2 x Atari Lynx II Repair and Recap.

The first Atari Lynx II did not turn on but when powering the console at 5v bypassing the power stage it worked properly.

I had to replace all the electrolytic capacitors and the critical components of the power stage.

• 1 x MOSFET MTDJ055E with a equivalent one.
• 2 x Transistor 2N3906.
• 1 x Zener Diode 1N5991B.
• 1 x 120 Ohm resistor.

The second Atari Lynx II working correctly so consequently i have only replaced the electrolytic capacitors.

Gallery of the repair:

Hybrid SID Player with a real SID 8580R5 running on Olimex PIC32-T795.

After trying the sid player of Bakisha and have added some features (es: Big LCD ILI9341 / Real Sid) of course with the help of Bakisha, thanks Branko

I also wanted to try the Hybrid SID Player by Markus Gritsch. The schematic (omitting some components) and the firmware are untouched and released some years ago (2011-2012) by Markus Gritsch on the forum of Dangerous Prototype.

Since the CUI32 DEV Board where is born the Hybrid SID Player is no longer available from many years, i have used the DEV Board PIC32-T795 from Olimex based on the same MCU the PIC32MX795F512H.

I have made a hack on the PIC32-T795 development board because the two pins used for the rotary encoder are not available because they are used for the RTC, i just had to remove the MHz Crystal and two capacitors from the PIC32-T795 board, so i have solder two wires directly on the dev board pcb.

The purpose of all these experiments is make some hardware changes and new implementations to the final project that i will choose and then make an all-in-one pcb and make it public to anyone who wants to build it.

Gallery:

Video:

I continue the experiments with STM32 and the SID Player by Bakisha. I must thank Branko (Bakisha) for his patience and support.

I have added the LCD support (ILI9341) for the SID Player on the STM32F407VET6 DEV Board.

… and an external SID for the SID Player on the STM32F401CCU6 DEV Board.

I have used the ARMSID by Nobomi but it works quite well with a real SID 8580R5 too,  there are only a little problems of timing that need to be fixed.

STM32F407VET6 SID Player + LCD (ILI9341) Video:

STM32F401CCU6 SID Player + ARMSID Video:

I wanted to try Bakisha SID Player also with the STM32F407VET6 (previous post: STM32F401CCU6) ARM Cortex-M4 32bit MCU based Development Board which runs at frequencies up to 168MHz.

After some hardware and software changes i was able to use the SD Card support, buttons and LED on the pcb.

What i would like to do is install a TFT LCD screen compatible with this DEV Board and modify the software to display the various information that is now are sent via serial.

The MCUs that uses this DEV Board reaches a frequency of 168 Mhz and consequently i should not have problems of CPU overload taking away precious cycles times of the SID Player.

I leave you with some photos and a video.

Gallery:

SDCARD SDIO (Native) to SPI1 Pins:

Video:

source: github.com/Bakisha/STM32-SID-PLAYER

The Commodore parallel cable is a companion cable for the Commodore serial cable (IEC) and gives you an additional parallel connection between a Commodore 1541, 1570 or 1571 drive and a Commodore 64 machine or via XUM1541 (PROMICRO)/ZoomFloppy …

The cable is supported by the following Commodore software:

• The DOS accelerators Dolphin DOS and Speed DOS.
• The disk copiers 15 Second Copy, Burst Nibbler and Maverick.

VIA 6522 Fix:

With the Commodore 1541-II disk drive there’s still an open issue after the parallel cable installation, you need also to cut the track between the PIN1 and PIN2 of the VIA 6522 (the same VIA where the parallel cable is installed).

No more to say.

I leave you the links, good reading.

Gallery:

source: d81.de/R.I.P/Para1541II.shtml ist.uwaterloo.ca/~schepers/1541port.html

I’m not posting anything new, it simply something that i wanted to do from ten years, assemble the “project” Hackvision using Arduino, now i’m using a clone: ELEGOO UNO R3.

There is nothing more to say and like you can see from the photos the games run well.

The games are compiled with ARDUINO IDE with the TV-OUT library.

Gallery:

Electronic diagram:

source: nootropicdesign.com/hackvision/games/

STM32 (Arm Cortex MCUs) SID Player by Bakisha.

SID chip (6581 and 8580) and 6502 CPU emulator for STM32 (Arm Cortex MCUs). Compiled with Arduino IDE and uploaded with ST-LINK V2.

NOTE:

I have added to the original code of Bakisha the visualization of the 3 SID voices via 3 x Green LED.

Useless to write more about this, watch the video and the photos.

Special thanks goes to Bakisha for his work.

Components used for this project:

• 1 x BreadBoard.
• 1 x STM32F401CCU6 (STM32 Black Pill) or STM32F407VET6
• 18 x BreadBoard jumper.
• 1 x SD Card Module.
• 3 x Green LED.
• 1 x Resistor (100 Ohm)
• 1 x Capacitor (100 nF)
• 1 x Capacitor (10 uF – 16v)
• 1 x Potentiometer (10KOhm)
• 1 x Jack Audio 3.5 Female.

You can found the schematic here.

Gallery:

Video:

source: github.com/Bakisha/STM32-SID-PLAYER

A person in need of my help of which i have already repaired several devices has contacted me and asked if i could make a repair of one of his Commodore PET with two different trouble.

• The first fault was black screen on power up, meaning no image was displayed.
• The second fault that occurred after a couple of days was a raster video distortion of the CRT monitor accompanied by a smell of burning (see photo)

The first fault was solved by replacing the UD7 ROM (901465-02) with an eprom (2532), the correct functioning test could be done by connecting the LCD monitor that i use for repairs via a video adapter.

The second fault was brilliantly resolved by replacing the voltage regulator installed on the pcb monitor, a 7812 which on the pin output did not always return 12v but rather a mix between 3v, 6v, 10v.

I also removed some pieces of foam rubber (see photo) which due to the glue used has damaged the back of the monitor PCB leaving obvious traces of corrosion and a black sticky stain that i have removed.

I also rebuilt a missing pin of the ROM UF14 (901447-10) that someone had thought to fix in a very rough way (see photo)

Gallery of the repair:

Download:

• BASIC 2 - UD7 ROM (901465-02) (782)

Philips NMS 8245: The usual melted belt of the Floppy Drive.

Gallery:

Philips Videopac G7000 a little bit Dirty but Working. Nothing to write this time, just needed only a good clean up.

Gallery:

Dirty and Ruined Intellivision *Black Screen* repair.

It would not have been nice to put the intellivision in a very worn state and without a controller inside the spare parts box without even trying it :-)

Obviously the intellivision was not working, black screen.

The repair was simple, i have replaced the AM9114 (U8-B) RAM with a NEC 2114 and everything started working better than before :-)

I have also removed both labels in a pitiful conditions, now it looks better than before.

Gallery of the repair:

The restoration of the Sorcerer II of the Compudata (Exidy) was very simple, it was enough to replace all the tantalum capacitors with electrolytics one and make a good cleaning.

I tried the Sorcerer with the software downloadable at this link and to do a better understand the idea of the long loading (average 7 minutes) i have recorded the WAV file of the tape format on a Tape Cassette and used an old recorder to load the software, everything worked perfectly on the first try.

from Wikipedia;

The Sorcerer is a home computer system released in 1978 by the video game company Exidy.

It was comparatively advanced when released, especially when compared to the contemporary more commercially successful Commodore PET and TRS-80, but due to company focus on the coin operated video game marketplace resources were restricted for personal computer expansion and a separate division of the company was created.

Exidy Data Systems was headed by Paul Terrell to expand the product line to include small business computing with international distribution and technology license agreements to supplement corporate funding.

Distribution agreements with Dick Smith Electronics in Australia and Liveport in the UK as well as Compudata which included a manufacturing license to build, market and distribute the Tulip line of computers in Europe. Exidy sold the PC division to a Wall Street firm, Biotech, in 1983.

Gallery:

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