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) (635)

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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Texas Instruments TI-99/4A Repair.

Defect:

• Garbage boot screen.

Replaced parts:

• 2 x TMS4116-15 RAM (U102 / U105)

Gallery of the repair:

This Amiga 4000 is completely devastated on both sides of the PCB by the leaked acid of the battery and kept in a humid room for at least 20 years.

There are still a couple of things to keep, but i will do it later if necessary.

First of all, a premise: All the repairs i do are for hobby purpose ONLY. It is NOT a job, and i fix stuff for a selected people group that i consider needs my help. All other people please ask somewhere else to get your items repaired back.

A guy contacted me asking help for a repair and after an exchange of messages i agreed to repair his Amiga 4000 which at boot only displayed a Black screen.

I immediately noticed a fairly important damage caused by battery and caps acid leakage.

After cleaned everything and replaced capacitors on motherboard / 3640 and PSU (the fault persisted, of course).

Next, i used the Chucky DIAGROM: the DIAGROM is useful to understand what might be that doesn’t work, and the output via RS232 is also very useful if nothing is displayed on the screen.

Unfortunately the DIAGROM worked partially because the mouse was completely dead and therefore i have used the output via Serial but this is also worked partially because evidently also the serial is dead but in some precarious moments i  have tried to run the Sound test and no sound was reproduced.

Moral: Partially working Serial port + Mouse not working + Audio not working = Paula.

Replaced the PAULA (U400) everything started to work correctly apart the FASTRAM with 4 x 4MB SIMM modules each the system sees only 2 in the U852/U853 positions for a total of 8MB.

The problem was a short circuit probably caused by the acid leaking from the battery, i had to clean the PCB for the tenth time and the problem was fixed.

No more other to say, except that i am happy i succeeded to repaired this Amiga 4000 for a person that needed my help.

Gallery of the repair:

12►

Video:

Texas Instruments TI-99/4A Repair (1 of 6)

Defect:

• Black Screen and deafening sound in background.

Replaced parts:

• 1 x TMS 4732/2532 ROM (U610)

—————————————————————————————————————————————————-

 Texas Instruments TI-99/4A Repair (2 of 6)

Defect:

• Black Screen and deafening sound in background.

Replaced parts:

• 1 x MCM 6810P (128 x 8-Bit Random-Access Memory TTL/DTL) (U608)

—————————————————————————————————————————————————-

Texas Instruments TI-99/4A Repair (3 of 6)

Defect:

• Black Screen and deafening sound in background.

Replaced parts:

• 1 x 74LS138 (U504)
• 1 x 74LS138 (U505)

—————————————————————————————————————————————————-

Texas Instruments TI-99/4A Repair (4 of 6)

Defect:

• Black Screen and deafening sound in background.

Replaced parts:

• 1 x TMS 9900NL CPU (U600)

—————————————————————————————————————————————————-

Texas Instruments TI-99/4A Repair (5 of 6)

Defect:

• Garbage Boot Screen.

Replaced parts:

• 1 x TMS4116-15 RAM (U106)

—————————————————————————————————————————————————-

Texas Instruments TI-99/4A Repair (6 of 6)

Defect:

• Various problems with audio playback.

Replaced parts:

• 1 x SN76494N – Digital Complex Sound Generator (U511)

—————————————————————————————————————————————————-

There are not many interesting things to recover, for example the 256k x 4 ZIP Ram are absolutely useless.

So what i have recovered that could helpful (never) is the Motorola 68030RC20B CPU, the 68882RC25 math coprocessor and 3 x Clock Oscillator.

Gallery:

This monitor is the PAL predecessor to the Commodore 1802. It appears to be a contemporary of the CM-141 and the brown-casing 1802. They both have dual inputs (Composite video/audio, and chroma/luma/audio) with a switch in front to select between them.

The Monitor although in excellent condition don’t work correctly, the image displayed was in black and white.

The problem was the oxidation of a little trimmer (see photo / orange trimmer) and it was enough to turn it a bit and put it back in its original position.

Other small defects fixed:

• Bad geometry – Calibration of the Deflection yoke.
• Out of Focus – Calibration Trimmer Focus on Flyback.
• V-HOLD fine adjustment on the Monitor PCB.
• Glued a piece of plastic broken at the base of the monitor.

Gallery:

12►

Download: Commodore Monitor Model 1801 Instruction Manual (775)

source: gona.mactar.hu/Commodore/monitor/