701 replacement and key test fixture from Hey Birt! iz8dwf 2020-11-07 | The friendly Jeff Birt sent some presents! Good stuff for repairing and testing Commodore machines!Hey Birt! youtube channel:youtube.com/channel/UC2V0T-vGOewtuCW3pazzczQDesign and Engineering of 8701 Replacement video:youtube.com/watch?v=e5o8c656j3QRejuvenating vintage keyboard contacts video:youtube.com/watch?v=n9gGz2n-sBU&t=1074s
Dead Commodore 16. Making a MOS7501/8501 replacement adapter with a 6502. Part 1. iz8dwf 2020-10-17 | I had this C16 since a many years, it was donated by a coworker back in 2003 when I was living in Sardinia Island. It has a bad 8501 CPU. Now it's about time that I attempt to make a "socket add-on" to use the more commonly available 6502 in place of the 7501/8501. In this first part, I study the MOS7501 and try to implement the missing logic parts into a couple of CPLDs.Not everything goes well though.Many thanks to Gerrit Heitsch for providing scope captures of real 8501 signals and discussing the implementation details of these CPUs.Second revision of the adapter video:youtu.be/XXCURhguHTY6510 to 7501/8501 adapter and kernel hack:http://hackjunk.com/2017/06/23/commodore-16-plus-4-8501-to-6510-cpu-conversionTED architecture documents:http://www.zimmers.net/anonftp/pub/cbm/schematics/computers/plus4/264_Hardware_Spec.pdfhttp://www.zimmers.net/anonftp/pub/cbm/schematics/computers/plus4/264_Hardware_Spec_DocE.jpgMOS 7501 preliminary datasheet:http://www.zimmers.net/anonftp/pub/cbm/documents/chipdata/7501/index.htmlMOS 6510 datasheet:http://archive.6502.org/datasheets/mos_6510_mpu.pdfMOS 6502 datasheet:http://archive.6502.org/datasheets/mos_6500_mpu_nov_1985.pdfAtmel/Microchip PLD design resources:microchip.com/design-centers/fpgas-and-plds/splds-cplds/pld-design-resourcesDLC5 III parallel JTAG cable schematic:http://dev.ivanov.eu/index.php?page=dlc5-jtagUrJTAG for Linux:http://urjtag.org
Restoring a C64 PCB 326295 Rev A. The first C64 PCB revision. iz8dwf 2020-10-11 | A nice C64 Fab. 326295 REV. A PCB, donated by Adrian Black needs some parts thatwere removed in the past.This is the first PCB revision of the Commodore 64 and was mostly found in the "silver label" breadbin models. Shortly after getting my VIC-20 in June 1982, a classmate and friend (his name is Antonio) got a C64, so we spent many afternoons in his room playing with that computer that was so much powerful than my VIC-20.Of course it was a PAL silver label breadbin.After a couple of years, I got a C64 too, and we thought at the time thatthe new rainbow logo was much more cool :)Things have changed a bit in these years.Color "bleeding" update: R10 was still 300 ohms (wrong value), after replacing it with 120 ohms,the color interference got better even with the original 6567R56A. Using a 6567R8 completelyfixes the color issue even with the wrong R10 value.Data I/O 2900 repair and testing:youtube.com/watch?v=h48vDtih3FMAdrian's Digital Basement youtube channel:youtube.com/user/craig1blackMusic on this video: Francis Preve - Wild Pogo
The 82S100 PLA and its Soviet clone. Lets make a NOS C64 PLA. iz8dwf 2020-09-19 | A quick glance at the famous PLA, the Signetics 82S100 and its close relatives, including the least famous P556PT2 (R556RT2 in latin alphabet).How we can find and program an original field-programmable PLA and what are the other options (much easier ones) to substitute a broken PLA on a C64 or other digital devices of the past.C64 PLA Dissected:ftp://ftp.zimmers.net/pub/cbm/c64/firmware/C64_PLA_Dissected.pdfMattis Lind's 82S100 replacement:github.com/MattisLind/82S100replacementEPROM to PLA adapter:http://vic20.de/html/eprom_pla_8296_und_c64.htmlList of Soviet ICshttps://ganswijk.home.xs4all.nl/chipdir/soviet/chips.htm
CBM PET 4032 (2001N) display logic repair. Remotely! iz8dwf 2020-04-18 | Commodore PET 4032 (2001-32N variant), S/N: 1330939, video display logic diagnose and repair help via remote chat.Elder0010 (the owner of this PET) home page:http://www.elder0010.comPET test rom image:drive.google.com/drive/folders/1fyLbr1kcG98a2FDOMo1H5pj9lIdJpHcx?usp=sharingHow character generation works on PETs:youtu.be/PTKSLsCMRos?t=529
The Data I/O 2900 device programmer. Introduction and (easy) repair. iz8dwf 2020-03-28 | My "new" Data I/O device programmer (S/N 6601688 of November 22 1990). A vintage programmer for vintage devices (a lot of them).Repair process and introduction to the serial terminal menu and the TaskLink program interface.To make the firmware disks:1) Download the .zip archive2) Extract the archive, it will result in 4 .exe files plus a readme.txt, the .exe can run on any windows version.3) Get 4 DOS-formatted (or even better formatted into the 2900's internal drive if you have an older firmware already booting).3-alt) You can try a gotek adapter in place of the real floppies, but I've not tested this.4) Execute in turn each of the exe files, each with a different floppy disk inserted into the drive. ( It worked with a Windows 10 PC using an USB floppy disk drive. Any older version should work too, and of course with "regular" floppy disk drives too.)5) Read the Readme,txt file contained in the archive :)Data I/O 2900 brochure:http://www.bitsavers.org/test_equipment/dataIO/brochures/Data_IO_2900_Mar_1990.pdfData I/O on groups.io:groups.io/g/DataioEPROMMatthieu Benoit's Data I/O 2900 resource page:http://matthieu.benoit.free.fr/167.htm
Making a vector monitor for Atari Asteroids arcade. pt.1: Theory iz8dwf 2020-03-13 | This is the first video about my attempt to convert an old black and white TV to a vector monitor suitable for my Atari Asteroid arcade project.In this video we'll try to understand what's a vector monitor and how different is from a regular TV set.Part 2 video:youtube.com/watch?v=5PQaKYQ3CRAPart 3 video:youtube.com/watch?v=PKXyUhuLZUMPart 4 video:youtube.com/watch?v=xNVZ1HK8R1wPart 5 video:youtu.be/nMicXIlprQsCathode ray tube (wikipedia):en.wikipedia.org/wiki/Cathode-ray_tubeA28-14W CRT datasheet:frank.pocnet.net/sheets/124/a/A28-14W.pdfRaster scan (wikipedia):en.wikipedia.org/wiki/Raster_scanAnalog television (wikipedia):en.wikipedia.org/wiki/Analog_televisionA beginners guide to Bitmapshttp://paulbourke.net/dataformats/bitmapsList of vector games (wikipedia):en.wikipedia.org/wiki/Category:Vector_arcade_gamesElectrohome G05-801 XY monitor information:http://www.amazingarcading.com.au/G05-801_Dezbaz.htmVectrex game console:it.wikipedia.org/wiki/VectrexJürgen Müller X/Y deflection board and Asteroids pages:http://www.e-basteln.de/arcade/asteroids/intro/Information about arcade vector monitors:http://www.andysarcade.de/vec_monitors.htmlAtari Asteroids arcade information:http://www.andysarcade.de/asteroids.htmlThe Secret Life of Vector Generators:http://www.jmargolin.com/vgens/vgens.htmThe Secret Life of Vector Monitors:http://www.jmargolin.com/xy/xymon.htm
Atari Asteroids arcade 2xPCB repair pt.1 - Inspection and previous repairs damages iz8dwf 2020-02-29 | First video on my journey fixing Atari Asteroids arcada PCBs. These two boards have been damaged badly by a previous repair attempt. We are going to inspect the two PCBs, see what can be done before attempting to power up and see a fast and very effective way of re-tinning PCB edge connectors.Asteroids was probably the first (or the second) arcade game I've played in my life, so it deserves to be in the list of my arcade repairs.Repair video of the first board:youtube.com/watch?v=Tu10tQlWd3YRepair video of the second board:youtube.com/watch?v=06chac2uBc0Useful links about this famous game:en.wikipedia.org/wiki/Asteroids_(video_game)http://www.andysarcade.de/asteroids.htmlarcade-museum.com/game_detail.php?game_id=6939
8 bit troubleshooting tools: The NOP generator iz8dwf 2020-02-22 | This video scratches the surface on 8-bit MPUs "NOP generators" as a general troubleshooting tool.How to make simple socket adapters for the MOS6502 and Zilog Z80 processors. What you can check on a malfunctioning board when a NOP generator is installed.Why isn't possible to make a NOP generator for the MOS6510/8500 (and the very similar 7501/8501).Adrian Digital Basement video on 1541C repair using a NOP generator:youtube.com/watch?v=-gDKl15WYucProgramming the 6502 by R. Zaks:archive.org/details/Programming_the_6502_OCR/mode/2upProgramming the Z80 by R. Zaks:archive.org/details/Programming_the_Z-80_2nd_Edition_1980_Rodnay_Zaks/mode/2up
