The composite video mod for the computer Microdigital TK-83 unlike the Sinclair ZX81 it’s more easier.

You no need to install the usual transistor with 1 or 2 resistors / capacitor. The transistor is already installed on the motherboard of the Microdigital TK-83, so just pick up the video signal as described in the picture.

I remind you that the output signal will be in NTSC standard for the Microdigital TK-83 produced in Brazil (PAL-M)

Autopsy:

12►

from Wikipedia:

TK83 was a Sinclair ZX81 clone made by Microdigital Eletrônica Ltda., a computer company located in Brazil.

The TK83 had the ZILOG Z80A processor running at 3.25 MHz, 2 KB SRAM expandable up to 64 KB and 8 KB of ROM with the BASIC interpreter and a Joystick port. The keyboard was made of layers of conductive (membrane) material and followed the Sinclair pattern. The video output was sent via a RF modulator to a TV set tuned at VHF channel 3, and it featured black characters on a white background. The maximum resolution was 64 x 44 pixels black and white, for graphic plotting. There were some special characters (shade patterns) useful for games and basic images.

Although being a ZX81 clone, the TK83 did not have the ULA chip from Ferranti, used in the former. Instead it was manufactured with a dozen of TTL integrated circuits, which resulted in a somewhat large power consumption. This could be noted as the computer’s case used to become quite hot after some minutes of operation.

source: wikipedia

Autopsy:

123►

from Wikipedia:

The Amstrad CPC (short for Colour Personal Computer) is a series of 8-bit home computers produced by Amstrad between 1984 and 1990. It was designed to compete in the mid-1980s home computer market dominated by the Commodore 64 and the Sinclair ZX Spectrum, where it successfully established itself primarily in the United Kingdom, France, Spain, and the German-speaking parts of Europe.

The series spawned a total of six distinct models: The CPC464, CPC664, and CPC6128 were highly successful competitors in the European home computer market. The later plus models, 464plus and 6128plus, efforts to prolong the system’s lifecycle with hardware updates, were considerably less successful, as was the attempt to repackage the plus hardware into a game console as the GX4000.

The CPC models’ hardware is based on the Zilog Z80A CPU, complemented with either 64 or 128 kB of memory. Their computer-in-a-keyboard design prominently features an integrated storage device, either a compact cassette deck or 3″ floppy disk drive. The main units were only sold bundled with a colour or monochrome monitor that doubles as the main unit’s power supply. Additionally, a wide range of first and third party hardware extensions such as external disk drives, printers, and memory extensions, was available.

The CPC series was pitched against other home computers primarily used to play video games and enjoyed a strong supply of game software. The comparatively low price for a complete computer system with dedicated monitor, its high resolution monochrome text and graphic capabilities and the possibility to run CP/M software also rendered the system attractive for business users, which was reflected by a wide selection of application software.

During its lifetime, the CPC series sold approximately three million units.

Replacement/Adaptation of a power switch for Amstrad CPC 464:

source: wikipedia cpcwiki.eu

I have decided to replace my Amiga 1000 keyboard (US version) with the space key yellowed and a hole in the plastic caused by a wrong installation with a Amiga 1000 keyboard (Italian version) cosmetically perfect and running.

I bought a few things from the site Retro Innovations of Jim Brain.

6540 Rom Adapter:

• This PCB converts the MOS 6540 DIP pinout to a JEDEC standard 2764-27512 EPROM pinout.  The optional 5 upper address lines are available via pads complete with provision for pullup resistors (10K).

Commodore IEC Disk Drive Cable:

• This very short cable is useful for my second Ultimate 1541.

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.

Changelog SD HxCFloppyEmulator v1.8.2.30 (fat) & v2.1.2.30 (slim):

• SDCard Support : Delay added right after any command (PNY microSD support).
• Watchdog delay changed to 16s.
• Brownout reset setting changed.

Download:

• HxC Floppy Emulator Firmware v1.8.2.30 (1026)
• Slim HxC Floppy Emulator Firmware v2.1.2.30 (992)

source: hxc2001.free.fr

Autopsy:

123►

The Genius PC is a home computer from VTech. Released in the late 90s, it is one of the last microcomputers.

This computer have different names in each country, making it even harder to track down the information.

• France : VTech Genius PC
• Germany : VTech Genius IQ 128 and VTech TV 512
• UK : VTech IT Unlimited
• USA : VTech Precomputer Unlimited
• Also mentioned on the french packaging : Switzerland, the Netherlands, Canada.

Hardware:

• Motorola MC68EC000, 16-bit external databus, 32MHz
• 256K of RAM
• 2M of ROM – Sharp LH537NWN mask ROM
• Mass storage : 128KB flash memory – AM29F010
• Cartridge port, apparently on memory bus with system ROM and storage flash. The french system comes with cartridges only containing straps, likely shorting some pins enable extra features…

Downlod: VTECH Unlimited Manual (1632)

Hardware Video Review:

source: pulkomandy.tk/projects/avrstuff/wiki/geniuspc

This program works as a program launcher for Commodore machines. Even if it was originally intended for a device with sd2iec firmware, it works also with any CBM drive (without sd2iec functions of course).

It is a multi-system version derived from the discontinued sd2brwse v.0.6 by Hannu Nuotio (fork() of sdbrowse v.0.7)

The Vic-20 Mega-Cart Installer is based on sys.asm sources of mega-tools by Daniel Kahlin, sort routine by Michael Kircher.

Current supported machines:

• C64.
• C64DTV.
• Vic-20 unexpanded.
• Vic-20 +3K RAM.
• Vic-20 +8K RAM or plus (for FE3 use this version)
• Vic-20 with Mega-Cart.
• C16 / C116 / Plus4.
• C128 in 64 mode.
• C128 80 Columns.

Tested drives:

• MMC2IEC
• SD2IEC
• uIEC
• C64-SD (any version, with ITS modules too)
• 1541 (with JiffyDOS too)
• 1541-II
• 1571
• 1581

Changelog:

• v.0.1 – 01-Sep-2009 (Start of project, C64/C64DTV only)
• v.0.2 – 21-Oct-2009 (First working version for Vic-20 +8K RAM)
• v.0.3 – 06-Jan-2010 (Added memory config auto-detection for Vic-20 selected program)
• v.0.4 – 19-Jan-2010 (Added support for Vic-20 with Mega-Cart and manual start mode)
• v.0.5 – 10-Feb-2010 (Added support for Vic-20 unexpanded and Vic-20 +3K RAM)
• v.1.0 – 05-Mar-2010 (First public version, minor issues fixed, C64 and Vic-20 supported)
• v.1.1 – 22-Jun-2010 (Added support for D41 and DNP file images, sd2iec firmware v.0.9.0 or higher required)
• v.1.2 – 09-Oct-2010 (Added SJLOAD speed-up option to the manual mode of the Mega-cart version)
• v.1.3 – 31-May-2012 (Added support for C16/C116/Plus4, Sort directories, cosmetic changes)
• v.1.4 – 19-Jul-2012 (Added JIFFYDTV speed-up support for C64-DTV, Clear screen before RUN)
• v.1.5 – 03-Mar-2013 (Added support for C128, and uppercases disk images D64,D81,D71 etc.)
• v.1.6 – 20-Aug-2013 (Added support for Tap files using ITS modules, case insensitive disk images Dnp, TaP, m2I etc.)

Download: CBM FileBrowser v1.6 (3641)

source: vic20.it/cbmfilebrowser

Some new games or tools (Cracked / Trained or Unrealeased) for Commodore 64 have been released from your favorites groups: Sitzgruppe, TRIAD, Lifeless Incorporated, Prof. Pi^2, Onslaught, Nostalgia, Genesis Project and Laxity.

Download:

• Pimple Panic Preview (1070)
• Defmon &D (1063)
• Motor Massacre / Road Raiders 101% +18DIR (1110)
• Warriors +6 101% (1052)
• Stalingrad Campaign +D and Map (1089)
• The Vice Squad (preview) (1069)
• Bunker Runner (1075)
• Schloss-Geist +4H (1044)
• Hells Bells +H (1045)
• Frospi +4 (1102)
• Cuby +3H (1075)
• The Great Escape +2H (1070)
• Lemmings [unofficial] Preview + (1065)
• The Vice Squad Preview +4 (1056)
• Dictator 101% +h (1077)
• All Games in One Archive (2757)

source: csdb.dk

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.

Changelog SD HxCFloppyEmulator v1.8.2.26 (fat) &  v2.1.2.26 (slim):

• Device init : the whole internal memory is now cleared at power-up.

Download:

• HxC Floppy Emulator Firmware v1.8.2.26 (1038)
• Slim HxC Floppy Emulator Firmware v2.1.2.26 (987)

source: hxc2001.free.fr

ASAP is a player of 8-bit Atari music for modern computers and mobile devices. It emulates the POKEY sound chip and the 6502 processor.

The project was initially based on the routines from the Atari800 emulator, but the current version has a completely new original emulation core.

Changelog ASAP 3.1.5 (2013-08-17):

• Android: fixed playback on Android 4.1+, disconnecting headset pauses playback, updates position and avoids “process not responding” during seek, starts in root directory if there’s no memory card.
• GStreamer plugin gets autoplugged (read: SAPs play in GStreamer-based players).
• WASAP plays music to its very end.
• Fixed crash on malformed RMT files.
• Restored Audacious 2.x compatibility.
• DEB packages.
• foobar2000 `*.fb2k-component` package.

Download: ASAP v3.1.5 (1408)

source: asap.sourceforge.net

If you are the lucky owners of these eprom: Motorola MCM 68766C you can do something really cute, hardware permitting. Example: use this EPROM like a ROM for some Devices and Computers Commodore without using an adapter ;-D

I had to use the EPROM programmer Promenade C1 for Commodore 64 to burn these eprom because all my programmers don’t support these type of eprom.

Download:

• Eprom Motorola MCM68766C Datasheet (1892)
• Prom-Shell v2.00 (760)

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.

Firmware Slim SD HxCFloppyEmulator v2.1.2.24:

• SD Access enhanced : Better handling, track buffer size increased.
• Floppy interface mode enhanced : New Pin02/Pin34 Custom settings.
• SDCard file system support enhanced : Now support FAT 12, FAT 16 & FAT 32 formatted SDCard ! Any SDCard size are now supported !
• Direct access mode : New function to get and set easily the current index number in “file selector” & indexed mode.
• Lots of internal code optimizations/improvements and corrections…
• Write Support completely redesigned / reworked :
• Low level track format support added !:
  • The host computer/machine can now do low level format of the disk images ! By this way the floppy disk image can be formatted with the right disk layout from the machine. All the tracks parameters used by the machine (sector size, interleave/skew, gap, format value, index mark…) will be written to the virtual disk tracks ! By this way the user have just to copy some blank HFE images to the SDCard, and format them with the host machine as with a real floppy disk to make them usable. Some blank disk images with various density will be available for download on the HxC2001 website.
  • SD/DD/HD sector write support : all sector sizes are now supported ! : 128B, 256B, 512B, 1024B, 2048B, 4096B, 8192B…
  • Unaligned track/sector write is now possible : Sectors of host formatted images and images imported from stream files (Kryoflux…) can now be written !

Download:

• Firmware Slim SD HxCFloppyEmulator v2.1.2.24 (1052)

source: hxc2001.free.fr

For retro computing fans, arcade enthusiasts and fpga developers, newbies and experts. The replay will let you relive and revive classics or develop new tech.

source: fpgaarcade.com