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Kernel JiffyDos Installation and Keyboard Repair for my friend Damiano (manosoft.it). To repair the keyboard you must clean the contacts very well on the pcb.

Powerup and Testing my Sinclair Spectrum 128k (RGB with Bright MOD) after a long time.

Video:

I received this computer to be repaired for a friend some days ago. The computer displays only a black screen and some times a random character without any sound beep at the startup boot.

I have replaced the PLA IC 324745-01 (UE5) and 324744-01 (UE6) with two EPROM 27C512 70ns (suitably programmed), the Universal PLA adapter was kindly donated by Manosoft.

The computer also had another defect, apparently the fault was not only in the two PLA. The computer starts with the classic beep but the screen remain black, the faulty is the IC 6545 (CRTC) and that was replaced.

This model uses a ROM daughterboard instead of a single 23128 ROM (EPROM 27C128 pinout compatible). I have made an adapter to preserve the original state of 8296 and allow the insertion of the daughterboard after the replacement of the two PLA that are different (in size) to the original one.

Have been replaced 4 tantalum capacitors short-circuited with 4 electrolytic capacitors. The computer has been tested and works perfectly.

I have gathered all photos of some phases of the work that i have done on the Atari 1200XL.

Below the descriptions:

• SIO 5v Enabled (you have to short-circuit the resistor R63 to get the 5v on the SIO of the Atari 1200XL)
• Repairing Keyboard (i have stretched the springs of a few keys for make the right pressure. The work must be completed using the liquid graphite where the contacts are more ruined)

I have gathered all photos of some phases of the work that i have done on the Tatung Einstein TC01.

Below the descriptions:

• Replaced 2 x 74LS157 (IOO6/IOO7) Multiplexer.
• Replaced UK Power Connector.
• Repaired some not working keys.
• External Floppy Drive 3.5″. Yes, it’s better than 3″ ;-D

Todo:

• Repair the defect of the vertical sync of the Monitor Tatung TM01

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I have gathered all photos of some phases of the work that i have done on the TRS-80 Model 1.

Below the descriptions:

• Cleaning of Nicotine.
• Replaced a bad capacitor.
• Testing.
• Floppy Drive before restoration.
• Replaced Australian Power Connector of the Floppy Drive.
• Restoration phases of the Floppy Drive.
• *Making the floppy disk for TRS-80 Model 1.
• Audio patch cable to hear the sound of the games.

*Is not been easy to make the Floppy for the TRS-80 Model 1 SSSD 35 TRK in FM format. Fortunately i have a old motherboard Pentium 133 with the right IO chip that supports writing format: MFM / FM SSSD.

Download: Some TRS-80 Model 1 games in ImageDisk format. (1121)

Video:

• Radio Shack TRS-80 Model 1 (Testing Floppy Drive)
• Radio Shack TRS-80 Model 1 (Frogger with Sound)
• Radio Shack TRS-80 Model 1 (Attack Force with Sound)

I have received this computer Commodore CBM 8296-D 1 year ago. The computer has never worked, it only displays a black screen without any sound beep at the startup boot.

The repair it was very simple, i have replaced the PLA IC 324745-01 (UE5) and 324744-01 (UE6) with two EPROM 27C512 70ns (suitably programmed). The Universal PLA adapter was kindly donated by Manosoft.

Download:

• PLA Rom 8296(D) (870)
• EDIT Rom 324243-02b (860)

Sorry, this entry is only available in Italian.

I was very lucky in this repair, the fault is a broken belt that is used for the operation of the Floppy “Quick Disk”.

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I post some screenshots and a video of the repairing of a NEC PC-Engine LT console.

Defect in the console:

Some capacitors have leaked acid on the pcb, i had to clean with the right product made especially for cleaning the pcb before proceeding with the replacement operation. The LCD screen is was disassembled to remove the dirt inside.

This is a little description of the repair of a Radio Shack TRS-80 Model 1 for a Friend.

The computer comes with several problems.

• Some IC are dead or in shorted state.
• Keyboard flat cable.
• One key “L” is dead.

Finding the cause of the fault has not been easy, i had to ask for a help to Ian, this dude is an expert of TRS-80 repairs.

How you can see from the photos, i had to replace a number of IC.

• 4 x Video RAM 2102 (Z62 / Z63 / Z46 / Z48)
• 1 x Z80 (Z40)
• 1 X 74LS157 (Z31)
• 1 X 74LS93 (Z32)

Stage of the defect (before and after):

Keyboard repair (replacement of internal contacts):

Micro Computer Technical Reference Handbook:

Download: {title} ({hits})

I have customized the keyboard of my C64 with my alias. I have used some keys of a broken C16.

This is the story of a Commodore CBM (PET) 3032 recovered in a pitiful state.

The motherboard was covered of rust and many IC are in short circuit. I had to replace some IC (broken or full of rust), rebuild some paths of the pcb and clean very well.

I have also restored the inside of the case, using an anti-rust gel painting.

Photos and Description of the work made:

Read more…

This is a Video RGB Hack for the console Sega SG-1000 II (Mark 2).

The Sega 315-5066 Video Chip inside the Sega SG-1000 II (Mark 2) used in the latest version of the console uses two video output formats: NTSC Composite video (converted to RF), and RGB (not connected).

The RGB Video is the stuff from which all other formats are born. Once your RGB is tapped it can be easily converted to Component or S-video, giving stunning output far superior to what the Sega SG-1000 II natively offers (only RF).

There are several caveats, of course. The biggest is the quality of the RGB output – it’s not very bright, and will result in an image without much contrast, so you will probably need to add an amplifier. Even on monitors that display a very good image without the amp you’ll sometimes find the sync signal needs an amp to generate a stable image.

I have used the same RGB/Sync Amplifier used on the PC-Engine, components and the Original schematic are shown below.

Schematic:

Components:

• 4 x 2SC1815 (Transistor)
• 4 x 220 μF 16v (Electrolytic capacitor)
• 4 x 10 μF 16v (Electrolytic capacitor)
• 4 x 75 Ω (Resistor)
• 8 x 10 KΩ (Resistor)
• 1 x 300 Ω (Resistor)

The three photos below show the connection between the RGB Amplifier and the PCB of the Sega SG-1000 II.