This is a short story of the Roland MT32 Midi repair.

The MT32 MIDI interface had an annoying audio problem (you can listen to the audio files attached to this post).

It seemed like the classic problem of exhausted electrolytic capacitors, but instead it was due to the ROM ROLAND R15449121 (TC534000P) position IC37.

To replace the original ROM it would have been enough to use an OTP Eprom 27C040 which however i didn’t have in the laboratory so i used a FLASHROM AM29F040 by modifying some connections.

The filename of the file used to program the FLASHROM is “r15449121.ic37.bin” which you can find in the archive attached to this post.

Below is the documentation how to adapt the AM29F040 instead of a 27C040.

• Atmel AT27C040 – 4Mb (512K x 8) OTP, EPROM (32-pin Package)
• Amd AM29F040 – 4Mb (512K x 8) FLASHROM (32-pin Package)

Tie 29F040 WE (PIN 31) and connect to VCC (PIN 32)
Tie 29F040 A18 (PIN 1) and connect to PIN 31 on Socket or PCB

Monkey Island Audio difference before and after repair:

• Before the Repair (282)
• After the Repair (281)

Gallery:

Download: Roland MT32 (various OS and extra ROMs) (375)

source: Synth Eprom Dumps

SD-1000/PiCOLECO/PiRTO-II are Flash Multicarts for Sega SC3000/SG-1000,CBS ColecoVision,Mattel Intellivision by Andrea Ottaviani based on the cheap version of the Raspberry Pi Pico clone (purple PCB).

I wanted to try and assemble this interesting project and i must say that i was very satisfied. I also contacted Andrea for a small problem of loading the ROMs for the Multicart Intellivision and he was immediately available even though it was Sunday lunch time :-)

I assembled two Multicarts for each console model because as soon as i informed my friend Andry about this project he wanted them too :-D

The Multicarts you see in this article are NOT for sale, for more information about firmware,flashing fw,gerber,3D case model i recommend you visit the github site where these projects are published.

• SD-1000: https://github.com/aotta/SD-1000
• PiCOLECO: https://github.com/aotta/PiCOLECO
• PiRTO II: https://github.com/aotta/PiRTOII

How much did i spend for each multicart?

• 6 x Raspberry Purple Pi Pico clone (Aliexpress): €18.12
• 5 x JLCPCB PiCOLECO PCB: €1.87
• 5 x JLCPCB PiRTO II PCB: €3.74
• 5 x JLCPCB SD-1000: €3.74
• 1 x JLCPCB Shipping Charge: €6.66
• 1 x JLCPCB Customs duties & taxes: €3.52
• 1 x JLCPCB PAYPAL FEE: €0.47
• 6 x Diode 1N4148 (spare parts)
• 2 x Transistor BC547 (spare parts)
• 2 x Angled Push Button (spare parts)
• 4 x Push Button (spare parts)

More or less for each single Flash Multicart complete with all components you will spend around €6.00.

This includes the components that i already had at home and the minimum order from JLCPCB for each PCB which are 5 pieces, as a result i did the division on the JLCPCB invoice total.

Download the ROMs for Sega SC3000/SG-1000, ColecoVision, Intellivision (including CFG mappers) fully renamed and divided into folders in alphabetical order here.

Flash Multicarts Cartridge Case Shell Cover:

The last photo with a small modification of the hole to insert colored button covers.

 

How to update the firmware with the case closed? You have to press the button on the PI Pico Purple while inserting USB-C for firmware updating.
Totally excluded unscrewing and retightening the screws each time, so 1.5mm micro hole in the right position, perfect.

 

 

Gallery:

12►

I wanted to remake the RGB connections of my CBS ColecoVision console a bit and design a new diagram for connecting the RGB video output.

This console was sold with an external modulator (CBS Electronics Adaptateur Antenne 7466 – 6F) that converted the signal from RGB to RF and it seems a Scart cable was not provided for direct connection to the television.

The original ColecoVision D-SUB DB15 to Scart cable that i have doesn’t have the correct pinout but it works perfectly with another ColecoVision always with RGB output but with an internal encoder that converts the Y (B-Y) (R-Y) to RGB signals (PAL Secam Converter A).

This fact is really curious, apparently there are more versions with RGB output as well as RF.

I decided to remove the old RGB cable that i soldered internally about 15 years ago and replace it with an RGB cable connected to the Coleco native connector.

The problem with doing this operation has always been the D-SUB DB15 connector which must be of a certain size, otherwise it won’t fit.

Brilliantly solved using a SNK NeoGeo Joypad extension cable, where we have a DB15 D-SUB connector pre-cast in the plastic where all 15 pins are used (in theory only 14 are needed for the NeoGeo Joypad, but all 15 are connected)

I cut the cable from the neogeo joypad male connector side and soldered the wires to a Scart connector and for the Fast Switching signal before connecting it to pin 16 of the scart i used a 100ohm resistor in series, i did not use the Function Switching signal.

One more thing, the Audio signal from the console native RGB connector is very low, so i made a jumper (see photo) to bypass a resistor and a ceramic capacitor, therefore i took the audio directly from PIN 7 of the SN76489 (Sound Generator).

Of course everything works perfectly.

Gallery of work done:

.- the inexpensive dual-SID/FM replacement that you can build yourself -.

SIDKick pico by Frenetic is a microcontroller-based C64 SID replacement. Analog inputs for paddles and mice are available just as for the original SID.

Changelog:

• This release contains the fix for the NTSC-specific bug of firmware version 0.20.

Note:

There are different .uf2-files are firmware files with PWM and/or DAC output, flashing (RGB-)LED on/off AND for hardware revision 0.1 and 0.2.

Review:

My SID Player plays SID tunes with the SIDKick-pico.
SIDKick-Pico by Frenetic.

Download: SIDKick-Pico Firmware v0.201 (317)

source: c64-wiki.com github.com/frntc/SIDKick-pico restore-store.de