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 (949)
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 (903)
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:
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 (909)
source: csdb.dk
Batch of repairs in one week (report):
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.
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:
We begin to explain what is this PHA-2037. This interface/Converter for the Home Computer Texas Instruments TI-99/4a is used to convert the video signals from Component (Y/Pb/Pr) to RGB (Scart Standard).
The defect of the PHA-2037 that i have received for repairing is to display images without the “BLUE” color in this case of the Video Component “Pb”.
The problem was in one of the three LM 318 (Op Amp). Just replaced, the PHA-2037 has begun to work properly.
PS: How you can see from a photo a pin of a transistor has not been cut. Maybe it was better to do it. :D
Gallery of the repair:
Some new games or tools (Cracked / Trained or Unrealeased) for Commodore 64 have been released from your favorites groups.
Titles:
- Hyper Circuit +23D
- The Catacombs of Cherubim +4
- Rust’n'Steel +4C
- Yloa’s Complex Preview
- Qualot +3E
- Rogue Preview
- Voivod Attack +22D
- Yloa Preview
- Hummdinger +18D
- Block’n'Tropic +6
- Urban Warrior + [seuck]
- Energy Warrior +20D
- Yucatan +27D
- Girlguard Preview [german]
- Alley Cat +18D
- Quak Attak +18D
- Block’n'Tropic +6
- Zodiac +23D
- Kong 64 +28D
- Que +2
- Dragonfire +2DGMF 101%
- Code Hunter +17D
- Ladybug 2015
- Ladybug 2015 +1H
- Dragonfire +2F 101%
- Chicken Chase +15D
- Denarius +28D
- Quantarallax Preview +2
- Sputnik Preview
- Wildfire Preview
- Worron +3
- Flimbo’s Quest Preview +2
- Galax-i-birds +27D
- Nuker Preview V2 +4
- Firefighter Mario +3
- Łazik
- Frogger Arcade Preview
- Robocop +8DFHIR 101%
- Squirm 2 Preview
- Robotfindskitten
- Vault Man 2 Preview
- Ferris’s Christmas Caper +17D
- Cosmic Warrior +1 [inglish]
- Robo +
- Squid Jump Preview
- Slither X +1
Download: All Games in One Archive (3490)
source: csdb.dk
The High Voltage SID Collection (HVSC) is a freeware hobby project which organises Commodore 64 music (also known as SID music) into an archive for both musicians and fans alike.
The work on the collection is done completely in the Team and contributors’ spare time and is proudly one of the largest and most accurate computer music collections known.
This update features (all approximates):
- 672 new SIDs
- 132 fixed/better rips
- 5 repeats/bad rips eliminated
- 812 SID credit fixes
- 133 SID model/clock infos
- 10 tunes from /DEMOS/UNKNOWN/ identified
- 4 tunes from /GAMES/ identified
- 22 tunes moved out of /DEMOS/ to their composers’ directories
- 12 tunes moved out of /GAMES/ to their composers’ directories
Download:
source: www.hvsc.c64.org
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