Archive

Posts Tagged ‘repair’

Another Gotek (HXC) with some Enhancements

August 5th, 2018 No comments
Another Gotek (HXC) with some Enhancements

Another Gotek (HXC) with some Enhancements.

Enhancements:

  • OLED Display
  • Piezo Buzzer
  • Push Button for select
Another Gotek (HXC) with some Enhancements

Credits for the best firmware Jean-françois Del Nero.

Sony HITBit HB-75P (Keyboard repair)

July 15th, 2018 No comments
Sony HITBit HB-75P (Keyboard repair)

Sony HITBit HB-75P (Keyboard repair).

Defect:

  • Some keyboard key doesn’t work (3, MINUS, Q, SPACE, CODE [DX]).

Fix:

  • Cleaning the PAD inside the Key Switch.
  • Redone the soldering of the pcb pad (space switch) that was broken at the base.

Gallery:

Sony HB-F1XD (MSX2) Audio Repair

July 15th, 2018 No comments
Sony HB-F1XD (MSX2) Repair

Sony HB-F1XD (MSX2) Repair.

Defect:

  • Missing Sounds.

Replaced parts:

  • 3 x SMD Capacitors. (2 x 10uF – 1 x 100uF) on the Audio/Video Encoder PCB.

Gallery of the repair:

Download: Sony HB-F1XD (MSX2) Technical manual (33)

Commodore Amiga 1200 Full Recap

July 15th, 2018 No comments
Commodore Amiga 1200 Full Recap

Commodore Amiga 1200 Sostiuzione Condensatori.

Gallery:

Hantarex PCB Coin-OP Monitor Full Recap

July 15th, 2018 No comments
Hantarex PCB Coin-OP Monitor Full Recap

Hantarex PCB Coin-OP Monitor Full Recap.

Not very funny but someone has to do it. 8-)

Retro Things to be repaired for some friends

July 6th, 2018 No comments
Retro Things to be repaired

Retro Things to be repaired for some friends.

  • 1 x Amiga 1200 (Full Recap)
  • 1 x Atari 800 XL (don’t runs anything)
  • 1 x Atari 1010 (check)
  • 1 x Commodore 1571 (freezed/error)
  • 1 x Hantarex PCB Coin-op Monitor (Full Recap)
  • 1 x Sony HITBit HB-F1XD MSX2 (missing sound)
  • 1 x Sony HITBit HB-75P (keyboard problem)

Commodore VIC-20 (ASSY 250403) Repair

Commodore VIC-20 (ASSY 250403) Repair

Commodore VIC-20 (ASSY 250403) Repair

Defect:

  • Black Screen.

Replaced parts:

  • Replaced MOS 65245 [74LS245] (UF8)

Gallery of the work done:

Commodore 128 (REV 310381) Repair

May 3rd, 2018 1 comment
Commodore 128 (REV 310381) Repair

Commodore 128 (REV 310381) Repair

Defect:

  • Black Screen.

Replaced parts:

  • Replaced 74LS08 (U61)
  • Replaced CPU 8502R0 (U6)
  • Replaced PLA 8721R3 (U11)

Gallery of the work done:

Phase5 CyberStorm MK2 @ 100Mhz (040 Hack – Stable)

March 18th, 2018 No comments
Phase5 CyberStorm MK2 @ 100Mhz (040 Hack - Stable)

Phase5 CyberStorm MK2 @ 100Mhz (040 Hack – Stable)

This is a simple hack to overclock the Cyberstorm MK2 at 100Mhz without needed adapters or simply replacing the oscillator which causes instability or malfunctions.

The hack consists downgrading the Cyberstorm MK2 to 040 simply by moving the two resistors can you see marked in the photos.

For some CPU or MK2 models it is also advisable to replacing the original voltage regulator LT1085CM at 3.3v with this one LT912CM 3.5v but if the amiga is stable after hours of operation you can also avoid the replacing the voltage regulator.

Gallery of the work done:

source: Cosmos Blog

Commodore Amiga 4000 – 64Mb Fast Memory Hack

March 18th, 2018 No comments
Commodore Amiga 4000 - 64Mb Fast Memory Hack

Commodore Amiga 4000 – 64Mb Fast Memory Hack.

The Amiga 4000 motherboard can be ´hacked´ to handle 64Mb of Fast Memory (4 SIMM modules of 16 MB each)

To do this, you have to solder a new GAL and make some bridges between FASTRAM SIMM -> GAL -> CHIP RAMSEY.

This work is not complicated but you need to have a good practice with the soldering iron and PLCC soldering.

Gallery of the work done:

Download: Amiga 4000 64Mb Hack (572)

source: Cosmos Blog John Hertell Blog

Upgrading Commodore A3640 CPU Card (part two)

March 18th, 2018 No comments
Upgrading Commodore A3640 CPU Card (part two)

Upgrading Commodore A3640 CPU Card (part two)

I have replaced the CPU 060 EC version with a 060 FULL with FPU REV 1.

When using the adapter with a non EC version of the 060 you must also use a fixed version of the kickstart v3.1 with the exec.library modified to support the FPU.

Gallery of the work done:

Download: Kickstart v3.1 Exec Patch Version for 3k & 4k - Ready to Burn! (675)

Upgrading Commodore A3640 CPU Card (part one)

March 18th, 2018 No comments
Upgrading Commodore A3640 CPU Card (part one)

Upgrading Commodore A3640 CPU Card (part one)

Works that have been done:

  • Upgrading GAL (U204 & U209)
  • Socket for Oscillator.
  • Overclocking.
  • Replacing all capacitors (the recap was already done but for the CPU adapter 040 -> 060 was necessary use smd capacitors for the little space available)
  • CPU Adapter 040 -> 060.
  • CPU Motorola 68EC060

Gallery of the work done:

Amiga 4000 repair with Floppy Drive that is not recognized

March 18th, 2018 No comments
Commodore Amiga 4000 repair with Floppy Drive that is not recognized

Commodore Amiga 4000 repair with Floppy Drive that is not recognized.

Defect:

  • Floppy Drive Dead (not recognized)

Repair:

  • Replace CIA 8520 (U300).

Gallery of the work done:

Commodore Monitor 1084S-P Repair

March 5th, 2018 No comments
Commodore 1084S-P Repair

Commodore Monitor 1084S-P Repair.

Defect:

  • Completly dead with only a loud whistling noise in background.

Repair:

  • Replaced the flyback transformer (AT2079/30102) everything has started to work perfectly.
  • It’s mandatory to made a calibration of the SCREEN and FOCUS with the two trimmer placed on the rear side of the flyback transformer.

Note:

A loud whistling noise indicates a bad flyback transformer (also known as an LOPT).

Gallery:

Download: Commodore Monitor 1084S-P Schematics (219)

Commodore 8032 / CompuThink Disk Drive / Woltron ROM-BUS

February 14th, 2018 No comments
Commodore CBM 8032 (HP - Early version 1980) - CompuThink Disk Drive Controller - External Dual Disk Drive - Woltron ROM-BUS Adapter

Commodore CBM 8032 (HP – Early version 1980) – CompuThink Disk Drive Controller – External Dual Disk Drive – Woltron ROM-BUS Adapter.

  • COMPU/THINK (CompuThink) Dual Disk Drive Controller with 8k RAM per commodore PET 8032 (It could be a Prototype or a Clone Board with ASSY 001-35 – DD DSK CTL COMP).
  • COMPU/THINK External Dual Disk Drive 800k DD/DS.
  • WOLTRON ROM (CompuThink C-DOS & TOOLKit) + PET/CBM Expansion BUS Adapter + PIA (Peripheral Interface Adapter) Motorola MC6821.

Unfortunately there is no documentation on the net of this Computhink card that seems to be a prototype or a clone, also there is no documentation or photos of the BUS/ROM Adapter by Woltron.

I spent sleepless nights looking for the starting SYS for the disk management software on the eprom, i have disassembled 24k of code (C-DOS Roms / Basic Roms Patched / Edit Roms Patched) in machine language.

I did it and found it the starting sys ($E790 – SYS 59280), although everything seems to work perfectly after the sys command is printed on the screen (*DOS-40*) and by typing the directory command ($d,1) or the format command ($f,1) the floppy starts to run correctly but the head does not move, while the exit command ($h) work correctly,
i need to say that i replaced the FDC1791 and some floppy disk logic and also one floppy disk drive, but nothing changed.

My suspicion falls on the PROM 82S123 there is no dump on the net, reading this PROM of 32 bytes, only the first 8 Bytes are filled, this is right ? we’ll never know.

All EPROM and PROM have been dumped and you can find them in the archive below.

Gallery:

Download: C-DOS 4.0 - Basic/Edit Roms Patched - PROM 82S123 (179)