Archive

Archive for the ‘Retro Computers and other stuff…’ Category

Testing ICE Felix HC-90 (ZX Spectrum Clone) for a friend

January 25th, 2016 1 comment
I.C.E. Felix HC-90 (ZX Spectrum Clone)

Testing ICE Felix HC-90 (ZX Spectrum Clone) for a friend.

This is a series of ZX Spectrum clones was manufactured in Romania from 1985 to 1994, by ICE Felix. The designation HC means Home Computer, and for the first three models in the series, the number is the year of first manufacture. Models in the series were: HC 85, HC 88, HC 90, HC 91, HC91+ (HC128), HC 2000, HC386.

The earliest version, HC 85, closely resembled the Spectrum, with a built-in BASIC interpreter, Z80A processor, 48 KB RAM, tape, and TV interfaces. It was used in schools/universities and as a personal computer.

An optional Interface 1 extension was available for the HC 85, HC 90, and HC 91. It was functionally similar to the ZX Interface 1, but instead of Microdrives it supported single-density or double-density floppy disks. The HC 90 had a redesigned circuit board supporting fewer, larger memory chips; it was functionally equivalent with the HC 85.

The HC 91 had a modified keyboard with 50 keys instead of 40. It had 64 KB RAM and extra circuitry which provided CP/M support, if the Interface 1 extension was also present.

The HC 2000 (manufactured from 1992–94) had a built-in 3.5-inch 720 KB disk, and 64 KB RAM, it could be used both as a Spectrum clone with added disk functionality (only 48 KB RAM available) or in CP/M mode, giving access to the full 64 KB memory. Essentially, it brought the HC 91, Interface 1, and floppy disk in a single case.

The last model to be made in the Z80 line was the HC91+. It was a ZX Spectrum 128K clone in a HC91 case and keyboard and had some compatibility problems. For the first time, the AY-8910 sound chip was offered as an add-on service and was soldered on the board by factory technicians. Demoscene demos had problems running multi-colour effects and displaying sound VU-meter like effects lacking some data from the AY chip probably.

Gallery:

source: wikipedia

MicroTech – SpaceMaker II

January 6th, 2016 No comments

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 (1068)

Commodore 64c Embossed Label

January 4th, 2016 No comments
Commodore 64c Embossed Label

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/

Commodore-MOS KIM-1

December 19th, 2015 1 comment

The KIM-1, short for Keyboard Input Monitor, was a small 6502-based single-board computer developed and produced by MOS Technology, Inc. and launched in 1976. It was very successful in that period, due to its low price (following from the inexpensive 6502) and easy-access expandability.

The KIM-1 consisted of a single printed circuit board with all the components on one side. It included three main ICs; the MCS6502 CPU, and two MCS6530 Peripheral Interface/Memory Devices. Each MCS6530 comprises a mask programmable 1024 x 8 ROM, a 64 x 8 RAM, two 8 bit bi-directional ports, and a programmable interval timer. The KIM-1 brochure said “1 K BYTE RAM” but it actually had 1152 bytes. The memory was composed of eight 6102 static RAMs(1024 x 1 bits) and the two 64 byte RAMs of the MCS6530s. In the 1970s memory sizes were expressed in several ways. Semiconductor manufacturers would use a precise memory size such as 2048 by 8 and sometimes state the number of bits (16384). Mini and mainframe computers had various memory widths (8 bits to over 36 bits) so manufacturers would use the term “words”, such as 4K words. The early hobbyist computer advertisements would use both “words” and “bytes”. It was common to see “4096 words”, “4K (4096) words” and “4 K bytes”. The term KB was unused or very uncommon. The KIM-1 was introduced in the April 1976 issue of Byte magazine and the advertisement stated “1 K BYTE RAM” and “2048 ROM BYTES”.

Also included were six 7-segment LEDs (similar to those on a pocket calculator) and a 24-key calculator-type keypad. Many of the pins of the I/O portions of the 6530s were connected to two connectors on the edge of the board, where they could be used as a serial system for driving a Teletype Model 33 ASR and paper tape reader/punch).

One of these connectors also doubled as the power supply connector, and included analog lines that could be attached to a cassette tape recorder.

Earlier microcomputer systems such as the MITS Altair used a series of switches on the front of the machine to enter data. In order to do anything useful, the user had to enter a small program known as the “bootstrap loader” into the machine using these switches, a process known as booting. Once loaded, the loader would be used to load a larger program off a storage device like a paper tape reader. It would often take upwards of five minutes to load the tiny program into memory, and a single error while flipping the switches meant that the bootstrap loader would crash the machine. This could render some of the bootstrap code garbled, in which case the programmer had to reenter the whole thing and start all over again.

The KIM-1 included a somewhat more complex built-in Terminal Interface Monitor software called TIM that was “contained in 2048 bytes of ROM in two 6530 ROM/RAM/IO arrays”. This monitor software included the ability to run a cassette tape for storage, drive the LED display, and run the keypad. As soon as the power was turned on, the monitor would run and the user could immediately start interacting with the machine via the keypad. The KIM-1 was one of the first single-board computers, needing only an external power supply to enable its use as a stand-alone experimental computer. This fact, plus the relatively low cost of getting started, made it quite popular with hobbyists through the late 1970s.

Gallery:

Download: Commodore-MOS KIM-1 Docs (1149)

 source: wikipedia

Multiface 128 by Romantic Robot UK Ltd for Sinclair ZX Spectrum

December 16th, 2015 No comments

The Multiface 128 by Romantic Robot UK Ltd  is a true multi purpose interface with:

  • Fully universal and 100% automatic BACK-UP facility for tape, microdrive, Discovery, Plus D or Disciple.
  • 8K RAM extension – suitable for our GENIE, LIFEGUARD, or as a buffer, etc.
  • MULTI TOOLKIT to study/modify/develop programs, POKE infinite lives, etc.

Gallery:

Download: Multiface 128 User Manual (1626)

source: worldofspectrum.org

Opus Discovery 1 for Sinclair ZX Spectrum

December 16th, 2015 6 comments

The Opus Discovery 1 is a true disk drive system for your Spectrum. 250K floppy drive and interface. Video output port (monochrome). Joystick port. Peripheral Through port. Parallel printer port.

Gallery:

Opus Discovery 1 + ZX Spectrum 48k Blue Fairy version :D

Download:

source: worldofspectrum.org

Commodore Single Disk 2031 (High Profile)

December 8th, 2015 No comments
Commodore Single Disk 2031 (High Profile)

The Commodore 2031 and Commodore 4031 are single-unit 5¼” floppy disk drives for Commodore International computers. They use a similar steel case form to the Commodore 9060/9090 hard disk drives, and use the IEEE-488 interface common to Commodore PET/CBM computers. Essentially, both models are a single-drive version of the Commodore 4040.

The Commodore 2031LP is functionally the same as the 2031, but used the lower-profile tan case of the second version of the Commodore 1541 floppy disk drive intended for home computer use.

These drive models use a single-density, single-side floppy data storage format similar to that used by the Commodore 1540 & Commodore 1541 drives, but with a slightly different data marker indicating which model originally formatted the disk. The low-level disk format is similar enough to allow reading between models, but different enough that one series of drive models cannot reliably write to disks formatted with one of the other model series. A different of one extra ‘header’ byte is what causes this write incompatibility.

Gallery:

Comparison Commodore Floppy Drive 2031 (Low Profile) & 2031 (High Profile):

Comparison Commodore Floppy Drive 2031 (Low Profile) & 2031 (High Profile)

 

Fix the Commodore Floppy Drive 2031 (High Profile)

Removed the filter capacitors RIFA in the power plug.

Download: Commodore Floppy Drive 2031LP/HP Rom (1199)

source: wikipedia

Repair/Restoration Commodore Floppy Drive 2031LP

December 6th, 2015 No comments
Commodore Floppy Drive 2031LP

The Commodore 2031 and Commodore 4031 are single-unit 5¼” floppy disk drives for Commodore International computers. They use a similar steel case form to the Commodore 9060/9090 hard disk drives, and use the IEEE-488 interface common to Commodore PET/CBM computers. Essentially, both models are a single-drive version of the Commodore 4040.

The Commodore 2031LP is functionally the same as the 2031, but used the lower-profile tan case of the second version of the Commodore 1541 floppy disk drive intended for home computer use.

These drive models use a single-density, single-side floppy data storage format similar to that used by the Commodore 1540 & Commodore 1541 drives, but with a slightly different data marker indicating which model originally formatted the disk. The low-level disk format is similar enough to allow reading between models, but different enough that one series of drive models cannot reliably write to disks formatted with one of the other model series. A different of one extra ‘header’ byte is what causes this write incompatibility.

Gallery:

Repair/Restoration Commodore Floppy Drive 2031LP

Defect:

  • Lock lever of the Floppy Drive broken.
  • When the Floppy Drive is powered up, red LED stays on and spindle motor runs continuously.

Repair/Restoration:

  • Replaced the Lock lever with a new one taken from a Commodore Floppy Drive 1541 (spare parts)
  • Replaced the ROM (UAB5 901484-05) with a EPROM MCM 68766 supplied from my friend Giacomo Vernoni.

Note:

The Eprom programming was done with a EPROM programmer Promenade by Jason-Ranheim Co. for Commodore 64.

Repair/Restoration Gallery:

Download: Commodore Floppy Drive 2031LP/HP Rom (1199)

source: wikipedia

Asem AM 100 (Apple // Plus Clone made in Italy)

November 8th, 2015 4 comments
Asem AM 100

The Home Computer Asem AM 100 is a clone of the Apple II+ (Apple // Plus). This computer was manufactured and assembled by ASEM S.p.A. Artegna (UD) / Italy.

The AM 100 is fully compatible with all the software available for the Apple II and II+. I have personally tested many programs and i’ve never found problems of compatibility.

Unfortunately this computer is arrived faulty, the repair was more simple than i expected, thanks to the IC sockets located on the computer motherboard.

Works that have been made:

  • Replacing IC 74LS161 which shows a vertical band on the screen.
  • Removing RIFA filter capacitor located inside the PSU.
  • Regeneration of the Keyboard PAD. Some keys did not work properly. The Keyboard PAD have been regenerated using a suitable product that can be found for sale on eBay. Try: KEYPAD FIX
  • General cleaning of the case outside/inside, monitor and keyboard.
  • EPROM dump.

All these works are documented with photos that you can find below.

Gallery repairs:

Under the cover gallery:

Final photos:

Interesting discovery:

Inside the Floppy Drive reader (Apple clone) i have found the same mechanics (Mistumi / Newtronics) of the Commodore Floppy Drive 1541. See the first three pictures of the gallery: Under the cover.

Download: ASEM AM 100 full Eprom Dump (1206)

Dk’tronics Keyboard for Sinclair ZX Spectrum

August 31st, 2015 No comments
Dk'tronics Keyboard for Sinclair ZX Spectrum

The DK’tronics keyboard for the Sinclair ZX Spectrum is a sturdy, solid-looking, black ABS case with a set of grey alphanumeric keys on the left and a 3×4 red numeric keypad set on the right.

The Spectrum is removed from its case by unscrewing the case halves, gently pulling out the two keyboard connecting ribbon cables and unscrewing the two small circuit board screws. The reverse process is then undertaken with the DK’tronics keyboard. Precise instructions are supplied so any incompetent can do it – even I managed !

The keys have a pleasant feel to them, the spring pressure was just about right to allow for my fumbling efforts, and generally the legends supplied on transparent stick-on plastic labels, are easy to read.

Gallery:

source: worldofspectrum.org

MSX – Frael Bruc 100 (Boxed)

July 19th, 2015 No comments
MSX - Frael Bruc 100

The Bruc 100 is one of the few home computer designed and manufactured in Italy by Frael (Franchi Electronics) . Released in the 1987 it was sold along with the computer courses of the School 2F.

There are two models. The first has no cartridge slot but only one extension BUS. On the second model the extension BUS has been replaced by a cartridge port.

The Bruc 100 is not totally an MSX1 computer. The cartridge port (or the extension BUS) and the cassette tape connector are a bit different. This computer doesn’t support the FM-Pac nor floppy disk controllers, etc because the port does not provide + 12V nor -12V. The cartridge port also has the particularity of having two /SLTSL signals (pin 4 for slot 2 and pin 16 for slot 3).

The Basic of Bruc 100 is not the MSX-Basic but it is very similar. The keyboard is a bit different from a MSX. There are 107 keys which a number pad, shortcut keys and some mirror keys.

Gallery:

Replacement of non polarized plug C7/C8:

source: computerhistory.it msx.org

Commodore Single Drive Floppy Disk VC-1540 (Boxed)

June 22nd, 2015 1 comment
Commodore Single Drive Floppy Disk VC-1540 (Boxed)

The Commodore 1540 (also known as the VIC-1540) introduced in 1982 is the companion floppy disk drive for the Commodore VIC-20 home computer. It uses single-sided 5¼” floppy disks, on which it stores roughly 170 kB of data utilizing Commodore’s GCR data encoding scheme. The launch price in Germany was 1898 DM (approximate 970 EUR). The US-American version is named VIC 1540 and the German version VC 1540.

Because of the low price of both the VIC-20 and the 1540, this combination was the first computer with a disk drive to be offered on the US market for less than $1000 USD, although the combination of the Commodore 64 and 1541 would prove more enduring. The 1540 is an “intelligent peripheral” in that it has its own MOS Technology 6502 CPU (just like its VIC-20 host) and the resident Commodore DOS on board in ROM – contrary to almost all other home computer systems of the time, where the DOS was loaded from a boot floppy and was executed on the computer’s CPU.

Due to a timing conflict with the C64′s video chip, the C64 doesn’t work properly with the 1540. The better-known 1541 is mechanically and nearly electronically identical to the 1540 but has a revised ROM that permits it to work with the C64 by slowing the drive down slightly. However, it is possible to revert the 1541 into 1540 mode with a Commodore BASIC software command (OPEN 15,8,15, “UI-” : CLOSE 15) to permit better speed when used with a VIC-20.

Commodore Single Drive Floppy Disk VC-1540 (close-up)

The 1540 is relatively rare. While cheaper than most other drives of the day, it was more expensive than the VIC-20 computer itself, and the disk media was also still relatively pricey. Also, the relatively small memory of the VIC meant that the faster program loading times of the drive did not gain more than a few seconds compared to tape media. Thirdly, almost all commercial software for the VIC-20 was sold on cartridge or cassette tape media, giving low incentive to buy a floppy drive. The C64 followed close on the heels of the VIC-20, quickly discontinuing the 1540. Most 1540s still in existence were modified with a 1541 ROM so it would work with a C64. Unmodified 1540s are now considered collector’s items.

Gallery:

source: wikipedia

Adam Coleco Vision Family Computer System (Boxed)

June 22nd, 2015 No comments
Adam Coleco Vision Family Computer System

The Coleco Adam is a Home Computer, and expansion for the ColecoVision (port 3), released in 1983 by American toy manufacturer Coleco. It was an attempt to follow on the success of the company’s ColecoVision video game console. The Adam was not very successful, partly because of early production problems, and was orphaned in early 1985.

Coleco announced the Adam at the Summer Consumer Electronics Show (CES) in June 1983, and executives predicted sales of 500,000 by Christmas 1983. From the time of the computer’s introduction to the time of its shipment, the price increased, from USD $525 to $725.

Coleco’s 1983 announcement of the Adam received favorable press coverage. The Boston Phoenix, observing that the computer’s $600 price was comparable to the lowest price for a letter-quality printer alone, stated “a nice trick if they can do it!” It was, in fact, a trick; the computers were shown behind tinted glass that hid the fact that they were hand-made and had non-working tape drives.

In June the company promised to ship the computer by August. In August it promised to ship a half million Adams by Christmas, but missed shipping dates of 1 September, 15 September, 1 October, and 15 October. Ahoy! reported that Coleco had not shipped by early October because of various problems. Each month of delay could mean losing the opportunity to sell 100,000 units, the magazine reported, adding that missing the Christmas season would result in “inestimable losses”. The company only shipped 95,000 units by December, which were very defective; Creative Computing later reported that “the rumored return rate was absolutely alarming”. One store manager stated that five of six sold Adams had been returned, and expected that the sixth would likely be returned after being opened on Christmas. Coleco partnered with Honeywell Information Systems to open up repair chain stores around the nation. By December 1983 the press reported that company executives at a news conference “fielded questions about Coleco’s problems with its highly-publicized new Adam home computer, which has been plagued by production delays and complaints of defects”, with the company only able to fulfill one third of its Canadian orders for Christmas. Less than 10% of Adam units had defects, the company claimed, “well below industry standards”.

Gallery:

Gallery (Cleaning the Keyboard):

Gallery (The big Box & Under the Cover):

Adam ColecoVision Video (Daisy-wheel Printer Test / Tape Loading / Game Cartridge):

source: wikipedia

Multitech Micro-Professor MPF-II (Boxed)

May 30th, 2015 9 comments
Multitech Micro-Professor MPF-II

Microprofessor II (MPF II), introduced in 1982, was Multitech’s (later renamed Acer) second branded computer product and also one of the earliest Apple II clones. It does not look like most other computers. The case of the MPF II was a slab with a small chiclet keyboard on its lower part.

In 1983, the Multiprofessor II retailed in the UK for £269.00 including VAT.

One key feature of the MPF II was its Chinese BASIC, a version of Chinese-localized BASIC based on Applesoft BASIC. There was also a version sold in Europe that did not have Chinese localization.

Multitech Micro-Professor MPF-II (under the cover)

Differences to Apple II:

The MPF II was not totally compatible with the Apple II.

The MPF II did not have Apple II’s text mode. All the text was drawn on the screen by software rather than generated by hardware. It was the only cost-effective way to generate Chinese text on screen at a time when a hardware-based Chinese character generator could cost hundreds of U.S. dollars.

Like Apple II, MPF II had two graphics buffers. However the second buffer was at address A000H while with Apple II it was at 4000H. The keyboard input was mapped to a different address than the Apple II making impossible to play Apple’s games on the MPF II.

MPF-II keyboard interface was very simple and consisted of an 8 bit output port and an input port that were directly connected to keyboard matrix. The Apple joystick interface was not there, and instead the joystick appeared as a keyboard with arrow keys and two other buttons.

The external slot interface was also not compatible with the Apple II and could not use many standard interface cards including the Disk II controller.

Technical information:

  • CPU: MOS Technology 6502
  • Clock rate: 1 MHz
  • RAM: 64 KB (including 16KB RAM mapped at the same address as the ROM)
  • ROM: 16 KB (12 KB of which is a BASIC interpreter)
  • Text modes: 40×24 (using graphics mode)
  • Graphics modes: 280×192
  • Colours: 8 colours
  • Sound: 1 channel of 1-bit sound
  • Connectors: Keyboard, Printer, Expansion port, cassette recorded input and output, Composite and TV-out
  • Optional peripherals: 55 key full-size keyboard, Floppy disc drive, Thermal and Dot-matrix printers, Joystick
  • Power supply: External PSU, 5,12V

Multitech Micro-Professor MPF-II – PapaTudo (Pacman Clone) by Microsoft:

Multitech Micro-Professor MPF-II (testing some games) Multitech Micro-Professor MPF-II (testing some games) Multitech Micro-Professor MPF-II (testing some games)

Gallery:

Powersupply Pinout:

Multitech Micro-Professor MPF-II Loading TK-2000 Game:

source: wikipedia mpf-ii.blogspot.it TK-2000 games download

Atari The Educator / Atari 1025 Printer / Atari 1030 Modem (all Boxed)

May 30th, 2015 No comments

Atari The Educator

Atari The Educator (Boxed)

The package includes:

  • Basic Cartridge.
  • Software & State Capital software on tape.
  • The Program Recorder Atari 410.

Download: Atari Educator Owners Guide (1798)

Atari 1025 80-Column Printer

Atari 1025 Printer (Boxed)

Printer Specifications:

  • 40 cps (80-column 10 cpi mode)
  • 5 cpi expanded (40 col), 10 cpi (80 col), 16.7 cpi condensed (132-col)
  • 5×7 character dot matrix.
  • Buffer: 132 chrs at 16.7 cpi, 80 chrs at 10 cpi.
  • Paper: roll,fanfold,single sheets. optional:roll paper holder, tractor feed.

Atari 1030 Modem

Atari 1030 Modem (Boxed)

With the introduction of Atari all new XL line of computers came the all new Atari 1030 direct connect modem. The modem had a very unique feature packed into it. Just like the Atari 850 interface, the Atari 1030 modem had not only its device driver in ROM which would automatically upload into the computers memory, but also its software as well.

The Atari 1030 came with an on-board software package called ModemLink which would automatically upload into the computers memory. However there was a catch, like all previous Atari software, ModemLink had no provisions for Uploading or Downloading software, also in order to use the on-board ModemLink software any disk drives that were connected to your system had to be turned OFF.

Later Atari 1030′s were packaged with “The New Atari 1030 Software Package” which was a diskette with Amodem, Tscope and DiskLink software. Amodem was written by Jim Steinbrecher of Atari telecom fame, Tscope was written by Joe Miller and was for use with Compuserve.

Gallery:

source: atarimuseum.com