Someone has to do this tedious job and also i advise you do not postpone the capacitors replacement.

Macintosh Recap:

• 1 x Macintosh Portable
• 1 x Macintosh SE (battery removed)
• 1 x Macintosh LC520
• 1 x Macintosh Color Classic

Gallery of the Macintosh Recap:

A new donation from Paolo Cognetti.

Donated items:

• ZX Spectrum + (Complete/Boxed) with keyboard problems
• Philips MSX Printer VW-0010
• Philips MSX QuickDisk VY-0002
• Apple II/II+ Joystick
• ABT Apple II+ External Keypad
• ZX Spectrum + Manual
• SCSI Iomega ZIP Drive + Cable
• Some ZX Spectrum Tape Cassette
• Macintosh Plus Motherboard
• Some PCMCIA Cards

Thanks Paolo.

Repairing Radio Shack TRS-80 Model 1 ..for the third time

Defect:

• SHIFT keyboard switch broken.
• Garbage Screen on boot (already repaired).
• Flat cable of the Keyboard broken (already repaired)

Repair:

• Replaced the keyboard switch with a new one taken from a keyboard (the good one) of the Texas Instruments TI-99/4A that helps me many times.
• Replaced a 2102 Video SRAM.
• Rebuilt the keyboard flat cable.

Gallery of he repair:

We had a few problems yesterday with the firewall which has caused a bit of site downtime. We’re very sorry now the problem was fixed.

Forth, the Language.

Forth is a different language. It’s aged and a little weird.
What’s cool about it? It’s a very low-level and minimal language without any automatic memory management. At the same time, it easily scales to become a very high-level and domain-specific language, much like Lisp. Compared to C64 Basic, Forth is more attractive in almost every way.

It is a lot more fast, memory effective and powerful. Compared to C, specifically cc65, the story is a little different. It’s hard to make a fair comparison. Theoretically Forth code can be very memory efficient, and it’s possible to make Forth code that is leaner than C code. But it is also true that cc65 code is generally much faster than Forth code.

Download: durexForth v1.5.2 + Manual (940)

source: csdb.dk

Forth, the Language.

Forth is a different language. It’s aged and a little weird.
What’s cool about it? It’s a very low-level and minimal language without any automatic memory management. At the same time, it easily scales to become a very high-level and domain-specific language, much like Lisp. Compared to C64 Basic, Forth is more attractive in almost every way.

It is a lot more fast, memory effective and powerful. Compared to C, specifically cc65, the story is a little different. It’s hard to make a fair comparison. Theoretically Forth code can be very memory efficient, and it’s possible to make Forth code that is leaner than C code. But it is also true that cc65 code is generally much faster than Forth code.

Download: durexForth v1.5.1 + Manual (893)

source: csdb.dk

Jungle King Coin-op – Taito Original – Insert Coins Workaround-Fix

Defect:

• The game works only in Demo mode because doesn’t work the insert coins switch.

Solution:

• I followed a guide that i have found online where recommend to cut the pins 3-4-9-10 of the IC 74LS08 (IC28) which is just below the little ROM PCB (no bootleg). This problem or bug is present on both version, original or bootleg of Jungle King.

Gallery:

source: wiki.aussiearcade.com.au

The HxC Floppy Drive Emulator is a software and hardware system created by jfdn aka Jeff.

The aim of this project is to replace the floppy disk drive by an electronic device emulating the floppy disk drive (list of supported Computer/Hardware).

There are two differents emulators:

• A USB version which allows to connect the floppy disk drive interface of the computer to a PC via a USB cable.
• A SDCARD version which allows to emulate floppy disks which images are stored in a SDCARD.

Release notes for the HxCFloppyEmulator software v2.1.4.0:

• New Loader : *.ANA AnaDisk file loader.
• New Loader : VFDDAT file loader.
• New Loader : Densei Sirius VFD DAT Loader.
• New Writer : *.DIM writer.
• New Writer : *.ADZ writer.
• New Writer : *.TRD Writer.
• New Loader : Atari ST *.STW Loader.
• New Writer : Atari ST *.STW Writer.
• New Writer : Atari ST *.ST Writer.
• New Writer : Atari ST *.STX Writer.
• STX Loader/Writer : Flakey bits mask support added, Loader/writer improved.
• SCP Loader/Writer : Loader/writer improved.
• D88 Loader : Gap3 setting corrected.
• Dos disk browser : More disks layouts.
• libhxcfe : New track support : AED6200P.
• XML format definitions : Mictrotan 65 TANDOS.
• Flux Stream Analyzer : Possible segmentation fault corrected.
• Flux Stream Analyzer : Input filtering reduced.
• Kryoflux Stream Loader (*XX.X.raw) / analyser : NFA over index support added.
• Track editor : Add & Remove track functions added.
• Track editor : RPM & Bitrate change functions added.
• Track editor : Insertion function added.
• Track editor : Negative offset support.
• Disk viewer : Image CRC32, library version and file name displayed.
• Disk viewer : Track(s) type displayed.
• Disk viewer : Cells density displayed.
• Progess bar added for the loaders/writers.
• SD/USB Emulator setting window : Advanced pinout settings added.
• Code sources fixes/changes for GCC, Clang and VS2015 x86 & x64 compilation support.
• And many more fixes and improvements..

Download:

• HxC Floppy Emulator Software v2.1.4.0 (1758)

source: hxc2001.free.fr lotharek.pl

Forth, the Language.

Forth is a different language. It’s aged and a little weird.
What’s cool about it? It’s a very low-level and minimal language without any automatic memory management. At the same time, it easily scales to become a very high-level and domain-specific language, much like Lisp. Compared to C64 Basic, Forth is more attractive in almost every way.

It is a lot more fast, memory effective and powerful. Compared to C, specifically cc65, the story is a little different. It’s hard to make a fair comparison. Theoretically Forth code can be very memory efficient, and it’s possible to make Forth code that is leaner than C code. But it is also true that cc65 code is generally much faster than Forth code.

Download: durexForth v1.5.0 + Manual (893)

source: csdb.dk

In the Commodore Pets and CBMs, ROM expansion area is available in empty sockets on the main logic board. These sockets are addressed as 4K byte blocks and are used by many of the software packages available for Pet and CBM!.

These include the Commodore Word Processors, the BPI business package, VISICALC from Personal Software, Inc., Rabbit from Eastern House Software, BASIC Programmers TOOLKIT from Palo Alto ICs, Sort from Matric Software, Inc., and many others.

Several of these ROMs are to be installed in the same ROM socket within the Pet. Spacemaker II is a utility device which allows switching of up to four ROMs into any socket from a single board. Since Spacemaker II is jumper programmable for each of its four ROM sockets.

ROM type may be different for each socket. Switching can be done with a side mounted switch or via ROM DRIVER, an accessory device which allows software and keyboard control of ROM selection.

Spacemaker II is also available for changing character sets with Math or Foreign language ROMs available from West River Electronics.

Gallery:

Download: MicroTech - SpaceMaker II Manual (1057)

Batch of repairs in one week (report):

• 1 x Amiga 500 (Green screen of death – Replaced 4 x DRAM)
• 1 x Amiga 500+ (Leaked battery acid – Cleaning / Replaced GARY socket)
• 1 x Amiga 600 (Distorted Clipped Saturated audio – Replaced LF347 / Total Recap / Cleaning)
• 2 x Amiga 600 (Total Recap / Cleaning)
• 2 x Amiga 1200 (Total Recap / Cleaning)
• 1 x Texas Instruments PHA-2037 (Missing Pb Component Video Signal – Replaced LM318)

The problem is quite simple to find. You have to make some measurements on the LF347 (Op AMP) with the computer running and without sound.

You have to measuring pin 1 and pin 7 and should have a voltage of about 2.5V if the voltage as in my case is of 11.30v and 11.37v. Something is not working.

After replacing the LF347 with a LM324 or better a TL084 the right voltages are back and the sound works again.

Gallery of the repair:

*UPDATE*

After a couple of days, i have realized that the Amiga 600 still had some problems with the sound, although subtle but annoying and after a few measurements i have concluded that the LM324 is not fully compatible and cannot replace the LF324 (at least on the Amiga 600/1200).

After removing the LM324 and replaced with a TL084 everything has started to work much better than before.

This is the latest version of C64c and was cost reduced even more.

Instead of a metal plate on the top there is the logo only engarved in plastic case itself.

The keyboard has been held on the upper housing part with brackets (not with screws as normal). In addition, the housing itself was only held together with clamps.

Gallery:

source: scacom.bplaced.net/Collection/64/

I have done an accurate cleaning of the leaked battery acid on the mainboard.

I have also replaced the GARY socket destroyed by battery acid and rebuild a pcb track with a wire.

Gallery of the repair:

The problem of the green screen of death is usually due to a problem of DRAM,FAT AGNUS (chip or socket), GARY.

In this case all four DRAMs are failed. The pin 18 (IO/3) was always at high level.

Replacing DRAM everything has started to work properly.

Gallery of the repair: