Agvelli's blog

To drive the 3 Lego motors I use two 754410. Each ic has 2 h-bridge driver. To provide 9 volts for lego motors and 5 volts for logic signals I use 7809 and 7805 voltage regulators to drop down 12 volts from power supply. M1, M2, M3 are board outputs to motors C1, C2, C3 are input control pins; you can start and stop motor and set clockwise / anticlockwise rotation I use an old 12v/2A  power supply taken from an external hard disk  BOM: 2 x SN754410NE 1 x LM7805 1 x LM7809 2 x 0.33uF (input capacitors) 2 x 0.1uF (output capacitors) 2 x 16 pin sockets 12v power supply connector for power supply

After HD replacement, It’s time to reinstall AmigaOS. Booting from “Amiga Install Disk” floppy….. DF0 makes a bad sound and is not able to read floppy. OK, disconnect DF0 cable and turn DF1 as DF0 (DF1 is newer than DF0, I bought it after Commodore bankruptcy to have an emergency working removable devices). Booting again from “Install Disk” floppy….. Amiga starts reading floppy but after a while it returns “bad block” errors…. floppy is corrupted . What can I do? I can try to find working floppies… (NAAAAHH!) or replace floppy with an sd/usb adapter. As for hard disk, you can find expensive “floppy emulator” devices or…  The Gotek floppy. The Gotek floppy is a cheap PC floppy emulator; it has a standard floppy connector to communicate to the motherboard and an usb port for usb storage devices. Putting floppy image files on usb pendrive, the Gotek is able to read images data as a real floppy. Hervé Messinger, wrote a new firmware for this device to read Amiga ...

My 15 years old Quantum Trailblazer is dead. Powering on the Amiga, the hd makes noise as a grinder and system doesn’t start. I have to find a replacement. I can choose between: a recent scsi hard disk, as 72GB, 10/15krpm uwscsi disks used in servers: it requires scsi connector adapter; to allow AmigaOS manage disks greater than 4GB, the latest FFS update is needed; a less recent scsi hard disk, as 9GB, 10krpm uwscsi disks used in older servers: it has the same requirements of the previous, but has more working hours and so is near its end of life; a scsi-ide adapter, to connect cheap ide drives: this kind of adapter is too expensive; a scsi-sd device: you can find on web people selling handmade scsi-sd devices;  interesting solution, but for hobbyist’s product I wish to access source to hack or improve the device, but the code isn’t public; something else…? Yes, an internal Iomega Jaz. I found an  Iomega Jaz (2GB)  on ebay for less than 10€. It has 50 ...

I started this project many years ago. I was inspired by usb gadgets firing foam rockets. I though to build my rocket launcher using Lego and control it using pc’s usb port (or modded Dockstar’s usb port). I developed the project using Lego Digital Designer software, free downloadable from Lego web site.The LDD library has a large set of bricks and you can choose all needed components.When a first version is ready you must review your schema to minimize the number and the type of bricks. Below, the latest optimized schema. Download schematics I bought a couple of complete set from Lego as base kit (Lego 9391 and Lego 8293) and missing bricks  and parts from ebay. When b uilding the real lego model I did some changes to the schema. 

Opening Amiga case after years, I looked at NVRAM battery to check if it was in a good condition or started to leak. It seemed fatter than standard batteries, so I've chosen to replace it. The battery is placed on the upper side of A3000T motherboard, near disks connectors, in a very uncomfortable place to reach (look at the picture below, the red box is the battery place). Instead of put the new battery on the original place, I connected 2 long wires (green on the picture) on motherboard and put the battery in a different place. To avoid future battery’s leakages on motherboard I put the battery on a chocolate egg’s surprise container. 

CPU: Motorola 68030+68882@25MHz on motherboard and 68040@40MHz (on cyberstorm mk2 board) Fast RAM: 40MByte, 8MByte on motherboard, 32Mbyte on cyberstorm mk2 board Chipset ECS, 2MByte of Chip RAM Graphic card: GVP EGS 28/24 Spectrum, 2MByte of RAM, ZIII Floppy: 2 high density FDD, 1.760MByte Hard Disk and SCSI devices: Quantum Trailblazer SCSI (850MByte), SCSI CDROM Genlock on video slot Operating System: AmigaOS 3.1