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:

12►

Under the cover gallery:

12►

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 (1228)

Tynemouth Software PET microSD & PET ROM-RAM-Tester replacement boards

PET ROM-RAM-Tester:

This is a board which plugs into the 6502 CPU socket on something like a Commodore PET and can selectively replace the onboard ROM (it includes a test software) or RAM.

PET microSD:

Disk drive replacement for Commodore Pet range of computers, the 2001, 3000, 4000 and 8000 series. It also works with vic-20/c16/Plus4/c64/128*

*IEEE-488 adapter required.

You can buy these boards from here.

Packaging:

source: tynemouthsoftware.co.uk

UK1541 is a real time drive emulator with cycle-exact 6502 instructions execution and VIA’s emulation just by tiny MCU, LCP1114, Cortex M0, 48Mhz (0,84 DMIPS/Mhz).

Developed by Krzysztof Switajski aka Kisiel/ICON.

Features:

• LCD TFT Screen 2,2“ , 320 x 240, True Color.
• MSP430.
• LPC1114.
• Infra Red receiver, for remote control.
• CR2032 battery holder.
• Mini jack connector as replacement for IEC port.
• DB9 connector for joystick.
• User Port connector, for power and signals like 8-bit parallel aka burst.
• Two buttons , MENU and RESET.

Features for the latest Core Version (1.1.4.012015):

• Core 6502 running at 1Mhz with illegal opcodes – 16kB Flash ROM, multiple custom roms not available now
• 4KB Ram, from $0000 till $0fff
• VIA port and timers emulation
• SD card 1 – 8GB, FAT32, formatted in Windows.
• d64 35 / 40 track with read and write (beta testing)
• Update from standard SD card.

Gallery:

source: wiki.projekt64.filety.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 v1.4.3 + Manual (1022)

source: csdb.dk

Commodore VIC-20: latest games from VIC-20 Denial forum.

Download: All Games in One Archive (1537)

source: VIC-20 Denial Forum

Relaunch64 is an IDE (text-editor) for C64 assembler-coding on Windows, Linux and Mac OS X. Relaunch64 has a clean and intuitive user interface, yet it offers many features that make coding faster and easier.

Java 7 or higher is required to run Relaunch64. The program is licensed under the GNU GPL 3 (or higher) and free for private and professional use.

This editor works together with common cross assemblers like Kick Assembler, ACME, or 64tass. Other assemblers might work as well, but syntax highlighting may not be 100% correct.

Download: Relaunch64 v3.3.5 (Windows/OSx/Linux) (1188)

source: popelganda.de

This is what we read on the homepage of the 1541 Ultimate-II:

source: 1541ultimate.net

Available on stock the new version of the V3 C64SD Princess by Manosoft. For more information please visit the Manosoft website.

source: manosoft.it

Jean-François DEL NERO (who’s behind the HxC SD Floppy Emulator) recently has released a version of the HxC emulator firmware that is compatible with the STM32 chip used in the Gotek floppy emulators.

This means that the great functionality of the HxC SD emulator is now available on cheaper and more widely available hardware.

The bootloader to convert the Gotek floppy drive in HxC compatible must be purchased on the website HXC 2001 by sending an email to Jean-François DEL NERO. The price of the bootloader is one-off 10 Euro per Gotek that you want to update. Future updates of the software are free and can be made from a USB stick

The HXC Usb (Gotek) firmware supports:

Flashing the Gotek floppy emulator with HxC firmware:

source: hxc2001.com

Replacing electrolytic capacitors Commodore Amiga 1200.

As you can see from the photos, the latest motherboard (Gallery full Recap Amiga 1200 #3) of Amiga 1200 suffered the classic problem of leaking capacitors.

Gallery full Recap Amiga 1200 #1:

Gallery full Recap Amiga 1200 #2:

Gallery full Recap Amiga 1200 #3:

Amiga 4000 badly Distorted Clipped Saturated audio Repair.

The problem is quite simple to find. You have to make some measurements on the integrated SMD LF347 (Op AMP) with the computer running and no sound.

You need to measuring pin 1 and pin 7 and should have a voltage of about 2.5V if the voltage as in my case (see photo) is  of 11.43v and 11.37v. Something is not working.

At this point you must also perform a new measurement on the pin 14 and pin 8, if also in this case it has a higher voltage of 2.5v evidently there is’ something that doesn’t work or with the LF347 or with the 750ohm resistor (R440 and R430).

The other three measurements to be done are the two input voltages, pin 4 should be about 12V and -12V on pin 11 approximately. In my case (see picture) are + 12.28v and -12.04v and are fine.

The third measurement is the Voltage Reference (Vref), this is very important, should not be less than 2v or greater than 3v. In my case (see photo) was 5.30v. This problem could be caused either by the circuit that provides the VRef (2 resistors and two capacitors) or just the same ic that creates problems with the Vref input.

In my case the failure was caused of the integrated SMD LF347 that i have replaced with a LM324. After replacing the voltages are back to normal, in the example photo you can see the Vref at 2.33v

The Amiga sound now works very well.

I have repaired several Commodore Amiga 4000 with the LF347 burned and from my personal experience can say that the acid leakage of capacitors C404, C433 and C443 make some short circuits on pins of the LF347 that obviously dies.

Audio before and after the repair:

• Amiga 4000 audio before the repair (1062)
• Amiga 4000 audio after the repair (1076)

Gallery:

Nothing of easier to put a socket for the oscillator to allow overclocking.

Gallery:

Yet another Commodore 64 repaired

Defect:

• White Flashing Screen then Black Screen.

Replace parts:

• 2 x 74LS257
• 1 x 6569 VIC-II

Note:

• After replacing the VIC-II (6569) the screen has stopped flashing but there was still some component broken.

I did this repair for a friend of mine after i heard that the new power supply cost 89.00 Euros !!

I have inserted a female RCA connector thus avoiding that the problem of “broken” cable happen again.

Gallery:

After the explosion of the filter capacitor (see video) i have removed the charred component.

Gallery:

Video: