Autopsy:

1234►

This computer/console in good cosmetic condition is arrived for a repair from a friend a few weeks ago. The defect is The Black Screen of Death, the computer turns on but doesn’t turn off, the standby LED remains faint green.

Unfortunately after several hours spent to trying the fault and i have tried just everything, the computer is still dead, my suspicion falls on the Custom Chip “SCOTCH” IX 1267CE from Sharp.

Components that have been tested and replaced:

• Tested all capacitors.
• Tested all transistors.
• Tested all SMD fuses.
• Test all the Coils.
• Tested all voltages.
• Replaced 74LS08 ic that controls the logic of power on/standby.
• Replaced 74LS244 ic that controls the logic of power on/standby.
• Replaced the power supply.

Download: Sharp X68000 Schematics (1591)

from Wikipedia:

The Sharp X68000, often referred to as the X68k, is a home computer released only in Japan by the Sharp Corporation. The first model was released in 1987, with a 10 MHz Motorola 68000 CPU (hence the name), 1 MB of RAM and no hard drive; the last model was released in 1993 with a 25 MHz Motorola 68030 CPU, 4 MB of RAM and optional 80 MB SCSI hard drive. RAM in these systems is expandable to 12 MB, though most games and applications did not require more than two.

The X68k ran an operating system developed for Sharp by Hudson Soft, called Human68k, which features commands very similar to those in MS-DOS (typed in English). Pre-2.0 versions of the OS had command line output only for common utilities like “format” and “switch”, while later versions included forms-based versions of these utilities, greatly improving their usability. At least three major versions of the OS were released, with several updates in between. Other operating systems available include NetBSD for X68030 and OS-9.

Early models had a GUI called “VS” (Visual Shell); later ones were packaged with SX-WINDOW. A third GUI called Ko-Windows existed; its interface is similar to Motif. These GUI shells could be booted from floppy disk or the system’s hard drive. Most games also booted and ran from floppy disk; some were hard disk installable and others require hard disk installation.

Since the system’s release, Human68k, console, and SX-Window C compiler suites and BIOS ROMs have been released as public domain and are freely available for download.

Early machines use the rare Shugart Associates System Interface (SASI) for the hard disk interface; later versions adopted the industry-standard small computer system interface (SCSI). Per the hardware’s capability, formatted SASI drives can be 10, 20 or 30 MB in size and can be logically partitioned as well. Floppy disks came in a couple of different formats, none of which are natively readable on other platforms, although software exists that can read and write these disks on a DOS or Windows 98 PC.

source: wikipedia

I have received these computers to be repaired for a friend.

Defects found on the Commodore VIC-20:

• Error message (device not present) when trying to access the IEC devices, like a Floppy Drive.

Defects found on the Commodore 64:

• Black screen of death after installing the missing roms.

The repair of the Commodore VIC-20 was made by replacing a HEX Inverter Buffer 7406.

The repair of the Commodore C64 was made by replacing the MOS 906114-01 (PLA – Programmable Logic Array).

Gallery of repairs:

This is the official demo party results from Stary Piernik 8 (Top 3 Entries only). See also the CSDB Stary Piernik 8 section for more informations and download.

C64 Demo:

• Fogyish
• In Thorn by Sabath
• Kazachski piesek by Provocator

C64 Music:

• Nasty Bitch by Wacek
• One Life by Surgeon
• Filth And Scottish Words 50% by Randall

C64 Graphics:

• The Jungle by JSL
• Black Sun Logo by Miras
• Gdzie by Maciaszczyk

Download: Stary Piernik 8 full Party stuff (1026)

source: noname.c64.org/csdb/

Thanks go to: Damiano (manosoft) and my Brother Alessandro.

Things that have been donated:

• 4 x Box of Verbatim Datalife 3.5  2HD Floppy Disk.
• 1 x Apple Keyboard for my iMac G3 “Bondi Blue” M5521
• 1 x Iomega Zip Drive SCSI + Cable.
• 1 x Iomega Zip Drive USB + Cable.
• 11 x Zip Disk.
• Some 3.5 Floppy Disk.

Autopsy:

The Mupi CineVisor was a must in the 70/80′s year and was used to project movies on the small screen.

The CineVisor was very cheap compared to a classic projector and perfectly manageable by children, don’t require special aptitude like the super8 projectors.

Autopsy:

Finally i have replaced my old and inaccurate Capacitor tester with a better one. My lab is beginning to have a semblance semi professional ;-D

Download: Peak Atlas ESR+ 70 User Guide (1366)

Video Review:

Mentor Colour 6 (Pong clone) has been Repaired

Defects:

• Black screen of death.
• No sound.

The problem of the power supply has been fixed by replacing the transitor CS 9013 that is used in a very bizarre way to lower the voltage from 9v to 6.85v. The problem of the audio was always caused by a transistor CS 9013 brutally in short circuit. In this case, the transistor is used like a amplifier.

The transistor CS 9013 can be replaced with a BC 337 that it’s equivalent.

Autopsy:

from Ira Goldklang’s TRS-80.com Homepage:

This is the fast way to transfer data from one location to another – by telephone with the Telephone Interface II. It’s a full “originate/answer” acoustic coupler which allows two TRS-80‘s to talk to each other. You can also communicate with another computer which has “originate only” capability (like our Telephone Interface I). You can pass all types of data or prograas between computers, or one of you can operate the other’s computer via the telephone lines. No direct connection to the telephone line is required.

It’s very simple to operate. Just dial the phone number at the location of the TRS-80 you desire to communicate with; after the connection is made, each telephone handset is placed on its interface. Now you’re ready to receive and transmit data. Requires RS-232 Serial Interface Card, Expansion Interface, RS-232 Conununications Package and Level II. Adds versatility to your TRS-80.

Specifications: Baud Rate: Up to 300. Mode: Originate and Answer, full or half duplex. Receive Sensitivity: -45 dBm. Power Requirement: U.L. listed 120-volt AC power module. Size: 2-3/8 x 4-3/4 x 10-1/4″.

source: trs-80.com

I thank a friend for the donation.

Donated item:

• Sandy Sinclair QL  Printer Converter.
  • The Sandy Printer Converter was a serial to parallel printer interface made by Sandy (UK).

Autopsy:

Commodore Amiga 1000 256kb Trapdoor Expansion Cartridge.

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 v1.8.2.40 (fat) & v2.1.2.40 (slim):

• Index signal behavior corrected while the host system attempt to format a drive without image loaded.

Download:

• HxC Floppy Emulator Firmware v1.8.2.40 (1015)
• Slim HxC Floppy Emulator Firmware v2.1.2.40 (1043)

source: hxc2001.free.fr

Autopsy:

12►

from Secret Weapons of Commodore homepage:

Introduced CES 1978
Hardware 6504 CPU (28-pin 6502, 8K addressable memory, on-chip clock, IRQ line only) @ 1MHz, 6530 RIOT (64 bytes RAM, 1KB ROM, 2 I/O ports, 8-bit timer), 6332 ROM. Two ROM sockets; the 6332 is occupying only one of them. The 6504 is socketed; the remainder are soldered directly to the board.
Graphics and Sound If you can call it that. Four 7-element LED displays for the timers and four dome indicator LEDs. Piezoelectric beeper.
Eventual Fate Released summer 1978 in USA, UK and West Germany.

This chess machine is an 22 x 16 x 5cm (rear, approximately 8 x 6 x 2 inch; front is 3.5cm/1.2 inches high) machine, off-white (similar to early VIC-20s), with a dark brown base. The 7-element LEDs are in groups of two, one labeled “FROM (Time white)” and the other “TO (Time black)”; the four dome LEDs are labeled “Check”, “CHESSmate LOSES”, “CHESSmate IS PLAYING WHITE” and “CHESSmate IS PLAYING BLACK”.

The “keyboard” is a membrane setup (similar to the Sinclair ZX-80) with 19 keys (A-H, 1-8, NEW GAME, CLEAR, ENTER), but only 11 matrix lines (A-H and 1-8 share lines). A-H are also, respectively, labeled WHITE, BOARD VERIFY, CHESS CLOCK, DISPLAY TIME, STOP CLOCK, SKILL LEVEL, GAME MOVES, and BLACK. The rear plate reads: “Commodore International Limited / Power supply: AC adaptor model C160 / Power rating: AC 10V 600 mA / CHESSmate, 201490 01, made in Hong Kong / CAUTION: DO NOT OPEN MACHINE. UNAUTHORIZED SERVICE VOIDS WARRANTY.” This is printed in English, French and German. On the internal view, the ICs are, from left to right, the 6530 RIOT, the 6332 ROM (next to the empty socket for the option ROM), and the 6504.

The Chessmate was developed by Peter Jennings, the original author of KIM-1 Microchess, under contract to Commodore in 1977. The Chessmate’s hardware is in fact based on the KIM-1, but the ROMs are of course filled with Microchess 1.5, not the KIM’s monitor. This was the same version released for the PET; the empty ROM socket on Martijn’s board was intended primarily for upgrades to the chess program. The keyboard mapping is dissimilar to the KIM as well; some of the ports were actually used for sound, and Commodore made some rearrangements to the unit for ease of manufacture after Peter released the unit to them. While simultaneously released in the USA, UK and West Germany, it was significantly more popular in the latter country than in the others (presumably due to greater interest in chess there). Peter received a royalty for each unit produced, and still owns a first-production Chessmate (sadly non-functional) and the original KIM-1 used to create Microchess and develop the Chessmate’s custom version.

As mentioned, the Chessmate has very different ROMs from the KIM-1, and part of this difference extends to the RIOTs. The 6530 and 6532 RIOT “ROM, I/O and Timer” chips, a series of custom multifunction chips developed by MOS Technology, were designed as integrated-design cost cutters, reducing the chip count on the board as it gave the functionality of several chips and didn’t cost much more to manufacture than a regular ROM. Unfortunately, this has one important consequence: RIOTs are rarely transferable between units, because of differing CS logic between models, differing ROM contents, and some versions use fewer CS lines to get additional I/O lines.

This means that the RIOT you find in your Atari 2600 (yes, VCSes have Commodore-designed chips!) is not swappable with the RIOT you would find in a Chessmate, or in a KIM-1; even the KIM-1 by itself is bad on this point, since it had several revisions alone (my unit is Revision D). Martijn’s Chessmate has a RIOT labeled “6530 024 3279″, meaning produced on the 32nd week of 1979; this is one of the last 6530 RIOT production runs known, unfortunate because the later MOS 6532 RIOT is not pin-compatible with the 6530. The “24″ is also worrisome: this means there are no less than 24 6530 RIOT versions floating around in various units, and to the great despair of anyone wishing to repair a moribund representative of these intriguing units, virtually none of them are compatible with any other.

Download:

• Microchess (KIM-1) HTML Manual by Peter Jennings
• Chessamate Commodore Schematics & Manual (476)

Video:

source: floodgap.com/retrobits/ckb/secret/

This gallery shows some stages of the cleaning and repairing the Commodore CBM 610.

12►

Defects found on the Commodore CBM 610:

• Black Screen of Death.
• Garbage characters on the screen.
• Keyboard Yellowed.
• Filter capacitor exploded.

The black screen of death was fixed by replacing the CPU MOS 6509A and the problem of garbage characters on the screen was fixed by replacing the ROM characters with a EPROM 2532 suitably programmed.

The yellowed keyboard was replaced with a new one in good condition of the Commodore CBM 710. I like Commodore. What will be the difference of a CBM 710 and a CBM 610 keyboard? nothing, are the same! no! on the keyboard of the CBM 710 has two wires reversed! (brown/red) ;-D

The filter capacitor exploded has been removed.

Autopsy:

123►

from Wikipedia:

The Commodore CBM-II series was a short-lived range of 8-bit personal computers from Commodore Business Machines (CBM), released in 1982 and intended as a follow-on to the Commodore PET series.

The CBM-II had two incarnations, the P series (P = personal, or, home use) and the B series (B = business use). The B series was available with a built-in monochrome monitor (hi-profile) with detached keyboard, and also as a single unit with built-in keyboard but no monitor (lo-profile). These machines were known as the “Porsche PETs” for their unique styling.

The P series used the VIC-II 40-column color video chip like the C64. It also included two standard Atari-style joystick ports. The 6509 CPU ran at 1 MHz in the P series due to the use of the VIC-II chip.

The B series used a 6545 CRTC video chip to give an 80-column “green screen” monochrome output more suitable for word processing and other business use than the VIC-II’s 40-column display. Most models have the Motorola 68B45 installed which is a pin compatible variant rather than the MOS 6545A1 2 MHz part. On the B series the 6509 CPU ran at 2 MHz.

Features common to both the P and B series included an MOS Technology 6509 CPU, an enhanced version of the venerable 6502, that was capable of addressing up to 1 megabyte of RAM via bank switching (however, no CBM-II model came with more than 256 kilobytes of RAM, 1/4 megabyte). The sound chip was the 6581 SID, the same one that was used in the popular Commodore 64 (C64) but with some limitations as it was over-clocked to 2 MHz. Additionally, the CBM-II had an industry-standard RS-232 serial interface and an IEEE-488 parallel bus (for use by disk drives and printers) just like the PET/CBM series. The CBM-II’s built-in operating system used an enhanced version of CBM BASIC version 4.0.

An optional Intel 8088-based coprocessor board allowed the CBM-II series to run CP/M-86 1.1 and MS-DOS 1.25; however, the computers were not IBM PC compatible and very little, if any, software taking advantage of this capability ever appeared. The coprocessor board only ran on hi-profile machines due to power supply and mechanical spacing requirements.

The production naming within the United States and Canada was the B128/B256 and CBM128-80/CBM 256-80 while in Europe they were known as the 600 and 700 series respectively (no “B” in front of the model number). The P machine was known worldwide as the 500 series. There are prototype models though such as the B500 (earlier B128 design) and B700 (earlier CBM 128-80/CBM 256-80 design) known to exist.

Due to the popularity of the C64, the P series was cancelled in the United States before it could be officially released; however, a few dealers who received preproduction units sold them. As these computers had not received approval from the Federal Communications Commission, this caused legal problems for Commodore. The units were recalled and destroyed, but a very small number exist today, in private collections. At least one model, the P500, was commercially released in Europe but only sold in small numbers.

source: wikipedia

Autopsy:

The Memotech Memopack is a 16K RAM Expansion Pack for Sinclair ZX-81.

This version of the MEMOPAK 16K is fully compatible with either the Sinclair 16K or another MEMOPAK 16K; or a MEMOPAK 32K; or you can work with it just by itself.

TIPS: The default switches for the Master Position are: (Off, On, On, Off).

Download: Memotech Memopack Manual (1618)