ELECTRONIC ENGINEERING
INTRODUCTION FLOPPYmate requires an interface between the USB and the serial IEC bus. The hardware described in this Blog provides an interface (SER2IEC) between UART and the serial IEC bus for peripheral devices like disk drives 1540, 1541, 1570, 1571 and 1581. UART interface Decide on one of these UART interface types for your FLOPPYmate:USB… Read more FLOPPYmate hardware
INTRODUCTION When working with a 15X1 floppy drive, it comes in quite handy to know the track, the drive is currently accessing. This blog presents a kind of drive-modding for 15X1 afficionados. FEATURES SINGLE IC GAL22V10 SOLUTION 2 DIGITS LATCHED BCD INTERFACE (0 TO 79) LET’S GET STARTED Circuit Description The State Machine in this… Read more C64 Track Display 1541, 1571
INTRODUCTION In the late seventies vector graphic arcade video games like Asteroids became a huge success. A few years later the GCE Vectrex Home Arcade System was released. But even today the unique CRT phosphor glow hasn’t lost any of its fascination. This blog decribes a circuit which will turn a monochrome TV set into… Read more Vector Clock
INTRODUCTION This is a simple approach using a GAL and an ADC to generate a sine wave. A simple State Machine is looping though 47 different states and outputting data words accordingly. In order to avoid unpredictable output sequences all states have to be unique. The requirement that each state has to be unique limits… Read more Generating sine waves with a GAL
OVERVIEW The FLOPPYmate application is a convenient tool for backing up individual PRG files and/or whole disks, sending DOS commands, as well as checking the drive’s spindle speed. Furthermore the data of a whole track can be displayed as binary and GCR. It’s the answer to how to fast backup and restore 1541, 1571 and… Read more FLOPPYmate software
HARDWARE OVERVIEW UART interface, 2x DCDC, ATmega16 Microcontroller, 2x PWM DAC, regulator LM723, OpAmp LM324, inverter CD4069 Supported devices Lattice, National, ST:GAL16V8, GAL18V10, GAL20V8, GAL20XV10, GAL20RA10, GAL22V10, GAL6001 (GAL39V18), GAL6002GAL26V12 & GAL26CV12 by using a simple 28-pin to 24-pin adapter Atmel:ATF16V8, ATF20V8, ATF22V10 FEATURES No parallel port and driver trouble Power over USB Programms all… Read more GALmate hardware
OVERVIEW The GALmate application lets you read and programm GAL devices.Whereas easyABEL and vDosPlus software provide a compiler suitable for ABEL-HDL design files. The compiler (easyABEL) and vDosPlus are optional. The application and related documents are provided in the download section below. FEATURES Sytem Requirements and Installation Operating System Windows 7 or later(Linux and OS… Read more GALmate software
INTRODUCTION FLOPPYmate requires a high speed data transfer to read/write an entire track within a single disk revolution. This task requires a data transfer rate of at least 40KB/s. High speed (>8 KB/s) data transfer from or to a 1541 Disk Drive is commonly achieved using a 8 bit parallel cable connected to Port A… Read more 6522 Fast Serial Driver
INTRODUCTION Troubleshooting a dead C64 often reveals a faulty PLA IC as the root cause. The PLA does the address decoding and bank switching. SIGNETICS 82S100 (later PHILIPS PLS100) Bipolar Programmable Logic Arrays were used in early revisions of the C64 Mainboard assy, which were then replaced by MOS 8700-001 and MOS 906114-01. This blog… Read more C64 PLA Replacement
INTRODUCTION The C64 can only work properly with stable clocking. In a C64 II the MOS 8701 IC generates two major clocks and maintains the fixed frequency and phase relationship. COLOR_CLK is the main crystal oscillator clock and DOT_CLOCK is derived thereof. This blog presents a replacement circuit for the MOS 8701 IC. Orginal MOS… Read more C64 MOS 8701 Replacement